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Sample records for 4-phenylethynylphthalic anhydride pepa

  1. Phenylethynyl Phthalic Anhydride

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1997-01-01

    Controlled molecular weight PhenylEthynyl Terminated Imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with PhenylEthynyl Phthalic Anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2pyrrolidinone or N N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  2. Low Viscosity Imides Based on Asymmetric Oxydiphthalic Anhydride

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Criss, Jim M., Jr.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.

    2008-01-01

    A series of low-melt viscosity imide resins were prepared from asymmetric oxydiphthalic dianhydride (a-ODPA) and 4-phenylethynylphthalic anhydride as the endcap, along with 3,4' - oxydianiline (3,4' -ODA), 3,4' -methylenedianiline (3,4' -MDA), 3,3' -methylenedianiline (3,3' - MDA) and 3,3'-diaminobenzophenone (3,3'-DABP), using a solvent-free melt process. These imide oligomers displays low-melt viscosities (2-15 poise) at 260-280 C, which made them amenable to low-cost resin transfer molding (RTM) process. The a-ODPA based RTM resins exhibits glass transition temperatures (Tg's) in the range of 265-330 C after postcure at 343 C. The mechanical properties of these polyimide/carbon fiber composites fabricated by RTM will be discussed.

  3. Maleic anhydride

    Integrated Risk Information System (IRIS)

    Maleic anhydride ; CASRN 108 - 31 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  4. Phthalic anhydride

    Integrated Risk Information System (IRIS)

    Phthalic anhydride ; CASRN 85 - 44 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  5. Imide oligomers endcapped with phenylethynyl phthalic anhydrides and polymers therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Smith, Jr., Joseph G. (Inventor)

    1996-01-01

    Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  6. Imide Oligomers Endcapped with Phenylethynl Phthalic Anhydrides and Polymers Therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1998-01-01

    Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N.N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or cheznicauy to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydxide(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  7. PEPA-1* genotype affects return rate for hatchery steelhead

    USGS Publications Warehouse

    Reisenbichler, R.R.; Hayes, M.C.; Rubin, S.P.; Wetzel, L.A.; Baker, B.M.

    2006-01-01

    Allozymes continue to be useful as genetic markers in a variety of studies; however, their utility often hinges on the selective neutrality of the allelic variation. Our study tested for neutrality between the two most common alleles (*100 and *110) at the cytosol nonspecific dipeptidase locus (PEPA-1*) in steelhead Oncorhynchus mykiss from Dworshak National Fish Hatchery in Idaho. We tested for differential growth and survival among fish with the * 100/100, *100/ 110, and *110/110 genotypes rearing in a hatchery or a natural stream. We repeated the study for two year-classes, using heterozygous (*100/110) adults to make the experimental crosses. This design avoided differences in family contribution among genotypes because each cross produced all three genotypes. We divided the progeny from each family into two groups. One group was reared in a hatchery for 1 year and then released for migration to the sea and subsequent return to the hatchery as adults. The other group was released into a natural stream and monitored for 3 years. We found no significant differences in size or survival among PEPA-1* genotypes for either the naturally reared fish or the hatchery-reared fish immediately prior to release as smolts. For females, survival to returning adult also was similar among genotypes; however, hatchery-reared males with the *110/110 genotype returned at a higher rate than did males with the *100/ 100 genotype; heterozygous males were intermediate. These results indicate that selection occurs at the PEPA-1* locus or at one or more loci tightly linked to it. The finding of nearly equal frequencies for these two alleles in the source population suggests that selection differentials among genotypes reverse or vary from year to year; otherwise, steady directional selection would drive the *100 allele to low frequencies or extinction. Locus PEPA-1* seems inappropriate for genetic marks in studies of steelhead that span the full life cycle and probably should be avoided

  8. Novel PEPA-functionalized graphene oxide for fire safety enhancement of polypropylene

    NASA Astrophysics Data System (ADS)

    You Xu, Jia; Liu, Jie; Li, Kai Dan; Miao, Lei; Tanemura, Sakae

    2015-04-01

    Polypropylene (PP) is a general-purpose plastic, but some applications are constrained by its high flammability. Thus, flame retardant PP is urgently demanded. In this article, intumescent flame retardant PP (IFRPP) composites with enhanced fire safety were prepared using 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane (PEPA) functionalized graphene oxide (PGO) as synergist. The PGO was prepared through a mild chemical reaction by the covalent attachment of a caged-structure organic compound, PEPA, onto GO nanosheets using toluene diisocynate (TDI) as the intermediary agent. The novel PEPA-functionalized graphene oxide not only improves the heat resistance of GO but also converts GO and PEPA from hydrophobic to hydrophilic materials, which leads to even distribution in PP. In our case, 7 wt% addition of PGO as one of the fillers for IFRPP composites significantly reduces its inflammability and fire hazards when compared with PEPA, by the improvement of first release rate peak (PHRR), total heat release, first smoke release rate peak (PSRR) and total smoke release, suggesting its great potential as the IFR synergist in industry. The reason is mainly attributed to the barrier effect of the unburned graphene sheets, which protects by the decomposition products of PEPA and TDI, promotes the formation of graphitized carbon and inhibits the heat and gas release.

  9. Epoxies from maleic anhydride

    SciTech Connect

    Ahmad, I.; Tumi, S.O.; Bashish, M.; El-Abib, A.R.

    1989-02-01

    The epoxidation of maleic anhydride by hydrogen peroxide in the presence of sodium molybdate catalyst is first order with respect to both maleic anhydride and sodium molybdate concentration. The reaction is zero order with respect to hydrogen peroxide concentration. The calculated rates are reported and a reaction mechanism is proposed.

  10. Roles of the Peptide Transport Systems and Aminopeptidase PepA in Peptide Assimilation by Helicobacter pylori.

    PubMed

    Ki, Mi Ran; Lee, Ji Hyun; Yun, Soon Kyu; Choi, Kyung Min; Hwang, Se Young

    2015-10-01

    Peptide assimilation in Helicobacter pylori necessitates a coordinated working of the peptide transport systems (PepTs) and aminopeptidase (PepA). We found that H. pylori hydrolyzes two detector peptides, L-phenylalanyl-L-3-thiaphenylalanine (PSP) and L-phenylalanyl-L-2- sulfanilylglycine (PSG), primarily before intake and excludes their antibacterial effects, whereas Escherichia coli readily transports them with resultant growth inhibition. PSP assimilation by H. pylori was inhibited by aminopeptidase inhibitor bestatin, but not by dialanine or cyanide-m-chlorophenylhydrazone, contrary to that of E. coli. RT- and qRT-PCR analyses showed that H. pylori may express first the PepTs (e.g., DppA and DppB) and then PepA. In addition, western blot analysis of PepA suggested that the bacterium secretes PepA in response to specific inducers.

  11. Isomeric oxydiphthalic anhydride polyimides

    NASA Technical Reports Server (NTRS)

    Gerber, Margaret K.; Pratt, J. Richard; Stclair, Terry L.

    1988-01-01

    Much of the polyimide research at Langley Research Center has focused on isomeric modification of the diamine component; polyimides having considerably improved processability and adhesion have resulted. The present structure-property study was designed to investigate how isomeric attachment of the three oxydiphthalic anhydride (ODPA) polyimides affects their properties. Each dianhydride, 3,4,3',4'-oxydiphthalic anhydride (4,4'-OPDA,I), 2,3,2',3'-oxydiphthalic anhydride (3,3'-ODPA,II), and 2,3,3',4'-oxydiphthalic anhydride (3,4'-OPDA,III), was reacted with p-phenylenediamine, 4,4'-oxydianiline, 3,3'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, and 4,4'-bis(3-aminophenoxy)benzophenone in DMAc. The inherent viscosities of the resulting poly(amic acids) were determined. Thermally imidized films were studied for their creasability and solubility, as well as by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and wide angle X-ray scattering (WAXS). A comparison of these properties will be made.

  12. Succinic anhydrides from epoxides

    SciTech Connect

    Coates, Geoffrey W.; Rowley, John M.

    2013-07-09

    Catalysts and methods for the double carbonylation of epoxides are disclosed. Each epoxide molecule reacts with two molecules of carbon monoxide to produce a succinic anhydride. The reaction is facilitated by catalysts combining a Lewis acidic species with a transition metal carbonyl complex. The double carbonylation is achieved in single process by using reaction conditions under which both carbonylation reactions occur without the necessity of isolating or purifying the product of the first carbonylation.

  13. Succinic anhydrides from epoxides

    SciTech Connect

    Coates, Geoffrey W; Rowley, John M

    2014-12-30

    Catalysts and methods for the double carbonylation of epoxides are disclosed. Each epoxide molecule reacts with two molecules of carbon monoxide to produce a succinic anhydride. The reaction is facilitated by catalysts combining a Lewis acidic species with a transition metal carbonyl complex. The double carbonylation is achieved in single process by using reaction conditions under which both carbonylation reactions occur without the necessity of isolating or purifying the product of the first carbonylation.

  14. The trigger enzyme PepA (aminopeptidase A) of Escherichia coli, a transcriptional repressor that generates positive supercoiling.

    PubMed

    Nguyen Le Minh, Phu; Nadal, Marc; Charlier, Daniel

    2016-06-01

    Escherichia coli aminopeptidase A (PepA) is a trigger enzyme endowed with catalytic activity and DNA-binding properties prominent in transcriptional regulation and site-specific DNA recombination. The current work demonstrates that PepA is a repressor in its own right, capable of specifically inhibiting transcription initiation at promoter P1 of the carAB operon, encoding carbamoylphosphate synthase. Furthermore, in vitro topology studies performed with DNA minicircles demonstrate that PepA binding constrains a single positive supercoil in the carP1 control region. Such a topological event is understood to constitute an impediment to transcription initiation and may serve as a mechanism to regulate gene expression.

  15. In vitro performance characteristics of a high-flux hemodialyzer with a novel polyester-polymer-alloy (PEPA) membrane.

    PubMed

    Smith, M D; Mahiout, A

    2002-05-01

    Despite improvements in hemodialyzers with respect to their clearance of middle and high molecular mass molecules, accumulation of specific solutes in the circulation of dialysis patients continues to be a medical problem. A new membrane material, polyester-polymer alloy (PEPA) which has been developed to have a filtration profile akin to that of the natural kidney, is now being used in hemodialyzers. This study evaluates the performance of a PEPA-based hemodialyzer alongside a selection of available competing high-flux dialyzers using official standardized methods. The new membrane material appears to be a viable alternative which offers performance at least as good as that of the competition. The promising results obtained with the PEPA membrane suggest that a detailed clinical performance study should be undertaken.

  16. Unexpected Diversity of pepA Genes Encoding Leucine Aminopeptidases in Sediments from a Freshwater Lake.

    PubMed

    Tsuboi, Shun; Yamamura, Shigeki; Imai, Akio; Iwasaki, Kazuhiro

    2016-01-01

    We herein designed novel PCR primers for universal detection of the pepA gene, which encodes the representative leucine aminopeptidase gene, and investigated the genetic characteristics and diversity of pepA genes in sediments of hypereutrophic Lake Kasumigaura, Japan. Most of the amino acid sequences deduced from the obtained clones (369 out of 370) were related to PepA-like protein sequences in the M17 family of proteins. The developed primers broadly detected pepA-like clones associated with diverse bacterial phyla-Alpha-, Beta-, Gamma-, and Deltaproteobacteria, Acidobacteria, Actinobacteria, Aquificae, Chlamydiae, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Spirochetes as well as the archaeal phylum Thaumarchaeota, indicating that prokaryotes in aquatic environments possessing leucine aminopeptidase are more diverse than previously reported. Moreover, prokaryotes related to the obtained pepA-like clones appeared to be r- and K-strategists, which was in contrast to our previous findings showing that the neutral metalloprotease gene clones obtained were related to the r-strategist genus Bacillus. Our results suggest that an unprecedented diversity of prokaryotes with a combination of different proteases participate in sedimentary proteolysis. PMID:26936797

  17. Unexpected Diversity of pepA Genes Encoding Leucine Aminopeptidases in Sediments from a Freshwater Lake

    PubMed Central

    Tsuboi, Shun; Yamamura, Shigeki; Imai, Akio; Iwasaki, Kazuhiro

    2016-01-01

    We herein designed novel PCR primers for universal detection of the pepA gene, which encodes the representative leucine aminopeptidase gene, and investigated the genetic characteristics and diversity of pepA genes in sediments of hypereutrophic Lake Kasumigaura, Japan. Most of the amino acid sequences deduced from the obtained clones (369 out of 370) were related to PepA-like protein sequences in the M17 family of proteins. The developed primers broadly detected pepA-like clones associated with diverse bacterial phyla—Alpha-, Beta-, Gamma-, and Deltaproteobacteria, Acidobacteria, Actinobacteria, Aquificae, Chlamydiae, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Spirochetes as well as the archaeal phylum Thaumarchaeota, indicating that prokaryotes in aquatic environments possessing leucine aminopeptidase are more diverse than previously reported. Moreover, prokaryotes related to the obtained pepA-like clones appeared to be r- and K-strategists, which was in contrast to our previous findings showing that the neutral metalloprotease gene clones obtained were related to the r-strategist genus Bacillus. Our results suggest that an unprecedented diversity of prokaryotes with a combination of different proteases participate in sedimentary proteolysis. PMID:26936797

  18. Modelling and performance analysis of clinical pathways using the stochastic process algebra PEPA

    PubMed Central

    2012-01-01

    Background Hospitals nowadays have to serve numerous patients with limited medical staff and equipment while maintaining healthcare quality. Clinical pathway informatics is regarded as an efficient way to solve a series of hospital challenges. To date, conventional research lacks a mathematical model to describe clinical pathways. Existing vague descriptions cannot fully capture the complexities accurately in clinical pathways and hinders the effective management and further optimization of clinical pathways. Method Given this motivation, this paper presents a clinical pathway management platform, the Imperial Clinical Pathway Analyzer (ICPA). By extending the stochastic model performance evaluation process algebra (PEPA), ICPA introduces a clinical-pathway-specific model: clinical pathway PEPA (CPP). ICPA can simulate stochastic behaviours of a clinical pathway by extracting information from public clinical databases and other related documents using CPP. Thus, the performance of this clinical pathway, including its throughput, resource utilisation and passage time can be quantitatively analysed. Results A typical clinical pathway on stroke extracted from a UK hospital is used to illustrate the effectiveness of ICPA. Three application scenarios are tested using ICPA: 1) redundant resources are identified and removed, thus the number of patients being served is maintained with less cost; 2) the patient passage time is estimated, providing the likelihood that patients can leave hospital within a specific period; 3) the maximum number of input patients are found, helping hospitals to decide whether they can serve more patients with the existing resource allocation. Conclusions ICPA is an effective platform for clinical pathway management: 1) ICPA can describe a variety of components (state, activity, resource and constraints) in a clinical pathway, thus facilitating the proper understanding of complexities involved in it; 2) ICPA supports the performance analysis of

  19. Maleic anhydride from normal butane

    SciTech Connect

    Cooley, S.D.; Doshi, B.

    1987-01-01

    Worldwide about one billion pounds of maleic anhydride is used annually in the manufacture of a number of commercially valuable products, including unsaturated polyester resins, agricultural chemicals, and lubricating oil additives. Maleic anhydride is not found in nature. It was first prepared in 1834 by heating malic acid (hydroxy-succinic acid, a compound found in apples and many other fruits). Maleic anhydride was not available commercially until ca. 1930 when the catalytic air oxidation of benzene was begun by National Aniline and Chemical on an industrial scale. The estimated worldwide production in 1985 was 1023 million pounds coming from more than 35 plants varying in capacity from 6 million pounds to 170 million pounds annually.

  20. Process for the production of phthalic anhydride

    SciTech Connect

    Miserlis, C. D.

    1984-03-06

    A system for producing phthalic anhydride by the catalytic oxidation of nathphalene, wherein without creating a significant pressure drop in the system substantially aff of the catalyst particles are removed from the product stream before the product stream is sent to a battery of switch condensers for recovery of the phthalic anhydride.

  1. Solvent free low-melt viscosity imide oligomers and thermosetting polymide composites

    NASA Technical Reports Server (NTRS)

    Chuang, Chun-Hua (Inventor)

    2012-01-01

    .[.This invention relates to the composition and a solvent-free process for preparing novel imide oligomers and polymers specifically formulated with effective amounts of a dianhydride such as 2,3,3',4-biphenyltetra carboxylic dianydride (a-BPDA), at least one aromatic diamine and an endcapped of 4-phenylethynylphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260-280.degree. C. When the imide oligomer melt is cured at about 371.degree. C. in a press or autoclave under 100-500 psi, the melt resulted in a thermoset polyimide having a glass transition temperature (T.sub.g) equal to and above 310.degree. C. A novel feature of this process is that the monomers; namely the dianhydrides, diamines and the endcaps, are melt processable to form imide oligomers at temperatures ranging between 232-280.degree. C. (450-535.degree. F.) without any solvent. These low-melt imide oligomers can be easily processed by resin transfer molding (RTM), vacuum-assisted resin transfer molding (VARTM) or the resin infusion process with fiber preforms e.g. carbon, glass or quartz preforms to produce polyimide matrix composites with 288-343.degree. C. (550-650.degree. F.) high temperature performance capability..]. .Iadd.This invention relates to compositions and a solvent-free reaction process for preparing imide oligomers and polymers specifically derived from effective amounts of dianhydrides such as 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), at least one aromatic polyamine and an end-cap such as 4-phenylethynyphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260.degree. C.-280.degree. C..Iaddend.

  2. The novel silicon-containing epoxy/PEPA phosphate flame retardant for transparent intumescent fire resistant coating

    NASA Astrophysics Data System (ADS)

    Shi, Yanchao; Wang, Guojian

    2016-11-01

    A series of novel silicon-containing epoxy/PEPA phosphate flame retardants (EPPSi) were synthesized by polyphosphoric acid (PPA), caged bicyclic phosphate 1-oxo-4-hydroxymethyl-2,6,7-trioxa-L-phosphabicyclo [2.2.2] octane (PEPA), and different ratios of silicon-containing epoxy 1,1,3,3-tetramethyl-1,3-bis(3-(oxiran-2-ylmethoxy)propyl)disiloxane (TMSEP) to 1,4-butanediol diglycidyl ether (BDE). The chemical structure of EPPSi was confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance spectroscopy (1H NMR). Afterwards, the transparent intumescent fire resistant coatings were prepared by mixing EPPSi and melamine formaldehyde resin. The influence of silicon on the fire protection of coatings was intensively investigated by fire protection test, intumescence ratio, scanning electron microscope (SEM), compressive strength test, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and real-time FTIR. It was found that the fire resistant coatings obtained the best fire protection when the ratio of TMESP/BDE was 20/100, while excessive TMSEP made the fire protection of coatings deceased sharply. The intumescence ratio, compressive strength test and SEM result showed that a synergistic effect existed between phosphorus and silicon, which improved the foam structure and compressive strength of the char layer significantly. XPS result proved the out-migration effect of silicon. The high concentration silicon on surface played an important protecting role for the inner char residue and improved the fire protection of the coatings. TGA result demonstrated that silicon enhanced the thermo-oxidation resistance of coatings efficiently. Furthermore, real-time FTIR revealed the intumescent process of the fire resistant coatings according to the chemical structure changes of char residue.

  3. Improved zein articles using polyethylenemaleic anhydride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Developing corn protein (zein) articles with improved physical properties and solvent resistance will have a beneficial impact on companies that use corn. The effect of using the crosslinking reagent polyethylenemaleic anhydride (PEMA) on the properties and solubility of zein articles were studied. ...

  4. Solvent Free Low-Melt Viscosity Imide Oligomers And Thermosetting Polyimide Composites

    NASA Technical Reports Server (NTRS)

    Chuang, CHun-Hua (Inventor)

    2006-01-01

    This invention relates to the composition and a solvent-free process for preparing novel imide oligomers and polymers specifically formulated with effective amounts of a dianhydride such as 2,3,3',4-biphenyltetra carboxylic dianydride (a-BPDA), at least one aromatic diamine' and an endcapped of 4-phenylethynylphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260-280" C. When the imide oligomer melt is cured at about 371 C. in a press or autoclave under 100-500 psi, the melt resulted in a thermoset polyimide having a glass transition temperature (T(sub g)) equal to and above 310 C. A novel feature of this process is that the monomers; namely the dianhydrides, diamines and the endcaps, are melt processable to form imide oligomers at temperatures ranging between 232-280 C. (450-535 F) without any solvent. These low-melt imide oligomers can be easily processed by resin transfer molding (RTM), vacuum-assisted resin transfer molding (VARTM) or the resin infusion process with fiber preforms e.g. carbon, glass or quartz preforms to produce polyimide matrix composites with 288-343C (550-650 F) high temperature performance capability.

  5. Preparation of poly(glycidylmethacrylate-divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride, phthalic anhydride, and maleic anhydride for ion chromatography.

    PubMed

    Liu, Junwei; Wang, Yong; Wu, Shuchao; Zhang, Peimin; Zhu, Yan

    2016-08-01

    In this work, poly(glycidylmethacrylate-divinylbenzene) microspheres were prepared and applied for the preparation of weak acid cation exchange stationary phases. Succinic anhydride, phthalic anhydride, and maleic anhydride were selected as carboxylation reagents to prepare three weak acid cation exchangers by direct chemical derivatization reaction without solvent or catalyst. The diameters and dispersity of the microspheres were characterized by scanning electron microscopy; the amount of accessible epoxy groups and mechanical stability were also measured. The weak acid cation exchangers were characterized by Fourier transform infrared spectroscopy; the content of carboxyl groups was measured by traditional acid base titration method. The chromatographic properties were characterized and compared by separating alkali, alkaline earth metal ions and ammonium and polar amines. The separation properties enhanced in the order of succinic anhydride, phthalic anhydride, and maleic anhydride modified poly(glycidylmethacrylate-divinylbenzene) cation exchangers.

  6. Preparation of poly(glycidylmethacrylate-divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride, phthalic anhydride, and maleic anhydride for ion chromatography.

    PubMed

    Liu, Junwei; Wang, Yong; Wu, Shuchao; Zhang, Peimin; Zhu, Yan

    2016-08-01

    In this work, poly(glycidylmethacrylate-divinylbenzene) microspheres were prepared and applied for the preparation of weak acid cation exchange stationary phases. Succinic anhydride, phthalic anhydride, and maleic anhydride were selected as carboxylation reagents to prepare three weak acid cation exchangers by direct chemical derivatization reaction without solvent or catalyst. The diameters and dispersity of the microspheres were characterized by scanning electron microscopy; the amount of accessible epoxy groups and mechanical stability were also measured. The weak acid cation exchangers were characterized by Fourier transform infrared spectroscopy; the content of carboxyl groups was measured by traditional acid base titration method. The chromatographic properties were characterized and compared by separating alkali, alkaline earth metal ions and ammonium and polar amines. The separation properties enhanced in the order of succinic anhydride, phthalic anhydride, and maleic anhydride modified poly(glycidylmethacrylate-divinylbenzene) cation exchangers. PMID:27288092

  7. Dicarboxylic acid anhydride condensation with compounds containing active methylene groups. 4: Some 4-nitrophthalic anhydride condensation reactions

    NASA Technical Reports Server (NTRS)

    Oskaja, V.; Rotberg, J.

    1985-01-01

    By 4-nitrophthalic anhydride condensation with acetoacetate in acetic anhydride and triethylamine solution with subsequent breakdown of the intermediate condensation product, 5-nitroindanedione-1,3 was obtained. A 4-nitrophthalic anhydride with acetic anhydride, according to reaction conditions, may yield two products: in the presence of potassium acetate and at high temperatures 4-(or 5-)-nitro-2-acetylbenzoic acid is formed: in the presence of triethylamine and at room temperature 5-( or 6-)-nitrophthalic acetic acid is isolated. A 4-nitrophthalic anhydride and malonic acid in pyridine solution according to temperature yield either 5-( or 6-)-nitrophthalic acetic acid or 4-(or 5-)-nitro-2-acetylbenzoic acid.

  8. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 19: Condensation of phthalic and substituted phthalic anhydrides with benzoylacetic ester

    NASA Technical Reports Server (NTRS)

    Rotberg, Y. T.; Oshkaya, V. P.

    1985-01-01

    Phthalylbenzoylacetic ester and its nitro and halogen derivatives were prepared through condensation of phthalic anhydride, nitrophthalic anhydride, and phthalic halide anhydride with benzoylacetic ester in a solution of acetic anhydride and triethylamine. The condensation of hemipinic acid anhydride proceeds similarly, but under more drastic conditions. Derivatives of indan-1,3-dione are also formed, with a small yield, in the reaction of nitrophthalic anhydrides with benzoylacetic ester in the presence of increased quantities of triethylamine.

  9. Chemicals from coal - The Eastman experience. [Anhydride

    SciTech Connect

    Larkins, T.H.

    1986-03-01

    Tennessee Eastman Company is a major producer of chemicals, fibers and plastics. It is located in Kingsport, Tennessee, headquarters for the Eastman Chemicals Division of Eastman Kodak Company. Eastman Companies employ a total of 12,250 people in Kingsport. Other domestic Eastman Chemicals Division plants are located in Texas, South Carolina, Arkansas and New York. The authors began to witness a flow of products from one of the most highly technical and sophisticated chemical processes in operation in the world. The Eastman ''Chemicals-from-Coal'' facility is not a sunfuel plant. To be sure, we are producing syngas from coal, but the syngas is used to produce acetic anhydride. Acetic anhydride is very important to Eastman. This chemical intermediate eventually finds its way into such diverse products as aspirin, cigarette filters, tool handles, and photographic film. It also is used to make other chemical intermediates such as cellulose esters, anhydrides, triacetin, and acetate ester solvents, all of which have a variety of end uses. The chemicals-from-coal project had its inception in the late 1960's when Eastman stepped up its program of energy conservation and began a search for lower cost chemical feedstocks. Our concern started before the national concern caused by a ten-fold increase in petroleum prices during the past decade.

  10. Photocrosslinked poly(ester anhydride)s for peptide delivery: Effect of oligomer hydrophobicity on PYY3-36 delivery.

    PubMed

    Mönkäre, Juha; Hakala, Risto A; Kovalainen, Miia; Korhonen, Harri; Herzig, Karl-Heinz; Seppälä, Jukka V; Järvinen, Kristiina

    2012-01-01

    The treatment for many diseases can be improved by developing more efficient peptide delivery technologies, for example, biodegradable polymers. In this work, photocrosslinked poly(ester anhydride)s based on functionalized poly(ε-caprolactone) oligomers were investigated for their abilities to achieve controlled peptide delivery. The effect of oligomer hydrophobicity on erosion and peptide release from poly(ester anhydride)s was evaluated by developing a sustained subcutaneous delivery system for an antiobesity drug candidate, peptide YY3-36 (PYY3-36). Oligomer hydrophobicity was modified with alkenylsuccinic anhydrides containing a 12-carbon alkenyl chain. PYY3-36 was mixed as a solid powder with methacrylated poly(ester anhydride) precursors, and this mixture was photocrosslinked at room temperature to form an implant for subcutaneous administration in rats. The oligomer hydrophobicity controlled the polymer erosion and PYY3-36 release as the increased hydrophobicity via the alkenyl chain prolonged polymer erosion in vitro and sustained in vivo release of PYY3-36. In addition, photocrosslinked poly(ester anhydride)s increased the bioavailability of PYY3-36 by up to 20-fold in comparison with subcutaneous administration of solution, evidence of remarkably improved delivery. In conclusion, this work demonstrates the suitability of photocrosslinked poly(ester anhydride)s for use in peptide delivery.

  11. Photocrosslinkable polyesters and poly(ester anhydride)s for biomedical applications.

    PubMed

    Seppälä, Jukka; Korhonen, Harri; Hakala, Risto; Malin, Minna

    2011-12-01

    Crosslinking is a feasible way to prepare biodegradable polymers with potential in biomedical applications such as controlled release of active agents and tissue engineering. A synthesis route in which functional telechelic aliphatic polyester oligomers are used as precursors for the preparation of crosslinked polyesters and poly(ester anhydride)s is described. Mechanical properties, degradation characteristics and rate, and bioactivity can be modified widely by controlling the chemical composition and architecture of the crosslinkable oligomers. In tissue engineering, photocrosslinking allows to use crosslinkable oligomers in advanced manufacturing techniques like micromolding in capillaries, stereolithography and two-photon polymerization. PMID:22052651

  12. Preparation of {alpha}, {beta}-unsaturated carboxylic acids and anhydrides

    DOEpatents

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Tustin, G.C.

    1998-01-20

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  13. Preparation of .alpha., .beta.-unsaturated carboxylic acids and anhydrides

    DOEpatents

    Spivey, James Jerry; Gogate, Makarand Ratnakav; Zoeller, Joseph Robert; Tustin, Gerald Charles

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  14. Scandium trifluoromethanesulfonate as an extremely active Lewis acid catalyst in acylation of alcohols with acid anhydrides and mixed anhydrides

    SciTech Connect

    Ishihara, K.; Kubota, M.; Kurihara, H.; Yamamoto, H.

    1996-07-12

    Scandium triflate catalyzes the acylation of alcohols with acid anhydrides or the esterification of alcohols by carboxylic acids in the presence of p-nitrobenzoic anhydrides. The catalytic activity of the scandium triflates is found to be quite high allowing the acylation of secondary and tertiary alcohols.

  15. PETIs as High-Temperature Resin-Transfer-Molding Materials

    NASA Technical Reports Server (NTRS)

    Connell, John N.; Smith, Joseph G., Jr.; Hergenrother, Paul M.

    2005-01-01

    Compositions of, and processes for fabricating, high-temperature composite materials from phenylethynyl-terminated imide (PETI) oligomers by resin-transfer molding (RTM) and resin infusion have been developed. Composites having a combination of excellent mechanical properties and long-term high-temperature stability have been readily fabricated. These materials are particularly useful for the fabrication of high-temperature structures for jet-engine components, structural components on highspeed aircraft, spacecraft, and missiles. Phenylethynyl-terminated amide acid oligomers that are precursors of PETI oligomers are easily made through the reaction of a mixture of aromatic diamines with aromatic dianhydrides at high stoichiometric offsets and 4-phenylethynylphthalic anhydride (PEPA) as an end-capper in a polar solvent such as N-methylpyrrolidinone (NMP). These oligomers are subsequently cyclodehydrated -- for example, by heating the solution in the presence of toluene to remove the water by azeotropic distillation to form low-molecular-weight imide oligomers. More precisely, what is obtained is a mixture of PETI oligomeric species, spanning a range of molecular weights, that exhibits a stable melt viscosity of less than approximately 60 poise (and generally less than 10 poise) at a temperature below 300 deg C. After curing of the oligomers at a temperature of 371 deg C, the resulting polymer can have a glass-transition temperature (Tg) as high as 375 C, the exact value depending on the compositions.

  16. Synthesis and Characterization of Poly(maleic Anhydride)s Cross-linked Polyimide Aerogels

    NASA Technical Reports Server (NTRS)

    Guo, Haiquan; Meador, Mary Ann B.

    2015-01-01

    With the development of technology for aerospace applications, new thermal insulation materials are required to be flexible and capable of surviving high heat flux. For instance, flexible insulation is needed for inflatable aerodynamic decelerators which are used to slow spacecraft for entry, descent and landing (EDL) operations. Polyimide aerogels have low density, high porosity, high surface area, and better mechanical properties than silica aerogels and can be made into flexible thin films, thus they are potential candidates for aerospace needs. The previously reported cross-linkers such as octa(aminophenyl)silsesquioxane (OAPS) and 1,3,5-triaminophenoxybenzene (TAB) are either expensive or not commercially available. Here, we report the synthesis of a series of polyimide aerogels cross-linked using various commercially available poly(maleic anhydride)s, as seen in Figure 1. The amine end capped polyimide oligomers were made with 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA) and diamine combinations of dimethylbenzidine (DMBZ) and 4, 4-oxydianiline (ODA). The resulting aerogels have low density (0.12 gcm3 to 0.16 gcm3), high porosity (90) and high surface area (380-554 m2g). The effect of the different poly(maleic anhydride) cross-linkers and polyimide backbone structures on density, shrinkage, porosity, surface area, mechanical properties, moisture resistance and thermal properties will be discussed.

  17. Process for the production of maleic anhydride

    SciTech Connect

    Click, G.T.; Barone, B.J.

    1986-06-24

    A process is described for the vapor phase oxidation of hydrocarbons having 4 carbon atoms to produce maleic anhydride comprising contacting the hydrocarbons with a fixed bed vanadium-phosphorus-oxygen catalyst, containing P:V in an atomic ration of 1/2 to 3:1 whereby the catalyst gradually decreases in selectivity, wherein the improvement comprises contacting the catalyst with phosphorus compound of phosphorus halide, phosphorus oxyhalide, organic phospines, organic phosphites, organic phosphates or mixtures thereof at a temperature in the range of about 0/sup 0/ to 600/sup 0/C and thereafter contacting the catalyst with a flow of stream at a temperature in the range of 300/sup 0/ to 600/sup 0/C in an amount and for a sufficient duration whereby the catalyst is regenerated.

  18. Process for the continuous separation of maleic anhydride from process gases

    SciTech Connect

    Ceisel, S.C.; Conrad, J.F.; Lestan, E.M.; Nelson, A.P.

    1990-07-17

    This patent describes a process for recovery of maleic anhydride from a gaseous mixture of a reactor effluent gas stream containing maleic anhydride. It comprises: contacting the mixture with maleic anhydride in a gas phase wherein the maleic anhydride is injected into a gas stream effluent from an oxidation reactor. The gas stream effluent is at a temperature of from about 200{degrees}F. to about 350{degrees}F., and maleic anhydride is recovered in a condenser.

  19. Alternating Poly(ester-anhydride) by Insertion Polycondensation.

    PubMed

    Haim-Zada, Moran; Basu, Arijit; Hagigit, Tal; Schlinger, Ron; Grishko, Michael; Kraminsky, Alexander; Hanuka, Ezra; Domb, Abraham J

    2016-06-13

    We report on a synthetic method where polyanhydride is used as starting material and the ester monomers are inserted through complete esterification, leading to an alternating ester-anhydride copolymer. The molar ratio of ricinoleic acid (RA) and sebacic acid (SA) was optimized until polysebacic acid is completely converted to carboxylic acid-terminated RA-SA and RA-SA-RA ester-dicarboxylic acids. These dimers and trimers were activated with acetic anhydride, polymerized under heat and vacuum to yield alternating RA-SA copolymer. The resulting alternating poly(ester-anhydride) have the RA at regular intervals. The regular occurrences of RA side chains prevent anhydride interchange, enhancing hydrolytic stability, which allows storage of the polymer at room temperature. PMID:27198864

  20. Health and Environmental Effects Profile for maleic anhydride

    SciTech Connect

    Not Available

    1986-07-01

    The Health and Environmental Effects Profile for maleic anhydride was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human-health, aquatic-life, and environmental effects of hazardous-waste constituents. Maleic anhydride has been determined to be a systemic toxicant. An Acceptable Daily Intake (ADI), for maleic anhydride is 0.10 mg/kg/day for oral exposure. The Reportable Quantity (RQ) value for maleic anhydride is 100.

  1. Mutational analysis of intervening sequences connecting the binding sites for integration host factor, PepA, PurR, and RNA polymerase in the control region of the Escherichia coli carAB operon, encoding carbamoylphosphate synthase.

    PubMed

    Devroede, Neel; Huysveld, Nadine; Charlier, Daniel

    2006-05-01

    Transcription of the carAB operon encoding the unique carbamoylphosphate synthase of Escherichia coli reflects the dual function of carbamoylphosphate in the biosynthesis of arginine and pyrimidine nucleotides. The tandem pair of promoters is regulated by various mechanisms depending on the needs of both pathways and the maintenance of a pyrimidine/purine nucleotide balance. Here we focus on the linker regions that impose the distribution of target sites for DNA-binding proteins involved in pyrimidine- and purine-specific repression of the upstream promoter P1. We introduced deletions and insertions, and combinations thereof, in four linkers connecting the binding sites for integration host factor (IHF), PepA, PurR, and RNA polymerase and studied the importance of phasing and spacing of the targets and the importance of the nucleotide sequence of the linkers. The two PepA binding sites must be properly aligned and separated with respect to each other and to the promoter for both pyrimidine- and purine-mediated repression. Similarly, the phasing and spacing of the IHF and PEPA2 sites are strictly constrained but only for pyrimidine-specific repression. The IHF target is even dispensable for purine-mediated regulation. Thus, a correct localization of PepA within the higher-order nucleoprotein complex is a prerequisite for the establishment of pyrimidine-mediated repression and for the coupling between purine- and pyrimidine-dependent regulation. Our data also suggest the existence of a novel cis-acting pyrimidine-specific regulatory target located around position -60. Finally, the analysis of a P1 derivative devoid of its control region has led to a reappraisal of the effect of excess adenine on P1 and has revealed that P1 has no need for a UP element.

  2. Method for epoxy foam production using a liquid anhydride

    DOEpatents

    Celina, Mathias

    2012-06-05

    An epoxy resin mixture with at least one epoxy resin of between approximately 50 wt % and 100 wt %, an anhydride cure agent of between approximately 0 wt % and approximately 50 wt %, a tert-butoxycarbonyl anhydride foaming agent of between proximately 0.1-20 wt %, a surfactant and an imidazole or similar catalyst of less than approximately 2 wt %, where the resin mixture is formed from at least one epoxy resin with a 1-10 wt % tert-butoxycarbonyl anhydride compound and an imidazole catalyst at a temperature sufficient to keep the resin in a suitable viscosity range, the resin mixture reacting to form a foaming resin which in the presence of an epoxy curative can then be cured at a temperature greater than 50.degree. C. to form an epoxy foam.

  3. Thermochemistry of diphenic anhydride. A combined experimental and theoretical study

    NASA Astrophysics Data System (ADS)

    Agostinha, M.; Matos, R.; Miranda, Margarida S.; Pinto, Natália A. B.; Morais, Victor M. F.; Dhananjaya, N.; Liebman, Joel F.

    The standard (p° = 0.1 MPa) molar enthalpy of formation for solid and gaseous diphenic anhydride (2,2'-biphenyldicarboxylic anhydride, dibenz[c,e]oxepin-5,7-dione) was derived from the standard molar enthalpy of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry, and the standard molar enthalpy of sublimation, at T = 298.15 K, measured by Calvet microcalorimetry: -(258.4 ± 4.9) kJ mol-1. In addition, ab initio and density functional theory calculations have been performed at a variety of levels. The degree of aromaticity of diphenic anhydride is discussed in the context of other oxygen-containing (ring and keto) heterocycles and related carbocycles: this species is surprisingly destabilized.

  4. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic). 721.10038 Section 721.10038... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  5. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic). 721.10038 Section 721.10038... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  6. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic). 721.10038 Section 721.10038... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  7. Low Melt Viscosity Resins for Resin Transfer Molding

    NASA Technical Reports Server (NTRS)

    Harris, Frank W.

    2002-01-01

    In recent years, resin transfer molding (RTM) has become one of the methods of choice for high performance composites. Its cost effectiveness and ease of fabrication are major advantages of RTM. RTM process usually requires resins with very low melt viscosity (less than 10 Poise). The optimum RTM resins also need to display high thennal-oxidative stability, high glass transition temperature (T(sub g)), and good toughness. The traditional PMR-type polyimides (e.g. PMR-15) do not fit this requirement, because the viscosities are too high and the nadic endcap cures too fast. High T(sub g), low-melt viscosity resins are highly desirable for aerospace applications and NASA s Reusable Launch Vehicle (RLV) program. The objective of this work is to prepare low-melt viscosity polyimide resins for RTM or resin film infusion (RFI) processes. The approach involves the synthesis of phenylethynyl-terminated imide oligomers. These materials have been designed to minimize their melt viscosity so that they can be readily processed. During the cure, the oligomers undergo both chain extension and crosslinking via the thermal polymerization of the phenylethynyl groups. The Phenylethynyl endcap is preferred over the nadic group due to its high curing temperature, which provides broader processing windows. This work involved the synthesis and polymerization of oligomers containing zig-zag backbones and twisted biphenyl structures. Some A-B type precursors which possessed both nitro and anhydride functionality, or both nitro and amine functionality, were also synthesized in order to obtain the well defined oligomers. The resulting zig-zag structured oligomers were then end-capped with 4-phenylethynylphthalic anhydride (PEPA) for further cure. The properties of these novel imide oligomers are evaluated.

  8. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  9. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  10. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... articles that contact food of Types I, II, III, IV-A, IV-B, V, VI-B (except carbonated beverages), VII-A... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene-maleic anhydride copolymers. 177.1820 Section 177.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  11. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Styrene-maleic anhydride copolymers. 177.1820 Section 177.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated...

  12. Rheological studies on the reaction of zein with polyethylenemaleic anhydride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There continues to be interest in developing solvent-resistant articles from biobased renewable materials to successfully complete with petro-chemical products. It was previously shown that reaction of zein with polyethylenemaleic anhydride (PEMA) provides articles that are solvent-resistant. The ge...

  13. IDENTIFYING AIRWAY SENSITIZERS: MRNA CYTOKINE PROFILES INDUCED BY VARIOUS ANHYDRIDES

    EPA Science Inventory

    Abstract:
    Exposure to low molecular weight (LMW) chemicals in the workplace has been linked to a variety of respiratory effects. Within the LMW chemicals, one of the major classes involved in these effects are the acid anhydrides. The immunological basis of respiratory hyp...

  14. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 1: Condensation of phthalic anhydride with acetoacetic and malonic ester

    NASA Technical Reports Server (NTRS)

    Oshkaya, V. P.; Vanag, G. Y.

    1985-01-01

    Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ester and a derivative of indan-1,3-dione which after boiling with hydrochloric acid yielded indan-1,3-dione. Phthalylmalonic ester was obtained from phthalic anhydride and malonic ester in the presence of triethylamine.

  15. Maleic anhydride catalysts and process for their manufacture

    SciTech Connect

    Haddad, M.S.; Meyers, B.L.; Eryman, W.S.

    1990-06-12

    This patent describes a catalyst for the production of maleic anhydride by the oxidation of a member of the group consisting of benzene, butane, butene and butadiene. It comprises a phosphorus-vanadium-mixed oxide and exists in the form of geometric shapes, the shapes having been heated in an inert atmosphere at a temperature of about 650{degrees} to about 1300{degrees} F. prior to being exposed to an oxygen-containing gas at an elevated temperature.

  16. Use fluid bed reactor for maleic anhydride from butane

    SciTech Connect

    Arnold, S.C.; Neri, A.; Suciu, G.D.; Verde, L.

    1985-09-01

    A new process is described that incorporates three major improvements over the conventional air oxidation of benzene in a fixed-bed reactor system. The new ALMA Process was developed jointly by Alusuisse Italia and Lummus Crest. It includes the following process improvements: n-Butane feedstock, fluidized-bed reactor system, and a continuous maleic anhydride recovery system using an organic solvent. A summary of the process is given, as well as the steps in its development and its economic advantages.

  17. Biosynthetic Study on Antihypercholesterolemic Agent Phomoidride: General Biogenesis of Fungal Dimeric Anhydrides.

    PubMed

    Fujii, Ryuya; Matsu, Yusuke; Minami, Atsushi; Nagamine, Shota; Takeuchi, Ichiro; Gomi, Katsuya; Oikawa, Hideaki

    2015-11-20

    To elucidate the general biosynthetic pathway of fungal dimeric anhydrides, a gene cluster for the biosynthesis of the antihy-percholesterolemic agent phomoidride was identified by heterologous expression of candidate genes encoding the highly reducing polyketide synthase, alkylcitrate synthase (ACS), and alkylcitrate dehydratase (ACDH). An in vitro analysis of ACS and ACDH revealed that they give rise to anhydride monomers. Based on the established monomer biosynthesis, we propose a general biogenesis of dimeric anhydrides involving a single donor unit and four acceptor units.

  18. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... alkyl amines, sodium salts, compds. with ethanolamine. (a) Chemical substance and significant new uses... anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine (PMN...

  19. 40 CFR 721.10316 - Dicyclopentadiene polymer with maleic anhydride and alkyl alcohols (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... anhydride and alkyl alcohols (generic). 721.10316 Section 721.10316 Protection of Environment ENVIRONMENTAL... anhydride and alkyl alcohols (generic). (a) Chemical substance and significant new uses subject to reporting... and alkyl alcohols (PMN P-02-872) is subject to reporting under this section for the significant...

  20. 40 CFR 721.10316 - Dicyclopentadiene polymer with maleic anhydride and alkyl alcohols (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... anhydride and alkyl alcohols (generic). 721.10316 Section 721.10316 Protection of Environment ENVIRONMENTAL... anhydride and alkyl alcohols (generic). (a) Chemical substance and significant new uses subject to reporting... and alkyl alcohols (PMN P-02-872) is subject to reporting under this section for the significant...

  1. 40 CFR 721.10316 - Dicyclopentadiene polymer with maleic anhydride and alkyl alcohols (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... anhydride and alkyl alcohols (generic). 721.10316 Section 721.10316 Protection of Environment ENVIRONMENTAL... anhydride and alkyl alcohols (generic). (a) Chemical substance and significant new uses subject to reporting... and alkyl alcohols (PMN P-02-872) is subject to reporting under this section for the significant...

  2. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  3. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  4. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  5. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  6. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  7. TRIMELLITIC ANHYDRIDE-INDUCED EOSINOPHILIA IN A MURINE MODEL OF OCCUPATIONAL ASTHMA

    EPA Science Inventory

    TRIMELLITIC ANHYDRIDE-INDUCED EOSINOPHILIA IN A MURINE MODEL OF OCCUPATIONAL ASTHMA. J F Regal, ME Mohrman, E Boykin and D Sailstad. Dept. of Pharmacology, University of Minnesota, Duluth, MN, USA and NHEERL, ORD, US EPA, RTP, NC, USA.
    Trimellitic anhydride (TMA) is a small m...

  8. Initiation precursors and initiators in laser-induced copolymerization of styrene and maleic anhydride in acetone

    NASA Technical Reports Server (NTRS)

    Miner, Gilda A.; Meador, Willard E.; Chang, C. Ken

    1990-01-01

    The initiation step of photopolymerized styrene/maleic anhydride copolymer was investigated at 365 nm. UV absorption measurements provide decisive evidence that the styrene/maleic anhydride charge transfer complex is the sole absorbing species; however, key laser experiments suggest intermediate reactions lead to a monoradical initiating species. A mechanism for the photoinitiation step of the copolymer is proposed.

  9. Immunogenicity of peanut proteins containing poly(anhydride) nanoparticles.

    PubMed

    De S Rebouças, Juliana; Irache, Juan M; Camacho, Ana I; Gastaminza, Gabriel; Sanz, María L; Ferrer, Marta; Gamazo, Carlos

    2014-08-01

    In the last decade, peanut allergy has increased substantially. Significant differences in the prevalence among different countries are attributed to the type of thermal processing. In spite of the high prevalence and the severe reaction induced by peanuts, there is no immunotherapy available. The aim of this work was to evaluate the potential application of poly(anhydride) nanoparticles (NPs) as immunoadjuvants for peanut oral immunotherapy. NPs loaded with raw or roasted peanut proteins were prepared by a solvent displacement method and dried by either lyophilization or spray-drying. After physicochemical characterization, their adjuvant capacity was evaluated after oral immunization of C57BL/6 mice. All nanoparticle formulations induced a balanced T(H)1 and T(H)2 antibody response, accompanied by low specific IgE induction. In addition, oral immunization with spray-dried NPs loaded with peanut proteins was associated with a significant decrease in splenic T(H)2 cytokines (interleukin 4 [IL-4], IL-5, and IL-6) and enhancement of both T(H)1 (gamma interferon [IFN-γ]) and regulatory (IL-10) cytokines. In conclusion, oral immunization with poly(anhydride) NPs, particularly spray-dried formulations, led to a pro-T(H)1 immune response.

  10. Immunogenicity of Peanut Proteins Containing Poly(Anhydride) Nanoparticles

    PubMed Central

    De S. Rebouças, Juliana; Irache, Juan M.; Camacho, Ana I.; Gastaminza, Gabriel; Sanz, María L.

    2014-01-01

    In the last decade, peanut allergy has increased substantially. Significant differences in the prevalence among different countries are attributed to the type of thermal processing. In spite of the high prevalence and the severe reaction induced by peanuts, there is no immunotherapy available. The aim of this work was to evaluate the potential application of poly(anhydride) nanoparticles (NPs) as immunoadjuvants for peanut oral immunotherapy. NPs loaded with raw or roasted peanut proteins were prepared by a solvent displacement method and dried by either lyophilization or spray-drying. After physicochemical characterization, their adjuvant capacity was evaluated after oral immunization of C57BL/6 mice. All nanoparticle formulations induced a balanced TH1 and TH2 antibody response, accompanied by low specific IgE induction. In addition, oral immunization with spray-dried NPs loaded with peanut proteins was associated with a significant decrease in splenic TH2 cytokines (interleukin 4 [IL-4], IL-5, and IL-6) and enhancement of both TH1 (gamma interferon [IFN-γ]) and regulatory (IL-10) cytokines. In conclusion, oral immunization with poly(anhydride) NPs, particularly spray-dried formulations, led to a pro-TH1 immune response. PMID:24899075

  11. The molecular mechanism of flop-selectivity and subsite recognition for an AMPA receptor allosteric modulator: Structures of GluA2 and GluA3 complexed with PEPA

    PubMed Central

    Ahmed, Ahmed H.; Ptak, Christopher P.; Oswald, Robert E.

    2011-01-01

    Glutamate receptors are important potential drug targets for cognitive enhancement and the treatment of schizophrenia in part because they are the most prevalent excitatory neurotransmitter receptors in the vertebrate central nervous system. One approach to the application of therapeutic agents to the AMPA subtype of glutamate receptors is the use of allosteric modulators, which promote dimerization by binding to a dimer interface thereby reducing desensitization and deactivation. AMPA receptors exist in two alternatively spliced variants (flip and flop) that differ in desensitization and receptor activation profiles. Most of the structural information on modulators of the AMPA receptor target the flip subtype. We report here the crystal structure of the flop-selective allosteric modulator, PEPA, bound to the binding domains of the GluA2 and GluA3 flop isoforms of AMPA receptors. Specific hydrogen bonding patterns can explain the preference for the flop isoform. This includes a bidentate hydrogen bonding pattern between PEPA and N754 of the flop isoforms of GluA2 and GluA3 (the corresponding position in the flip isoform is S754). Comparison with other allosteric modulators provides a framework for the development of new allosteric modulators with preferences for either the flip or flop isoforms. In addition to interactions with N/S754, specific interactions of the sulfonamide with conserved residues in the binding site are characteristics of a number of allosteric modulators. These, in combination, with variable interactions with five subsites on the binding surface lead to different stoichiometries, orientations within the binding pockets, and functional outcomes. PMID:20199107

  12. Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

    PubMed

    Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

    2014-10-01

    The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

  13. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine (PMN...

  14. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine (PMN...

  15. Perylenetetracarboxylic anhydride as a precursor of fluorescent carbon nanoonion rings

    NASA Astrophysics Data System (ADS)

    Baldoví, Herme G.; Herance, José Raul; Manuel Víctor, Víctor; Alvaro, Mercedes; Garcia, Hermenegildo

    2015-07-01

    Thermal annealing at 400 °C of perylenetetracarboxylic anhydride in low molecular mass PEG gives rise to the formation of well defined nanoobjects of 2.5 nm height and size distribution from 10 to 65 nm (average 40 nm) after purification of the raw mixture with silicagel chromatography. TEM reveals that the flat nanoobjects are constituted of concentric graphenic rings (0.34 nm interlayer distance). The morphology of the nanoparticles resembles onion rings of nanometric dimensions (nanoonion rings C-NOR). C-NOR particles have an excitation dependent emission with λem from 430 to 570 nm and a maximum emission quantum yield of 0.49. C-NOR particles can be internalized into Hep3B human hepatoma cells as determined by confocal fluorescence microscopy and are remarkably biocompatible affecting slightly cell viability according to the MTT test.

  16. Development of ALMA process: Advances maleic anhydride production technology

    SciTech Connect

    Arnoia, S.C.; Komeya, M.; Pedretti, D.; Stanecki, J.W.

    1987-01-01

    Shin-Daikyowa Petrochemical Co. (SDPC) has initiated a project to build a 15,000 MTA maleic anhydride plant at Yokkaichi, Japan. For technology, SDPC evaluated many alternatives and elected to utilize the ALMA Process in what will be the first full-scale plant for this new process. Startup is scheduled for late 1988. This paper describes the economic advantages of the ALMA Process and their technical bases which have led to its selection by SDPC. The advantages are in variable costs (primarily feed and energy) for any size plant, and in initial capital as well for plants larger than 10,000 MTA. They are derived from the use of n-butane feed, a fluidized-bed reactor system, and a non-aqueous recovery system.

  17. Acetylation of barnyardgrass starch with acetic anhydride under iodine catalysis.

    PubMed

    Bartz, Josiane; Goebel, Jorge Tiago; Giovanaz, Marcos Antônio; Zavareze, Elessandra da Rosa; Schirmer, Manoel Artigas; Dias, Alvaro Renato Guerra

    2015-07-01

    Barnyardgrass (Echinochloa crus-galli) is an invasive plant that is difficult to control and is found in abundance as part of the waste of the paddy industry. In this study, barnyardgrass starch was extracted and studied to obtain a novel starch with potential food and non-food applications. We report some of the physicochemical, functional and morphological properties as well as the effect of modifying this starch with acetic anhydride by catalysis with 1, 5 or 10mM of iodine. The extent of the introduction of acetyl groups increased with increasing iodine levels as catalyst. The shape of the granules remained unaltered, but there were low levels of surface corrosion and the overall relative crystallinity decreased. The pasting temperature, enthalpy and other gelatinisation temperatures were reduced by the modification. There was an increase in the viscosity of the pastes, except for the peak viscosity, which was strongly reduced in 10mM iodine.

  18. Carboxy terminated rubber based on natural rubber grafted with acid anhydrides and its adhesion properties

    NASA Astrophysics Data System (ADS)

    Klinpituksa, P.; Kongkalai, P.; Kaesaman, A.

    2014-08-01

    The chemical modification of natural rubber by grafting of various polar functional molecules is an essential method, improving the versatility of rubber in applications. This research investigated the preparation of natural rubber-graft-citraconic anhydride (NR-g-CCA), natural rubber-graft-itaconic anhydride (NR-g-ICA), and natural rubber-graft-maleic anhydride (NR-g-MA), with the anhydrides grafted to natural rubber in toluene using benzoyl peroxide as an initiator. Variations of monomer content, initiator content, temperature and reaction time of the grafting copolymerization were investigated. The maximum degrees of grafting were 1.06% for NR-g-CCA, 4.66% for NR-g-ICA, and 5.03% for NR-g-MA, reached using 10 phr citraconic anhydride, 10 phr of itaconic anhydride, or 8 phr of maleic anhydride, 3 phr benzoyl peroxide, at 85, 80 and 80°C for 2, 2 and 3 hrs, respectively. Solvent-based wood adhesives were formulated from these copolymers with various contents of wood resin in the range 10-40 phr. The maximal 289 N/in cleavage peel and 245.7 KPa shear strength for NR-g-MA (5.03% grafting) were obtained at 40 phr wood resin.

  19. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification... adhesive is a device composed of polyvinylmethylether maleic anhydride, acid copolymer,...

  20. Highly efficient peptide formation from N-acetylaminoacyl-AMP anhydride and free amino acid

    NASA Technical Reports Server (NTRS)

    Mullins, D. W., Jr.; Lacey, J. C., Jr.

    1983-01-01

    The kinetics of formation of the N-blocked dipeptide, N-acetylglycylglycine, from N-acetylglycyl adenylate anhydride and glycine in aqueous solution at 25 C, and at various PH's are reported. The reaction is of interest in that over a physiologically relevant pH range (6-8), peptide synthesis proceeds more rapidly than hydrolysis, even at those pH's at which this compound becomes increasingly susceptible to base-catalyzed hydrolysis. Under similar conditions, the corresponding unblocked aminoacyl adenylate anhydrides are considerably more unstable, and undergo appreciable hydrlysis in the presence of free amino acid. Because N-blocked aminoacyl adenylate anhydrides serve as model compounds of peptidyl adenylate anhydrides, these results suggest that primitive amino acid polymerization systems may have operated by cyclic reactivation of the peptidyl carboxyl group, rather than that of the incoming amino acid.

  1. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  2. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  3. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  4. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC)...

  5. Atmospheric chemistry of toxic contaminants. 3. Unsaturated aliphatics: Acrolein, acrylonitrile, maleic anhydride

    SciTech Connect

    Grosjean, D. )

    1990-12-01

    Detailed mechanisms are outlined for the chemical reactions that contribute to in-situ formation and atmospheric removal of the unsaturated aliphatic contaminants acrolein, acrylonitrile, and maleic anhydride. In-situ formation of small amounts of acrolein and maleic anhydride may involve the reaction of OH (and O{sub 3}) with 1,3-dienes and the reaction of OH with aromatic hydrocarbons, respectively. There is no known pathway for in-situ formation of acrylonitrile. Rapid removal of acrolein (half-life = less than one day) and of maleic anhydride (half-life = several hours) is expected from their rapid reactions with OH (major), O{sub 3}, and NO{sub 3}. These reactions lead to formaldehyde and glyoxal from acrolein and to dicarbonyls from maleic anhydride. Acrylonitrile is removed at a slower rate (half-life = 2-7 days) by reaction with OH, leading to formaldehyde and formyl cyanide.

  6. Poly(butylene succinate-co-butylene adipate)/cellulose nanocrystal composites modified with phthalic anhydride.

    PubMed

    Zhang, Xuzhen; Zhang, Yong

    2015-12-10

    As a kind of biomass nanofiller for polymers, cellulose nanocrystal (CNC) has good mechanical properties and reinforcing capability. To improve the compatibility of poly(butylene succinate-co-butylene adipate) (PBSA)/CNC composites, phthalic anhydride was used as a compatilizer during melt mixing, leading to the significant improvement of the mechanical properties and thermal stability of the composites, which is related to the better dispersion of CNC in the composites. The addition of phthalic anhydride could accelerate the crystallization of PBSA component as evidenced by the curves of isothermal crystallization of the composites, but had little effect on the crystalline polymorphs of PBSA component. The addition of phthalic anhydride could strongly improve the hydrophobicity of the composites. The good mechanical properties, fast crystallization and improved hydrophobicity of PBSA/CNC composites with phthalic anhydride are favor to their practical commercial utilization.

  7. Differential labeling of the subunits of respiratory complex III with (3H)succinic anhydride, (14C)succinic anhydride, and p-diazobenzene-(35S)sulfonate

    SciTech Connect

    Ho, S.H.; Rieske, J.S.

    1985-12-01

    Exposure of antimycin-treated Complex III (ubiquinol-cytochrome c reductase) purified from bovine heart mitochondria to (3H)succinic anhydride plus (35S)p-diazobenzenesulfonate (DABS) resulted in somewhat uniform relative labeling of the eight measured subunits of the complex by (3H)succinic anhydride. In contrast, relative labeling by (35S)DABS was similar to (3H)succinic anhydride for the subunits of high molecular mass, i.e., core proteins, cytochromes, and the iron-sulfur protein, but greatly reduced for the polypeptides of molecular mass below 15 kDa. With Complex II depleted in the iron-sulfur protein the relative labeling of core protein I by exposure of the complex to (3H)succinic anhydride was significantly enhanced, whereas labeling of the polypeptides represented by SDS-PAGE bands 7 and 8 was significantly inhibited. Dual labeling of the subunits of Complex III by 14C- and 3H-labeled succinic anhydride before and after dissociation of the complex by sodium dodecyl sulfate, respectively, was measured with the complex in its oxidized, reduced, and antimycin-inhibited states. Subunits observed to be most accessible or reactive to succinic anhydride were core protein II, the iron-sulfur protein, and polypeptides of SDS-PAGE bands 7,8, and 9. Two additional polypeptides of molecular masses 23 and 12kDa, not normally resolved by gel-electrophoresis, were detected. Reduction of the complex resulted in a significant change of 14C/3H labeling ratio of core protein only, whereas treatment of the complex with antimycin resulted in decreases in 14C/3H labeling ratios of core proteins I and II, cytochrome c1, and a polypeptide of molecular mass 13kDa identified as an antimycin-binding protein.

  8. Determination of the Preferred Structure, Dynamics, and Planarity of Substituted Anhydrides by Cp-Ftmw

    NASA Astrophysics Data System (ADS)

    McMahon, Timothy J.; Bailey, Josiah R.; Bird, Ryan G.; Pratt, David

    2016-06-01

    The planarity of five-membered rings is derived from a competition between ring-angle strain and stability of the torsional angles. The planar form maximizes the already stressed, smaller-than-normal, C-C bond angles, while puckering reduces the unfavorable eclipsed interactions. The structure, dynamics, and planarity of three anhydrides, succinic, methylsuccinic, and methylene (itaconic) anhydride, were studied and compared using chirped-pulse Fourier transform microwave spectroscopy.

  9. Room temperature (nπ∗) phosphorescence of indanetrione (anhydrous ninhydrine) in phthalic anhydride matrix

    NASA Astrophysics Data System (ADS)

    Roy, J.; Bhattacharya, S.; Mondal, S.; Ghosh, Sanjib

    1997-02-01

    Indanetrione, a cis vicinal cyclic triketone, is found to exhibit room temperature (nπ∗) phosphorescence (RTP) in a phthalic anhydride matrix in addition to (nπ∗) fluorescence. The compound does not show RTP in benzophenone mixed crystals or in any other solvent studied. A rigid binding of the cyclic triketone in the phthalic anhydride matrix, lowering the T 1 → S 0 nonradiative rate, has been proposed as the explanation for RTP.

  10. Organocatalytic kinetic resolution of racemic secondary nitroallylic alcohols combined with simultaneous desymmetrization of prochiral cyclic anhydrides.

    PubMed

    Roy, Suparna; Chen, Kan-Fu; Gurubrahamam, Ramani; Chen, Kwunmin

    2014-10-01

    This study describes an organocatalytic kinetic resolution of racemic secondary nitroallylic alcohols (2) combined with simultaneous desymmetrization of prochiral cyclic anhydrides (1). The experimental results revealed that enantioselective alcoholysis of 3-substituted glutaric anhydrides afforded hemiesters (3) with high levels of enantioselectivities (up to 99% ee) in the presence of cinchonidine-derived thiourea catalyst (IV). The highly optical enrichment (up to 95% ee) of (S)-nitroallylic alcohols (2) was recovered.

  11. Low molecular weight chemicals, hypersensitivity, and direct toxicity: the acid anhydrides.

    PubMed Central

    Venables, K M

    1989-01-01

    The acid anhydrides are a group of reactive chemicals used widely in alkyd and epoxy resins. The major hazards to health are mucosal and skin irritation and sensitisation of the respiratory tract. Most occupational asthma caused by acid anhydrides appears to be immunologically mediated. Immunological mechanisms have been proposed to explain an influenza-like syndrome and pulmonary haemorrhage, but direct toxicity may also be important in the aetiology of these conditions. PMID:2653411

  12. Convergence of biological nitration and nitrosation via symmetrical nitrous anhydride.

    PubMed

    Vitturi, Dario A; Minarrieta, Lucia; Salvatore, Sonia R; Postlethwait, Edward M; Fazzari, Marco; Ferrer-Sueta, Gerardo; Lancaster, Jack R; Freeman, Bruce A; Schopfer, Francisco J

    2015-07-01

    The current perspective holds that the generation of secondary signaling mediators from nitrite (NO2(-)) requires acidification to nitrous acid (HNO2) or metal catalysis. Herein, the use of stable isotope-labeled NO2(-) and LC-MS/MS analysis of products reveals that NO2(-) also participates in fatty acid nitration and thiol S-nitrosation at neutral pH. These reactions occur in the absence of metal centers and are stimulated by autoxidation of nitric oxide ((•)NO) via the formation of symmetrical dinitrogen trioxide (nitrous anhydride, symN2O3). Although theoretical models have predicted physiological symN2O3 formation, its generation is now demonstrated in aqueous reaction systems, cell models and in vivo, with the concerted reactions of (•)NO and NO2(-) shown to be critical for symN2O3 formation. These results reveal new mechanisms underlying the NO2(-) propagation of (•)NO signaling and the regulation of both biomolecule function and signaling network activity via NO2(-)-dependent nitrosation and nitration reactions.

  13. Chirally selective, intramolecular interaction observed in an aminoacyl adenylate anhydride

    NASA Technical Reports Server (NTRS)

    Lacey, J. C., Jr.; Hall, L. M.; Mullins, D. W., Jr.; Watkins, C. L.

    1985-01-01

    The interaction between amino acids and nucleotide bases is studied. The proton NMR spectrum of N-acetylphenylalanyl-AMP-anhydride is analyzed H8 and H2 signals, two upfield signals of equal size, and five phenylalanine ring proton signals are observed in the spectrum; the upfield movement of the proton and the racemization of the N-acetyl L-phenylalanine material are examined. The differences in the position of the signals due to the diastereoisomers are investigated. The separation of the D and L amino acyl adenylates using HPLC is described. H-1 NMR spectra of the isomers are examined in order to determine which isomer displays the strongest interaction between the phenyl ring and the adenine ring. The spectra reveal that the L isomer shows the highest upfield change of both H8 and H2 signals. It is noted that the phenyl ring lies over C2 of the adenine ring with the phenyl meta and para protons extended past the adenine ring and the phenyl ortho protons.

  14. The application of Fourier transform Raman spectroscopy to the analysis of poly(anhydride) homo- and co-polymers

    NASA Astrophysics Data System (ADS)

    Tudor, A. M.; Melia, C. D.; Davies, M. C.; Hendra, P. J.; Church, S.; Domb, A. J.; Langer, R.

    Fourier transform Raman spectroscopy was used to characterise a homologous series of aliphatic poly(anhydrides), poly[ bis( p-carboxyphenoxy) alkane anhydrides] and a selection of co-polymers of sebacic/ [bis( p-carboxyphenoxy) propane anhydride] P(SA-CPP). The techniqe is compared to conventional infrared for characterisation work, highlighting the advantage of small sample requirement and minimal sample preparation necessary for acquisition of spectral information. It is possible to differentiate between aromatic and aliphatic anhydride bonding, and in conjunction with other diagnostic bands to monitor the change in individual monomer composition within a co-polymer mixture.

  15. Allergy to methyltetrahydrophthalic anhydride in epoxy resin workers.

    PubMed

    Nielsen, J; Welinder, H; Horstmann, V; Skerfving, S

    1992-11-01

    One hundred and forty four current and 26 former workers in a plant producing barrels for rocket guns from an epoxy resin containing methyltetrahydrophthalic anhydride (MTHPA; time weighted average air concentration up to 150 micrograms/m3) were studied. They showed higher frequencies of work related symptoms from the eyes (31 v 0%; p < 0.001), nose (53 v 9%; p < 0.001), pharynx (26 v 6%; p < 0.01), and asthma (11 v 0%; p < 0.05) than 33 controls. Also they had higher rates of positive skin prick test to a conjugate of MTHPA and human serum albumin (16 v 0%; p < 0.01), and more had specific IgE and IgG serum antibodies (18 v 0%; p < 0.01 and 12 v 0%; p < 0.05 respectively). There were statistically significant exposure-response relations between exposure and symptoms from eyes and upper airways, dry cough, positive skin prick test, and specific IgE and IgG antibodies. There was a non-significant difference in reaction to metacholine between exposed workers and non-smoking controls. In workers with and without specific IgE antibodies, differences existed in frequency of nasal secretion (54 v 23%; p < 0.05) and dry cough (38 v 12%; p < 0.05). Workers with specific IgG had more dry cough (38 v 12%; p < 0.05), but less symptoms of non-specific bronchial hyperreactivity (0 v 26%; p < 0.05). Atopic workers sneezed more than non-atopic workers (65 v 30%; p < 0.01). In a prospective study five sensitised workers who left the factory became less reactive to metacholine, and became symptom free. In 41 workers who stayed, there was no improvement, despite a 10-fold reduction in exposure. The results show the extreme sensitising properties of MTHPA.

  16. Biodegradable polymers derived from renewable resources: Highly branched copolymers of itaconic anhydride

    NASA Astrophysics Data System (ADS)

    Wallach, Joshua Andrew

    In an effort to design cyclic anhydride containing polymers that are derived from renewable resources and have biodegradable characteristics, three copolymer systems using itaconic anhydride have been studied. Two of the systems were copolymers with stearate based monomers; vinyl stearate and stearyl methacrylate, while the third was a copolymer with a methacrylate terminated poly (lactic acid) (PLA) macromonomer. For the stearate systems, stearyl methacrylate showed good copolymerization with equal conversions for both monomers. On the other hand vinyl stearate did not show as good results due to its decreased reactivity, which resulted in a copolymer highly enriched in itaconic anhydride with significant amounts of unreacted vinyl stearate under all copolymer compositions. These differing results were confirmed through analysis of reactivity ratios showing a results that are more favorable for copolymerization for the methacrylate system. Copolymers from both systems showed single melting transitions in a precarious range of 45--50°C arising from the stearyl side groups, though after quenching from the melt this shifted to below room temperature. Anhydride retention was confirmed through structural analysis. Similar to the stearyl methacrylate system, methacrylate terminated PLA macromonomers were copolymerized with itaconic anhydride. PLA's acceptance as a biodegradable material derived from renewable resources, make it a viable choice, with which to design anhydride containing copolymers. Good copolymerization was shown for all compositions studied with retention of the anhydride, though at high itaconic anhydride concentrations conversions were reduced significantly. Copolymers showed glass transition temperatures ranging from 32°C for 85 mole % PLA macromonomer to 73°C for 85 mole % itaconic anhydride. An effort to produce PLA macromonomers through a process of chemical recycling commercial PLA was also undertaken. Promising results were obtained showing

  17. Comparison of acid anhydrides with carboxylic acids in enantioselective enzymatic esterification of racemic menthol.

    PubMed

    Xu, J; Zhu, J; Kawamoto, T; Atsuo, T; Hu, Y

    1997-01-01

    Optical resolution of racemic menthol has been efficiently achieved by lipase-catalyzed enantioselective esterification in an organic solvent. The performance of the reaction using an acid anhydride as an acyl donor was compared with that using its corresponding free acid. The reactivities of acid anhydrides were found to be higher than their corresponding free acids, but acid anhydrides were also found to be easily hydrolyzed into free acids under the catalysis of the same enzyme. The existence of a too-high concentration of an acid anhydride in a micro-aqueous reaction system will cause dehydration and thus deactivation of the enzyme, and will enhance non-selective esterification of a chiral alcohol, which will reduce the optical purity of the product. All these drawbacks, however, could be effectively overcome in a semi-batch reaction system into which propionic anhydride was continuously fed. This system showed some advantages over a batch reaction system using free propionic acid: the reaction time of dl-menthol was shortened by half, the stability of the enzyme was much enhanced, and the optical purity of the product (l-menthyl ester) was kept at a similarly high level (> 98% ee). PMID:9631262

  18. Pinosylvin-Based Polymers: Biodegradable Poly(Anhydride-Esters) for Extended Release of Antibacterial Pinosylvin.

    PubMed

    Bien-Aime, Stephan; Yu, Weiling; Uhrich, Kathryn E

    2016-07-01

    Pinosylvin is a natural stilbenoid known to exhibit antibacterial bioactivity against foodborne bacteria. In this work, pinosylvin is chemically incorporated into a poly(anhydride-ester) (PAE) backbone via melt-condensation polymerization, and characterized with respect to its physicochemical and thermal properties. In vitro release studies demonstrate that pinosylvin-based PAEs hydrolytically degrade over 40 d to release pinosylvin. Pseudo-first order kinetic experiments on model compounds, butyric anhydride and 3-butylstilbene ester, indicate that the anhydride linkages hydrolyze first, followed by the ester bonds to ultimately release pinosylvin. An antibacterial assay shows that the released pinosylvin exhibit bioactivity, while in vitro cytocompatibility studies demonstrate that the polymer is noncytotoxic toward fibroblasts. These preliminary findings suggest that the pinosylvin-based PAEs can serve as food preservatives in food packaging materials by safely providing antibacterial bioactivity over extended time periods. PMID:27071713

  19. Collagen functionalized with unsaturated cyclic anhydrides-interactions in solution and solid state.

    PubMed

    Potorac, S; Popa, M; Picton, L; Dulong, V; Verestiuc, L; Le Cerf, D

    2014-03-01

    Maleic anhydride (CMA) and itaconic anhydride modified collagen (CITA) were prepared as precursors for production of interpenetrated polymer networks (IPN). Calculated values for Huggins coefficient in aqueous diluted and semi-diluted solutions of modified collagen indicated a slightly tendency of aggregation for itaconic anhydride-modified collagen. In semi-diluted solution collagen (Coll) and CMA present slightly differences in the thixotropic behavior, while CITA has a pronounced thixotropic behavior. Flow and oscillatory measurements revealed an elastic behavior of the collagen solutions, pure and modified with MA or ITA, as the storage modulus (G') has always a superior value compared with the loss modulus (G″). The denaturation temperature (Td) of unmodified collagen increased from 34°C to 40°C for CMA and to 39°C for CITA respectively, by formation of covalent bonds that stabilize the triple helix. PMID:23784667

  20. Synthesis and testing of catalysts for the production of maleic anhydride from a fermentation feedstock

    SciTech Connect

    Yedur, S.K.; Berglund, K.A.; Dulebohn, J.; Werpy, T.

    1996-03-01

    It is necessary to develop alternate pathways for the production of chemicals that are traditionally produced from fossil fuels to reduce dependency on nonrenewable energy sources. In this paper, an alternate technology is presented for producing maleic anhydride from a fermentation feedstock. The process involves the catalytic oxydehydrogenation of fermentation-derived succinic anhydride to produce maleic anhydride. Various catalysts have been synthesized and tested for the oxydehydrogenation reaction. Iron phosphate based catalysts are found to be the best on the basis of high conversions and selectivities obtained. The effects of temperature, oxygen concentration, contact time, and the total time on stream on the performance of the catalyst are investigated, and an optimum set of conditions for the operation of the bench-scale reactor is presented. The bulk and surface compositions, the surface areas, and the bulk crystallographic structure of the catalysts are also reported.

  1. UNIFAC parameters for maleic anhydride and 2-methyl furan in p-dioxane system

    SciTech Connect

    Daumn, K.J.

    1983-01-01

    The purpose of this work was to develop a method for calculating equilibrium concentrations for reversible liquid phase reactions from a minimum of experimental data. The example reaction studied was the Diels Alder reaction between 2-methyl furan and maleic anhydride. Specifically, interaction parameters of the UNIFAC model for groups in the compounds 2-methyl furan, maleic anhydride and the solvent, p-dioxane, were determined. The activity coefficient of each substance was then predicted by the UNIFAC method. Equilibrium constants at 45/sup 0/C for the Diels Alder reaction between 2-methyl furan and maleic anhydride were then calculated from these activity coefficients and two previously determined sets of equilibrium concentrations at 45/sup 0/C. These two equilibrium constants were within 12% of each other, which demonstrated the validity of the method.

  2. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated...

  3. TRIMELLITIC ANHYDRIDE-INDUCED EOSINOPHILLA IN A MOUSE MODEL OF OCCUPATIONAL ASTHMA

    EPA Science Inventory

    Trimellitic anhydride (TMA) is a low molecular weight chemical known to cause occupational asthma. The present study was designed to determine if TMA could elicit eosinophil infiltration into the lung of a sensitized mouse similarly to previous studies with the protein allergen ...

  4. TRIMELLITIC ANHYDRIDE (TMA) HYPERSENSITIVITY IN MICE AFTER DERMAL AND INTRATRACHAEL (IT) EXPOSURES

    EPA Science Inventory

    ABSTRACT for 2001 DMS213

    TRIMELLITIC ANHYDRIDE (TMA) HYPERSENSITIVITY IN
    MICE AFTER DERMAL AND INTRATRACHEAL (IT) EXPOSURES. E Boykin, M Ward, MJ Selgrade, and D Sailstad. NHEERL, ORD, US EPA, RTP, NC, USA.
    TMA causes respiratory hypersensitivity (RH) responses. W...

  5. A firefly inspired one-pot chemiluminescence system using n-propylphosphonic anhydride (T3P).

    PubMed

    Kato, Dai-ichiro; Shirakawa, Daiki; Polz, Robin; Maenaka, Mika; Takeo, Masahiro; Negoro, Seiji; Niwa, Kazuki

    2014-12-01

    A simple reaction procedure for chemiluminescence of firefly luciferin (D-luc) using n-propylphosphonic anhydride (T3P) is reported. A luminescent photon is produced as a result of one-pot reaction, only requiring mixing with the substrate carboxylic acid and T3P in the presence of a mild organic base. PMID:25350893

  6. Nano-encapsulation of coenzyme Q10 using octenyl succinic anhydride modified starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Octenyl succinic anhydride modified starch (OSA-ST) was used to encapsulate Coenzyme Q10 (CoQ10). CoQ10 was dissolved in rice bran oil (RBO), and incorporated into an aqueous OSA-ST solution. High pressure homogenization (HPH) of the mixture was conducted at 170 MPa for 5-6 cycles. The resulting ...

  7. Formation and stability of Vitamin E enriched nanoemulsions stabilized by Octenyl Succinic Anhydride modified starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vitamin E (VE) is highly susceptible to autoxidation; therefore, it requires systems to encapsulate and protect it from autoxidation.In this study,we developed VE delivery systems, which were stabilized by Capsul® (MS), a starch modified with octenyl succinic anhydride. Influences of interfacial ten...

  8. SELECTIVE HYDROGENATION OF ANHYDRIDES TO LACTONES UNDER SUPERCRITICAL CARBON DIOXIDE MEDIUM

    EPA Science Inventory

    Selective Hydrogenation of Anhydrides to Lactones Under Supercritical Carbon Dioxide Medium

    Endalkachew Sahle-Demessie Unnikrishnan R Pillai
    U.S. EPA , 26 W. Martin Luther King Dr. Cincinnati, OH 45268 Phone: 513-569-7739
    Fax: 513-569-7677
    Abstract:
    Hydrogenat...

  9. A firefly inspired one-pot chemiluminescence system using n-propylphosphonic anhydride (T3P).

    PubMed

    Kato, Dai-ichiro; Shirakawa, Daiki; Polz, Robin; Maenaka, Mika; Takeo, Masahiro; Negoro, Seiji; Niwa, Kazuki

    2014-12-01

    A simple reaction procedure for chemiluminescence of firefly luciferin (D-luc) using n-propylphosphonic anhydride (T3P) is reported. A luminescent photon is produced as a result of one-pot reaction, only requiring mixing with the substrate carboxylic acid and T3P in the presence of a mild organic base.

  10. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Octenylsuccinic anhydride (OSA)-modified starches with degree of substitution of 0.018 (OS-S-L) and 0.092 (OS-S-H) were prepared from granular native waxy maize starch in an aqueous slurry system. The substitution distribution of OS groups was investigated by enzyme hydrolysis followed by chromatogr...

  11. Adsorption and reaction of maleic anhydride on Mo(110), monolayer Pd(111)/Mo(110), and multilayer Pd(111)/Mo(110)

    SciTech Connect

    Xu, C.; Goodman, D.W.

    1996-04-03

    The adsorption and reaction of maleic anhydride and deuterated maleic anhydride on Mo(110), monolayer Pd/Mo(110), and multilayer Pd(111)/Mo(110) surfaces have been studied using temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). Maleic anhydride adsorbs irreversibly on the Mo(110) surface at 100 K. Heating to 1200 K yields adsorbed carbon (C{sub ads}) and gas-phase CO and H{sub 2}. In contrast, the adsorption of maleic anhydride on monolayer Pd(111)/Mo(110) and multilayer Pd(111)/Mo(110) surfaces is largely reversible with the chemisorbed maleic anhydride desorbing at 365 and 375 K, respectively. Approximately 15% of the chemisorbed maleic anhydride decomposes upon heating to 400K, forming CO, CO{sub 2} and C{sub 2}H{sub 2}; C{sub 2}H{sub 2} further dehydrogenates upon heating to C{sub ads} and gas-phase H{sub 2}. The HREELS measurements indicate that maleic anhydride is bonded to multilayer Pd(111)/Mo(110) through the olefin bond in a di-{sigma} configuration, while on monolayer Pd(111)/Mo(110), the maleic anhydride is bonded to the surface through the olefin via a {pi}-bond. On the Mo(110) surface, maleic anhydride is bonded to the surface through the ring oxygen with the molecular plane perpendicular to the surface. As a result of this modified adsorption geometry, the carbonyl stretching mode is red-shifted nearly 150 cm{sup -1} on the monolayer Pd(111)/Mo(110) surface, unshifted on the multilayer Pd(111)/Mo(110) surface, and blue-shifted by nearly 100 cm{sup -1} on the Mo(110) surface. 31 refs., 14 figs., 3 tabs.

  12. Triamine-Modified Polyimides Having Improved Processability and Low Melt Flow Viscosity

    NASA Technical Reports Server (NTRS)

    Meador, Michael A. (Inventor); Nguyen, Baochan N. (Inventor); Eby, Ronald K. (Inventor)

    2001-01-01

    Addition-cured polyimides that contain the reaction product of an aromatic triamine or trianhydride analogue thereof, a reactive end group such as 5-norbornene-2, 3-dicarboxylic acid, ester derivatives of 5-norbornene-2, 3-dicarboxylic acid, anhydride derivatives of 5-norbornene-2, 3-dicarboxylic acid, or 4-phenylethynylphthalic anhydride, an aromatic diamine, and a dialkyl ester of an aromatic tetracarboxylic acid. The resultant starlike polyimides; exhibit lower melt flow viscosity than its linear counterparts, providing for improved processability of the polyimide. Also disclosed are methods for the synthesis of these polyimides as well as composite structures formed using these polyimides.

  13. Wheat Gluten Blends with Maleic Anhydride-Functionalized Polyacrylate Cross-Linkers for Improved Properties.

    PubMed

    Diao, Cheng; Xia, Hongwei; Parnas, Richard S

    2015-10-14

    A family of polyacrylate-based cross-linkers was synthesized to maximize the toughness of high Tg, high modulus wheat gluten blends in the glassy state. Mechanical testing and damping measurements were conducted to provide an example where the work of fracture and strength of the blend substantially exceeds polystyrene while maintaining flexure stiffness in excess of 3 GPa. The new rubbery cross-linkers, polymethyl acrylate-co-maleic anhydride and polyethyl acrylate-co-maleic anhydride, improve WG mechanical properties and reduce water absorption simultaneously. MDSC, FTIR, HPLC, and NMR data confirmed the cross-linking reaction with wheat gluten. Flexural, DMA, and water absorption testing were carried out to characterize the property improvements. DMA was conducted to investigate the relationship between energy damping and mechanical property improvement. If the cross-linker damping temperature is close to the testing temperature, the entire sample exhibits high damping, toughness, and strength.

  14. Electron paramagnetic resonance and FT-IR spectroscopic studies of glycine anhydride and betaine hydrochloride

    NASA Astrophysics Data System (ADS)

    Halim Başkan, M.; Kartal, Zeki; Aydın, Murat

    2015-12-01

    Gamma irradiated powders of glycine anhydride and betaine hydrochloride have been investigated at room temperature by electron paramagnetic resonance (EPR). In these compounds, the observed paramagnetic species were attributed to the R1 and R2 radicals, respectively. It was determined that the free electron interacted with environmental protons and 14N nucleus in both radicals. The EPR spectra of gamma irradiated powder samples remained unchanged at room temperature for two weeks after irradiation. Also, the Fourier Transform Infrared (FT-IR), FT-Raman and thermal analyses of both compounds were investigated. The functional groups in the molecular structures of glycine anhydride and betaine hydrochloride were identified by vibrational spectroscopies (FT-IR and FT-Raman).

  15. Oil additive and telomer applications of 4-esters of trimellitic anhydride

    SciTech Connect

    Puskas, I.; Fields, E.K.; Piasek, E.J.

    1981-08-01

    Three methods for the selective 4-esterification of trimellitic anhydride (TMA) briefly reviewed are: (1) reaction of the acid chloride derivative of TMA with alcohols or phenols in the presence of stoichiometric quantities of a tertiary nitrogen base, (2) reaction between the carboxyl group of TMA and an ester of a low-boiling organic acid via a trans-acidolysis mechanism, and (3) thermal reaction of TMA with alcohols. A large number of esters prepared by these methods were evaluated as potential rust inhibitors in lubricating oils, and some differences in rust prevention were noted for esters resulting from the different modes of preparation. However, the data were in agreement that rust-preventing properties increase with increasing chain length in the ester moiety, and esters with more than 20 carbons in the chain performed excellently. The synthesis and applications of 4-tert-butyl pertrimellitate anhydride are described. The structure of the compound was also documented. (BLM)

  16. Homogeneous esterification of xylan-rich hemicelluloses with maleic anhydride in ionic liquid.

    PubMed

    Peng, Xin-Wen; Ren, Jun-Li; Sun, Run-Cang

    2010-12-13

    Generation of bioenergy, new functional polymers, or chemicals and biomaterials from hemicelluloses are important uses for biomass. In this paper, a novel functional biopolymer with carbon-carbon double bond and carboxyl groups was prepared by a homogeneous esterification of xylan-rich hemicelluloses (XH) with maleic anhydride in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid using LiOH as catalyst. The biopolymers with degrees of substitution (DS) between 0.095 and 0.75 were accessible in a completely homogeneous system by changing reaction temperature, reaction time, the dosage of catalyst, and the molar ratio of maleic anhydride to anhydroxylose unit in XH. Results obtained from FT-IR and (13)C NMR spectroscopies confirmed the structure of hemicellulosic derivatives with carbon-carbon double bond and carboxyl groups, implying an efficient method to prepare a novel and important functional biopolymer for biomaterials.

  17. Amino acid dependent formation of phosphate anhydrides in water mediated by carbonyl sulfide.

    PubMed

    Leman, Luke J; Orgel, Leslie E; Ghadiri, M Reza

    2006-01-11

    Carbonyl sulfide (COS), a component of volcanic gas emissions and interstellar gas clouds, is shown to be an efficient condensing agent in the context of phosphate chemistry in aqueous solutions. We report that high-energy aminoacyl-phosphate anhydrides and aminoacyl adenylates are generated in solutions containing amino acids, COS, and the corresponding phosphate molecule. We further show that the mixed anhydrides of amino acids and inorganic phosphate are phosphorylating agents, producing pyrophosphate in better than 30% yield in the presence of Ca2+ precipitates. The amino acid dependent activations of phosphate reported here, which occur in parallel with the production of peptides, suggest that these two reactions may have shared a common intermediate on the prebiotic Earth.

  18. Preparation of hydrophilic styrene maleic anhydride copolymer fibers for use in papermaking

    DOEpatents

    Rave, Terence W.

    1979-01-01

    Hydrophilic fibers may be prepared by discharging a heated and pressurized dispersion of a styrene-maleic anhydride copolymer into a zone of reduced temperature and pressure, and then modifying the fibers so produced by treatment with an aqueous admixture of selected cationic and anionic water-soluble, nitrogen-containing polymers. Blends of the hydrophilic fibers with wood pulp provide paper products having improved physical properties.

  19. Preparation of chitin nanofibers by surface esterification of chitin with maleic anhydride and mechanical treatment.

    PubMed

    Aklog, Yihun Fantahun; Nagae, Tomone; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Ifuku, Shinsuke

    2016-11-20

    Esterification with maleic anhydride significantly improved the mechanical disintegration of chitin into uniform 10-nm nanofibers. Nanofibers with 0.25° of esterification were homogeneously dispersed in basic water due to the carboxylate salt on the surface. Esterification proceeded on the surface and did not affect the relative crystallinity. A cast film of the esterified chitin nanofibers was highly transparent, since the film was free from light scattering. PMID:27561471

  20. Synthesis and Characterization of Organic Impurities in Bortezomib Anhydride Produced by a Convergent Technology

    PubMed Central

    Ivanov, Andrey S.; Shishkov, Sergey V.; Zhalnina, Anna A.

    2012-01-01

    A profile of impurities in bortezomib anhydride, produced by a recently developed convergent technology, has been characterized. HPLC-MS analysis of the drug essence revealed three impurities: an epimer of bortezomib, resulting from partial racemization of l-phenylalanine’s stereogenic center during the chemical synthesis, and two epimeric products of oxidative degradation of bortezomib, in which boron is replaced by the OH group. The impurities were obtained by chemical synthesis and characterized by physical methods. PMID:22396904

  1. Covalent modification of graphite oxide with acetic anhydride to enhance dispersibility in organic solvents

    NASA Astrophysics Data System (ADS)

    Li, Jingjing; Yang, Anwei; Zhang, Chen; Zhang, Lei; Sun, Feifei; Ma, Ning

    2016-05-01

    Graphite oxide (GO) was modified by acetic anhydride via a catalyzed ring-opening reaction of the attached epoxy groups at very mild condition. The dispersion of the modified GO is thus largely imporved in many organic solvents and the highest GO concentration reaches 2.0mg/mL in alkyl(aryl) chlorides, ethers, alcohols and cyclohexane, which is amongst the highest value for GO in organics.

  2. Novel synthetic method for the preparation of amphiphilic hyaluronan by means of aliphatic aromatic anhydrides.

    PubMed

    Huerta-Angeles, Gloria; Bobek, Martin; Příkopová, Eva; Šmejkalová, Daniela; Velebný, Vladimír

    2014-10-13

    The present work describes a novel and efficient method of synthesis of amphiphilic hyaluronan (HA) by esterification with alkyl fatty acids. These derivatives were synthesized under mild aqueous and well controlled conditions using mixed aliphatic aromatic anhydrides. These anhydrides characterized by the general formula RCOOCOC6H2Cl3 can be easily prepared by the reaction of the corresponding fatty acid (R) with 2,4,6-trichlorobenzoyl chloride (TCBC) in the presence of triethylamine. The aliphatic aromatic anhydrides RCOOCOC6H2Cl3 then react with the polysaccharide and enable the synthesis of aliphatic acid esters of HA in good yields. No hydrolytic degradation of hyaluronic acid could be observed. Parameters controlling the degree of esterification were systematically studied. Fatty acids with different chain lengths can be introduced applying this methodology. The degree of substitution was decreasing with increasing length of hydrophobic chain. The reaction products were fully characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), SEC-MALLS and chromatographic analyses. Although the esterified HA products exhibited aggregation in solution as demonstrated by NMR, microscopy and rheology, they were still water-soluble.

  3. Novel Synthesis of Phytosterol Ester from Soybean Sterol and Acetic Anhydride.

    PubMed

    Yang, Fuming; Oyeyinka, Samson A; Ma, Ying

    2016-07-01

    Phytosterols are important bioactive compounds which have several health benefits including reduction of serum cholesterol and preventing cardiovascular diseases. The most widely used method in the synthesis of its ester analogous form is the use of catalysts and solvents. These methods have been found to present some safety and health concern. In this paper, an alternative method of synthesizing phytosterol ester from soybean sterol and acetic anhydride was investigated. Process parameters such as mole ratio, temperature and time were optimized. The structure and physicochemical properties of phytosterol acetic ester were analyzed. By the use of gas chromatography, the mole ratio of soybean sterol and acetic anhydride needed for optimum esterification rate of 99.4% was 1:1 at 135 °C for 1.5 h. FTIR spectra confirmed the formation of phytosterol ester with strong absorption peaks at 1732 and 1250 cm(-1) , which corresponds to the stretching vibration of C=O and C-O-C, respectively. These peaks could be attributed to the formation of ester links which resulted from the reaction between the hydroxyl group of soybean sterol and the carbonyl group of acetic anhydride. This paper provides a better alternative to the synthesis of phytosterol ester without catalyst and solvent residues, which may have potential application in the food, health-care food, and pharmaceutical industries. PMID:27240315

  4. Study on oil absorbency of succinic anhydride modified banana cellulose in ionic liquid.

    PubMed

    Shang, Wenting; Sheng, Zhanwu; Shen, Yixiao; Ai, Binling; Zheng, Lili; Yang, Jingsong; Xu, Zhimin

    2016-05-01

    Banana cellulose contained number of hydrophilic hydroxyl groups which were succinylated to be hydrophobic groups with high oil affinity. Succinic anhydride was used to modify banana cellulose in 1-allyl-3-methylimidazolium chloride ionic liquid in this study. The modified banana cellulose had a high oil absorption capacity. The effects of reaction time, temperature, and molar ratio of succinic anhydride to anhydroglucose on the degree of substitution of modified banana cellulose were evaluated. The optimal reaction condition was at a ratio of succinic anhydride and anhydroglucose 6:1 (m:m), reaction time 60min and temperature 90°C. The maximum degree of acylation reaction reached to 0.37. The characterization analysis of the modified banana cellulose was performed using X-ray diffractometer, Fourier transform infrared spectrometer, scanning electron microscopy and thermogravimetry. The oil absorption capacity and kinetics of the modified banana cellulose were evaluated at the modified cellulose dose (0.025-0.3g), initial oil amount (5-30g), and temperature (15-35°C) conditions. The maximum oil absorption capacity was 32.12g/g at the condition of the cellulose dose (0.05g), initial oil amount (25g) and temperature (15°C). The kinetics of oil absorption of the cellulose followed a pseudo-second-order model. The results of this study demonstrated that the modified banana cellulose could be used as an efficient bio-sorbent for oil adsorption. PMID:26877005

  5. Photoelectron-photoabsorption (PePa) database

    NASA Astrophysics Data System (ADS)

    Śmiałek, Małgorzata A.; Mason, Nigel J.

    2016-03-01

    In this paper a recently launched Photoelectron-Photoabsorption Database is presented. The database was developed in order to gather all the photoelectron and photoabsorption spectra measured by various collaborators over the years as well as to ease the access to the data to the potential users. In the paper the main features of the database were described and its outline explained. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  6. Reactive Additives for Phenylethynyl-Containing Resins

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Smith, Joseph G., Jr.; Hergenrother, Paul M.; Rommel, Monica L.

    2005-01-01

    ,4'-oxydianiline (3,4'-ODA), 1,3-bis(3-aminophenoxy) benzene (1,3-APB), and 4-phenylethynylphthalic anhydride (PEPA). PERA-1 was made from 3,5-diamino- 4.-phenylethynylbenzophenon and equimolar amounts of phthalic anhydride and PEPA. To make PERA-1 in the imide form, the aforementioned ingredients were processed by refluxing in glacial acetic acid. To make the amide form of PERA-1, the ingredients were reacted in N-methyl-2-pyrrolidinone (NMP) under nitrogen at a temperature of 23 C (see figure). On the basis of the processability and other properties, a blend comprising 20 weight percent of PERA-1 and 80 weight percent PETI-5 was selected for further evaluation. Relative to neat PETI-5, the blend exhibited an increase in Tg; improved processability; and comparable values of shear strength in adhesion to titanium panels, open-hole compressive properties, compression properties after impact, and resistance to microcracking.

  7. Gas-Phase Structures of Ketene and Acetic Acid from Acetic Anhydride Using Very-High-Temperature Gas Electron Diffraction.

    PubMed

    Atkinson, Sandra J; Noble-Eddy, Robert; Masters, Sarah L

    2016-03-31

    The gas-phase molecular structure of ketene has been determined using samples generated by the pyrolysis of acetic anhydride (giving acetic acid and ketene), using one permutation of the very-high-temperature (VHT) inlet nozzle system designed and constructed for the gas electron diffraction (GED) apparatus based at the University of Canterbury. The gas-phase structures of acetic anhydride, acetic acid, and ketene are presented and compared to previous electron diffraction and microwave spectroscopy data to show improvements in data extraction and manipulation with current methods. Acetic anhydride was modeled with two conformers, rather than a complex dynamic model as in the previous study, to allow for inclusion of multiple pyrolysis products. The redetermined gas-phase structure of acetic anhydride (obtained using the structure analysis restrained by ab initio calculations for electron diffraction method) was compared to that from the original study, providing an improvement on the description of the low vibrational torsions compared to the dynamic model. Parameters for ketene and acetic acid (both generated by the pyrolysis of acetic anhydride) were also refined with higher accuracy than previously reported in GED studies, with structural parameter comparisons being made to prior experimental and theoretical studies. PMID:26916368

  8. Gas-Phase Structures of Ketene and Acetic Acid from Acetic Anhydride Using Very-High-Temperature Gas Electron Diffraction.

    PubMed

    Atkinson, Sandra J; Noble-Eddy, Robert; Masters, Sarah L

    2016-03-31

    The gas-phase molecular structure of ketene has been determined using samples generated by the pyrolysis of acetic anhydride (giving acetic acid and ketene), using one permutation of the very-high-temperature (VHT) inlet nozzle system designed and constructed for the gas electron diffraction (GED) apparatus based at the University of Canterbury. The gas-phase structures of acetic anhydride, acetic acid, and ketene are presented and compared to previous electron diffraction and microwave spectroscopy data to show improvements in data extraction and manipulation with current methods. Acetic anhydride was modeled with two conformers, rather than a complex dynamic model as in the previous study, to allow for inclusion of multiple pyrolysis products. The redetermined gas-phase structure of acetic anhydride (obtained using the structure analysis restrained by ab initio calculations for electron diffraction method) was compared to that from the original study, providing an improvement on the description of the low vibrational torsions compared to the dynamic model. Parameters for ketene and acetic acid (both generated by the pyrolysis of acetic anhydride) were also refined with higher accuracy than previously reported in GED studies, with structural parameter comparisons being made to prior experimental and theoretical studies.

  9. Exposure to methylhexahydrophthalic anhydride (MHHPA) in two workplaces of the electric industry.

    PubMed

    Pfäffli, Pirkko; Hämeilä, Mervi; Riala, Riitta; Tornaeus, Jarkko; Wirmoila, Ritva

    2004-04-01

    Methylhexahydrophthalic anhydride (MHHPA) is a hardener for hot-cured epoxy resins employed as insulators in the electric industry. MHHPA has only been measured as an ingredient with other alicyclic anhydrides, albeit there are also large processes which use only MHHPA. We collected MHHPA vapour in a set of devices: Teflon filter, glass spiral, TenaxTA tube connected consecutively together. Elution was performed with a solvent mixture of methyl-tert-butyl ether (70%), acetonitrile (30%), and acetic anhydride (0.5%). By capillary GC-ECD, the regression was linear (0.9994) in the practical low concentration range of 0.04-1 microg ml(-1) being equal to 0.001-0.035 mg m(-3) in 30 l of air. The exposure was measured in two factories manufacturing electric appliances. The assembled objects were first impregnated with a liquid epoxy/hardener mixture, and then the resin hardened at elevated temperature. In condenser manufacturing, the operators' 8 h exposure ranged from 0.068 to 0.118 mg m(-3), and the short-term exposure was during operation at ovens mean 1.90 mg m(-3). The impregnation of coiled resistors and transfer of them to ovens caused the worst exposures, short-term mean 3.846 mg m(-3) and long-term mean 2.191 mg m(-3). During the 'baking', the ovens were closed and evacuated, but when the hot objects were moved out of the ovens, they continued during chilling to emit MHHPA, mean 0.366 mg m(-3). In the adjacent areas, assembling, control rooms, offices, the exposure was still significant, 0.017-0.043 mg m(3), due to leaks from the high exposure areas. Mechanical general ventilation and local exhausts were functioning. Respirators were available for short supervising of the hot equipment.

  10. Exposure to methylhexahydrophthalic anhydride (MHHPA) in two workplaces of the electric industry.

    PubMed

    Pfäffli, Pirkko; Hämeilä, Mervi; Riala, Riitta; Tornaeus, Jarkko; Wirmoila, Ritva

    2004-04-01

    Methylhexahydrophthalic anhydride (MHHPA) is a hardener for hot-cured epoxy resins employed as insulators in the electric industry. MHHPA has only been measured as an ingredient with other alicyclic anhydrides, albeit there are also large processes which use only MHHPA. We collected MHHPA vapour in a set of devices: Teflon filter, glass spiral, TenaxTA tube connected consecutively together. Elution was performed with a solvent mixture of methyl-tert-butyl ether (70%), acetonitrile (30%), and acetic anhydride (0.5%). By capillary GC-ECD, the regression was linear (0.9994) in the practical low concentration range of 0.04-1 microg ml(-1) being equal to 0.001-0.035 mg m(-3) in 30 l of air. The exposure was measured in two factories manufacturing electric appliances. The assembled objects were first impregnated with a liquid epoxy/hardener mixture, and then the resin hardened at elevated temperature. In condenser manufacturing, the operators' 8 h exposure ranged from 0.068 to 0.118 mg m(-3), and the short-term exposure was during operation at ovens mean 1.90 mg m(-3). The impregnation of coiled resistors and transfer of them to ovens caused the worst exposures, short-term mean 3.846 mg m(-3) and long-term mean 2.191 mg m(-3). During the 'baking', the ovens were closed and evacuated, but when the hot objects were moved out of the ovens, they continued during chilling to emit MHHPA, mean 0.366 mg m(-3). In the adjacent areas, assembling, control rooms, offices, the exposure was still significant, 0.017-0.043 mg m(3), due to leaks from the high exposure areas. Mechanical general ventilation and local exhausts were functioning. Respirators were available for short supervising of the hot equipment. PMID:15054537

  11. Bimetallic complexes of spiro-azacrown ligands as catalysts of phosphoester and phosphoric anhydride cleavage.

    PubMed

    Wang, Qi; Mikkola, Satu; Lönnberg, Harri

    2004-09-01

    The ability of bimetallic homo- and heteronuclear complexes of two spiro-linked ligands, viz. a biazacrown (i.e., 2,6,10,14,18,22-hexaazaspiro[11.11]tricosane (1)) and an azacrown-crown ether (i.e., 14,17,20,23,26-pentaoxa-2,6,10-triaza-spiro[11.15]heptacosane (2)), to promote the cleavage of the phosphoester linkage of dinucleoside 3',5'-phosphates and the phosphoric anhydride bridge of dinucleoside 5',5'-triphosphates was studied. In both reactions, the bimetallic homonuclear Cu2+ and Zn2+ complexes were better catalysts than their monometallic counterparts. The acceleration was two- to five-fold with the phosphoester cleavage and 3- to 20-fold with the phosphoric anhydride cleavage. Interestingly, the most-efficient catalyst of the phosphoester cleavage was the heterodinuclear Ni2+,Zn2+ complex of 1, the catalytic activity of which was up to 5- and 100-fold that of the homodinuclear Zn2+ and Ni2+ complexes, respectively. Moreover, this cooperative acceleration was observed to depend on the identity of the 5'-linked nucleoside: 3',5'-UpU and 3',5'-ApU were cleaved much faster than 3',5'-UpA, and no cooperative acceleration was observed with 3',5'-ApA. The reaction was second-order in hydroxide ion concentration, suggesting that a double deprotonation took place on going from the initial to the transition state. Evidently, in addition to deprotonation of the attacking 2'-OH group, N(3)H of the 5'-linked uridine was displaced by one of the metal ions of the cleaving agent. With the phosphoric anhydride cleavage, no similar cooperativity of two different metal ions was observed, but the greatest rate-acceleration was achieved with the homodinuclear Cu2+ complexes.

  12. Bimetallic complexes of spiro-azacrown ligands as catalysts of phosphoester and phosphoric anhydride cleavage.

    PubMed

    Wang, Qi; Mikkola, Satu; Lönnberg, Harri

    2004-09-01

    The ability of bimetallic homo- and heteronuclear complexes of two spiro-linked ligands, viz. a biazacrown (i.e., 2,6,10,14,18,22-hexaazaspiro[11.11]tricosane (1)) and an azacrown-crown ether (i.e., 14,17,20,23,26-pentaoxa-2,6,10-triaza-spiro[11.15]heptacosane (2)), to promote the cleavage of the phosphoester linkage of dinucleoside 3',5'-phosphates and the phosphoric anhydride bridge of dinucleoside 5',5'-triphosphates was studied. In both reactions, the bimetallic homonuclear Cu2+ and Zn2+ complexes were better catalysts than their monometallic counterparts. The acceleration was two- to five-fold with the phosphoester cleavage and 3- to 20-fold with the phosphoric anhydride cleavage. Interestingly, the most-efficient catalyst of the phosphoester cleavage was the heterodinuclear Ni2+,Zn2+ complex of 1, the catalytic activity of which was up to 5- and 100-fold that of the homodinuclear Zn2+ and Ni2+ complexes, respectively. Moreover, this cooperative acceleration was observed to depend on the identity of the 5'-linked nucleoside: 3',5'-UpU and 3',5'-ApU were cleaved much faster than 3',5'-UpA, and no cooperative acceleration was observed with 3',5'-ApA. The reaction was second-order in hydroxide ion concentration, suggesting that a double deprotonation took place on going from the initial to the transition state. Evidently, in addition to deprotonation of the attacking 2'-OH group, N(3)H of the 5'-linked uridine was displaced by one of the metal ions of the cleaving agent. With the phosphoric anhydride cleavage, no similar cooperativity of two different metal ions was observed, but the greatest rate-acceleration was achieved with the homodinuclear Cu2+ complexes. PMID:17191909

  13. A sulfonic anhydride derivative from dibenzyl trisulphide with agro-chemical activities.

    PubMed

    Williams, L A D; Vasquez, E; Klaiber, I; Kraus, W; Rosner, H

    2003-06-01

    In the present study, the biologically active natural product dibenzyl trisulphide (DTS) which was previously isolated from the sub-tropical shrub Petiveria alliacea was transformed to methyl benzyl sulphonic anhydride (MBSA) using a "one pot" transformation method. The anhydride was evaluated for anti-microbial activities on the bacteria, Bacillus subtilis and Pseudomonas fluorescens and found to be 2.5 fold more effective than the commercial agents isoniazid and ampicillin in inhibiting the growth of B. subtilis, while on P. fluorescens it was 2.5, 5.0 and 10.0 fold more inhibitory than isoniazid, ampicillin and dibenzyl trisulphide, respectively. DTS was inactive on B. subtillis. The MIC value (microgram/spot) found for DTS on the plant pathogenic fungus, Cladosporium cucumerinum was 5.0 microgram/spot, while MBSA gave a value of 0.1 microgram/spot, compared with 1.25 and 0.16 microgram/spot for the commercial agents ketoconazole and nystatin, respectively. On the larval nematode (Meloidogyne incognita) MBSA inflicted 97.72% and 57.47% Abbotts nematicidal activities at 125.0 and 62.5 ppm, respectively, while DTS had no effect at 125.0 ppm. Nematodes which were immobilized by the low concentrations of MBSA were unable to re-activate when exposed to 10.0 ppm picrotoxin, thus suggesting that the anhydride nematicidal activity is independent of the GABA-ergic neurophysiological pathway.MBSA demonstrated a strong dose dependent radicular suppression effect (r=0.984), on the radicles of Latuca sativa germinating seeds. DTS was weakly active.

  14. A sulfonic anhydride derivative from dibenzyl trisulphide with agro-chemical activities.

    PubMed

    Williams, L A D; Vasquez, E; Klaiber, I; Kraus, W; Rosner, H

    2003-06-01

    In the present study, the biologically active natural product dibenzyl trisulphide (DTS) which was previously isolated from the sub-tropical shrub Petiveria alliacea was transformed to methyl benzyl sulphonic anhydride (MBSA) using a "one pot" transformation method. The anhydride was evaluated for anti-microbial activities on the bacteria, Bacillus subtilis and Pseudomonas fluorescens and found to be 2.5 fold more effective than the commercial agents isoniazid and ampicillin in inhibiting the growth of B. subtilis, while on P. fluorescens it was 2.5, 5.0 and 10.0 fold more inhibitory than isoniazid, ampicillin and dibenzyl trisulphide, respectively. DTS was inactive on B. subtillis. The MIC value (microgram/spot) found for DTS on the plant pathogenic fungus, Cladosporium cucumerinum was 5.0 microgram/spot, while MBSA gave a value of 0.1 microgram/spot, compared with 1.25 and 0.16 microgram/spot for the commercial agents ketoconazole and nystatin, respectively. On the larval nematode (Meloidogyne incognita) MBSA inflicted 97.72% and 57.47% Abbotts nematicidal activities at 125.0 and 62.5 ppm, respectively, while DTS had no effect at 125.0 ppm. Nematodes which were immobilized by the low concentrations of MBSA were unable to re-activate when exposed to 10.0 ppm picrotoxin, thus suggesting that the anhydride nematicidal activity is independent of the GABA-ergic neurophysiological pathway.MBSA demonstrated a strong dose dependent radicular suppression effect (r=0.984), on the radicles of Latuca sativa germinating seeds. DTS was weakly active. PMID:12668029

  15. Heterogeneous catalyst for the production of ethylidene diacetate from acetic anhydride

    DOEpatents

    Ramprasad, D.; Waller, F.J.

    1998-06-16

    This invention relates to a process for producing ethylidene diacetate by the reaction of acetic anhydride, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled without loss in activity.

  16. Adsorption of alkenyl succinic anhydride from solutions in carbon tetrachloride on a fine magnetite surface

    NASA Astrophysics Data System (ADS)

    Balmasova, O. V.; Ramazanova, A. G.; Korolev, V. V.

    2016-06-01

    The adsorption of alkenyl succinic anhydride from a solution in carbon tetrachloride on a fine magnetite surface at a temperature of 298.15 K is studied using fine magnetite, which forms the basis of magnetic fluids, as the adsorbent. An adsorption isotherm is recorded and interpreted in terms of the theory of the volume filling of micropores (TVFM). Adsorption process parameters are calculated on the basis of the isotherm. It is shown that at low equilibrium concentrations, the experimental adsorption isotherm is linear in the TVFM equation coordinates.

  17. Kinetics and fixed-bed reactor modeling of butane oxidation to maleic anhydride

    SciTech Connect

    Sharma, R.K.; Cresswell, D.L. ); Newson, E.J. )

    1991-01-01

    This paper reports on selective oxidation kinetics of n-butane to maleic anhydride in air studied over a commercial, fixed-bed vanadium-phosphor oxide catalyst. The temperature range was 573-653 K with butane concentrations up to 3 mol % in the feed, which is within flammability limits but below ignition temperatures. The rate data were modeled using power law kinetics with product inhibition and included total oxidation and decomposition reactions. Kinetic parameters were estimated using a multiresponse, nonlinear regression algorithm showing intercorrelation effects. The kinetics were combined with independent measurements of catalyst diffusivity and reactor heat transfer using a one- dimensional heterogeneous reactor model.

  18. Selective oxidation of n-butane to maleic anhydride; 4. Recycle reactor studies

    SciTech Connect

    Bej, S.K.; Rao, M.S. )

    1992-09-01

    This paper reports on the selective oxidation of n-butane to aleic anhydride which has been modeled using recycle reactor data. Two different types of models have been tested based on the concept that V[sup 5+] is the selective site and V[sup 4+] is the nonselective site and vice versa. Recycle reactor data support the model which assumes V[sup 5+] as the selective site as the selective site and V[sup 4+] as the nonselective site. The model has been used to predict the performance of an integral reactor and tested with experimental integral reactor data.

  19. Maleic anhydride-polyether-polyamine reaction product and motor fuel composition containing same

    SciTech Connect

    Sung, R.L.

    1987-04-21

    A material is described having a use as a motor fuel additive for controlling engine octane requirement increase (ORI), controlling and reducing hydrocarbon and carbon monoxide engine emissions, and having carburetor detergency properties. The material is the reaction product of maleic anhydride, a polyether polyamine, preferably a polyether diamine, and a hydrocarbyl polyamine, preferably an n-alkyl-alkylene diamine. A concentrate comprising the prescribed reaction product dissolved in a hydrocarbon solvent is also described. Motor fuels containing the reaction product additive of the instant invention show improved ORI control and carburetor detergency in comparison with motor fuels without the reaction product additive.

  20. Perfluoroalkylation of Unactivated Alkenes with Acid Anhydrides as the Perfluoroalkyl Source.

    PubMed

    Kawamura, Shintaro; Sodeoka, Mikiko

    2016-07-18

    An efficient perfluoroalkylation of unactivated alkenes with perfluoro acid anhydrides was developed. Copper salts play a crucial role as a catalyst to achieve allylic perfluoroalkylation with the in situ generated bis(perfluoroacyl) peroxides. Furthermore, carboperfluoroalkylation of alkene bearing an aromatic ring at an appropriate position on the carbon side chain was found to proceed under metal-free conditions to afford carbocycles or heterocycles bearing a perfluoroalkyl group. This method, which makes use of readily available perfluoroalkyl sources, offers a convenient and powerful tool for introducing a perfluoroalkyl group onto an sp(3) carbon to construct synthetically useful skeletons. PMID:27254318

  1. Heterogeneous catalyst for the production of ethylidene diacetate from acetic anhydride

    DOEpatents

    Ramprasad, Dorai; Waller, Francis Joseph

    1998-01-01

    This invention relates to a process for producing ethylidene diacetate by the reaction of acetic anhydride, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled without loss in activity.

  2. SELECTIVE HYDROGENATION OF MALEIC ANHYDRIDE TO Y-BUTYROLACTONE OVER PD/AL(2)O(3) CATALYST USING SUPERCRITICAL CO(2) AS SOLVENT

    EPA Science Inventory

    A selective hydrogenation of maleic anhydride to either y-butyrolactone or succinic anhydride over simple Pd/Al(2)O(3) catalyst under supercritical CO(2) medium is described for the first time which has considerable promise for obht lab-scale as well as industrial selective hydro...

  3. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...): Do not release into the environment in quantities that allow surface water concentrations to exceed 6...-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721.3635 Protection of..., ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). (a) Chemical substance...

  4. Kinetic resolution of racemic α-hydroxyphosphonates by asymmetric esterification using achiral carboxylic acids with pivalic anhydride and a chiral acyl-transfer catalyst.

    PubMed

    Shiina, Isamu; Ono, Keisuke; Nakahara, Takayoshi

    2013-11-25

    A practical protocol is developed to directly provide chiral α-acyloxyphosphonates and α-hydroxyphosphonates from (±)-α-hydroxyphosphonates utilizing the transacylation process to generate the mixed anhydrides from acid components and pivalic anhydride in the presence of organocatalysts (s-value = 33-518).

  5. Soluble Synthetic Analogs of Malaria Pigment: Structure of Mesohematin Anhydride [FeIII(MP-IX)]2 and Solution Interaction with Chloroquine

    SciTech Connect

    D Bohle; E Dodd; A Kosar; L Sharma; P Stephens; L Suarez; D Tazoo

    2011-12-31

    Changing the vinyl groups of hematin anhydride to either ethyl or hydrogen groups results in increased solubility (Por=porphyrin). Determination of the weak binding constants of the antimalarial drug chloroquine to dimers of these hematin anhydride analogues suggests that solution-phase heme/drug interactions alone are unlikely to be the origin of the action of the drug.

  6. One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

    PubMed Central

    Khalifeh, Reza

    2015-01-01

    Summary An efficient and odourless procedure for a one-pot synthesis of thioesters by the reaction of benzoic anhydrides, thiourea and various organic halides (primary, allylic, and benzylic) or structurally diverse, electron-deficient alkenes (ketones, esters, and nitriles) in the presence of Et3N has been developed. In this method, thiobenzoic acids were in situ generated from the reaction of thiourea with benzoic anhydrides, which were subjected to conjugate addition with electron-deficient alkenes or a nucleophilic displacement reaction with alkyl halides. PMID:26425185

  7. Flexible Polyimide Aerogel Cross-linked by Poly(maleic Anhydride-alt-alkylene)

    NASA Technical Reports Server (NTRS)

    Guo, Haiquan; Meador, Mary Ann B.; Wilkewitz, Brittany Marie

    2014-01-01

    Aerogels are potential materials for aerospace applications due to their lower thermal conductivity, lighter weight, and low dielectric constant. However, silica aerogels are restricted due to their inherent fragility, hygroscopic nature, and poor mechanical properties, especially in extreme aerospace environments. In order to fit the needs of aerospace applications, developing new thermal insulation materials that are flexible, and moisture resistant is needed. To this end, we fabricated a series of polyimide aerogels crosslinked with different poly(maleic anhydride-alt-alkylene)s as seen in Scheme 1. The polyimide oligomers were made with 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA), and different diamines or diamine combinations. The resulting aerogels have low density (0.06 gcm3 to 0.16 gcm3) and high surface area (240-440 m2g). The effect of the different backbone structures on density, shrinkage, porosity, surface area, mechanical properties, moisture resistance and thermal properties will be discussed. These novel polyalkylene-imide aerogels may be potential candidates for applications such as space suit insulation for planetary surface missions, insulation for inflatable structures for habitats, inflatable aerodynamic decelerators for entry, descent and landing (EDL) operations, and cryotank insulation for advance space propulsion systems. Scheme 1. Network of polyimide aerogels crosslinked with deifferent poly(maleic anhydride).

  8. Gelatin-based biomaterial engineering with anhydride-containing oligomeric cross-linkers.

    PubMed

    Loth, Tina; Hötzel, Rudi; Kascholke, Christian; Anderegg, Ulf; Schulz-Siegmund, Michaela; Hacker, Michael C

    2014-06-01

    Chemically cross-linked gelatin hydrogels are versatile cell-adhesive hydrogel materials that have been established for a variety of biomedical applications. The most prominent cross-linker is glutaraldehyde, which, however, has been described to cause compatibility problems and loss of microscopic but relevant structural features. A recently developed oligomeric cross-linker that contains anhydride functionalities was evaluated as cross-linker for the fabrication of gelatin-based hydrogels and microparticles. In a fast curing reaction, hydrogels composed of gelatin and oligomeric cross-linker were fabricated with good conversion over a wide concentration range of constituents and with cross-linkers of different anhydride contents. Hydrogel properties, such as dry weight and mechanics, could be controlled by hydrogel composition and rheological properties correlated to elastic moduli from 1 to 10 kPa. The gels were shown to be cytocompatible and promoted cell adhesion. In soft formulations, cells migrated into the hydrogel bulk. Gelatin microparticles prepared by a standard water-in-oil emulsion technique were also treated with the novel oligomers, and cross-linking degrees matching those obtained with glutaraldehyde were obtained. At the same time, fewer interparticular cross-links were observed. Fluorescein-derivatized cross-linkers yielded labeled microparticles in a concentration-dependent manner. The oligomeric cross-linkers are presented as an efficient and possibly more functional and compatible alternative to glutaraldehyde. The engineered hydrogel materials hold potential for various biomedical applications.

  9. Preparation, characterization and antibacterial activity of octenyl succinic anhydride modified inulin.

    PubMed

    Zhang, Xiaoyun; Zhang, Ye-Wang; Zhang, Hongyin; Yang, Qiya; Wang, Haiying; Zhang, Guochao

    2015-01-01

    Octenyl succinic anhydride modified inulin (In-OSA) was synthesized via chemical modification of inulin with octenyl succinic anhydride (OSA). The esterification of inulin with OSA was confirmed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and degree of substitution (DS) calculation. Antibacterial activity of In-OSA against Staphylococcus aureus and Escherichia coli was investigated by minimum inhibitory concentration (MIC) and inhibition rate determination. The results showed that inhibition rates against both E.coli and S. aureus increased with the increase of the In-OSA concentration. And the MICs against E. coli and S. aureus were 1% and 0.5% (w/v), respectively. The antibacterial mechanism was analyzed with the results of the proteins and nucleic acids leakage, SEM and negative staining transmission electron microscopy (TEM). Both the leakages of proteins and nucleic acids increased with the increase of the In-OSA concentration. The leakage occurred mainly in the early stage which indicated that cell membrane and wall were destroyed by In-OSA quickly. The images of SEM and negative staining TEM suggested that the cell membranes and cell walls of S. aureus were damaged more severely and even destroyed completely; but only pores appeared on the surface of E. coli.

  10. Pomelo peel modified with acetic anhydride and styrene as new sorbents for removal of oil pollution.

    PubMed

    Chai, Wenbo; Liu, Xiaoyan; Zou, Junchen; Zhang, Xinying; Li, Beibei; Yin, Tiantian

    2015-11-01

    Pomelo peel (PP), as one of the well-known agricultural wastes, is cost-effective and environmentally friendly. Based on PP, two new kinds of oil sorbents were prepared by using acetic anhydride and styrene. The structures of raw pomelo peel (RP), acetic anhydride-treated pomelo peel (AP) and styrene-treated pomelo peel (SP) were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), contact-angle (CA) measurements. The optimum reaction conditions for preparation of AP and SP were also investigated. The resulting products exhibited better oil sorption capacity than that of RP for diesel and lubricating oil, also SP had better oil sorption capacity than AP, while the oil sorption capacities of SP for diesel and lubricating oil reached 18.91 and 26.36 g/g, respectively. Adsorption kinetics was well described by the pseudo-second-order model. The results indicated that AP and SP, especially SP could be used as the substitute for non-biodegradable oil sorption materials.

  11. Grafting of poly (lactic acid) with maleic anhydride using supercritical carbon dioxide

    NASA Astrophysics Data System (ADS)

    Khankrua, R.; Pivsa-Art, S.; Hiroyuki, H.; Suttiruengwong, S.

    2015-07-01

    The aim of this work was to modify poly lactic acid (PLA) via free radical grafting with maleic anhydride (MA) by using supercritical carbon dioxide (SCCO2). Benzoyl peroxide (BPO) was used as an initiator. The solubility of MA in SCCO2 was first determined to estimate the suitable grafting conditions and equilibrium. From the solubility study of MA in SCCO2, it was found that the solubility of MA in SCCO2 increased with the increasing pressure and dissolution time. PLA films were first prepared by compression molding. The ratio of MA to BPO was 2:1. The reaction temperature and pressure were 70°C and 100 bar respectively. The grafting reaction and the degree of grafting were characterized by nuclear magnetic resonance (NMR) spectroscopy and titration, respectively. Scanning electron microscope (SEM) technique and contact angle were used to confirm the changes in physical properties of PLA film grafted MA. NMR spectrum indicated that the grafting of MA onto PLA was successively achieved. Degree of grafting by using SCCO2 was as high as 0.98%. This provided rather high grafting degree compared with other processes. SEM pictures showed the rough surface structure on modified PLA film. In addition, contact angle results showed an improvement of the hydrophilicity by maleic anhydride grafting onto polymers.

  12. Effect of reagent access on the reactivity of coals. Final report. [Maleic anhydride; dialkylmaleates

    SciTech Connect

    Larsen, J.W.

    1983-04-01

    The objective of this work is to determine the extent to which the mass transport of reagents into solid coals limits the reactivity of those coals. The purpose of task one is to determine the effect of reagent access on the acid catalyzed depolymerization of coals using phenols and/or alkyl phenyl ethers. For task two, the purpose is to determine the effect of coal swelling on its rate of reaction with a dienophile. Work on depolymerization of coals in hot, acidic phenol has been completed. The conclusion is that due to incomplete depolymerization, the complications of competing Friedel-Crafts alkylation, and the condensation reactions of the solvent, the depolymerization of coals in hot, acidic phenol is not a useful technique for solubilizing coals for structural investigations. In task two, the rate of the Diels-Alder reaction between bituminous coals and maleic anhydride was found to be diffusion controlled. The observations of simple Fickian diffusion and reaction rate constants much slower than the Diels-Alder reaction of maleic anhydride and anthracene have no other reasonable explanation than rate limiting mass transport. The diffusion rates were found to be independent of the degree of solvent swelling of the coal. In addition, the dependence of the observed rates on temperature and the size of the dienophile were measured. Results obtained using a series of dialkylmaleates are presented. Size was found to play only a small role as long as the reagent is planar. 2 tables.

  13. Pomelo peel modified with acetic anhydride and styrene as new sorbents for removal of oil pollution.

    PubMed

    Chai, Wenbo; Liu, Xiaoyan; Zou, Junchen; Zhang, Xinying; Li, Beibei; Yin, Tiantian

    2015-11-01

    Pomelo peel (PP), as one of the well-known agricultural wastes, is cost-effective and environmentally friendly. Based on PP, two new kinds of oil sorbents were prepared by using acetic anhydride and styrene. The structures of raw pomelo peel (RP), acetic anhydride-treated pomelo peel (AP) and styrene-treated pomelo peel (SP) were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), contact-angle (CA) measurements. The optimum reaction conditions for preparation of AP and SP were also investigated. The resulting products exhibited better oil sorption capacity than that of RP for diesel and lubricating oil, also SP had better oil sorption capacity than AP, while the oil sorption capacities of SP for diesel and lubricating oil reached 18.91 and 26.36 g/g, respectively. Adsorption kinetics was well described by the pseudo-second-order model. The results indicated that AP and SP, especially SP could be used as the substitute for non-biodegradable oil sorption materials. PMID:26256347

  14. Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light emitting diodes

    NASA Astrophysics Data System (ADS)

    Rider, N. D.; Taha, Y. M.; Odame-Ankrah, C. A.; Huo, J. A.; Tokarek, T. W.; Cairns, E.; Moussa, S. G.; Liggio, J.; Osthoff, H. D.

    2015-01-01

    Photochemical sources of peroxycarboxylic nitric anhydrides (PANs) are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg) lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone) in the presence of a calibrated amount of nitric oxide (NO) and oxygen (O2). In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs) is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC) and thermal dissociation cavity ring-down spectroscopy (TD-CRDS). Using acetone, diethyl ketone (DIEK), diisopropyl ketone (DIPK), or di-n-propyl ketone (DNPK), respectively, the source produces peroxyacetic (PAN), peroxypropionic (PPN), peroxyisobutanoic (PiBN), or peroxy-n-butanoic nitric anhydride (PnBN) from NO in high yield (> 90%). Box model simulations with a subset of the Master Chemical Mechanism (MCM) were carried out to rationalize products yields and to identify side products. The use of UV-LED arrays offers many advantages over conventional Hg lamp setups, including greater light output over a narrower wavelength range, lower power consumption, and minimal generation of heat.

  15. Lysine adducts between methyltetrahydrophthalic anhydride and collagen in guinea pig lung.

    PubMed

    Jönsson, B A; Wishnok, J S; Skipper, P L; Stillwell, W G; Tannenbaum, S R

    1995-11-01

    The formation of adducts between methyltetrahydrophthalic anhydride (MTHPA), an important industrial chemical and potent allergen, and collagen from guinea pig lung tissue was investigated. Collagen peptides were obtained from the lung tissue by homogenization, defatting, washing, and digestion with collagenase. In experiments in vitro, lung tissue was exposed to 8.4 mumol (50 microCi) of 14C MTHPA. The amount of adducts was 97 nmol MTHPA/g of wet tissue as determined from the bound radioactivity. In a study in vivo, four guinea pigs were injected intratracheally with 8.4 mumol of 14C MTHPA each. The amount of adducts was 0-1.2 nmol MTHPA/g of wet tissue (determined by bound radioactivity). N epsilon-methyltetrahydrophthaloyl-L-lysine (MTHPL) was synthesized and characterized by NMR, UV, and mass spectrometry (MS). A method to analyze MTHPL, after derivatization with methanol and pentafluorobenzoyl chloride, using gas chromatography-MS was developed. Analysis of Pronase-digested MTHPA-exposed lung tissue showed a concentration of 19 nmol MTHPL/g wet lung in vitro and between 0 and 0.15 nmol MTHPL/g wet lung in vivo. Thus, 20% in vitro and 12-15% in vivo of the bound radioactivity was found as adducts with lysine. These results are a first step toward studies of allergenic epitopes in proteins and methods for biological monitoring of exposure to acid anhydrides.

  16. Selective conversion of furfural to maleic anhydride and furan with VO(x)/Al(2)O(3) catalysts.

    PubMed

    Alonso-Fagúndez, Noelia; Granados, Manuel López; Mariscal, Rafael; Ojeda, Manuel

    2012-10-01

    Furfural can be converted into maleic anhydride (73 % yield) through selective gas phase oxidation at 593 K with O(2) by using VO(x)/Al(2)O(3) (10 at(V) nm(-2)) as solid catalysts. The use of lower temperatures and/or O(2) pressures result in the additional formation of furan (maximum 9 % yield). Mechanistically, furfural (C(5)H(4)O(2)) is oxidized stepwise to furan (C(4)H(4)O), 2-furanone (C(4)H(4)O(2)), and finally, maleic anhydride (C(4)H(2)O(3)). The specific structure of the supported vanadium oxides and reaction conditions (temperature and reactants pressures) all influence furfural oxidation catalysis. We have found that Al(2)O(3)-supported polyvanadates are intrinsically more active (2.70 mmol h(-1) g-at V(-1)) than monovanadates (VO(4)) and V(2)O(5) crystals (0.89 and 0.70 mmol h(-1) g-at V(-1), respectively) in maleic anhydride and furan formation rates (553 K, 1.6 kPa furfural, 2.5 kPa O(2)). Our alternative approach enables the use of biomass instead of petroleum to synthesize maleic anhydride and furan from furfural. The potential variety of industrial applications is of enormous interest for the development of future biorefineries.

  17. Evolutionary importance of the intramolecular pathways of hydrolysis of phosphate ester mixed anhydrides with amino acids and peptides.

    PubMed

    Liu, Ziwei; Beaufils, Damien; Rossi, Jean-Christophe; Pascal, Robert

    2014-12-11

    Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide-phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation.

  18. Tetrahydrophthalic Anhydrides as Addition Curing Polyimide End Caps: Thermal Isomerization of Methylendianiline 3,6-Diphenyltetrahydrophthalic Bisimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Gilinsky-Sharon, Pessia; Gottlieb, Hugo E.; Meador, Mary Ann B.; Johnston, J. Christopher

    2005-01-01

    In depth NMR studies confirm that heating a 1:2 mixture of cis, cis, cis 3,6-diphenyltetrahydrophthalic anhydride (end cap 9c) with methylenedianiline at 316 C initially yields the corresponding highly congested cis, cis, cis 3,6-diphenyltetrahydrophthalic bisimide 11, which is converted at this temperature to the observed product, the less hindered trans, cis, trans isomer 12.

  19. Selective conversion of furfural to maleic anhydride and furan with VO(x)/Al(2)O(3) catalysts.

    PubMed

    Alonso-Fagúndez, Noelia; Granados, Manuel López; Mariscal, Rafael; Ojeda, Manuel

    2012-10-01

    Furfural can be converted into maleic anhydride (73 % yield) through selective gas phase oxidation at 593 K with O(2) by using VO(x)/Al(2)O(3) (10 at(V) nm(-2)) as solid catalysts. The use of lower temperatures and/or O(2) pressures result in the additional formation of furan (maximum 9 % yield). Mechanistically, furfural (C(5)H(4)O(2)) is oxidized stepwise to furan (C(4)H(4)O), 2-furanone (C(4)H(4)O(2)), and finally, maleic anhydride (C(4)H(2)O(3)). The specific structure of the supported vanadium oxides and reaction conditions (temperature and reactants pressures) all influence furfural oxidation catalysis. We have found that Al(2)O(3)-supported polyvanadates are intrinsically more active (2.70 mmol h(-1) g-at V(-1)) than monovanadates (VO(4)) and V(2)O(5) crystals (0.89 and 0.70 mmol h(-1) g-at V(-1), respectively) in maleic anhydride and furan formation rates (553 K, 1.6 kPa furfural, 2.5 kPa O(2)). Our alternative approach enables the use of biomass instead of petroleum to synthesize maleic anhydride and furan from furfural. The potential variety of industrial applications is of enormous interest for the development of future biorefineries. PMID:22847991

  20. Evolutionary Importance of the Intramolecular Pathways of Hydrolysis of Phosphate Ester Mixed Anhydrides with Amino Acids and Peptides

    PubMed Central

    Liu, Ziwei; Beaufils, Damien; Rossi, Jean-Christophe; Pascal, Robert

    2014-01-01

    Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide–phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation. PMID:25501391

  1. Kinetics of Hydrolysis of Acetic Anhydride by In-Situ FTIR Spectroscopy: An Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Haji, Shaker; Erkey, Can

    2005-01-01

    A reaction kinetics experiment for the chemical engineering undergraduate laboratory course was developed in which in-situ Fourier Transfer Infrared spectroscopy was used to measure reactant and product concentrations. The kinetics of the hydrolysis of acetic anhydride was determined by experiments carried out in a batch reactor. The results…

  2. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkyl amines, sodium salts, compds. with ethanolamine. (a) Chemical substance and significant new uses... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  3. Evolutionary Importance of the Intramolecular Pathways of Hydrolysis of Phosphate Ester Mixed Anhydrides with Amino Acids and Peptides

    NASA Astrophysics Data System (ADS)

    Liu, Ziwei; Beaufils, Damien; Rossi, Jean-Christophe; Pascal, Robert

    2014-12-01

    Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide-phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation.

  4. Aggregate structure and effect of phthalic anhydride modified soy protein on the mechanical properties of styrene-butadiene copolymer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aggregate structure of phthalic anhydride (PA) modified soy protein isolate (SPI) was investigated by estimating its fractal dimension from the equilibrated dynamic strain sweep experiments. The estimated fractal dimensions of the filler aggregates were less than 2, indicating that these partic...

  5. Vanadium-phosphorus-oxygen industrial catalysts for C/sub 4/ hydrocarbon selective oxidation to maleic anhydride

    SciTech Connect

    Wenig, R.W.

    1987-06-01

    The selective oxidation of n-butane to maleic anhydride by vanadium-phosphorus-oxygen (V-P-O) industrial catalysts varying in P-to-V ratio has been studied in a fixed bed integral reactor system. Catalyst characterization studies including x-ray diffraction, laser Raman spectroscopy, infrared spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, x-ray energy dispersive spectroscopy, and BET surface area measurements were used. A strong effect of P-to-V synthesis ratio on catalyst structure, catalyst morphology, vanadium oxidation state, and reactivity in n-butane selective oxidation was observed. A slight ''excess'' of catalyst phosphorus (P/V = 1.1 catalyst) was found to stabilize an active and selective (VO)/sub 2/P/sub 2/O/sub 7/ phase. The mechanism of n-butane selective oxidation to maleic anhydride was studied by in situ infrared spectroscopy using n-butane, 1-butene, 1,3-butadiene, crotyl alcohol, maleic acid, crotonic acid, and maleic anhydride feeds. During paraffin selective oxidation, highly reactive olefin species and maleic acid were observed on the surfaces of V-P-O catalysts. Further evidence in support of conjugated or possibly strained olefin and maleic acid reaction intermediates in n-butane and 1-butene partial oxidation to maleic anhydride was gathered.

  6. Perfluorosulfonic acid membrane catalysts for optical sensing of anhydrides in the gas phase.

    PubMed

    Ayyadurai, Subasri M; Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

    2010-07-15

    Continuous, on-site monitoring of personal exposure levels to occupational chemical hazards in ambient air is a long-standing analytical challenge. Such monitoring is required to institute appropriate health measures but is often limited by the time delays associated with batch air sampling and the need for off-site instrumental analyses. In this work, we report on the first attempt to use the catalytic properties of perfluorosulfonic acid (PSA) membranes to obtain a rapid, selective, and highly sensitive optical response to trimellitic anhydride (TMA) in the gas phase for portable sensor device application. TMA is used as starting material for various organic products and is recognized to be an extremely toxic agent by the National Institute for Occupational Safety and Health (NIOSH). Resorcinol dye is shown to become immobilized in PSA membranes and diffusionally constrain an orange brown product that results from acid-catalyzed reaction with more rapidly diffusing TMA molecules. FTIR, UV/vis, reaction selectivity to TMA versus trimellitic acid (TMLA), and homogeneous synthesis are used to infer 5,7- dihydroxyanthraquinone-2-carboxylic acid as the acylation product of the reaction. The color response has a sensitivity to at least 3 parts per billion (ppb) TMA exposure and, in addition to TMLA, excludes maleic anhydride (MA) and phthalic anhydride (PA). Solvent extraction at long times is used to determine that the resorcinol extinction coefficient in 1100 EW PSA membrane has a value of 1210 m(2)/g at 271.01 nm versus a value of 2010 m(2)/g at 275.22 nm in 50 vol% ethanol/water solution. The hypsochromic wavelength shift and reduced extinction coefficient suggest that the polar perfluorosulfonic acid groups in the membrane provide the thermodynamic driving force for diffusion and immobilization. At a resorcinol concentration of 0.376 g/L in the membrane, a partition coefficient of nearly unity is obtained between the membrane and solution concentrations and a

  7. Reaction pathway in vapour phase hydrogenation of maleic anhydride and its esters to {gamma}-butyrolactone

    SciTech Connect

    Messori, M.; Vaccari, A.

    1994-11-01

    The catalytic reactivity of maleic anhydride (MA), succinic anhydride (SA) and their dimethyl esters (dimethyl maleate and dimethyl succinate) in the vapour phase hydrogenation to {gamma}-butyrolacetone (GBL) was investigated. In order to obtain general data, both a multicomponent catalyst (CAT 1: Cu/Zn/Mg/Cr = 40:5:5:50, atomic ratio %), obtained by reduction of a nonstoichiometric spinel-type precursor, and a commercial catalyst (CAT 2: Cu/Mn/Ba/Cr = 44:8:1:47, atomic ratio %) were used. The MA/GBL solution exhibited the highest GBL production, while the SA/GBL solution was converted only partially due to a competitive adsorption of GBL on the active sites, as evidenced by the similar reactivities observed with pure anhydrides. The best carbon balances were observed with the esters, probably the result of lowest light hydrocarbon synthesis and tar formation. With all the feedstocks, the activity of CAT 2 is higher than that of CAT 1, which, however, gives the best yield in GBL due its lower activity in the overhydrogenation and hydrogenolysis reaction. It was found that n-butanol (BuOH) and butyric acid (BuA) derived mainly from GBL. On this basis, the reactivities of the main products observed were investigated separately, confirming the stability of tetrahydrofuran (THF), which reacted only at high temperature with low conversions to ethanol. On the other hand, GBL gave rise to overhydrogenation and/or hydrogenolysis, with high conversion (mainly with CAT 2), confirming its key role in both reactions. Furthermore, the formation in the catalytic tests with BuA and BuOH of n-butanal, notwithstanding the high H{sub 2}/organic ratio, implies that it is the main intermediate in the hydrogenolysis reactions. A new reaction scheme is proposed, pointing out the key role of GBL as the {open_quotes}intersection{close_quotes} of two possible reaction pathways, giving rise to THF or overhydrogenation and hydrogenolysis products, respectively. 44 refs., 4 figs., 6 tabs.

  8. Composite Properties of RTM370 Polyimide Fabricated by Vacuum Assisted Resin Transfer Molding (VARTM)

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Criss, James M.; Mintz, Eric A.; Shonkwiler, Brian; McCorkle, Linda S.

    2011-01-01

    RTM370 imide resin based on 2,3,3?,4?-biphenyl dianhydride (a-BPDA), 3,4'-oxydianinline (3,4'-ODA) with the 4-phenylethynylphthalic (PEPA) endcap has been shown to exhibit a high cured T(sub g) (370 C) and low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h. Previously, RTM370 resin has been successfully fabricated into composites reinforced with T650-35 carbon fabrics by resin transfer molding (RTM). RTM370 composites exhibit excellent mechanical properties up to 327?C (620?F), and outstanding property retention after aging at 288?C (550?F) for 1000 h. In this work, RTM370 composites were fabricated by vacuum assisted resin transfer molding (VARTM), using vacuum bags on a steel plate. The mechanical properties of RTM370 composites fabricated by VARTM are compared to those prepared by RTM.

  9. Polyimide Composites Properties of RTM370 Fabricated by Vacuum Assisted Resins Transfer Molding (VARTM)

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.

    2011-01-01

    RTM370 imide resin based on 2,3,3 ,4 -biphenyl dianhydride ( a-BPDA), 3,4 -oxydianinline (3,4 -ODA) with 4-phenylethynylphthalic (PEPA) endcap has shown to exhibit high Tg (370 C) and low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h. Previously, RTM370 resin has been fabricated into composites with T650-35 carbon fabrics by resin transfer molding (RTM) successfully. RTM370 composites exhibit excellent mechanical properties up to 327 C (620 F), and outstanding property retention after aging at 288 C (550 F) for 1000 hrs. In this presentation, RTM 370 composites will be fabricated by vacuum assisted resins transfer molding (VARTM), using vacuum bags without mold. The mechanical properties of RTM370 composites fabricated by VARTM will be compared to those of RTM370 made by RTM.

  10. RTM370 Polyimide Braided Composites: Characterization and Impact Testing

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Revilock, Duane M.; Ruggeri, Charles R.; Criss, Jim M., Jr.; Mintz, Eric A.

    2013-01-01

    RTM370 imide oligomer based on 2,3,3',4'-biphenyl dianhydride (a-BPDA), 3,4'-oxydianiline (3,4'-ODA) and terminated with the 4-phenylethynylphthalic (PEPA) endcap has been shown to exhibit a low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h and a high cured glass transition temperature (Tg) of 370 C. RTM370 resin has been successfully fabricated into composites reinforced with T650-35 carbon fabrics by resin transfer molding (RTM). RTM370 composites display excellent mechanical properties up to 327 C (620 F), and outstanding property retention after aging at 288degC (550 F) for 1000 h, and under hot-wet conditions. In ballistic impact testing, RTM370 triaxial braided T650-35 carbon fiber composites exhibited enhanced energy absorption at 288 C (550 F) compared to ambient temperature.

  11. Substituted Phthalic Anhydrides from Biobased Furanics: A New Approach to Renewable Aromatics.

    PubMed

    Thiyagarajan, Shanmugam; Genuino, Homer C; Śliwa, Michał; van der Waal, Jan C; de Jong, Ed; van Haveren, Jacco; Weckhuysen, Bert M; Bruijnincx, Pieter C A; van Es, Daan S

    2015-09-21

    A novel route for the production of renewable aromatic chemicals, particularly substituted phthalic acid anhydrides, is presented. The classical two-step approach to furanics-derived aromatics via Diels-Alder (DA) aromatization has been modified into a three-step procedure to address the general issue of the reversible nature of the intermediate DA addition step. The new sequence involves DA addition, followed by a mild hydrogenation step to obtain a stable oxanorbornane intermediate in high yield and purity. Subsequent one-pot, liquid-phase dehydration and dehydrogenation of the hydrogenated adduct using a physical mixture of acidic zeolites or resins in combination with metal on a carbon support then allows aromatization with yields as high as 84 % of total aromatics under relatively mild conditions. The mechanism of the final aromatization reaction step unexpectedly involves a lactone as primary intermediate.

  12. Preparation and Characterization of Octenyl Succinic Anhydride Modified Taro Starch Nanoparticles.

    PubMed

    Jiang, Suisui; Dai, Lei; Qin, Yang; Xiong, Liu; Sun, Qingjie

    2016-01-01

    The polar surface and hydrophilicity of starch nanoparticles (SNPs) result in their poor dispersibility in nonpolar solvent and poor compatibility with hydrophobic polymers, which limited the application in hydrophobic system. To improve their hydrophobicity, SNPs prepared through self-assembly of short chain amylose debranched from cooked taro starch, were modified by octenyl succinic anhydride (OSA). Size via dynamic light scattering of OSA-SNPs increased compared with SNPs. Fourier transform infrared spectroscopy data indicated the OSA-SNPs had a new absorption peak at 1727 cm-1, which was the characteristic peak of carbonyl, indicating the formation of the ester bond. The dispersibility of the modified SNPs in the mixture of water with nonpolar solvent increased with increasing of degree of substitution (DS). OSA-SNPs appear to be a potential agent to stabilize the oil-water systems.

  13. Poly(anhydride-esters) Comprised Exclusively of Naturally Occurring Antimicrobials and EDTA: Antioxidant and Antibacterial Activities

    PubMed Central

    2015-01-01

    Carvacrol, thymol, and eugenol are naturally occurring phenolic compounds known to possess antimicrobial activity against a range of bacteria, as well as antioxidant activity. Biodegradable poly(anhydride-esters) composed of an ethylenediaminetetraacetic acid (EDTA) backbone and antimicrobial pendant groups (i.e., carvacrol, thymol, or eugenol) were synthesized via solution polymerization. The resulting polymers were characterized to confirm their chemical composition and understand their thermal properties and molecular weight. In vitro release studies demonstrated that polymer hydrolytic degradation was complete after 16 days, resulting in the release of free antimicrobials and EDTA. Antioxidant and antibacterial assays determined that polymer release media exhibited bioactivity similar to that of free compound, demonstrating that polymer incorporation and subsequent release had no effect on activity. These polymers completely degrade into components that are biologically relevant and have the capability to promote preservation of consumer products in the food and personal care industries via antimicrobial and antioxidant pathways. PMID:24702678

  14. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    SciTech Connect

    Ramprasad, Dorai; Waller, Francis Joseph

    1999-01-01

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  15. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    SciTech Connect

    Ramprasad, D.; Waller, F.J.

    1999-04-06

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  16. Asymmetric Alternating Copolymerization of Meso-epoxides and Cyclic Anhydrides: Efficient Access to Enantiopure Polyesters.

    PubMed

    Li, Jie; Liu, Ye; Ren, Wei-Min; Lu, Xiao-Bing

    2016-09-14

    Synthesis of stereoregular polyesters with main-chain chirality was achieved for the first time by the asymmetric copolymerization of meso-epoxides and cyclic anhydrides using catalyst systems based on enantiopure bimetallic complexes. The combination of the biphenol-linked dinuclear aluminum complex with tert-butyl groups in the phenolate ortho-positions and a nucleophilic co-catalyst was found to be more efficient in catalyzing this asymmetric copolymerization, affording enantiomerically enriched polyesters (up to 91% ee) with completely alternating structure and narrow molecular weight distribution. It was discovered that the isotactic-enriched poly(cyclopentene phthalate) is a typical semicrystalline material with a melting endothermic peak at 221 °C. This study is expected to provide a promising route to prepare various stereoregular polyesters having a wide variety of physical properties and degradability. PMID:27562940

  17. Process for the production of 1:4 butanediol from maleic anhydride via ester hydrogenation

    SciTech Connect

    Towers, R.G.; Harris, N.; McKee, D.

    1986-01-01

    A process has been developed for the production of 1:4 butanediol (1:4 BDO from maleic anhydride (MA). The three process steps are:- a) Esterifiction of MA to produce a dialkyl maleate ester based on a modification of commercially proven esterification technology; b) Hydrogenation of the ester, at moderate temperatures and pressures, to 1:4 BD using novel low pressure ester hydrogenation technology. Gamma-Butyrolactone (gamma-BL) and tetrahydrofuran (THF) are produced as co-products. The 1:4 BD/Gamma-BL product ratio can be adjusted to respond to market requirements by recycle of the less desirable product, and THF productivity controlled over wide limits by variation of process parameters; c) Product separation by distillation.

  18. Preparation and Characterization of Octenyl Succinic Anhydride Modified Taro Starch Nanoparticles

    PubMed Central

    Jiang, Suisui; Dai, Lei; Qin, Yang; Xiong, Liu; Sun, Qingjie

    2016-01-01

    The polar surface and hydrophilicity of starch nanoparticles (SNPs) result in their poor dispersibility in nonpolar solvent and poor compatibility with hydrophobic polymers, which limited the application in hydrophobic system. To improve their hydrophobicity, SNPs prepared through self-assembly of short chain amylose debranched from cooked taro starch, were modified by octenyl succinic anhydride (OSA). Size via dynamic light scattering of OSA-SNPs increased compared with SNPs. Fourier transform infrared spectroscopy data indicated the OSA-SNPs had a new absorption peak at 1727 cm-1, which was the characteristic peak of carbonyl, indicating the formation of the ester bond. The dispersibility of the modified SNPs in the mixture of water with nonpolar solvent increased with increasing of degree of substitution (DS). OSA-SNPs appear to be a potential agent to stabilize the oil-water systems. PMID:26918568

  19. Enhanced Activity of Nanocrystalline Beta Zeolite for Acylation of Veratrole with Acetic Anhydride.

    PubMed

    Aisha Mahmood Abdulkareem, Al-Turkustani; Selvin, Rosilda

    2016-04-01

    Friedel-Craft acylation of veratrole using homogeneous acid catalysts such as AlCl3, FeCl3, ZnCl2, and HF etc. produces acetoveratrone, (3',4'-dimethoxyacetophenone), which is the intermediate for synthesis of papavarine alkaloids. The problems associated with these homogeneous catalysts can be overcome by using heterogeneous solid catalysts. Since acetoveratrone is a larger molecule, large pore Beta zeolites with smaller particle sizes are beneficial for the liquid-phase acylation of veratrole, for easy diffusion of reactants and products. The present study aims in the acylation of veratrole with acetic anhydride using nanocrystalline Beta Zeolite catalyst. A systematic investigation of the effects of various reaction parameters was done. The catalysts were characterized for their structural features by using XRD, TEM and DLS analyses. The catalytic activity of nanocrystalline Beta zeolite was compared with commercial Beta zeolite for the acylation and was found that nanocrystalline Beta zeolite possessed superior activity.

  20. One-pot synthesis of thermoplastic mixed paramylon esters using trifluoroacetic anhydride.

    PubMed

    Shibakami, Motonari; Tsubouchi, Gen; Sohma, Mitsugu; Hayashi, Masahiro

    2015-03-30

    Mixed paramylon esters prepared from paramylon (a storage polysaccharide of Euglena), acetic acid, and a long-chain fatty acid by one-pot synthesis using trifluoroacetic anhydride as a promoter and solvent were shown to have thermoplasticity. Size exclusion chromatography indicated that the mixed paramylon esters had a weight average molecular weight of approximately 4.9-6.7×10(5). Thermal analysis showed that these esters were stable in terms of the glass transition temperature (>90°C) and 5% weight loss temperature (>320°C). The degree of substitution of the long alkyl chain group, a dominant factor determining thermoplasticity, was controlled by tuning the feed molar ratio of acetic acid and long-chain fatty acid to paramylon. These results implied that the one-pot synthesis is useful for preparing structurally-well defined thermoplastic mixed paramylon esters with high molecular weight.

  1. Enhanced Activity of Nanocrystalline Beta Zeolite for Acylation of Veratrole with Acetic Anhydride.

    PubMed

    Aisha Mahmood Abdulkareem, Al-Turkustani; Selvin, Rosilda

    2016-04-01

    Friedel-Craft acylation of veratrole using homogeneous acid catalysts such as AlCl3, FeCl3, ZnCl2, and HF etc. produces acetoveratrone, (3',4'-dimethoxyacetophenone), which is the intermediate for synthesis of papavarine alkaloids. The problems associated with these homogeneous catalysts can be overcome by using heterogeneous solid catalysts. Since acetoveratrone is a larger molecule, large pore Beta zeolites with smaller particle sizes are beneficial for the liquid-phase acylation of veratrole, for easy diffusion of reactants and products. The present study aims in the acylation of veratrole with acetic anhydride using nanocrystalline Beta Zeolite catalyst. A systematic investigation of the effects of various reaction parameters was done. The catalysts were characterized for their structural features by using XRD, TEM and DLS analyses. The catalytic activity of nanocrystalline Beta zeolite was compared with commercial Beta zeolite for the acylation and was found that nanocrystalline Beta zeolite possessed superior activity. PMID:27451793

  2. Mechanism of highly improved electrical properties in polypropylene by chemical modification of grafting maleic anhydride

    NASA Astrophysics Data System (ADS)

    Zhou, Yao; Hu, Jun; Dang, Bin; He, Jinliang

    2016-10-01

    This paper reports excellent electrical properties in polypropylene grafted with maleic anhydride (PP-g-MAH) and a related mechanism of the enhanced electrical properties. The chemical structure of PP-g-MAH was analyzed and its effect on space charge accumulation, electrical breakdown strength and DC conductivity was studied. Compared with pure PP, the PP-g-MAH exhibits remarkably suppressed space charge accumulation, enhanced electrical breakdown strength and reduced conduction current. The mechanism enhancing the electrical properties was studied by measuring the trap level distribution. It can be explained that abundant deep traps are introduced in PP-g-MAH with the introduction of polar groups in MAH, which reduces the charge mobility and raises the charge injection barrier so as to suppress space charge accumulation. This investigation would contribute to propose a new material modification strategy for designing high-voltage direct current insulation material in addition to the inclusion of nanoparticles.

  3. Improved removal of malachite green from aqueous solution using chemically modified cellulose by anhydride.

    PubMed

    Zhou, Yanmei; Min, Yinghao; Qiao, Han; Huang, Qi; Wang, Enze; Ma, Tongsen

    2015-03-01

    Cellulose modified with maleic (M) and phthalic (P) anhydride, to be named CMA and CPA, were tested as feasible adsorbents for the removal of malachite green from aqueous solution. At the same time, the uptake ability of natural cellulose was also studied for comparison. The structure of material was characterized by FT-IR and XRD. The effects of solution pH, initial dye concentration, contact time and temperature were investigated in detail by batch adsorption experiments. The kinetic and isotherm studies suggested that the adsorption followed the pseudo-second-order model and Langmuir isotherm. The maximum adsorption capacity on CMA and CPA were 370 mg g(-1) and 111 mg g(-1), respectively. Furthermore, the thermodynamics studies indicated the spontaneous nature of adsorption of malachite green on adsorbents. All the studied results showed that the modified cellulose could be used as effective adsorption material for the removal of malachite green from aqueous solutions. PMID:25542168

  4. Preparation and Characterization of Octenyl Succinic Anhydride Modified Taro Starch Nanoparticles.

    PubMed

    Jiang, Suisui; Dai, Lei; Qin, Yang; Xiong, Liu; Sun, Qingjie

    2016-01-01

    The polar surface and hydrophilicity of starch nanoparticles (SNPs) result in their poor dispersibility in nonpolar solvent and poor compatibility with hydrophobic polymers, which limited the application in hydrophobic system. To improve their hydrophobicity, SNPs prepared through self-assembly of short chain amylose debranched from cooked taro starch, were modified by octenyl succinic anhydride (OSA). Size via dynamic light scattering of OSA-SNPs increased compared with SNPs. Fourier transform infrared spectroscopy data indicated the OSA-SNPs had a new absorption peak at 1727 cm-1, which was the characteristic peak of carbonyl, indicating the formation of the ester bond. The dispersibility of the modified SNPs in the mixture of water with nonpolar solvent increased with increasing of degree of substitution (DS). OSA-SNPs appear to be a potential agent to stabilize the oil-water systems. PMID:26918568

  5. Stability of a salicylate-based poly(anhydride-ester) to electron beam and gamma radiation

    PubMed Central

    Rosario-Meléndez, Roselin; Lavelle, Linda; Bodnar, Stanko; Halperin, Frederick; Harper, Ike; Griffin, Jeremy; Uhrich, Kathryn E.

    2011-01-01

    The effect of electron beam and gamma radiation on the physicochemical properties of a salicylate-based poly(anhydride-ester) was studied by exposing polymers to 0 (control), 25 and 50 kGy. After radiation exposure, salicylic acid release in vitro was monitored to assess any changes in drug release profiles. Molecular weight, glass transition temperature and decomposition temperature were evaluated for polymer chain scission and/or crosslinking as well as changes in thermal properties. Proton nuclear magnetic resonance and infrared spectroscopies were also used to determine polymer degradation and/or chain scission. In vitro cell studies were performed to identify cytocompatibility following radiation exposure. These studies demonstrate that the physicochemical properties of the polymer are not substantially affected by exposure to electron beam and gamma radiation. PMID:21909173

  6. Improved removal of malachite green from aqueous solution using chemically modified cellulose by anhydride.

    PubMed

    Zhou, Yanmei; Min, Yinghao; Qiao, Han; Huang, Qi; Wang, Enze; Ma, Tongsen

    2015-03-01

    Cellulose modified with maleic (M) and phthalic (P) anhydride, to be named CMA and CPA, were tested as feasible adsorbents for the removal of malachite green from aqueous solution. At the same time, the uptake ability of natural cellulose was also studied for comparison. The structure of material was characterized by FT-IR and XRD. The effects of solution pH, initial dye concentration, contact time and temperature were investigated in detail by batch adsorption experiments. The kinetic and isotherm studies suggested that the adsorption followed the pseudo-second-order model and Langmuir isotherm. The maximum adsorption capacity on CMA and CPA were 370 mg g(-1) and 111 mg g(-1), respectively. Furthermore, the thermodynamics studies indicated the spontaneous nature of adsorption of malachite green on adsorbents. All the studied results showed that the modified cellulose could be used as effective adsorption material for the removal of malachite green from aqueous solutions.

  7. Substituted Phthalic Anhydrides from Biobased Furanics: A New Approach to Renewable Aromatics.

    PubMed

    Thiyagarajan, Shanmugam; Genuino, Homer C; Śliwa, Michał; van der Waal, Jan C; de Jong, Ed; van Haveren, Jacco; Weckhuysen, Bert M; Bruijnincx, Pieter C A; van Es, Daan S

    2015-09-21

    A novel route for the production of renewable aromatic chemicals, particularly substituted phthalic acid anhydrides, is presented. The classical two-step approach to furanics-derived aromatics via Diels-Alder (DA) aromatization has been modified into a three-step procedure to address the general issue of the reversible nature of the intermediate DA addition step. The new sequence involves DA addition, followed by a mild hydrogenation step to obtain a stable oxanorbornane intermediate in high yield and purity. Subsequent one-pot, liquid-phase dehydration and dehydrogenation of the hydrogenated adduct using a physical mixture of acidic zeolites or resins in combination with metal on a carbon support then allows aromatization with yields as high as 84 % of total aromatics under relatively mild conditions. The mechanism of the final aromatization reaction step unexpectedly involves a lactone as primary intermediate. PMID:26235971

  8. Process for the manufacture of catalysts for the production of maleic anhydride

    SciTech Connect

    Edwards, R.C.

    1987-10-13

    A process is described for the manufacture of a phosphorus-vanadium oxide catalyst suitable for use in the manufacture of maleic anhydride from butane. The process comprises reacting at a temperature of about 0/sup 0/C to about 200/sup 0/C a vanadium compound in an organic ether solvent having from about 2 to about 10 carbon atoms, with a phosphoryl halide in the presence of water or an aliphatic alcohol having from about 1 to about 8 carbon atoms, eliminating the solvent and activating the catalyst by the addition of butane, benzene or another C/sub 4/ hydrocarbon feedstock and water and a phosphorus compound at a temperature of about 300/sup 0/C to about 500/sup 0/C wherein the amount of water added is about 1000 parts per million to about 40,000 parts per million by weight of the reactor feed gas stream.

  9. One-pot synthesis of thermoplastic mixed paramylon esters using trifluoroacetic anhydride.

    PubMed

    Shibakami, Motonari; Tsubouchi, Gen; Sohma, Mitsugu; Hayashi, Masahiro

    2015-03-30

    Mixed paramylon esters prepared from paramylon (a storage polysaccharide of Euglena), acetic acid, and a long-chain fatty acid by one-pot synthesis using trifluoroacetic anhydride as a promoter and solvent were shown to have thermoplasticity. Size exclusion chromatography indicated that the mixed paramylon esters had a weight average molecular weight of approximately 4.9-6.7×10(5). Thermal analysis showed that these esters were stable in terms of the glass transition temperature (>90°C) and 5% weight loss temperature (>320°C). The degree of substitution of the long alkyl chain group, a dominant factor determining thermoplasticity, was controlled by tuning the feed molar ratio of acetic acid and long-chain fatty acid to paramylon. These results implied that the one-pot synthesis is useful for preparing structurally-well defined thermoplastic mixed paramylon esters with high molecular weight. PMID:25563938

  10. Synthesis and characterization of antiseptic-based poly(anhydride-esters)

    PubMed Central

    Schmeltzer, Robert C.

    2013-01-01

    Poly(anhydride-esters) were prepared from catechol, fenticlor and hexachlorophene. The molecular weights (Mw) of the polymers were typically > 10,000 Da with glass transition temperatures (Tg) ranging from 23 to 84 °C. The thermal characteristics of the polymers paralleled the melting temperatures of the chemically incorporated antiseptic molecules. The in vitro release of the chemically incorporated antiseptic molecules were monitored over a 12 week period. For comparison, the in vitro release of physically admixed antiseptic molecules were also observed. After 12 weeks, the polymers were not completely degraded with drug release ranging from less than 1 to 55 %. Sessile-drop contact angles indicated that the polymers were relatively hydrophobic, contributing to the slow polymer degradation rates. PMID:24039323

  11. Functionalization of poly(dimethylsiloxane) surfaces with maleic anhydride copolymer films.

    PubMed

    Cordeiro, Ana L; Zschoche, Stefan; Janke, Andreas; Nitschke, Mirko; Werner, Carsten

    2009-02-01

    Combining advantageous bulk properties of polymeric materials with surface-selective chemical conversions is required in numerous advanced technologies. For that aim, we investigate strategies to graft maleic anhydride (MA) copolymer films onto poly(dimethylsiloxane) (PDMS) precoatings. Amino groups allowing the covalent attachment of the MA copolymer films to the PDMS (Sylgard 184) surface were introduced either by low-pressure ammonia plasma treatment, or by attachment of 3-aminopropyltriethoxysilane (APTES) onto air plasma-treated PDMS. The resultant coatings were extensively characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), contact angle measurements, and atomic force microscopy (AFM). The results show that the impact of the plasma treatment on the physical properties on the topmost surface of the PDMS is critically important for the characteristics of the layered coatings.

  12. Crystal structures of alkylperoxo and anhydride intermediates in an intradiol ring-cleaving dioxygenase

    PubMed Central

    Knoot, Cory J.; Purpero, Vincent M.; Lipscomb, John D.

    2015-01-01

    Intradiol aromatic ring-cleaving dioxygenases use an active site, nonheme Fe3+ to activate O2 and catecholic substrates for reaction. The inability of Fe3+ to directly bind O2 presents a mechanistic conundrum. The reaction mechanism of protocatechuate 3,4-dioxygenase is investigated here using the alternative substrate 4-fluorocatechol. This substrate is found to slow the reaction at several steps throughout the mechanistic cycle, allowing the intermediates to be detected in solution studies. When the reaction was initiated in an enzyme crystal, it was found to halt at one of two intermediates depending on the pH of the surrounding solution. The X-ray crystal structure of the intermediate at pH 6.5 revealed the key alkylperoxo-Fe3+ species, and the anhydride-Fe3+ intermediate was found for a crystal reacted at pH 8.5. Intermediates of these types have not been structurally characterized for intradiol dioxygenases, and they validate four decades of spectroscopic, kinetic, and computational studies. In contrast to our similar in crystallo crystallographic studies of an Fe2+-containing extradiol dioxygenase, no evidence for a superoxo or peroxo intermediate preceding the alkylperoxo was found. This observation and the lack of spectroscopic evidence for an Fe2+ intermediate that could bind O2 are consistent with concerted formation of the alkylperoxo followed by Criegee rearrangement to yield the anhydride and ultimately ring-opened product. Structural comparison of the alkylperoxo intermediates from the intra- and extradiol dioxygenases provides a rationale for site specificity of ring cleavage. PMID:25548185

  13. Interactions of poly (anhydride) nanoparticles with macrophages in light of their vaccine adjuvant properties.

    PubMed

    Gamazo, C; Bussmann, H; Giemsa, S; Camacho, A I; Unsihuay, Daisy; Martín-Arbella, N; Irache, J M

    2015-12-30

    Understanding how nanoparticles are formed and how those processes ultimately determine the nanoparticles' properties and their impact on their capture by immune cells is key in vaccination studies. Accordingly, we wanted to evaluate how the previously described poly (anhydride)-based nanoparticles of the copolymer of methyl vinyl ether and maleic anhydride (NP) interact with macrophages, and how this process depends on the physicochemical properties derived from the method of preparation. First, we studied the influence of the desolvation and drying processes used to obtain the nanoparticles. NP prepared by the desolvation of the polymers in acetone with a mixture of ethanol and water yielded higher mean diameters than those obtained in the presence of water (250nm vs. 180nm). In addition, nanoparticles dried by lyophilization presented higher negative zeta potentials than those dried by spray-drying (-47mV vs. -35mV). Second, the influence of the NP formulation on the phagocytosis by J774 murine macrophage-like cell line was investigated. The data indicated that NPs prepared in the presence of water were at least three-times more efficiently internalized by cells than NPs prepared with the mixture of ethanol and water. Besides, lyophilized nanoparticles appeared to be more efficiently taken up by J744 cells than those dried by spray-drying. To further understand the specific mechanisms involved in the cellular internalization of NPs, different pharmacological inhibitors were used to interfere with specific uptake pathways. Results suggest that the NP formulations, particularly, nanoparticles prepared by the addition of ethanol:water, are internalized by the clathrin-mediated endocytosis, rather than caveolae-mediated mechanisms, supporting their previously described vaccine adjuvant properties.

  14. Pd(II)-catalyzed regio-, enantio-, and diastereoselective 1,4-addition of azlactones formed in situ from racemic unprotected amino acids and acetic anhydride.

    PubMed

    Weber, Manuel; Peters, René

    2012-12-01

    A multicomponent reaction is reported generating highly enantioenriched and diastereomerically pure quaternary amino acid derivatives via 1,4-addition of azlactones to enones. The azlactone intermediates are generated in situ from unprotected α-amino acids and acetic anhydride. Previous attempts using bis-palladacycle catalysts required the use of a large excess of benzoic anhydride (which is very difficult to remove from the products), since acetic anhydride provided regioisomeric product mixtures. Key for the high regioselectivity is a pentaphenylferrocene monopalladacycle catalyst. PMID:23193999

  15. Application of palladium-catalyzed carboxyl anhydride-boronic acid cross coupling in the synthesis of novel bile acids analogs with modified side chains.

    PubMed

    Mayorquín-Torres, Martha C; Flores-Álamo, Marcos; Iglesias-Arteaga, Martin A

    2015-09-01

    Palladium-catalyzed cross coupling of 4-methoxycarbonyl phenyboronic acid with acetylated bile acids in which the carboxyl functions was activated by formation of a mixed anhydride with pivalic anhydride afforded the cross coupled compounds, which were converted in novel side chain modified bile acids by one pot carbonyl reduction/removal of the protecting acetyl groups by Wolff-Kishner reduction. Unambiguous assignments of the NMR signals and crystal characterization of the heretofore unknown compounds are provided.

  16. Kinetics of the reactions of the acid anhydrides with aromatic amines in aprotic solvents. M.S. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Sugg, E.; Mason, J. G.

    1983-01-01

    Work has revealed that diamine derivatives of diphenylmethane (IV), diphenyl ether (V), benzophenone (IV), fluorene (VII), and fluorenone (VIII) polymerizations with pyromellitic dianhydride in DMA were dependent on the basicity of the amine compound. The correlation between the basicity of the amine and its reactivity with phthalic anhydride was determined. Basicity measurements were made by potentiometric titration of each amine in an acetonitrile-water solvent system, from which the pKa of the amine could be determined. Reactivity was defined in terms of the second order rate constant derived form spectrophotometric examination of the reaction between each amine and phthalic anhydride in DMA. This reaction was expected to proceed in either one (for a monoamine) or two (for a diamine) stages.

  17. In situ FTIR study of n-butane selective oxidation to maleic anhydride on V-P-O catalysts

    SciTech Connect

    Wenig, R.W.; Schrader, G.L.

    1986-11-20

    The selective oxidation of n-butane to maleic anhydride on vanadium-phosphorus-oxygen (V-P-O) catalysts having P to V ratios of 0.9, 1.0, and 1.1 was studied by transmission infrared spectroscopy. Catalysts were exposed to mixtures of 1.5% n-butane in air at temperatures from 100 to 500/sup 0/C. Adsorbed n-butane, maleic anhydride, and carbon oxide species were observed on the catalyst surfaces. In addition, adsorbed maleic acid and highly reactive olefinic species could be detected. The nature of the adsorbed species present on the catalyst surface was dependent on the catalyst phosphorus loading, the reaction temperature, and the time of exposure under reaction conditions.

  18. Short communication: Difructose anhydride III promotes calcium absorption from the duodenum in cattle.

    PubMed

    Teramura, M; Nakai, T; Itoh, M; Sato, T; Ohtani, M; Kawashima, C; Hanada, M

    2015-04-01

    Difructose anhydride (DFA) III promotes the intestinal absorption of calcium via a paracellular pathway in rats. In dairy cows, DFA III reaches the duodenum without being degraded by ruminal bacteria and hence could be used to control hypocalcemia. The aims of the present study were to investigate the percentage of DFA III that appears in the duodenum of cows and to determine the effect of DFA III on calcium absorption from duodenal fluid. The first experiment was performed in 3 ruminally and duodenally cannulated dry Holstein cows in a 3 × 3 Latin square design. Each experimental period lasted 7 d. On the first day, the cows were ruminally fed one of the following treatments: 0 (DFA0), 50 (DFA50), or 100 (DFA100) g/d of DFA III, using cobalt-EDTA as a liquid phase marker. Difructose anhydride III was detected in duodenal fluid 1 h after feeding, and its concentration peaked 4 h after feeding, in a dose-dependent manner. The percentages of DFA III that appeared in the duodenum after the DFA50 and DFA100 treatments were 69.1 ± 7.0% and 67.9 ± 5.6%, respectively. The second experiment used the everted duodenal sacs of cattle (n = 7 in each group). Sacs were incubated in artificial mucosal fluid containing 1 mM DFA III or no DFA III (control) for 60 min with 100% O2 in a water bath at 37 °C. After incubation, the calcium concentration of the artificial serosal fluid in the everted sacs was measured. Calcium absorption was higher in the DFA III-treated group than in the control group (803 ± 161 and 456 ± 74 nmol/cm of sac, respectively). The above results demonstrate that approximately 70% of administered DFA III reached the duodenum of cows intact. Moreover, similar to its effects on calcium absorption in rats, DFA III promoted calcium absorption via a paracellular pathway in the duodenum of cows. PMID:25648815

  19. Preparation and in vitro evaluation of novel poly(anhydride-ester)-based amphiphilic copolymer curcumin-loaded micelles.

    PubMed

    Lv, Li; Shen, Yuanyuan; Li, Min; Xu, Xiaofen; Li, Min; Guo, Shengrong; Huang, Shengtang

    2014-02-01

    Novel poly(anhydride-ester)-b-poly(ethylene glycol) copolymers (PAE-b-PEGs) were synthesized by esterization of methyl poly(ethylene glycol) and poly(anhydride-ester), which were obtained by the melt polycondensation of alpha,omega-acetic anhydride-terminated poly(L-lactic acid), and characterized by 1H-NMR and gel permeation chromatography. The two poly(anhydride-ester)-b-poly(ethylene glycols) (denoted as PAE-b-PEG2k and PAE-b-PEG5k) thus obtained can self-assemble in water to form micelles with hydrodynamic diameters of 92.5 and 97.5 nm above their critical micelle concentrations of 3.78 and 2.36 microg/mL, respectively. The curcumin-loaded PAE-b-PEG2k and PAE-b-PEG5k micelles were prepared by the solid dispersion method, and they could encapsulate approximately 7% (w/w) curcumin. The diameters of the micelles were stable for 5 days. Curcumin is released faster from the micelles at pH 5.0 than at pH 7.4. Curcumin is released from the micelles at a fast rate during the initial 12 h, followed by a zero-order release during the subsequent 200 h, both at pH 5.0 and 7.4. The IC50 values of the curcumin-loaded PAE-b-PEG2k and PAE-b-PEG5k micelles against HeLa cells are 12.41 and 15.31 microg/mL, respectively, which is lower than that of free curcumin (25.90 microg/mL). The PAE-b-PEG2k micelles are taken up faster than the PAE-b-PEG5k micelles by HeLa cells. Curcumin-loaded micelles can induce G2/M phase cell cycle arrest and apoptosis of HeLa cells.

  20. Polyol-acid anhydride-n-alkyl-alkylene diamine reaction product and motor fuel composition containing same

    SciTech Connect

    Sung, R.L.; Jenkins, R.H. Jr.

    1987-02-17

    A fuel composition for an internal combustion engine comprising: (a) a major portion of a liquid hydrocarbon fuel and (b) a minor amount, as a deposit inhibitor additive, of a reaction product of a process comprising: (i) reacting a dibasic acid anhydride with a polyol, thereby forming an ester of maleic acid; (ii) reacting the ester of maleic acid with an N-alkyl-alkylene diamine, thereby forming the reaction product; and (iii) recovering the reaction product.

  1. Organic linkers on oxide surfaces: Adsorption and chemical bonding of phthalic anhydride on MgO(100)

    NASA Astrophysics Data System (ADS)

    Mohr, Susanne; Doepper, Tibor; Xu, Tao; Tariq, Quratulain; Lytken, Ole; Laurin, Mathias; Steinrueck, Hans-Peter; Goerling, Andreas; Libuda, Joerg

    2016-04-01

    To elucidate the adsorption behavior and interaction mechanisms of organic linker units on oxide surfaces, we have performed a model study under ultrahigh vacuum (UHV) conditions. We apply infrared reflection absorption spectroscopy (IRAS) in combination with density-functional theory (DFT), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). Phthalic anhydride (PAA) was deposited at temperatures between 100 and 300 K by physical vapor deposition (PVD) onto an ordered MgO(100) film grown on Ag(100). At 100 K, the first monolayer adsorbs molecularly with the molecular plane aligned parallel to the surface. Subsequent growth of a multilayer film at low temperature also occurs with preferential molecular alignment parallel to the surface. At 240 K, the multilayer desorbs without decomposition. At 300 K, a mixed monolayer of chemically modified ring-opened and intact phthalic anhydride exists on the surface. The chemically modified species binds in a strongly tilted geometry via opening of the anhydride ring to form a bis-carboxylate species. This species additionally stabilizes the coadsorbed molecular PAA via intermolecular interactions. Finally, surface defects and hydroxyl groups are found to increase the amount of surface bis-carboxylate at 300 K, whereas the relative amount of coadsorbed molecular PAA decreases.

  2. Mixed Anhydride Intermediates in the Reaction of 5(4H)-Oxazolones with Phosphate Esters and Nucleotides

    PubMed Central

    Liu, Ziwei; Rigger, Lukas; Rossi, Jean-Christophe; Sutherland, John D.; Pascal, Robert

    2016-01-01

    5(4H)-Oxazolones can be formed through the activation of acylated α-amino acids or of peptide C termini. They constitute potentially activated intermediates in the abiotic chemistry of peptides that preceded the origin of life or early stages of biology and are capable of yielding mixed carboxylic-phosphoric anhydrides upon reaction with phosphate esters and nucleotides. Here, we present the results of a study aimed at investigating the chemistry that can be built through this interaction. As a matter of fact, the formation of mixed anhydrides with mononucleotides and nucleic acid models is shown to take place at positions involving a mono-substituted phosphate group at the 3’- or 5’-terminus but not at the internal phosphodiester linkages. In addition to the formation of mixed anhydrides, the subsequent intramolecular acyl or phosphoryl transfers taking place at the 3’-terminus are considered to be particularly relevant to the common prebiotic chemistry of α-amino acids and nucleotides. PMID:27534830

  3. Separation of maleic anhydride grafted polypropylene using multidimensional high-temperature liquid chromatography.

    PubMed

    Prabhu, K N; Macko, T; Brüll, R; Remerie, K; Tacx, J; Garg, P; Ginzburg, A

    2016-04-01

    Functionalization addresses a property gap of polyolefins and opens new perspectives due to improved surface properties in applications like composites (e.g., glass fiber reinforced polypropylene) and anti-corrosive coatings for metals. Various techniques have been developed to characterize functionalized polyolefins, yet no analytical approach addressing their chemical heterogeneity exists. Using High Temperature Size Exclusion Chromatography (HT-SEC) coupled to infrared spectroscopy we could show for two model samples of polypropylene grafted maleic anhydride (PP-g-MA), differing in their nominal MA content, that the grafting density increases with decreasing molar mass. Crystallization Analysis Fractionation (CRYSTAF) does not enable to separate these samples according to their composition to the extent required. Yet, when using High Temperature High Performance Liquid Chromatography (HT-HPLC), with either silica gel or Mica as stationary phase and a gradient mobile phase, a deformulation into a grafted and a non-grafted fraction could be achieved. This was confirmed by analyzing the eluted fractions by infrared spectroscopy. Hyphenating the separation according to composition with a separation according to molar mass (HT-HPLC x HT-SEC) enabled for the first time to reveal the bivariate distribution of PP-g-MA with regard to the molar mass and composition. Using on-line infrared detection quantitative information on the compositional and molar mass parameters of the individual fractions could be obtained. PMID:26961914

  4. Granular size of potato starch affects structural properties, octenylsuccinic anhydride modification and flowability.

    PubMed

    Wang, Chan; Tang, Chuan-He; Fu, Xiong; Huang, Qiang; Zhang, Bin

    2016-12-01

    Native potato starch (PS) granules were separated into three size fractions: larger than 30μm (P-L), 15-30μm (P-M), and smaller than 15μm (P-S). The morphological and crystalline structure of fractionated potato starches were investigated by light and scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The P-L fraction showed ellipsoidal shape and B-type X-ray pattern, whereas the P-S fraction had spherical shape and A-type pattern. The fluorophore-assisted capillary electrophoresis data showed that the P-L fraction had more B2 chains and less short A and B1 chains than the P-S counterparts. Smaller granules with larger specific surface area had higher degree of substitution when reacted with octenylsuccinic anhydride (OSA), and showed more uniform distribution of octenylsuccinate substituents. Both OSA modified and unmodified P-S samples showed higher flowability compared with the P-L counterparts. PMID:27374555

  5. The use of maleic anhydride for the reversible blocking of amino groups on polypeptide chains

    PubMed Central

    Butler, P. J. G.; Harris, J. I.; Hartley, B. S.; Leberman, R.

    1969-01-01

    1. Maleic anhydride was shown to react rapidly and specifically with amino groups of proteins and peptides. Complete substitution of chymotrypsinogen was achieved under mild conditions and the extent of reaction could be readily determined from the spectrum of the maleyl-protein. 2. Maleyl-proteins are generally soluble and disaggregated at neutral pH. Trypsin splits the blocked proteins only at arginine residues and there is frequently selectivity in this cleavage, e.g. in yeast alcohol dehydrogenase and pig glyceraldehyde 3-phosphate dehydrogenase. 3. The group is removed by intramolecular catalysis at acid pH. The half-time was 11–12hr. at 37° at pH3·5 in ∈-maleyl-lysine or in maleyl-chymotrypsinogen. 4. The unblocking reaction can be used as the basis for a `diagonal'-electrophoretic separation of lysine peptides and N-terminal peptides, as shown by studies with β-melanocyte-stimulating hormone. PMID:5821728

  6. Dinuclear Zinc Salen Catalysts for the Ring Opening Copolymerization of Epoxides and Carbon Dioxide or Anhydrides.

    PubMed

    Thevenon, Arnaud; Garden, Jennifer A; White, Andrew J P; Williams, Charlotte K

    2015-12-21

    A series of four dizinc complexes coordinated by salen or salan ligands, derived from ortho-vanillin and bearing (±)-trans-1,2-diaminocyclohexane (L1) or 2,2-dimethyl-1,3-propanediamine (L2) backbones, is reported. The complexes are characterized using a combination of X-ray crystallography, multinuclear NMR, DOSY, and MALDI-TOF spectroscopies, and elemental analysis. The stability of the dinuclear complexes depends on the ligand structure, with the most stable complexes having imine substituents. The complexes are tested as catalysts for the ring-opening copolymerization (ROCOP) of CO2/cyclohexene oxide (CHO) and phthalic anhydride (PA)/CHO. All complexes are active, and the structure/activity relationships reveal that the complex having both L2 and imine substituents displays the highest activity. In the ROCOP of CO2/CHO its activity is equivalent to other metal salen catalysts (TOF = 44 h(-1) at a catalyst loading of 0.1 mol %, 30 bar of CO2, and 80 °C), while for the ROCOP of PA/CHO, its activity is slightly higher than other metal salen catalysts (TOF = 198 h(-1) at a catalyst loading of 1 mol % and 100 °C). Poly(ester-block-carbonate) polymers are also afforded using the most active catalyst by the one-pot terpolymerization of PA/CHO/CO2. PMID:26605983

  7. Cantharidin and Its Anhydride-Modified Derivatives: Relation of Structure to Insecticidal Activity

    PubMed Central

    Sun, Wenbo; Liu, Zhongyi; Zhang, Yalin

    2013-01-01

    Cantharidin is a natural compound of novel structure with ideal insecticidal activity. However, the relationship of structure to insecticidal activity of cantharidin and its derivatives has not been ever clarified. To explore what determines the insecticidal activity structurally of cantharidin-related compounds, two series target compounds 6 and 7 were synthesized by replacing the anhydride ring of norcantharidin with an aromatic amine or fatty amine with different electron density, respectively. The structures of these compounds were characterized by 1H NMR, 13C NMR and HRMS-ESI. A bioassay showed that compounds 6 (a–m) lacked any larvicidal activity against Plutella xylostella; whereas their ring-opened partners 7 (a–m) provided a variety of larvicidal activities against P. xylostella, and compound 7f indicated the highest larvicidal activity with LC50 value of 0.43 mM. The present work demonstrated that the form of the compound (cyclic or ring-opened) or their ability to hydrolyze facilely was the key to determine whether it exhibits larvicidal activity. Moreover, it revealed that the improvement of insecticidal activity required a reasonable combination of both aliphatic amide and aromatic amide moieties, and the type of substituent Y on the aniline ring was critical. PMID:23344017

  8. Highly carbonylated cellulose nanofibrous membranes utilizing maleic anhydride grafting for efficient lysozyme adsorption.

    PubMed

    Ma, Juncheng; Wang, Xueqin; Fu, Qiuxia; Si, Yang; Yu, Jianyong; Ding, Bin

    2015-07-22

    Construction of adsorptive materials for simple, efficient, and high-throughput adsorption of proteins is critical to meet the great demands of highly purified proteins in biotechnological and biopharmaceutical industry; however, it has proven extremely challenging. Here, we report a cost-effective strategy to create carbonyl groups surface-functionalized nanofibrous membranes under mild conditions for positively charged protein adsorption. Our approach allows maleic anhydride to in situ graft on cellulose nanofibrous membranes (CMA) to construct adsorptive membranes with large surface area and tortuous porous structure. Thereby, the resultant CMA membranes exhibited high adsorption capacity of 160 mg g(-1), fast equilibrium within 12 h, and good reversibility to lysozyme. Moreover, the dynamic adsorption was performed under low pressure-drops (750 Pa), with a relatively high saturation adsorption amount of 118 mg g(-1), which matched well with the requirements for proteins purification. Considering the excellent adsorption performance of the as-prepared adsorptive membranes, this simple and intriguing approach may pave a way for the design and development of robust and cost-effective adsorption membranes to meet the great demands for fast and efficient adsorption of positively charged proteins.

  9. Anhydrous formic acid and acetic anhydride as solvent or additive in nonaqueous titrations.

    PubMed

    Buvári-Barcza, A; Tóth, I; Barcza, L

    2005-09-01

    The use and importance of formic acid and acetic anhydride (Ac2O) is increasing in nonaqueous acid-base titrations, but their interaction with the solutes is poorly understood. This paper attempts to clarify the effect of the solvents; NMR and spectrophotometric investigations were done to reveal the interactions between some bases and the mentioned solvents. Anhydrous formic acid is a typical protogenic solvent but both the relative permittivity and acidity are higher than those of acetic acid (mostly used in assays of bases). These differences originate from the different chemical structures: liquid acetic acid contains basically cyclic dimers while formic acid forms linear associates. Ac2O is obviously not an acidic but an aprotic (very slightly protophilic) solvent, which supposedly dissociates slightly into acetyl (CH3CO+) and acetate (AcO-) ions. In fact, some bases react with Ac2O forming an associate: the Ac+ group is bound to the delta- charged atom of the reactant while AcO- is associated with the delta+ group at appropriate distance.

  10. Reactive blending of thermoplastic starch and polyethylene-graft-maleic anhydride with chitosan as compatibilizer.

    PubMed

    Jantanasakulwong, Kittisak; Leksawasdi, Noppol; Seesuriyachan, Phisit; Wongsuriyasak, Somchai; Techapun, Charin; Ougizawa, Toshiaki

    2016-11-20

    Cassava starch was melt-blended with glycerol (70/30wt%/wt%) at 140°C to prepare thermoplastic starch (TPS). Chitosan (CTS) was premixed with starch and glycerol, in acidified water (lactic acid 2wt%), at 1, 5 and 10wt%/wt%. TPS/CTS was then melt-blended (160°C) with polyethylene-graft-maleic anhydride (PE-MAH). Phase determination and scanning electron microscopy indicated TPS/PE-MAH/CTS had a co-continuous morphology and CTS-induced phase inversion to give dispersed PE-MAH particles in a TPS matrix. Tensile strength at break and elongation, melt viscosity, fracture toughness and water contact angle of TPS/PE-MAH were improved by CTS incorporation. TPS/PE-MAH/CTS blends decreased the melting temperature of TPS and PE-MAH compared to the neat polymers. FTIR confirmed a reaction had occurred between amino groups (NH2) of CTS and the MAH groups of PE-MAH. This reaction and the enhanced miscibility between TPS and CTS improved the mechanical properties of the TPS/PE-MAH/CTS blend, particularly at 5wt%/wt% CTS. PMID:27561475

  11. Concurrent release of admixed antimicrobials and salicylic acid from salicylate-based poly(anhydride-esters).

    PubMed

    Johnson, Michelle L; Uhrich, Kathryn E

    2009-12-01

    A polymer blend consisting of antimicrobials (chlorhexidine, clindamycin, and minocycline) physically admixed at 10% by weight into a salicylic acid-based poly (anhydride-ester) (SA-based PAE) was developed as an adjunct treatment for periodontal disease. The SA-based PAE/antimicrobial blends were characterized by multiple methods, including contact angle measurements and differential scanning calorimetry. Static contact angle measurements showed no significant differences in hydrophobicity between the polymer and antimicrobial matrix surfaces. Notable decreases in the polymer glass transition temperature (T(g)) and the antimicrobials' melting points (T(m)) were observed indicating that the antimicrobials act as plasticizers within the polymer matrix. In vitro drug release of salicylic acid from the polymer matrix and for each physically admixed antimicrobial was concurrently monitored by high pressure liquid chromatography during the course of polymer degradation and erosion. Although the polymer/antimicrobial blends were immiscible, the initial 24 h of drug release correlated to the erosion profiles. The SA-based PAE/antimicrobial blends are being investigated as an improvement on current localized drug therapies used to treat periodontal disease.

  12. Molecular and crystal structure of n-hexyloxybenzoic anhydride at low and room temperatures

    SciTech Connect

    Konstantinov, I. I.; Churakov, A. V.; Kuz'mina, L. G.

    2010-09-15

    The crystal and molecular structures of n-hexyloxybenzoic anhydride, C{sub 6}H{sub 13}-O-C{sub 6}H{sub 4}-C(O)-O-C(O)-C{sub 6}H{sub 4}-C{sub 6}H{sub 13}, at low (120 K) and room (296 K) temperatures have been investigated. The molecule has an asymmetric bent structure. The dihedral angle between the benzene ring planes is 48.5 deg. The aliphatic chain on one side of the molecule has a transoid orientation with respect to the 'internal' C4 atom of the closest benzene ring, whereas the aliphatic chain on the other side has a cissoid orientation with respect to the analogous C(4A) atom. The crystal packing does not exhibit any pronounced separation of the crystal space into closely packed aromatic or loosely packed aliphatic regions. No weak directional interactions are observed in the packing; this fact explains the absence of liquid-crystal properties for this compound.

  13. Effect of the degree of substitution of octenyl succinic anhydride-banana starch on emulsion stability.

    PubMed

    Bello-Pérez, Luis A; Bello-Flores, Christopher A; Nuñez-Santiago, María del Carmen; Coronel-Aguilera, Claudia P; Alvarez-Ramirez, J

    2015-11-01

    Banana starch was esterified with octenylsuccinic anhydride (OSA) at different degree substitution (DS) and used to stabilize emulsions. Morphology, emulsion stability, emulsification index, rheological properties and particle size distribution of the emulsions were tested. Emulsions dyed with Solvent Red 26 showed affinity for the oil phase. Backscattering light showed three regions in the emulsion where the emulsified region was present. Starch concentration had higher effect in the emulsification index (EI) than the DS used in the study because similar values were found with OSA-banana and native starches. However, OSA-banana presented greater stability of the emulsified region. Rheological tests in emulsions with OSA-banana showed G'>G" values and low dependence of G' with the frequency, indicating a dominant elastic response to shear. When emulsions were prepared under high-pressure conditions, the emulsions with OSA-banana starch with different DS showed a bimodal distribution of particle size. The emulsion with OSA-banana starch and the low DS showed similar mean droplet diameter than its native counterpart. In contrast, the highest DS led to the highest mean droplet diameter. It is concluded that OSA-banana starch with DS can be used to stabilize specific emulsion types.

  14. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride.

    PubMed

    Li, Conghu; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-10-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen.

  15. Catalyst optimization strategy: selective oxidation of o-xylene to phthalic anhydride.

    PubMed

    Wöelk, Hans-Jörg; Mestl, Gerhard

    2012-02-01

    The oxidation of o-xylene and/or naphthalene to phthalic anhydride is one of the important industrial processes based on catalytic selective oxidation reactions. Vanadia--titania catalysts have been used in the industrial phthalic anyhdride process for the last 50 years. The operation parameters like the temperature range of operation, reactor inlet pressures, contact times, o-xylene loadings, etc. were constantly improved during this period of continuous process optimization so as to optimize catalyst performance and increase its life time. However, a fundamental understanding of the mutual interaction of the rather complex reaction network and the catalyst formulation is still missing. Recently, a detailed study of by-product formation as function of process conditions allowed us to develop a novel, improved reaction scheme for the catalytic oxidation of o-xylene. Based on this understanding, a detailed investigation was conducted for the first time of the by-product formation under varying operation conditions and as a function of the active mass variation exploiting high-throughput, as well as bench scales reactors. This high-throughput testing allowed us to relate reaction kinetics to novel catalyst formulations.

  16. Reaction of octenylsuccinic anhydride with a mixture of granular starch and soluble maltodextrin.

    PubMed

    Bai, Yanjie; Shi, Yong-Cheng

    2013-11-01

    The reaction of octenylsuccinic anhydride (OSA) with a mixture of granular waxy maize starch and soluble maltodextrin was investigated. OSA was reacted with a 1:1 (w/w) mixture of the granular starch and maltodextrin at OSA levels of 1.5, 3, 9, and 15% (wt% based on starch weight). After the first 0.5h of the reaction, degree of substitution (DS) on maltodextrin reached 0.021, 0.030, 0.080, and 0.10 for 1.5, 3, 9, and 15% OSA, respectively, whereas DS for granular starch was only 0.0020, 0.0087, 0.014, and 0.016. At 2h of the reaction, the bound OS ratio of maltodextrin to granular starch was 10.8 when OSA concentration was 1.5% and the ratio decreased to ca. 5 at higher OSA concentrations. OSA preferred to react with maltodextrin than semi-crystalline granular starch when both existed in the system. OSA reacted with maltodextrin at a much faster rate and to a greater extent than with granular starch, but a significant amount of OSA reacted with granular starch at 3-15% OSA concentrations.

  17. Development of emulsifying property in Persian gum using octenyl succinic anhydride (OSA).

    PubMed

    Mohammadi, S; Abbasi, S; Scanlon, M G

    2016-08-01

    In the present study, the influence of octenyle succinic anhydride (OSA),gum concentration, pH, temperature and reaction time on esterification of Persian gum (PG), and its soluble (SFPG) and insoluble (IFPG) fractions, were investigated by response surface methodology (RSM) in order to optimize the reaction conditions based on the degree of substitution (DS). The individual effect of all independent variables as well as the interactive effects of temperature-OSA concentration, and OSA-PG concentrations on DS was significant. However, the latter interactive effect (OSA-SFPG) was not significant in case of SFPG. The IFPG did not have any esterification reaction with OSA. The highest DS for PG and SFPG were 0.0285 and 0.0303 at the optimal conditions, respectively. The FTIR spectrums also confirmed the carbonyl group attachment in OSA-PG and OSA-SFPG. The enhancement of emulsifying capability was also confirmed by ECI and EAI values, microscopic images as well as rheological measurements. PMID:27138859

  18. Analysis of octenylsuccinate rice and tapioca starches: Distribution of octenylsuccinic anhydride groups in starch granules.

    PubMed

    Whitney, Kristin; Reuhs, Bradley L; Ovando Martinez, Maribel; Simsek, Senay

    2016-11-15

    Characterization of the fine structure of octenylsuccinic anhydride (OSA) starch would lead to a better understanding of functional properties. OSA rice and tapioca starches were analyzed using microscopy, liquid chromatography and nuclear magnetic resonance. Chain length distribution of amylopectin changed significantly (P<0.05) after OSA esterification. Weight averaged degree of polymerization (DPw) decreased significantly (P<0.05) from 16.47 to 13.29 and from 14.87 to 12.47 in native and OSA rice and tapioca starches, respectively. The chain length distribution of pure amylopectin fractions suggested that OSA groups were not present in the amylopectin portion of the starch. (1)H NMR analysis of pure amylose and amylopectin fractions indicated that OSA substitution was present only in amylose fractions of rice and tapioca starches. Esterification with 3% OSA results in starch that has OSA substituted mainly on amylose chains or possibly on amylopectin chains that have been hydrolyzed from the amylopectin molecules during esterification. PMID:27283674

  19. Microwave measurements of the spectra and molecular structure for phthalic anhydride

    NASA Astrophysics Data System (ADS)

    Pejlovas, Aaron M.; Sun, Ming; Kukolich, Stephen G.

    2014-05-01

    The microwave rotational spectrum for phthalic anhydride (PhA) has been measured in the 4-14 GHz microwave region using a pulsed-beam Fourier transform (PBFT) Flygare-Balle type microwave spectrometer. Initially, the molecular structure was calculated using Gaussian 09 suite with mp2/6-311++G** basis and the calculations were used in predicting spectra for the measured isotopologues. The experimental rotational transition frequencies were measured and used to calculate the rotational and centrifugal distortion constants. The rotational constants for the normal isotopologue, four unique 13C substituted isotopologues and two 18O isotologues, were used in a least squares fit to determine nearly all structural parameters for this molecule. Since no substitutions were made at hydrogen sites, the calculated positions of the hydrogen atoms relative to the bonded carbon atoms were used in the structure determination. The rotational constants for the parent isotopologue were determined to be A = 1801.7622(9) MHz, B = 1191.71816(26) MHz, C = 717.44614(28) MHz. Small values for the centrifugal distortion constants were obtained; DJ = 0.0127 kHz, DJK = 0.0652 kHz, and DK = -0.099 kHz, indicating a fairly rigid structure. The structure of PhA is planar with a negative inertial defect of Δ = -0.154 amu Å2. Structural parameters from the mp2 and DFT calculations are in quite good agreement with measured parameters.

  20. Thermodynamic and kinetic evaluation of the polymerization process of epoxidized biodiesel with dicarboxylic anhydride

    NASA Astrophysics Data System (ADS)

    da Roza, Miriam B.; Nicolau, Aline; Angeloni, Luiz M.; Sidou, Pedro N.; Samios, Dimitrios

    2012-06-01

    This paper reports on a polymerization study of the epoxidized methyl esters (EME) obtained from soybean oil, with phthalic anhydride (PA) and 2-methyl-imidazole in the presence of soybean oil biodiesel (BD) as solvent. The gelation region for the system EME/PA/2MI without BD was determined using the Flory's theory occurring between X EME = 0.33 to 0.54. The evaluation of the polymerization enthalpy (ΔH) indicates that the experimental stoichiometric composition of the system EME/PA/2MI without solvent is near to X EME = X PA = 0.5. ΔH values higher than 76 J/g were observed for samples located in the theoretical gelation region. Different polymers were produced using the stoichiometric composition and varying only the amount of BD. Kinetics and thermodynamics of the polymerization reaction, using solvent, were evaluated by DSC technique. The results show that BD acts as solvent in the polymerization reaction and a compensation effect between activation energy and logarithm of pre-exponential factor was observed. Thermogravimetric analysis indicated that the degradations of the products include two well-defined processes. The compensation effect was observed in the thermal degradation kinetics too.

  1. Radiation grafting of maleic anhydride onto polypropylene in solid state via ultrafine blend

    NASA Astrophysics Data System (ADS)

    Tan, Xiumin

    2014-05-01

    A novel method to prepare maleic anhydride grafting onto poly (propylene) (PP-g-MAH) was described. It was performed by γ-irradiation in solid state via ultrafine blend in the absence of any initiator and the grafting mechanism was proposed based on the experimental results. First, ultrafine blend of MAH and PP was prepared through ultrasonic initiation in melt state and then cooled rapidly. Second, the blend was radiated by γ-irradiation in the circumstance of atmosphere. Effects of irradiation dose and MAH concentration on the amount of grafted MAH were investigated. Compared with the conventional solid-state radiation grafting method, PP-g-MAH obtained via this method shows a higher graft rate of MAH. This novel method also has the advantages of solventless, energy efficient, low cost and simple operation. Furthermore, it is very easy to get purified products. The molecular structures of grafted copolymer were characterized by Fourier-transform infrared spectroscopy. Differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscope were used to determine the degree of crystallinity and crystalline structure.

  2. Dodecenylsuccinic anhydride derivatives of gum karaya (Sterculia urens): preparation, characterization, and their antibacterial properties.

    PubMed

    Padil, Vinod Vellora Thekkae; Senan, Chandra; Černík, Miroslav

    2015-04-15

    Esterifications of the tree-based gum, gum karaya (GK), using dodecenylsuccinic anhydride (DDSA) were carried out in aqueous solutions. GK was deacetylated using alkali treatment to obtain deacetylated gum karaya (DGK). The DGK and its DDSA derivative were characterized using gel permeation chromatography/multiangle laser light scattering (GPC/MALLS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), proton nuclear magnetic resonance spectroscopy ((1)H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis, and rheological studies. The degree of substitution was found to be 10.25% for DGK using (1)H NMR spectroscopy. The critical aggregation concentration of DDSA-DGK was determined using dye solubilization and surface tension methods. The antibacterial activity of the DDSA-DGK derivative was then investigated against Gram-negative Escherichia coli and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. The DDSA-DGK derivative has the potential for use as a stabilizing agent in food and nonfood applications. It can also be developed as an antibacterial agent. PMID:25797306

  3. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch.

    PubMed

    Bai, Yanjie; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

    2014-06-15

    Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends.

  4. Nano-encapsulation of coenzyme Q10 using octenyl succinic anhydride modified starch.

    PubMed

    Cheuk, Sherwin Y; Shih, Frederick F; Champagne, Elaine T; Daigle, Kim W; Patindol, James A; Mattison, Christopher P; Boue, Stephen M

    2015-05-01

    Octenyl succinic anhydride modified starch (OSA-ST) was used to encapsulate coenzyme Q10 (CoQ10). CoQ10 was dissolved in rice bran oil and incorporated into an aqueous OSA-ST solution. High pressure homogenisation of the mixture was conducted at 170 MPa for 56 cycles. The resulting emulsion had a particle size range of 200-300 nm and the absolute zeta potential varied between 8.4 and 10.6 mV. CoQ10 retention of the emulsion and freeze dried products, determined by a hexane rinse, was 98.2%. Reconstitution of the freeze dried product in Mcllvaine citrate-phosphate buffers with pH values of 3-5 and temperatures at 4 and 25 °C had very little effect on the range and distribution of the nanoparticles' size. The inflection point of the zeta potential and pH plot occurred at the first pKa of succinic acid (pH 4.2), indicating succinate as the main influence over zeta potential.

  5. Effect of the degree of substitution of octenyl succinic anhydride-banana starch on emulsion stability.

    PubMed

    Bello-Pérez, Luis A; Bello-Flores, Christopher A; Nuñez-Santiago, María del Carmen; Coronel-Aguilera, Claudia P; Alvarez-Ramirez, J

    2015-11-01

    Banana starch was esterified with octenylsuccinic anhydride (OSA) at different degree substitution (DS) and used to stabilize emulsions. Morphology, emulsion stability, emulsification index, rheological properties and particle size distribution of the emulsions were tested. Emulsions dyed with Solvent Red 26 showed affinity for the oil phase. Backscattering light showed three regions in the emulsion where the emulsified region was present. Starch concentration had higher effect in the emulsification index (EI) than the DS used in the study because similar values were found with OSA-banana and native starches. However, OSA-banana presented greater stability of the emulsified region. Rheological tests in emulsions with OSA-banana showed G'>G" values and low dependence of G' with the frequency, indicating a dominant elastic response to shear. When emulsions were prepared under high-pressure conditions, the emulsions with OSA-banana starch with different DS showed a bimodal distribution of particle size. The emulsion with OSA-banana starch and the low DS showed similar mean droplet diameter than its native counterpart. In contrast, the highest DS led to the highest mean droplet diameter. It is concluded that OSA-banana starch with DS can be used to stabilize specific emulsion types. PMID:26256319

  6. Synthesis and characterization of new VPO catalysts for partial n-butane oxidation to maleic anhydride

    SciTech Connect

    Batis, N.H.; Batis, H. ); Ghorbell, A.; Vedrine, J.C.; Volta, J.C. )

    1991-03-01

    In order to try to control the V{sup 4+}/V{sup 5+} ratio of VPO catalysts for butane oxidation to maleic anhydride, a new method of preparation of these catalysts has been developed: it consists of the reaction of VC1{sub 3} (V{sup 3+}) with V{sub 2}O{sub 5} (V{sup 5+}) for the preparation of the precursor. Two series of catalysts have been prepared in aqueous and organic media. The V{sup 3+}/V{sup 5+} ratio has been varied and its influence on the physicochemical features and on the catalytic properties of the catalysts has been studied. The best catalysts in both preparation media correspond to V{sup 3+}/V{sup 5+} = 1 in the starting material. Catalysts have been characterized using X-ray diffraction, infrared spectroscopy, UV diffuse reflectance, Raman spectroscopy, {sup 31}P MAS NMR, and XPS techniques. The combination of all these techniques let the authors to conclude that the best catalyst consisted of an oxidized surface ({gamma}-VOPO{sub 4}) (V{sup 5+}) in interaction with reduced matrix ((VO){sub 2}P{sub 2}O{sub 7}) (V{sup 4+}).

  7. Locally delivered salicylic acid from a poly(anhydride-ester): impact on diabetic bone regeneration.

    PubMed

    Wada, Keisuke; Yu, Weiling; Elazizi, Mohamad; Barakat, Sandrine; Ouimet, Michelle A; Rosario-Meléndez, Roselin; Fiorellini, Joseph P; Graves, Dana T; Uhrich, Kathryn E

    2013-10-10

    Diabetes mellitus (DM) involves metabolic changes that can impair bone repair, including a prolonged inflammatory response. A salicylic acid-based poly(anhydride-ester) (SA-PAE) provides controlled and sustained release of salicylic acid (SA) that locally resolves inflammation. This study investigates the effect of polymer-controlled SA release on bone regeneration in diabetic rats where enhanced inflammation is expected. Fifty-six Sprague-Dawley rats were randomly assigned to two groups: diabetic group induced by streptozotocin (STZ) injection or normoglycemic controls injected with citrate buffer alone. Three weeks after hyperglycemia development or vehicle injection, 5mm critical sized defects were created at the rat mandibular angle and treated with SA-PAE/bone graft mixture or bone graft alone. Rats were euthanized 4 and 12weeks after surgery, then bone fill percentage in the defect region was assessed by micro-computed tomography (CT) and histomorphometry. It was observed that bone fill increased significantly at 4 and 12weeks in SA-PAE/bone graft-treated diabetic rats compared to diabetic rats receiving bone graft alone. Accelerated bone formation in normoglycemic rats caused by SA-PAE/bone graft treatment was observed at 4weeks but not at 12weeks. This study shows that treatment with SA-PAE enhances bone regeneration in diabetic rats and accelerates bone regeneration in normoglycemic animals.

  8. Separation of maleic anhydride grafted polypropylene using multidimensional high-temperature liquid chromatography.

    PubMed

    Prabhu, K N; Macko, T; Brüll, R; Remerie, K; Tacx, J; Garg, P; Ginzburg, A

    2016-04-01

    Functionalization addresses a property gap of polyolefins and opens new perspectives due to improved surface properties in applications like composites (e.g., glass fiber reinforced polypropylene) and anti-corrosive coatings for metals. Various techniques have been developed to characterize functionalized polyolefins, yet no analytical approach addressing their chemical heterogeneity exists. Using High Temperature Size Exclusion Chromatography (HT-SEC) coupled to infrared spectroscopy we could show for two model samples of polypropylene grafted maleic anhydride (PP-g-MA), differing in their nominal MA content, that the grafting density increases with decreasing molar mass. Crystallization Analysis Fractionation (CRYSTAF) does not enable to separate these samples according to their composition to the extent required. Yet, when using High Temperature High Performance Liquid Chromatography (HT-HPLC), with either silica gel or Mica as stationary phase and a gradient mobile phase, a deformulation into a grafted and a non-grafted fraction could be achieved. This was confirmed by analyzing the eluted fractions by infrared spectroscopy. Hyphenating the separation according to composition with a separation according to molar mass (HT-HPLC x HT-SEC) enabled for the first time to reveal the bivariate distribution of PP-g-MA with regard to the molar mass and composition. Using on-line infrared detection quantitative information on the compositional and molar mass parameters of the individual fractions could be obtained.

  9. Role of mast cell in the late phase of contact hypersensitivity induced by trimellitic anhydride

    PubMed Central

    Chai, Ok Hee

    2015-01-01

    Mast cells are known as effector cells of IgE-mediated allergic responses, but role of mast cells in contact hypersensitivity (CHS) has been considered controversial. In this study, we investigated role of mast cell in trimellitic anhydride (TMA)-induced CHS. The mice were sensitized to TMA on the back and repeatedly challenged with TMA on the left ear at 1-week intervals. The ear after challenge showed biphasic responses. The repetition of TMA challenge shifted in time course of ear response and enlarged the extent of early and late phase reactions in proportion to the frequency of TMA challenges in C57BL/6 mice. In late phase reaction, peak of ear response by single challenge showed at 24 hours after challenge, but the peak by repeat challenges at 8 hours after the last challenge. Number of mast cells and eosinophils per unit area increased in proportion to frequency of TMA challenges. However, mast cell-deficient WBB6F1/J-KitW/KitW-v mice developed the late phase reaction without the early phase reaction. The repetition of TMA challenge shifted in time course of ear response and enlarged the extent of ear response and the infiltration of eosinophils. The magnitude of these responses observed according to the frequency of the TMA challenge in mast cell-deficient WBB6F1/J-KitW/KitW-v mice was significantly lower than that in C57BL/6 mice. Also TMA elicited mast cell degranulation and histamine release from rat peritoneal mast cells in a concentration-dependent manner. Conclusively, TMA induces the early and late phase reactions in CHS, and mast cells may be required for TMA-induced CHS. PMID:26770872

  10. Evaporative Derivatization of Phenols with 2-Sulfobenzoic Anhydride for Detection by MALDI-MS

    PubMed Central

    Yao, Yuanyuan; Wang, Poguang; Giese, Roger

    2014-01-01

    RATIONALE Phenols are an important class of analytes, for example as bioactive environmental contaminants. Towards a goal of improving their detection by MALDI-TOF-MS or MALDI-TOF/TOF-MS, we studied their derivatization with 2-sulfobenzoic anhydride (SBA). We chose SBA for this purpose since it is commercially available, inexpensive, and forms an anionic derivative. METHODS In selected conditions developed here for phenols, a reaction mixture of one or more of such compounds in acetonitrile containing SBA and 4-dimethylaminopyridine (DMAP) is evaporated to a solid, heated at 60°C for 1 h, redissolved in 50% acetonitrile containing matrix, spotted onto a MALDI target, and subjected to negative ion MALDI-TOF/TOF-MS. RESULTS While conventional (solution-phase) reaction of 4-phenylphenol (model analyte) with SBA and DMAP only gave a 47% yield of SBA-tagged 4-phenylphenol, evaporative derivatization as above gave a 96% yield, and 25 pmol (4.3 ng) of 4-phenylphenol could be detected in this way by MALDI-TOF/TOF-MS at S/N = 260, whereas even 1 nmol of the nonderivatized phenol was not detected in the absence of derivatization. A wide range of responses was observed when a mixture of 15 phenols was derivatized, with the higher responses coming from phenols with a pKa value above 9. Without derivatization, phenols with pKa values below 5 were the most readily detected. CONCLUSION Evaporative derivatization with SBA (a convenient reagent) can improve the detection of phenols with relatively high pKa values (above 9) by negative ion MALDI-TOF-MS, and accomplish this in the absence of post-derivatization reaction cleanup. PMID:24519828

  11. Therapeutic effect of ethyl acetate extract from Asparagus cochinchinensis on phthalic anhydride-induced skin inflammation.

    PubMed

    Sung, Ji-Eun; Lee, Hyun-Ah; Kim, Ji-Eun; Go, Jun; Seo, Eun-Ji; Yun, Woo-Bin; Kim, Dong-Seob; Son, Hong-Joo; Lee, Chung-Yeoul; Lee, Hee-Seob; Hwang, Dae-Youn

    2016-03-01

    Asparagus cochinchinensis has been used to treat various diseases including fever, cough, kidney disease, breast cancer, inflammatory disease and brain disease, while IL-4 cytokine has been considered as key regulator on the skin homeostasis and the predisposition toward allergic skin inflammation. However, few studies have investigated its effects and IL-4 correlation on skin inflammation to date. To quantitatively evaluate the suppressive effects of ethyl acetate extracts of A. cochinchinensis (EaEAC) on phthalic anhydride (PA)-induced skin inflammation and investigate the role of IL-4 during their action mechanism, alterations in general phenotype biomarkers and luciferase-derived signals were measured in IL-4/Luc/CNS-1 transgenic (Tg) mice with PA-induced skin inflammation after treatment with EaEAC for 2 weeks. Key phenotype markers including lymph node weight, immunoglobulin E (IgE) concentration, epidermis thickness and number of infiltrated mast cells were significantly decreased in the PA+EaEAC treated group compared with the PA+Vehicle treated group. In addition, expression of IL-1β and TNF-α was also decreased in the PA+EaEAC cotreated group, compared to PA+Vehicle treated group. Furthermore, a significant decrease in the luciferase signal derived from IL-4 promoter was detected in the abdominal region, submandibular lymph node and mesenteric lymph node of the PA+EaEAC treated group, compared to PA+Vehicle treated group. Taken together, these results suggest that EaEAC treatment could successfully improve PA-induced skin inflammation of IL-4/Luc/CNS-1 Tg mice, and that IL-4 cytokine plays a key role in the therapeutic process of EaEAC. PMID:27051441

  12. Impact of dual-enzyme treatment on the octenylsuccinic anhydride esterification of soluble starch nanoparticle.

    PubMed

    Lu, Keyu; Miao, Ming; Ye, Fan; Cui, Steve W; Li, Xingfeng; Jiang, Bo

    2016-08-20

    The hypothesis of improving the esterification of sugary maize soluble starch through dual-enzyme pretreatment was investigated. Native starch nanoparticle (NSP) was enzymatically pretreated using β-amylase and transglucosidase (ESP) and then esterified with octenylsuccinic anhydride (OSA). The degree of substitution (DS), reaction efficiency (RE), molecular weight (Mw), molecular density (ρ) and in vitro digestibility were determined. Fourier transform infrared spectroscopy and confocal laser scanning microscopy were used to analyze starch particle and its OS derivatives. The emulsification properties of OS-NSP and OS-ESP were also compared. The results showed that dual-enzyme modification increased the DS and RE of OSA modified starch particle compared with the control. Enzymatic modification had a thinning effect at the surface of starch particle, resulting in lower Mw. The extent of reduction in ρ of OS-ESP was greater than that of OS-NSP. At equivalent DS, OSA modification of EPS was more effective than that of NPS in reducing digestibility. Also, there was brighter fluorescence spheres of OS-ESP in comparison to OS-NSP at equivalent DS, suggesting more OS groups were substituted on the chains near the branch points at less density areas. OS-ESP with higher DS (0.0197) had lower zeta-potential and average particle size for superior emulsion stabilization properties with high stability. The results revealed the OS-starch prepared under dual-enzyme pretreatment was a Pickering particle stabilizer for potential application in encapsulation and delivery of bioactive components. PMID:27178945

  13. Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride

    PubMed Central

    Timgren, Anna; Rayner, Marilyn; Dejmek, Petr; Marku, Diana; Sjöö, Malin

    2013-01-01

    Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous phase, both with and without salt in a phosphate buffer, was also studied. Quinoa, which had the smallest granule size, had the best capacity to stabilize oil drops, especially when the granules had been hydrophobically modified by heat treatment or by OSA. The average drop diameter (d32) in these emulsions varied from 270 to 50 μm, where decreasing drop size and less aggregation was promoted by high starch concentration and absence of salt in the system. Of all the starch varieties studied, quinoa had the best overall emulsifying capacity, and OSA modified quinoa starch in particular. Although the size of the drops was relatively large, the drops themselves were in many instances extremely stable. In the cases where the system could stabilize droplets, even when they were so large that they were visible to the naked eye, they remained stable and the measured droplet sizes after 2 years of storage were essentially unchanged from the initial droplet size. This somewhat surprising result has been attributed to the thickness of the adsorbed starch layer providing steric stabilization. The starch particle-stabilized Pickering emulsion systems studied in this work has potential practical application such as being suitable for encapsulation of ingredients in food and pharmaceutical products. PMID:24804025

  14. Elucidation of substituted ester group position in octenylsuccinic anhydride modified sugary maize soluble starch.

    PubMed

    Ye, Fan; Miao, Ming; Huang, Chao; Lu, Keyu; Jiang, Bo; Zhang, Tao

    2014-12-01

    The octenylsuccinic groups in esterification-modified sugary maize soluble starches with a low (0.0191) or high (0.0504) degree of substitution (DS) were investigated by amyloglucosidase hydrolysis followed by a combination of chemical and physical analysis. The results showed the zeta-potential remained at approximately the same value regardless of excessive hydrolysis. The weight-average molecular weight decreased rapidly and reached 1.22 × 10(7) and 1.60 × 10(7) g/mol after 120 min for low-DS and high-DS octenylsuccinic anhydride (OSA) modified starch, respectively. The pattern of z-average radius of gyration as well as particle size change was similar to that of Mw, and z-average radius of gyration decreased much more slowly, especially for high-DS OSA starch. Compared to native starch, two characteristic absorption peaks at 1726.76 and 1571.83 cm(-1) were observed in FT-IR spectra, and the intensity of absorption peaks increased with increasing DS. The NMR results showed that OSA starch had several additional peaks at 0.8-3.0 ppm and a shoulder at 5.56 ppm for OSA substituents, which were grafted at O-2 and O-3 positions in soluble starch. The even distribution of OSA groups in the center area of soluble starch particle has been directly shown under CLSM. Most substitutions were located near branching points of soluble starch particles for a low-DS modified starch, whereas the substituted ester groups were located near branching points as well as at the nonreducing ends in OSA starch with a high DS.

  15. Therapeutic effect of ethyl acetate extract from Asparagus cochinchinensis on phthalic anhydride-induced skin inflammation

    PubMed Central

    Sung, Ji-Eun; Lee, Hyun-Ah; Kim, Ji-Eun; Go, Jun; Seo, Eun-Ji; Yun, Woo-Bin; Kim, Dong-Seob; Son, Hong-Joo; Lee, Chung-Yeoul; Lee, Hee-Seob

    2016-01-01

    Asparagus cochinchinensis has been used to treat various diseases including fever, cough, kidney disease, breast cancer, inflammatory disease and brain disease, while IL-4 cytokine has been considered as key regulator on the skin homeostasis and the predisposition toward allergic skin inflammation. However, few studies have investigated its effects and IL-4 correlation on skin inflammation to date. To quantitatively evaluate the suppressive effects of ethyl acetate extracts of A. cochinchinensis (EaEAC) on phthalic anhydride (PA)-induced skin inflammation and investigate the role of IL-4 during their action mechanism, alterations in general phenotype biomarkers and luciferase-derived signals were measured in IL-4/Luc/CNS-1 transgenic (Tg) mice with PA-induced skin inflammation after treatment with EaEAC for 2 weeks. Key phenotype markers including lymph node weight, immunoglobulin E (IgE) concentration, epidermis thickness and number of infiltrated mast cells were significantly decreased in the PA+EaEAC treated group compared with the PA+Vehicle treated group. In addition, expression of IL-1β and TNF-α was also decreased in the PA+EaEAC cotreated group, compared to PA+Vehicle treated group. Furthermore, a significant decrease in the luciferase signal derived from IL-4 promoter was detected in the abdominal region, submandibular lymph node and mesenteric lymph node of the PA+EaEAC treated group, compared to PA+Vehicle treated group. Taken together, these results suggest that EaEAC treatment could successfully improve PA-induced skin inflammation of IL-4/Luc/CNS-1 Tg mice, and that IL-4 cytokine plays a key role in the therapeutic process of EaEAC. PMID:27051441

  16. Sensitivity of Neurospora crassa to a Marine-Derived Aspergillus tubingensis Anhydride Exhibiting Antifungal Activity That Is Mediated by the MAS1 Protein

    PubMed Central

    Koch, Liat; Lodin, Anat; Herold, Inbal; Ilan, Micha; Carmeli, Shmuel; Yarden, Oded

    2014-01-01

    The fungus Aspergillus tubingensis (strain OY907) was isolated from the Mediterranean marine sponge Ircinia variabilis. Extracellular extracts produced by this strain were found to inhibit the growth of several fungi. Among the secreted extract components, a novel anhydride metabolite, tubingenoic anhydride A (1) as well as the known 2-carboxymethyl-3-hexylmaleic acid anhydride, asperic acid, and campyrone A and C were purified and their structure elucidated. Compound 1 and 2-carboxymethyl-3-hexylmaleic acid anhydride inhibited Neurospora crassa growth (MIC = 330 and 207 μM, respectively) and affected hyphal morphology. We produced a N. crassa mutant exhibiting tolerance to 1 and found that a yet-uncharacterized gene, designated mas-1, whose product is a cytosolic protein, confers sensitivity to this compound. The ∆mas-1 strain showed increased tolerance to sublethal concentrations of the chitin synthase inhibitor polyoxin D, when compared to the wild type. In addition, the expression of chitin synthase genes was highly elevated in the ∆mas-1 strain, suggesting the gene product is involved in cell wall biosynthesis and the novel anhydride interferes with its function. PMID:25257783

  17. An Examination of the Chemistry of Peroxycarboxylic Nitric Anhydrides and Related Volatile Organic Compounds During Texas Air Quality Study 2000 Using Ground-Based Measurements

    SciTech Connect

    Roberts, James M.; Jobson, B Tom T.; Kuster, W. C.; Goldan, P. D.; Murphy, Paul; Williams, Eric; Frost, G. J.; Riemer, D.; Apel, Eric; Stroud, C.; Wiedinmyer, Christine; Fehsenfeld, Fred C.

    2003-08-19

    Measurements of peroxycarboxylic nitric anhydrides (PANs) along with related volatile organic compounds (VOCs) were made at the La Porte super site during the TexAQS 2000 Houston study. The PAN mixing ratios ranged up to 6.5 ppbv and were broadly correlated with O3, characteristic of a highly polluted urban environment. The anthropogenic PAN homologue concentrations were generally consistent with those found in other urban environments; peroxypropionic nitric anhydride (PPN) averaged 15%, and peroxyisobutyric nitric anhydride (PiBN) averaged 3% of PAN,. Some periods were noted where local petrochemical sources resulted in anomalous PANs chemistry. This effect was especially noticeable in the case of peroxyacrylic nitric anhydride (APAN) where local sources of 1,3-butadiene and acrolein resulted in APAN as high as 30% of PAN. Peroxymethacrylic nitric anhydride (MPAN) was a fairly minor constituent of the PANs except for two periods on 4 and 5 September when air masses from high biogenic hydrocarbons (BHC) areas were observed. BHC chemistry was not a factor in the highest ozone pollution episodes in Houston but may have an impact on daily average ozone levels in some circumstances.

  18. A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol.

    PubMed

    Pavarelli, Giulia; Velasquez Ochoa, Juliana; Caldarelli, Aurora; Puzzo, Francesco; Cavani, Fabrizio; Dubois, Jean-Luc

    2015-07-01

    We investigated the synthesis of maleic anhydride by oxidehydration of a bio-alcohol, 1-butanol, as a possible alternative to the classical process of n-butane oxidation. A vanadyl pyrophosphate catalyst was used to explore the one-pot reaction, which involved two sequential steps: 1) 1-butanol dehydration to 1-butene, catalysed by acid sites, and 2) the oxidation of butenes to maleic anhydride, catalysed by redox sites. A non-negligible amount of phthalic anhydride was also formed. The effect of different experimental parameters was investigated with chemically sourced 1-butanol, and the results were then confirmed by using genuinely bio-sourced 1-butanol. In the case of bio-1-butanol, however, the purity of the product remarkably affected the yield of maleic anhydride. It was found that the reaction mechanism includes the oxidation of butenes to crotonaldehyde and the oxidation of the latter to either furan or maleic acid, both of which are transformed to produce maleic anhydride.

  19. A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol.

    PubMed

    Pavarelli, Giulia; Velasquez Ochoa, Juliana; Caldarelli, Aurora; Puzzo, Francesco; Cavani, Fabrizio; Dubois, Jean-Luc

    2015-07-01

    We investigated the synthesis of maleic anhydride by oxidehydration of a bio-alcohol, 1-butanol, as a possible alternative to the classical process of n-butane oxidation. A vanadyl pyrophosphate catalyst was used to explore the one-pot reaction, which involved two sequential steps: 1) 1-butanol dehydration to 1-butene, catalysed by acid sites, and 2) the oxidation of butenes to maleic anhydride, catalysed by redox sites. A non-negligible amount of phthalic anhydride was also formed. The effect of different experimental parameters was investigated with chemically sourced 1-butanol, and the results were then confirmed by using genuinely bio-sourced 1-butanol. In the case of bio-1-butanol, however, the purity of the product remarkably affected the yield of maleic anhydride. It was found that the reaction mechanism includes the oxidation of butenes to crotonaldehyde and the oxidation of the latter to either furan or maleic acid, both of which are transformed to produce maleic anhydride. PMID:26073302

  20. Ab initio study of chemical bond interactions between covalently functionalized carbon nanotubes via amide, ester and anhydride linkages

    NASA Astrophysics Data System (ADS)

    Ben Doudou, Bessem; Chen, Jun; Vivet, Alexandre; Poilâne, Christophe

    2016-03-01

    In this paper, we have investigated the chemical bond interactions between covalently functionalized zigzag (5,0) and (8,0) SWCNT-SWCNT via various covalent linkages. Side-to-side junctions connected via amide, ester and anhydride linkages were particularly studied. The geometries and energy of the forming reaction were investigated using first-principles density functional theory. Furthermore, the band structures and the total density of states (DOS) of the junctions have also been analyzed. Our results show that several promising structures could be obtained by using chemical connection strategy and particularly the junctions formed by coupling amino functionalized SWCNT and carboxylic acid functionalized SWCNT was more favorable.

  1. Model vanadium-phosphorus-oxygen catalysts for the selective oxidation of C/sub 4/ hydrocarbons to maleic anhydride

    SciTech Connect

    Moser, T.P.

    1987-06-01

    Two model vanadium-phosphorus-oxygen catalysts, ..beta..-VOPO/sub 4/ and (VO)/sub 2/P/sub 2/O/sub 7/, were investigated for the selective oxidation of C/sub 4/ hydrocarbons to maleic anhydride. In situ laser Raman spectroscopy was used. Complementary techniques including x-ray powder diffraction and x-ray photoelectron spectroscopy were used for characterization of the fresh and used catalytic materials. The direct observation of phase stability and the participation of lattice oxygen during catalysis was possible using the in situ Raman technique. In particular, ..beta..-VOPO/sub 4/ and (VO)/sub 2/P/sub 2/O/sub 7/ demonstrated bulk structural integrity during n-butane oxidation. The relatively greater reducing capacity of 1-butene induced the ..beta..-VOPO/sub 4/ to (VO)/sub 2/P/sub 2/O/sub 7/ phase transformation. Direct structural identification of catalytically active centers for paraffin and olefin oxidation were investigated using an /sup 18/O-enriched ..beta..-VOPO/sub 4/ phase catalyst. Active sites responsible for complete combustion (Site I) and selective oxidation (Site II) were identified. The selective route for 1-butene oxidation involved predominantly Site II centers, while Site I centers were associated with complete combustion. In contrast, n-butane oxidation required the highly active Site I centers for initial activation and for the formation of an intermediate containing two oxygen atoms. Raman band assignments indicated these oxygen sites were associated with PO/sub 4/ units in the ..beta..-VOPO/sub 4/ lattice. Maleic anhydride conversion was particularly sensitive to the catalytic phase present. Significant combustion activity was observed when maleic anhydride was fed directly to an integral flow reactor charged with model catalysts. The combustion activity was least for (VO)/sub 2/P/sub 2/O/sub 7/, nominally a V(IV) phase. The ..beta..-VOPO/sub 4/ catalyst, nominally a V(V) phase, resulted in increased conversions of maleic anhydride.

  2. 1,8-Naphthalic anhydride antidote enhances the toxic effects of captan and thiram fungicides on Azospirillum brasilense cells.

    PubMed

    Gallori, E; Casalone, E; Colella, C M; Daly, S; Polsinelli, M

    1991-01-01

    The effects of ten fungicides, six herbicides and four insecticides on the nitrogen-fixing bacterium Azospirillum brasilense were examined. The fungicides captan and thiram were the most toxic among the compounds tested. Cell growth and nitrogenase activity of the bacterium were markedly inhibited by low concentrations of the two fungicides. Antidote 1,8-naphthalic anhydride increased by a factor of 2 the cellular level of glutathione. The addition of the antidote in the presence of captan or thiram caused a similar increase in the glutathione content, but at the same time enhanced the toxicity of the two fungicides.

  3. A new fluorescence reaction in protein cytochemistry: formation of naphthalimide fluorophores from primary amino groups and 1,8-naphthalic anhydride derivatives.

    PubMed

    Stockert, J C; Trigoso, C I; Braña, M F

    1994-01-01

    In this work we describe the formation of fluorescent naphthalimide derivatives as a new cytochemical method for revealing protein amino groups. The reaction is based on the condensation of 1,8-naphthalic anhydrides in organic solvents with primary aliphatic amines. Under optimal violet-blue (436 nm) excitation, a strong yellow-green emission is observed in specific cell components from blood smears treated with 3-amino-1,8-naphthalic anhydride in N,N-dimethylformamide, which were the most suitable reagent and solvent for microscopic studies. Cytoplasmic granules of mammalian eosinophils and avian heterophils showed the highest fluorescence reaction, which was abolished by blocking procedures for amino groups. Spectrofluorometric analysis confirmed the emission characteristics of the naphthalimides produced from n-butylamine and gelatin. Taking into account the chemical reactivity of 1,8-naphthalic anhydrides and present results, the reaction can be considered selective for lysine and arginine residues of proteins.

  4. Alternating copolymerization of propylene oxide with biorenewable terpene-based cyclic anhydrides: a sustainable route to aliphatic polyesters with high glass transition temperatures.

    PubMed

    Van Zee, Nathan J; Coates, Geoffrey W

    2015-02-23

    The alternating copolymerization of propylene oxide with terpene-based cyclic anhydrides catalyzed by chromium, cobalt, and aluminum salen complexes is reported. The use of the Diels-Alder adduct of α-terpinene and maleic anhydride as the cyclic anhydride comonomer results in amorphous polyesters that exhibit glass transition temperatures (Tg ) of up to 109 °C. The polymerization conditions and choice of catalyst have a dramatic impact on the molecular weight distribution, the relative stereochemistry of the diester units along the polymer chain, and ultimately the Tg of the resulting polymer. The aluminum salen complex exhibits exceptional selectivity for copolymerization without transesterification or epimerization side reactions. The resulting polyesters are highly alternating and have high molecular weights and narrow polydispersities.

  5. In situ fourier transform infrared study of crotyl alcohol, maleic acid, crotonic acid, and maleic anhydride oxidation on a V-P-O industrial catalyst

    SciTech Connect

    Wenig, R.W.; Schrader, G.L.

    1987-10-22

    Crotyl alcohol, maleic acid, crotonic (2-butenoic) acid, and maleic anhydride were fed to an in situ infrared cell at 300/sup 0/C containing a P/V = 1.1 vanadium-phosphorous-oxide (V-P-O) catalyst used for the selective oxidation of n-butane. Crotyl alcohol was used as a mechanistic probe for the formation of reactive olefin species observed during previous n-butane and 1-butene studies. Crotonic acid, maleic acid, and maleic anhydride were fed as probes for the existence of other possible adsorbed intermediates. Olefin species and maleic acid are proposed as possible reaction intermediates in n-butane selective oxidation to maleic anhydride. The involvement of peroxide species in the oxidation of butadiene to maleic acid is also discussed.

  6. Catalytic effect of gallium chloride in the diels-alder reaction between maleic anhydride and its derivatives and unsubstituted and substituted anthracenes

    SciTech Connect

    Kiselev, V.D.; Konovalov, A.I.; Shakirov, I.M.

    1985-11-10

    The stability of n, v complexes between gallium chloride and unsubstituted and substituted maleic anhydrides was determined in benzene by a thermochemical method; it was shown that the stability of the complexes decreases in the transition from maleic anhydrides with electron-donating substituents to maleic anhydrides with electron-withdrawing substituents. The reactivity of these dienophiles in the uncatalyzed Diels-Alder reactions with unsubstituted and substituted anthracenes in benzene and in the reactions catalyzed by gallium chloride was studied. The reactivity of the dienophiles varies similarly in the reactions with the investigated dienes, and this rules out treatment of steric hindrances as the reason for the reduced reactivity of the substituted dienophiles. A decrease in the catalytic effect was observed for the unreactive diene-dienophile pairs.

  7. Synthesis of comb-like copolymers from renewable resources: Itaconic anhydride, stearyl methacrylate and lactic acid

    NASA Astrophysics Data System (ADS)

    Shang, Shurui

    The synthesis and properties of comb-like copolymers and ionomers derived from renewable resources: itaconic anhydride (ITA), stearyl methacrylate (SM) and lactic acid (LA) are described. The copolymers based on ITA and SM (ITA-SM) were nearly random with a slight alternating tendency. The copolymers exhibited a nanophase-separated morphology, with the stearate side-chains forming a bilayer, semi-crystalline structure. The crystalline side-chains suppressed molecular motion of the main-chain, so that a glass transition temperature (Tg) was not resolved unless the ITA concentration was sufficiently high so that Tg > the melting point (Tm). The softening point and modulus of the copolymers increased with the increasing ITA concentration, but the thermal stability decreased. The ITA moiety along the main chain of the copolymers was neutralized with metal acetates to produce Na-, Ca- and Zn- random ionomers with comb-like architectures. In general, the incorporation of the ionic groups increased the Tg and suppressed the crystallinity of the side-chain packing. Ionomers with high SM side-chain density had two competing driving forces for self-assembled nano-phase separation: ionic aggregation and side-chain crystalline packing. Upon neutralization, a morphological transition from semi-crystalline lamella to spherical ionic aggregation was observed by small angle X-ray scattering (SAXS) analysis and transmission electron microscopy (TEM). Thermomechanical analysis revealed an increasing resistance to penetration deformation with an increasing degree of neutralization and an apparent rubbery plateau was observed above Tg. A controlled transesterification of PLA in glassware was an effective way to prepare a methacrylate functionalized PLA macromonomer with controlled molecular weight, which was used to synthesize a variety of copolymers. The copolymerization of this functionalized PLA macromonomer with ITA totally suppressed the side-chain crystallinity for the PLA chain

  8. Autoimmune response in MRL+/+ mice following treatment with dichloroacetyl chloride or dichloroacetic anhydride

    SciTech Connect

    Cai Ping; Koenig, Rolf; Khan, M. Firoze; Qiu, Suimin; Kaphalia, Bhupendra S.; Ansari, G.A.S. . E-mail: sansari@utmb.edu

    2006-10-15

    Dichloroacetyl chloride (DCAC) is formed from trichloroethene (TCE), which is implicated in inducing/accelerating autoimmune response. Due to its potent acylating activity, DCAC may convert proteins to neo-antigens and thus could induce autoimmune responses. Dichloroacetic anhydride (DCAA), which is a similar acylating agent, might also induce autoimmune responses. To evaluate if chloroacylation plays a role in the induction of autoimmunity, we have measured the autoimmune responses following treatment with DCAC or DCAA in autoimmune-prone MRL+/+ mice. Five-week-old female mice were injected intraperitoneally (twice weekly) with 0.2 mmol/kg of DCAC or DCAA in corn oil for 6 weeks. Total serum IgG, IgG1, and IgE levels were significantly increased in DCAC-treated mice as compared to controls. These increases corresponded with increases in DCAC-specific IgG and IgG1 levels. Total serum IgM was decreased in both DCAC- and DCAA-treated mice. Antinuclear antibodies, measured as an indication of systemic autoimmune responses, were increased in both DCAC- and DCAA-treated mice. Of eight Th1/Th2 cytokines measured in the serum, only IL-5 was significantly decreased in both treatment groups. The cytokine secretion patterns of splenic lymphocytes after stimulation with antibodies against CD3 (T cell receptor-mediated signal) and CD28 (costimulatory signal) differed between treatment and control groups. Levels of IL-1, IL-3, IL-6, IFN-{gamma}, G-CSF, and KC were higher in cultures of stimulated splenocytes from either DCAC- or DCAA-treated mice than from controls. The level of IL-17 was only increased in cultures from DCAC-treated mice. Increased lymphocytic populations were found in the red pulp of spleens following treatment with either DCAC or DCAA. In addition, thickening of the alveolar septa in the lungs of DCAC- or DCAA-treated mice was observed. The lung histopathology in exposed mice was consistent with the symptomology observed in welders exposed to DCAC

  9. Characterization of the Tautomycetin Biosynthetic Gene Cluster from Streptomyces griseochromogenes Provides New Insight into Dialkylmaleic Anhydride Biosynthesis#

    PubMed Central

    Li, Wenli; Luo, Yinggang; Ju, Jianhua; Rajski, Scott R.; Osada, Hiroyuki; Shen, Ben

    2010-01-01

    Tautomycetin (TTN) is a highly potent and specific protein phosphatase inhibitor isolated from Streptomyces griseochromogenes. The biological activity of TTN makes it an important lead for drug discovery, whereas its rare dialkylmaleic anhydride moiety and structural similarity to tautomycin (TTM), another potent phosphatase inhibitor with tremendous medicinal potential, draws attention to novel biosynthetic chemistries responsible for its production. To elucidate the biosynthetic machinery associated with TTN production, the ttn biosynthetic gene cluster from S. griseochromogenes was isolated and characterized, and its involvement in TTN biosynthesis confirmed by gene inactivation and complementation experiments. The ttn cluster was localized to a 79 kb DNA region, consisting of 19 open reading frames that encode two modular type I polyketide synthases (TtnAB), one type II thioesterase (TtnH), eight proteins for dialkylmaleic anhydride biosynthesis (TtnKLMNOPRS), four tailoring enzymes (TtnCDFI), two regulatory proteins (TtnGQ), and one resistance protein (TtnJ). A model for TTN biosynthesis is proposed on the basis of functional assignments from sequence analysis, which agrees well with previous feeding experiments, has been supported by in vivo gene inactivation experiments, and is supported by analogy to the recently reported ttm cluster. These findings set the stage to fully investigate TTN biosynthesis and to biosynthetically engineer new TTN analogues. PMID:19191560

  10. Immobilization of saccharides and peptides on 96-well microtiter plates coated with methyl vinyl ether-maleic anhydride copolymer.

    PubMed

    Satoh, A; Kojima, K; Koyama, T; Ogawa, H; Matsumoto, I

    1998-06-15

    We have previously reported a method to immobilize protein ligands on microtiter plates coated with methyl vinyl ether-maleic anhydride copolymer (MMAC) [Isosaki, K., et al. (1992) J. Chromatogr. 597, 123-128]. In this study, we improved the MMAC method to efficiently immobilize not only small ligands such as peptides and oligosaccharides, which could not be efficiently immobilized previously, but also heparin via its reducing end. Amino and hydrazino groups were introduced to MMAC-coated microtiter plate wells by coupling to acid anhydride groups of MMAC with 1,6-hexamethylenediamine and adipic acid dihydrazide, respectively. The amino groups introduced were allowed to react with peptides by use of divalent cross-linkers. Hydrazino groups were allowed to react with formyl groups of saccharides by reductive amination. Peptides and oligosaccharides were immobilized in a dose-dependent manner by these methods. In the case of the angiotensin peptide thus immobilized, the detection limit by monoclonal antibodies was as low as 0.1-1 fmol peptide per well. Application of 20-200 nmol oligosaccharides to the well was sufficient to immobilize and subsequently detect lectins. Furthermore, heparin immobilized on the hydrazinocoated wells was successfully used for the binding assay of annexin IV. PMID:9648659

  11. Light-Induced C-H Arylation of (Hetero)arenes by In Situ Generated Diazo Anhydrides.

    PubMed

    Cantillo, David; Mateos, Carlos; Rincon, Juan A; de Frutos, Oscar; Kappe, C Oliver

    2015-09-01

    Diazo anhydrides (Ar-N=N-O-N=N-Ar) have been known since 1896 but have rarely been used in synthesis. This communication describes the development of a photochemical catalyst-free C-H arylation methodology for the preparation of bi(hetero)aryls by the one-pot reaction of anilines with tert-butyl nitrite and (hetero)arenes under neutral conditions. The key step in this procedure is the in situ formation and subsequent photochemical (>300 nm) homolytic cleavage of a transient diazo anhydride intermediate. The generated aryl radical then efficiently reacts with a (hetero)arene to form the desired bi(hetero)aryls producing only nitrogen, water, and tert-butanol as byproducts. The scope of the reaction for several substituted anilines and (hetero)arenes was investigated. A continuous-flow protocol increasing selectivity and safety has been developed enabling the experimentally straightforward preparation of a variety of substituted bi(hetero)aryls within 45 min of reaction time. PMID:26239967

  12. Synthesis and characterization of CdS nanoparticle based multiwall carbon nanotube-maleic anhydride-1-octene nanocomposites

    NASA Astrophysics Data System (ADS)

    Malikov, E. Y.; Altay, M. C.; Muradov, M. B.; Akperov, O. H.; Eyvazova, G. M.; Puskás, R.; Madarász, D.; Kukovecz, Á.; Kónya, Z.

    2015-05-01

    CdS nanoparticles were synthesized by sonication from cadmium chloride and thiourea using a multiwall carbon nanotube (MWCNT)-maleic anhydride (MA)-1-octene system as the matrix. The matrix was obtained by the "grafting from" approach from oxidized carbon nanotubes and maleic anhydride-1-octene. Multiwall carbon nanotubes used for reinforcing the matrix were synthesized by Catalytic Chemical Vapor Deposition using Fe-Co/Al2O3 as the catalyst. The obtained nanostructures were characterized by FTIR, XRD, Raman spectroscopy, TEM, SEM and UV-vis spectroscopy. The average CdS particle diameter was 7.9 nm as confirmed independently by TEM and XRD. UV-vis spectroscopy revealed that the obtained nanostructure is an appropriate base material for making optical devices. The novelty of this work is the use of the MWCNT-MA-1-octene matrix obtained via the "grafting from" approach for the synthesis of uniformly dispersed CdS nanocrystals by ultrasonic cavitation to obtain a polymer nanocomposite.

  13. Polyimides Derived from Novel Asymmetric Benzophenone Dianhydrides

    NASA Technical Reports Server (NTRS)

    Chuang, Chun-Hua (Inventor)

    2015-01-01

    This invention relates to the composition and processes for preparing thermoset polyimides derived from an asymmetric dianhydride, namely 2,3,3',4'-benzophenone dianhydride (a-BTDA) with at least one diamine, and a monofunctional terminal endcaps. The monofunctional terminating groups include 4-phenylethynylphthalic anhydride ester-acid derivatives, phenylethyl trimellitic anhydride (PETA) and its ester derivatives as well as 3-phenylethynylaniline. The process of polyimide composite comprises impregnating monomer reactants of dianhydride or its ester-acid derivatives, diamine and with monofunctional reactive endcaps into glass, carbon, quartz or synthetic fibers and fabrics, and then stack up into laminates and subsequently heated to between 150-375.degree. C. either at atmosphere or under pressure to promote the curing and crosslinking of the reactive endcaps to form a network of thermoset polyimides.

  14. An atom-economic approach to carboxylic acids via Pd-catalyzed direct addition of formic acid to olefins with acetic anhydride as a co-catalyst.

    PubMed

    Wang, Yang; Ren, Wenlong; Shi, Yian

    2015-08-21

    An effective Pd-catalyzed hydrocarboxylation of olefins using formic acid with acetic anhydride as a co-catalyst is described. A variety of carboxylic acids are obtained in good yields with high regioselectivities under mild reaction conditions without the use of toxic CO gas.

  15. Highly water-soluble monoboronic acid probes that show optical sensitivity to glucose based on 4-sulfo-1,8-naphthalic anhydride.

    PubMed

    Cao, Zhi; Nandhikonda, Premchendar; Heagy, Michael D

    2009-05-01

    Two highly water-soluble monoboronic acid probes that display the more desirable off-on fluorescence response were synthesized based on 4-sulfo-1,8-naphthalic anhydride and a remarkable sensitivity for glucose rather than fructose and galactose was also observed.

  16. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Octadecanoic acid, ester with 1,2..., ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as octadecanoic acid,...

  17. SELECTIVE HYDROGENATION OF MALEIC ANHYDRIDE TO Y-BUTROLACTONE OVER PD/AL2O3 CATALYST USING SUPERCRITICAL CARBON DIOXIDE MEDIUM

    EPA Science Inventory

    Hydrogenation of maleic anhydride to g-butyrolactone over Pd/Al2O3 catalyst under supercritical carbondioxide medium

    Unnikrishnan R. Pillai and Endalkachew Sahle-Demessie
    National Risk Management Research laboratory (NRMRL), Clean Processes Branch, MS 443, United States...

  18. Efficacy of measures of hygiene in workers sensitised to acid anhydrides and the influence of selection bias on the results

    PubMed Central

    Drexler, H.; Schaller, K. H.; Nielsen, J.; Weber, A.; Weihrauch, M.; Welinder, H.; Skerfving, S.

    1999-01-01

    OBJECTIVES: Organic acid anhydrides are potential sensitisers and cause occupational airway diseases. In an intervention study the efficacy of measures of hygiene at the workplace and possible selection bias were investigated. METHODS: A first investigation with 110 workers exposed to hexahydrophthalic acid anhydride (HHPA) and methyltetrahydrophthalic acid anhydride (MTHPA) was carried out in July 1991. The results (skin prick test, specific serum IgE) showed that 20 people were sensitised, and in a challenge test the clinical relevance of the sensitisation was confirmed in six subjects. In December 1991, the hygiene conditions at the plant were improved. In November 1995 a second investigation of 84 people was performed (anamnesis, skin prick test, specific IgE, spirometry, and ambient and biological monitoring). The 27 people who had left the plant in the meantime were asked their reasons for leaving. RESULTS: The relative risk of people sensitised in 1991 of leaving the plant between 1991 and 1995 was 2.6 (95% confidence interval (95% CI) 1.4 to 4.9) compared with people without any sign of sensitisation. The percentage of people identified as sensitised in 1991, who were still working at the plant and came to the second investigation, was higher than for people without evidence of sensitisation (10/10 v 47/73; p < 0.05). In all the 10 sensitised people in 1991 the findings of the first investigation were confirmed in 1995. The rate of sensitisation in 1995 was 21%. None of the six people employed after 1991 showed evidence of sensitisation. Of the six people with clinically relevant sensitisation confirmed by a challenge test in 1991, five were still at their workplace. From 1991 they were only exposed to MTHPA at a reduced concentration (< 0.5-36 micrograms/m3 in 1995). All of them reported fewer symptoms than in 1991. No signs of bronchial obstruction were detected by spirometry at the workplace. CONCLUSIONS: In cross sectional studies there is a selection

  19. Formulation of salicylate-based poly(anhydride-ester) microspheres for short- and long-term salicylic acid delivery

    PubMed Central

    Rosario-Meléndez, Roselin; Ouimet, Michelle A.; Uhrich, Kathryn E.

    2013-01-01

    The formulation of salicylate-based poly(anhydride-ester) (PAE) microspheres was optimized by altering polymer concentration and homogenization speed to improve the overall morphology. The microspheres were prepared using three salicylate-based PAEs with different chemical compositions comprised of either a heteroatomic, linear aliphatic, or branched aliphatic moiety. These PAEs broadened the range of complete salicylic acid release to now include days, weeks and months. The molecular weight (Mw), polydispersity index (PDI) and glass transition temperature (Tg) of the formulated polymers were compared to the unformulated polymers. In general, the Mw and PDI exhibited decreased and increased values, respectively, after formulation, whereas the Tg changes did not follow a specific trend. Microsphere size and morphology were determined using scanning electron microscopy. These microspheres exhibited smooth surfaces, no aggregation, and size distributions ranging from 2-34 m in diameter. In vitro release studies of the chemically incorporated salicylic acid displayed widely tunable release profiles. PMID:23420391

  20. Synthesis and surface properties of aqueous dispersions of poly(ester-imide) prepared from anhydride terminated polyester prepolymer and diisocyanate.

    PubMed

    Banu, P; Sundar, S; Dhathathreyan, A; Radhakrishnan, G

    2004-09-15

    Aqueous dispersions of poly(ester-imide)s [P(E-I)s] have been prepared by dispersing the P(E-I)s in water without any external solubilizing agents. P(E-I)s were prepared from anhydride-terminated polyester prepolymer and diisocyanate. The -COOH groups in the polymer were then neutralized using triethylamine and the P(E-I)s were subsequently dispersed in water. The influence of the degree of ionization of polymers on the particle size and viscosity of the dispersion has been studied. The dispersions were crosslinked using polyaziridine. The crosslinked dispersion cast films were characterized for dynamic mechanical properties. As the ionic content increased the particle size decreased and the viscosity increased. When the amount of crosslinker added was varied, for a fixed percentage of ionization, the glass transition temperature Tg shifted to higher values. Critical surface tension (CST) measurements indicated reorganization of hydrophobic groups on the surface after crosslinking. PMID:15341840

  1. Immunologic and functional consequences of chemical (tetrachlorophthalic anhydride)-induced asthma after four years of avoidance of exposure

    SciTech Connect

    Venables, K.M.; Topping, M.D.; Nunn, A.J.; Howe, W.; Newman Taylor, A.J.

    1987-08-01

    Seven patients with occupational asthma caused by a chemical, tetrachlorophthalic anhydride (TCPA), left their work in 1980. They have subsequently avoided TCPA exposure and have been followed until 1985. One patient died in 1981. The six living patients reported continuing symptoms suggestive of asthma, and five who were studied in 1985 demonstrated mild bronchial hyperresponsiveness (histamine concentration provoking a 20% fall in FEV1 range 2.7 to 12.5 mg/ml). Specific IgE antibody to TCPA conjugated with human serum albumin was measured by a radioallergosorbent test and detected in all patients. After avoidance of exposure, specific IgE fell exponentially with a half-life of 1 year. Specific IgE was still detectable in 1985, and throughout the follow-up period, prick tests with the conjugate elicited immediate skin responses. In 1981 four patients had inhalation tests with TCPA, and specific IgE rose afterward and then fell again.

  2. An investigation of active and selective oxygen in vanadium phosphorus oxide catalysts for n-butane conversion to maleic anhydride

    SciTech Connect

    Lashier, M.E.

    1990-01-01

    The role of lattice oxygens in two model catalysts, {beta}-VOPO{sub 4} and (VO){sub 2}P{sub 2}O{sub 7}, was investigated for the selective and nonselective oxidation of C{sub 4} hydrocarbons to maleic anhydride and combustion products. Specific catalytic oxygen sites in each model catalyst were labeled with specific amounts of {sup 18}O. Labeled sites were identified by laser Raman spectroscopy and Fourier transform infrared spectroscopy. The level of {sup 18}O enrichment in each site was estimated from the laser Raman spectra and the stoichiometry of reactions involved in the synthesis of the labeled catalysts. Products of the anaerobic C{sub 4} hydrocarbon oxidation and, in the case of (VO){sub 2}P{sub 2}O{sub 7}, alternating pulses of oxygen with pulses of hydrocarbon, over labeled catalysts were monitored by quadrupole mass spectrometry. 146 refs., 51 figs., 7 tabs.

  3. Energy storage capacity of reversible liquid-phase Diels Alder reaction between maleic anhydride and 2- methyl furan

    SciTech Connect

    Sparks, B.G.; Poling, B.E.

    1983-07-01

    Calorimetry was used to determine the heat of reaction and equilibrium constant at 318 K for the reaction between maleic anhydride (A) and 2-methyl furan (B). The values were-60 kJ/gmol and 614 cm/sup 3//gmol, respectively. The motivation for this work was to find a single phase-reacting system that could be used to store solar energy. Thus, the energy storage capacity was calculated for a mixture of A and B, both initially at 7 kmol/m/sup 3/, in dioxane. The maximum apparent heat capacity of 7.37 J/cm/sup 3/ X K occurred at 334 K. This maximum value is 76% higher than the heat capacity of pure water.

  4. Mechanism for oxidation of n-butane to maleic anhydride on a vanadium-phosphorus oxide catalyst

    SciTech Connect

    Nechiporuk, P.P.; Mishchenko, Yu.A.; Avetisov, A.K.; Dulin, D.A.; Kalinovskii, I.O.; Gel'bshtein, A.I.

    1987-06-01

    The values of the kinetic isotope effect have been determined in reactions where n-butane is converted to partial (maleic anhydride) and complete oxidation products on a vanadium-phosphorus oxide catalyst when hydrogen is replaced by deuterium in different positions of the n-butane molecule. The absence of intra- and intermolecular H-D exchange in butane under conditions of its catalytic oxidation has been established. On the basis of the observed effects it has been concluded that the interaction of n-butane with the surface of the catalyst is irreversible under the conditions of catalysis and that the rate-limiting stage due to cleavage of the C-H bond in a methylene group of butane is common to reactions of partial and complete oxidation of butane.

  5. Synthesis and characterization of CdS nanocrystals in Maleic anhydride-Octene-1-Vinylbutyl Ether terpolymer matrix

    NASA Astrophysics Data System (ADS)

    Akperov, Oktay H.; Muradov, Mustafa B.; Malikov, Elvin Y.; Akperov, Elchin O.; Mammadova, Rasmiyya E.; Eyvazova, Goncha M.; Kukovecz, Ákos; Kónya, Zoltán

    2016-07-01

    A Maleic anhydride-Octene-1-Vinylbutyl Ether terpolymer was synthesized via the radical terpolymerization method in order to prepare a new matrix for CdS nanocrystal synthesis. CdS nanocrystals were synthesized through the reaction of thiourea with cadmium chloride. The synthesized terpolymer/CdS nanocrystal composites were characterized by several methods. Energy Dispersive X-ray analysis, Raman spectroscopy and powder X-ray diffraction methods. The room temperature UV-visible absorption spectra show a shift of the absorption edge towards higher energies. The band gap of the CdS nanocomposite is bigger than that of bulk CdS. Raman spectrum exhibits characteristic peaks of CdS. Images of the nanocomposite obtained with Atomic Force Microscopy and Transmission Electron Microscopy are the evidences of CdS nanocrystal formation in the terpolymer. Thermal investigation shows that the nanocomposite is more thermostable than the terpolymer which could be useful for application in thermo aggressive medium.

  6. Rapid microwaves synthesis of CoSi{sub x}/CNTs as novel catalytic materials for hydrogenation of phthalic anhydride

    SciTech Connect

    Zhang, Liangliang; Chen, Xiao; Jin, Shaohua; Guan, Jingchao; Williams, Christopher T.; Peng, Zhijian; Liang, Changhai

    2014-09-15

    CoSi{sub x}/CNTs catalysts with different CoSi{sub x} phases (CoSi, CoSi{sub 2}) have been rapidly synthesized via a microwave-assisted route and applied for the liquid phase hydrogenation of phthalic anhydride. The synthesized catalysts were analyzed and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy-energy dispersive X-ray spectroscopy, thermogravimetric/derivative thermogravimetric analysis. The reaction progress of cobalt silicides and the ratio of Co:Si were monitored at different microwave irradiation times by XRD, giving insight into the formation mechanism. Compared to the Co/CNTs catalyst, all the prepared CoSi{sub x}/CNTs catalysts exhibited excellent activity and good selectivity to phthalide under mild reaction conditions (180–220 °C and 4.0 MPa H{sub 2}). This novel methodology can be applied to the synthesis of other transition metal silicides such as FeSi, Ni{sub 2}Si, and Cu{sub 4}Si. - Graphical abstract: CoSi{sub x}/CNTs catalysts with different CoSi{sub x} phases (CoSi{sub 2}, CoSi) have been rapidly synthesized via microwave-assisted route, which involves the vaporization of CoCl{sub 2} and subsequent reaction of CoCl{sub 2} with Si. - Highlights: • CoSi{sub x}/CNTs catalysts have been rapid synthesized via microwave-assisted route. • The phases of CoSi{sub x} were controlled by varying microwave time and Co:Si ratio. • FeSi, Ni{sub 2}Si and Cu{sub 4}Si were also synthesized via microwave-assisted route. • CoSi{sub x}/CNTs catalysts can be applied in hydrogenation of phthalic anhydride.

  7. Modification of pineapple peel fibre with succinic anhydride for Cu2+, Cd2+ and Pb2+ removal from aqueous solutions.

    PubMed

    Hu, Xiuyi; Zhao, Mouming; Song, Guosheng; Huang, Huihua

    2011-01-01

    Research on chemical modification of pineapple peel fibre with succinic anhydride was carried out to create a novel adsorbent for Cu2+, Cd2+ and Pb2+ removal from aqueous solution. After pretreatment with iso-propyl alcohol and NaOH, pineapple peel fibre was modified via reaction with succinic anhydride for introduction of carboxylic functional groups. The modified pineapple peel fibre was characterized with Fourier transform infrared (FTIR) spectroscopy and evaluated for its adsorptive ability for Cu2+, Cd2+ and Pb2+ from synthetic metal solutions. The FTIR analysis proved the introduction of carboxylic functional groups in the backbone of the modified pineapple peel fibre. The modified pineapple peel fibre showed higher adsorptive capacity for Cu2+, Cd2+ and Pb2+ compared with raw pineapple peel and pineapple peel fibre pretreated with iso-propyl alcohol. The adsorption of Cu2+, Cd2+ and Pb2+ on the modified pineapple peel fibre depended on solution pH value, adsorption time and initial metal concentration. The maximum adsorption capacities of the modified fibre were observed at pH 5.4 for Cu2+ (27.68 +/- 0.83 mg g(-1) or 0.44 mmol g(-1)), at pH 7.5 for Cd2+ (34.18 +/- 1.02 mg g(-1) or 0.30 mmol g(-1)) and at pH 5.6 for Pb2+ (70.29 +/- 2.11 mg g(-1) or 0.34 mmol g(-1)) respectively. The adsorption followed the pseudo-second-order kinetics model and the experimental data coincided well with the Langmuir model.

  8. Mixed anhydrides (phosphoric-carboxyl) are also formed in the esterification of 5'-amp with n-acetylaminoacyl imidazolides - Implications regarding the origin of protein synthesis

    NASA Technical Reports Server (NTRS)

    Wickramasinghe, Nalinie S. M. D.; Lacey, James C., Jr.

    1992-01-01

    Procedure for the formation of aminoacyl esters of monoribonucleotides with aminoacyl imidazolides were first reported by Gottikh et al. (1970) and summarized in 1970. This reaction has been widely used by us and numbers of other workers as a convenient means of preparing aminoacyl esters of nucleotides. We have previously reported that, under conditions of excess imidazolide, large amounts of bis 2', 3' esters are formed in addition to the monoesters. However, to our knowledge, no one has reported that in addition to the esters, relatively large amounts of the mixed anhydride, with the amino acid carboxyl attached to the phosphate, are also formed at short reaction times. We report here on the relative amounts of anhydride and esters formed in this reaction of racemic mixtures of eleven N-acetyl amino acid imidazolides with 5'-AMP and discuss the relevance of the findings to the origin of protein synthesis.

  9. Adaptive control of a packedbed reactor for the partial oxidation of n-butane to maleic anhydride; I. unsteady-state model and dynamics of the reactor

    SciTech Connect

    Not Available

    1984-01-01

    A nonadiabatic, fixed-bed catalytic reactor is analyzed on the basis of data for the highly exothermic partial oxidation of n-butane to maleic anhydride, in order to study multivariable adaptive control. The nonlinear partial differential equations describing the axial and radial gradients of concentration and temperature are converted into a set of nonlinear, ordinary differential and algebraic equations using orthogonal collocation, preserving the nonlinearity of the reaction term. These equations describe satisfactorily the steady state and dynamic behavior. This two-dimensional model enables the relationship between the time and temperature of reaction, and between the concentration of maleic anhydride and the hot-spot temperature to be expressed adequately by seconddegree, low-order transfer functions. This technique is applicable for any process of reaction in a packed bed.

  10. Peroxycarboxylic Nitric Anhydrides as Markers of Anthropogenic and Biogenic VOC Photo-oxidation in the Alberta Oil Sands

    NASA Astrophysics Data System (ADS)

    Osthoff, H. D.; Huo, J. A.; Tokarek, T. W.; Odame-Ankrah, C. A.; Saowapon, M. T.; Chen, X.

    2014-12-01

    The peroxycarboxylic nitric anhydrides (molecular formula RC(O)O2NO2) are well-known byproducts of the photo-oxidation chemistry between NOx and volatile organic compounds (VOCs) that produces ozone (O3) and photochemical smog. More than 43 different PAN species are known; their relative abundances are chemical markers of the types and quantities of the VOCs involved in the O3-formation process. For example, MPAN (R: CH2=C(CH3)-) is primarily derived from isoprene and thus a marker of biogenic VOC oxidation, whereas PPN (R: C2H5-) is a photo-oxidation byproduct of anthropogenic VOCs. In the summer of 2013 an intensive air quality measurement campaign was conducted to investigate the impacts of emissions from the Alberta oil sands mining operations on the chemical composition of ambient air. As part of this effort, several peroxycarboxylic nitric anhydrides, specifically PAN (R: CH3-), PPN, MPAN, APAN (R: CH2=CH-), and PiBN (R: iC3H7-), were quantified by gas chromatography with electron capture detection at the AMS13 ground site near Fort McKay, Alberta. Furthermore, total peroxyacyl nitrates (ΣPAN) were quantified by thermal dissociation cavity ring-down spectroscopy (TD-CRDS). PAN mixing ratios typically peaked in the mid-afternoon (maximum PAN mixing ratio of 0.85 ppbv), constituting up to 25% of total odd nitrogen (NOy), and were usually below detection limits at night. ΣPAN was generally greater than the amount calculated by summation of individually measured PANs (SPANi) suggesting the presence of PAN species not measured by GC. During times of active photo-oxidation chemistry, the PPN:PAN and MPAN:PAN ratios varied considerably between days, depending on air mass origin and VOC composition. A linear combination model (LCM) was used to assess regional O3 production from the oxidation of biogenic hydrocarbons (via MPAN) relative to that of anthropogenic hydrocarbons (via PPN). The relative contribution of anthropogenic VOCs to regional O3 production varied

  11. Vapor-liquid equilibria and excess enthalpies for octane + N-methylacetamide, cyclooctane + N-methylacetamide, and octane + acetic acid anhydride at 125 C

    SciTech Connect

    Haan, A.B. de; Heine, A.; Fischer, K.; Gmehling, J.

    1995-11-01

    Isothermal P-x data and excess enthalpies have been measured at approximately 125 C for the binary mixtures of octane + N-methylacetamide, cyclooctane + N-methylacetamide, and octane + acetic anhydride. For each binary system linear temperature dependent interaction parameters were fitted to experimental data using the NRTL model. Activity coefficients at infinite dilution were derived from the P-x data at low concentrations using a flexible Legendre polynomial.

  12. Desymmetrization of cyclic anhydrides mediated by cinchona alkaloids: synthesis and olfactory properties of new fragrances based on (R)- and (S)-2-ethylhexanol.

    PubMed

    Cisko-Anić, Blazenka; Hamersak, Zdenko

    2009-11-01

    A series of enantiomerically pure new fragrances, derived from 2-ethylhexanol, have been prepared and their olfactory properties evaluated. The key step of the synthesis is cinchona-alkaloid-catalyzed desymmetrization of cyclic meso-anhydrides with (R)- and (S)-2-ethylhexanol and proceeded in good to excellent diastereoselectivities (92:8-98:2 dr). Enantiomerically pure alcohols were prepared by lipase-catalyzed kinetic resolution of 2-ethylhexanol using vinyl laurate as acyl donor.

  13. Preparation, characterization and luminescent properties of dense nano-silica hybrids loaded with 1,8-naphthalic anhydride.

    PubMed

    Wang, Jinpeng; Sun, Jihong; Li, Yuzhen; Wang, Feng

    2014-03-01

    Novel luminescent dense nano-silica hybrid materials (DNSS) modified with different amounts of (3-aminopropyl)triethoxysilane (APTES) and 1,8-naphthalic anhydride (NA) were successfully synthesized via two steps combined with post-grafting methods. Powder X-ray diffraction (XRD), N2-sorption analysis, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), photoluminescence (PL) spectroscopy and elemental analysis, as well as time-resolved decays were employed to characterize the resultant hybrid materials. The results revealed that luminescent organic molecules had been successfully loaded onto the amine-modified surface of nano-silica spheres. In addition, their fluorescence intensity and characteristic peak of emission spectra changed with increasing amount of APTES and NA additive. In particular, the characteristic peak showed a red shift from 390 to 450 nm, however, this was inconsistent with results calculated on the basis of the elemental analysis data, most probably because of the dispersion behaviors of NA molecules from the aggregating to the monolayer state. These observations demonstrated the existence of a quantum confinement effectiveness of NA-DNSS samples, and therefore a possible mechanism was put forward.

  14. Evaluation of an immunoaffinity extraction column for enrichment of adducts between human serum albumin and hexahydrophthalic anhydride in plasma.

    PubMed

    Johannesson, Gunvor A; Kristiansson, Monica H; Jönsson, Bo A G; Lindh, Christian H

    2008-03-01

    An immunoaffinity extraction (IAE) column was prepared for extraction of adducts between human serum albumin (HSA) and hexahydrophthalic anhydride (HHPA). HHPA is a strong sensitizer inducing immunoglobulin E antibodies in vivo. Polyclonal antibodies from a rabbit immunized with keyhole limpet hemocyananin-HHPA conjugate were purified using a Protein A Sepharose gel. To obtain antibodies with optimal affinity towards HHPA-protein adducts, HHPA-specific antibodies were selected using an N-hydroxysuccinimide-Sepharose column coupled with albumin-HHPA conjugate. Antibodies eluted from this column at pH 2.2 were selected to prepare the IAE column. The column was evaluated using 2 mL plasma spiked with HSA-HHPA conjugate. The column was eluted with glycine buffer at pH 2.0. The conjugates in the eluate were hydrolyzed to the corresponding HHP acid and quantified by mass spectrometry. The average recovery of HHPA adducts in 11 experiments was 68% with a coefficient of variation (CV) of 7%. The column's capacity to bind protein-HHPA adducts was found to be linear in the range of 0.15-1.2 nmol conjugate. The evaluation showed that the IAE column had adequate affinity towards the HHPA adducts and that the adducts could be extracted with good recovery and precision from a large volume of plasma.

  15. Study of yellow luminescence of binary terbium complexes based on 3,3',4,4'-biphthalic anhydride.

    PubMed

    Lin, Meijuan; Wang, Xiaoping; Tang, Qiang; An, Qi; Zeng, Huijuan; Ling, Qidan

    2014-01-20

    Three novel binary Tb(III) complexes (TbL2, TbL, and Tb2L; L=3,3',4,4'-biphenyl tetracarboxylic ligand) were synthesized by changing the molar ratio of Tb(III) to 3,3',4,4'-biphthalic anhydride (BPDA) (1∶2, 1∶1, and 2∶1, respectively). IR spectra indicate that there are two coordination modes of the carboxylate ligands with Tb3+ ions in the complexes. Most of them are in bridging mode; the others are in chelating mode. These complexes all have good thermal stability. The photophysical properties of these complexes are studied in detail using UV absorption spectra, fluorescence spectra, and transient fluorescence spectra. The results indicate that the photoluminescence properties of the complexes depend strongly on the molar ratio of Tb(III) to BPDA. When the molar ratio of Tb(III) to BPDA is 1∶1, complex TbL exhibits the strongest yellow light emission among the three Tb(III) complexes. However, complex Tb2L exhibits a weaker yellowish-green light emission when the molar ratio of Tb(III) to BPDA is 2∶1. The phenomenon of the yellow emission from terbium complexes is rarely reported.

  16. Linear, Mannitol-Based Poly(anhydride-esters) with High Ibuprofen Loading and Anti-Inflammatory Activity.

    PubMed

    Stebbins, Nicholas D; Yu, Weiling; Uhrich, Kathryn E

    2015-11-01

    Sugar alcohols, such as mannitol and xylitol, are biocompatible polyols that have been used to make highly cross-linked polyester elastomers and dendrimers for tissue engineering and drug delivery. However, research that utilizes the secondary hydroxyl groups as sites for pendant bioactive attachment and subsequent polymerization is limited. This work is the first report of a linear, completely biodegradable polymer with a sugar alcohol backbone and chemically incorporated pendant bioactives that exhibits sustained bioactive release and high bioactive loading (∼70%). With four pendant esters per repeat unit, this poly(anhydride-ester) has high loading and biodegrades into three biocompatible products: bioactive, sugar alcohol, and alkyl-based diacid. Ibuprofen serves as a representative bioactive, whereas mannitol is a representative polyol. Polymerization was achieved through reaction with (trimethylsilyl)ethoxyacetylene. Drug release via polymer degradation was quantified by high performance liquid chromatography. Additionally, a cytocompatibility study with fibroblast cells was performed to elucidate the polymer's suitability for in vivo use and a cyclooxygenase-2 (COX-2) assay was performed on the degradation media to ensure that released ibuprofen retained its anti-inflammatory activity. This work enables the future development of novel, biodegradable polymers exhibiting two key features: (i) polymer backbones with easily modified pendant groups, such as targeting moieties, and (ii) high drug loading using a multitude of bioactive classes.

  17. Diosgenin effectively suppresses skin inflammation induced by phthalic anhydride in IL-4/Luc/CNS-1 transgenic mice.

    PubMed

    Kim, Ji Eun; Go, Jun; Koh, Eun Kyoung; Song, Sung Hwa; Sung, Ji Eun; Lee, Hyun Ah; Kim, Dong Seob; Son, Hong Joo; Lee, Hee Seob; Lee, Chung Yeoul; Hong, Jin Tae; Hwang, Dae Youn

    2016-05-01

    To quantitatively evaluate the therapeutic effects of diosgenin (DG) and investigate the role of IL-4 on skin inflammation, alterations in luciferase-derived signal and general phenotype biomarkers were measured in IL-4/Luc/CNS-1 transgenic mice with phthalic anhydride (PA)-induced skin inflammation after treatment with DG for 4 weeks. High levels of luciferase-derived signal detected in the abdominal region and submandibular lymph node (SL) of the PA treated group was significantly decreased by 67-88% in the PA + DG cotreated group. Furthermore, the weight of the lymph node and spleen, IgE concentration, epidermis thickness, and number of infiltrated mast cells were lower in the PA + DG treated group than the PA + Vehicle treated group. Moreover, expression of IL-6 and vascular endothelial growth factor (VEGF) also decreased in the PA + DG cotreated group. These results suggest that PA-induced skin inflammation could be successfully suppressed by DG treatment in IL-4/Luc/CNS-1 Tg mice through attenuation of IL-4 and IL-6 expression, as well as decreased IgE concentration and mast cells infiltration. PMID:26998565

  18. Olefin-maleic-anhydride copolymer based additives: a novel approach for compatibilizing blends of waste polyethylene and crumb rubber.

    PubMed

    Tóth, Balázs; Varga, Csilla; Bartha, László

    2015-04-01

    In our work processing conditions and mechanical properties of waste polyethylene (PE)/crumb rubber (CR) blends have been improved by new types of compatibilizing additives synthesized from experimental olefin-maleic-anhydride copolymers at our laboratory. Compatibilizing additives have been introduced into the PE/CR blends in 0.2 wt% while CR concentration has been varied between 10 and 50 wt%. For comparison of the effects commercially available MA-g-PO type compatibilizing additives have also been applied. Tensile and Charpy impact tests of the compression moulded samples have been carried out. Several experimental additives have enhanced properties of the PE/CR blends either from the point of view of tensile or Charpy impact strength while commercial additives have had improving effects only on one of the abovementioned mechanical properties but not for both of them simultaneously. Since good mechanical properties could be achieved by our experimental compatibilizers good adhesion in the waste PE/CR samples have been considered and was proven by SEM graphs either.

  19. Anhydride-functional silane immobilized onto titanium surfaces induces osteoblast cell differentiation and reduces bacterial adhesion and biofilm formation.

    PubMed

    Godoy-Gallardo, Maria; Guillem-Marti, Jordi; Sevilla, Pablo; Manero, José M; Gil, Francisco J; Rodriguez, Daniel

    2016-02-01

    Bacterial infection in dental implants along with osseointegration failure usually leads to loss of the device. Bioactive molecules with antibacterial properties can be attached to titanium surfaces with anchoring molecules such as silanes, preventing biofilm formation and improving osseointegration. Properties of silanes as molecular binders have been thoroughly studied, but research on the biological effects of these coatings is scarce. The aim of the present study was to determine the in vitro cell response and antibacterial effects of triethoxysilypropyl succinic anhydride (TESPSA) silane anchored on titanium surfaces. X-ray photoelectron spectroscopy confirmed a successful silanization. The silanized surfaces showed no cytotoxic effects. Gene expression analyses of Sarcoma Osteogenic (SaOS-2) osteoblast-like cells cultured on TESPSA silanized surfaces reported a remarkable increase of biochemical markers related to induction of osteoblastic cell differentiation. A manifest decrease of bacterial adhesion and biofilm formation at early stages was observed on treated substrates, while favoring cell adhesion and spreading in bacteria-cell co-cultures. Surfaces treated with TESPSA could enhance a biological sealing on implant surfaces against bacteria colonization of underlying tissues. Furthermore, it can be an effective anchoring platform of biomolecules on titanium surfaces with improved osteoblastic differentiation and antibacterial properties.

  20. Preparation of fenofibrate dry emulsion and dry suspension using octenyl succinic anhydride starch as emulsifying agent and solid carrier.

    PubMed

    Pongsamart, Kasama; Kleinebudde, Peter; Puttipipatkhachorn, Satit

    2016-02-10

    Purpose of this study was to investigate the ability of octenyl succinic anhydride (OSA) starch as emulsifier and solid carrier in dry emulsion (DE) and dry suspension (DS) formulations. Fenofibrate (FF) was loaded at lower and higher than its saturation concentration in oil phase to prepare the DE and DS by spray drying method. The DE and DS were successfully prepared with 36-48% and 46% production yield, respectively. After reconstitution in water, the emulsion with mean droplet size of 1-2 μm was obtained. Solid state characterization revealed the amorphous state of FF and the crystalline state of OSA starch in both DE and DS formulations. Both DE and DS enhanced FF dissolution rate compared to pure material and DS showed the highest dissolution rate. The DE and DS could be compressed to the tablets with acceptable disintegration time and without changeable dissolution profile. Moreover, the dissolution profiles of both DE and DS remained unchanged after 2 months storage at 40 °C.

  1. Interaction of ozone exposure with airway hyperresponsiveness and inflammation induced by trimellitic anhydride in sensitized guinea pigs

    SciTech Connect

    Sun, Jian; Chung, K.Fan

    1997-09-01

    The effect of prior ozone (O{sub 3}) exposure on airway hyperresponsiveness and inflammation induced by trimellitic anhydride (TMA) has been investigated in TMA-sensitized guinea pigs. Airway responsiveness was measured as the concentration of acetylcholine needed to increase baseline lung resistance (RL) by 300% (PC300). Ozone (3 ppm, for 3 h) caused an increase in-log PC300 at 1 h after exposure, with return of -log PC300 to control levels at 8 h. Ozone also increased baseline RL at 8 h. TMA challenge increase -log PC300 in TMA-sensitized guinea pigs at 8 h after challenge from 3.85 {+-} 0.09 to 4.11 {+-} 0.09. Ozone exposure prior to TMA challenge prevented the induction of airway hyperresponsiveness with a mean -log PC300 of 3.51 {+-} 0.20, which was not different from that of control TMA-Sensitized group. Baseline RL was significantly higher in ozone-pretreated animals after TMA challenge when compared to those of either control or challenged with TMA alone. Ozone had no effect on TMA challenge-induced BAL eosinophilia and neutrophilia. We conclude that a single exposure to ozone inhibits the increase in airway responsiveness, but increases the bronchoconstrictor response induced by TMA in TMA-Sensitized guinea pigs; however, the inflammatory airway response to TMA is unchanged by preexposure to ozone. 29 refs., 2 figs., 1 tab.

  2. In vitro release of clomipramine HCl and buprenorphine HCl from poly adipic anhydride (PAA) and poly trimethylene carbonate (PTMC) blends.

    PubMed

    Dinarvand, Rassoul; Alimorad, Mohammed Massoud; Amanlou, Massoud; Akbari, Hamid

    2005-10-01

    Controlled drug-delivery technology is concerned with the systematic release of a pharmaceutical agent to maintain a therapeutic level of the drug in the body for modulated and/or prolonged periods of time. This may be achieved by incorporating the therapeutic agent into a degradable polymer vehicle, which releases the agent continuously as the matrix erodes. In this study, poly trimethylene carbonate (PTMC), an aliphatic polycarbonate, and poly adipic anhydride (PAA), an aliphatic polyanhydride, were synthesized via melt condensation and ring-opening polymerization of trimethylene carbonate and adipic acid, respectively. The release of clomipramine HCl and buprenorphine HCl from discs prepared with the use of PTMC-PAA blends in phosphate buffer (pH 7.4) are also described. Clomipramine HCl and buprenorphine HCl were both used as hydrophilic drug models. Theoretical treatment of the data with the Peppas model revealed that release of clomipramine HCl (5%) in devices containing 70% PTMC or more followed a Fickian diffusion model. However, the releases of buprenorphine HCl (5%) in the same devices were anomalous. For devices containing 50% and more PAA, surface erosion may play a significant role in the release of both molecules.

  3. In Vivo Evaluation of Nerve Guidance Conduits Comprised of a Salicylic Acid-based Poly(anhydride-ester) Blend

    NASA Astrophysics Data System (ADS)

    Lee, Yong Soo

    Unlike the central nervous system, peripheral nervous system can regenerate from injury. However, without surgical intervention, the results are often poor. Autologous nerve grafting is the golden standard for repairing peripheral nerve injury; but limited donor availability and donor site morbidity led researchers to seek alternative methods. Among the many alternative treatment options, synthetic nerve guidance conduits (NGCs) have been most actively developed. The goal of NGCs is to serve as a physical scaffold that aids the axonal regeneration process while preventing scar tissue formation that interferes with regeneration. Biocompatible and biodegradable NGCs would provide additional benefits: minimize foreign body reaction and avoid secondary surgeries to remove NGCs. We developed a unique NGC that incorporated the characteristics described above and can release an anti-inflammatory drug, salicylic acid. In this work, in vivo assays were performed to evaluate NGCs fabricated from a poly(anhydride-ester) blend. To further assist in the regeneration process, bovine native collagen type I hydrogel were inserted into the NGCs lumen which was then implanted in femoral nerve of mice for up to 16 weeks. These studies demonstrated in vivo biodegradability, biocompatibility, and axonal regeneration following an injury to the peripheral nerve. These studies provide greater insights into the importance of designing NGCs and how they aid in regeneration and functional recovery of subjects.

  4. Poly(isobutylene-alt-maleic anhydride) binders containing lithium for high-performance Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Ku, Jun-Hwan; Hwang, Seung-Sik; Ham, Dong-Jin; Song, Min-Sang; Shon, Jeong-Kuk; Ji, Sang-Min; Choi, Jae-Man; Doo, Seok-Gwang

    2015-08-01

    Anode materials including graphite are known to be thermodynamically unstable toward organic solvents and salts and become covered by a passivating film (Solid electrolyte interphase, SEI) which retards the kinetics because of the high electronic resistivity. To achieve high performance in lithium ion batteries (LIBs), the SEIs are required to be mechanically stable during repeated cycling and possess highly ion-conductive. In this work, we have investigated an artificial pre-SEI on graphite electrode using a polymer binder containing lithium (i.e., a Li-copolymer of isobutylene and maleic anhydride, Li-PIMA) and its effect on the anode performances. During charging, the polymer binder with the functional group (-COOLi) acts as a SEI component, reducing the electrolyte decomposition and providing a stable passivating layer for the favorable penetration of lithium ions. Hence, by using the binder containing lithium, we have been able to obtain the first Coulombic efficiency of 84.2% (compared to 77.2% obtained using polyvinylidene fluoride as the binder) and a capacity retention of 99% after 100 cycles. The results of our study demonstrate that binder containing lithium we have used is a favorable candidate for the development of high-performance LIBs.

  5. Immunosuppression of the Trimellitic Anhydride-Induced Th2 Response by Novel Nonanatural Products Mixture in Mice

    PubMed Central

    Bae, Min-Jung; Shin, Hee Soon; Shon, Dong-Hwa

    2013-01-01

    Many natural dietary products prevent or cure allergic inflammation; however, the ability of mixtures of these natural medicinals to suppress allergic skin inflammation is unknown. We examined the inhibitory effects of nonanatural products mixture (NPM-9), which provides immunoregulatory activation, on Th2-mediated skin allergic inflammation. Oral administration of NPM-9 in mice reduced ear thickness and specific IgE production in trimellitic anhydride- (TMA-)induced contact hypersensitivity (CHS). NPM-9 also suppressed IL-4 and IL-1β production in splenocytes but prevented only TMA-induced IL-1β production in inflamed ears. To characterize the mechanism of this effect, we examined NPM-9 immunosuppression on an OVA-induced Th2 allergic state. Oral administration of NPM-9 inhibited Th2-mediated serum IgE overproduction. NPM-9 also downregulated the polarized Th2 response, whereas it upregulated Th1 response in splenocytes. These data suggest that NPM-9 may be a useful therapeutic agent for allergic inflammatory diseases through its suppression of the Th2-mediated allergic response. PMID:24348718

  6. Processable Polyimides Containing APB and Reactive End Caps

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J.

    2003-01-01

    Imide copolymers that contain 1,3- bis(3-aminophenoxy)benzene (APB) and other diamines and dianhydrides and that are terminated with appropriate amounts of reactive end caps have been invented. The reactive end caps investigated thus far include 4-phenylethynyl phthalic anhydride (PEPA), 3- aminophenoxy-4-phenylethynylbenzop henone (3-APEB), maleic anhydride (MA), and 5-norbornene-2,3-dicarboxylic anhydride [also known as nadic anhydride (NA)]. The advantage of these copolyimides terminated with reactive groups, relative to other polyimides terminated with reactive groups, is a combination of (1) higher values of desired mechanical-property parameters and (2) greater ease of processing into useful parts.

  7. Alveolar macrophages have a dual role in a rat model for trimellitic anhydride-induced occupational asthma

    SciTech Connect

    Valstar, Dingena L.; Schijf, Marcel A.; Nijkamp, Frans P.; Storm, Gert; Arts, Josje H.E.; Kuper, C. Frieke; Bloksma, Nanne; Henricks, Paul A.J. . E-mail: p.a.j.henricks@pharm.uu.nl

    2006-02-15

    Occupational exposure to low molecular weight chemicals, like trimellitic anhydride (TMA), can result in occupational asthma. Alveolar macrophages (AMs) are among the first cells to encounter inhaled compounds. These cells can produce many different mediators that have a putative role in asthma. In this study, we examined the role of AMs in lung function and airway inflammation of rats exposed to TMA. Female Brown Norway rats were sensitized by dermal application of TMA or received vehicle alone on days 0 and 7. One day before challenge, rats received intratracheally either empty or clodronate-containing liposomes to deplete the lungs of AMs. On day 21, all rats were challenged by inhalation of TMA in air. Lung function parameters were measured before, during, within 1 h after, and 24 h after challenge. IgE levels and parameters of inflammation and tissue damage were assessed 24 h after challenge. Sensitization with TMA led to decreased lung function parameters during and within 1 h after challenge as compared to non-sensitized rats. AM depletion alleviated the TMA-induced drop in lung function parameters and induced a faster recovery compared to sham-depleted TMA-sensitized rats. It also decreased the levels of serum IgE 24 h after challenge, but did not affect the sensitization-dependent increase in lung lavage fluid IL-6 and tissue TNF-{alpha} levels. In contrast, AM depletion augmented the TMA-induced tissue damage and inflammation 24 h after challenge. AMs seem to have a dual role in this model for TMA-induced occupational asthma since they potentiate the immediate TMA-induced decrease in lung function but tended to dampen the TMA-induced inflammatory reaction 24 h later.

  8. Preparation and characterization of new succinic anhydride grafted Posidonia for the removal of organic and inorganic pollutants.

    PubMed

    Chadlia, Aguir; Mohamed, Khalfaoui; Najah, Laribi; Farouk, M'henni Mohamed

    2009-12-30

    The present work describes the preparation of new chelating materials derived from Posidonia for adsorption of heavy metal ions and dye in aqueous solution. The first part of this report deals with the chemical modification of Posidonia with succinic anhydride. Thus, we have obtained materials with various succinyl groups contents (from 29.8 to 39.2%). The obtained materials were characterized by infrared and CP/MAS (13)C-RMN spectroscopy. The rate of succinyl content of the modified Posidonia was determined by saponification. The second part is devoted to the evaluation of the adsorption capacity of metal ions such as Pb(2+) and dye such as direct red 75 (DR75) for raw and modified Posidonia materials. Two possible ways for the adsorption of these pollutants are studied: adsorption of each pollutant alone onto these supports, and cumulative adsorption of both metal ions and dye on the same supports. In the last case, the pollutant is adsorbed successively from two different solutions. The effects of pollutants concentration, support dose, pH, contact time and temperature on adsorption of each pollutant were evaluated. The results showed that the raw and modified Posidonia show a high capacity for Pb(2+) adsorption. The capacity of modified Posidonia saturated with Pb(2+) to adsorb DR75 was found 147.12 mg g(-1). While the adsorption capacity of the nonsaturated modified Posidonia was equal to 81.63 mg g(-1). The pseudo-second-order model was the best to represent adsorption kinetics of DR75. The pseudo-first-order model would be better for fitting the adsorption kinetic process of Pb(2+) onto raw and modified Posidonia. The adsorption isotherms of Pb(2+) could be described by the Jossens equation model. Any of the tested models can describe the adsorption of DR75 onto the studied materials. These results confirm that the adsorption of DR75 from aqueous solution was multilayer.

  9. Evaluation of methods for measuring relative permeability of anhydride from the Salado Formation: Sensitivity analysis and data reduction

    SciTech Connect

    Christiansen, R.L.; Kalbus, J.S.; Howarth, S.M.

    1997-05-01

    This report documents, demonstrates, evaluates, and provides theoretical justification for methods used to convert experimental data into relative permeability relationships. The report facilities accurate determination of relative permeabilities of anhydride rock samples from the Salado Formation at the Waste Isolation Pilot Plant (WIPP). Relative permeability characteristic curves are necessary for WIPP Performance Assessment (PA) predictions of the potential for flow of waste-generated gas from the repository and brine flow into repository. This report follows Christiansen and Howarth (1995), a comprehensive literature review of methods for measuring relative permeability. It focuses on unsteady-state experiments and describes five methods for obtaining relative permeability relationships from unsteady-state experiments. Unsteady-state experimental methods were recommended for relative permeability measurements of low-permeability anhydrite rock samples form the Salado Formation because these tests produce accurate relative permeability information and take significantly less time to complete than steady-state tests. Five methods for obtaining relative permeability relationships from unsteady-state experiments are described: the Welge method, the Johnson-Bossler-Naumann method, the Jones-Roszelle method, the Ramakrishnan-Cappiello method, and the Hagoort method. A summary, an example of the calculations, and a theoretical justification are provided for each of the five methods. Displacements in porous media are numerically simulated for the calculation examples. The simulated product data were processed using the methods, and the relative permeabilities obtained were compared with those input to the numerical model. A variety of operating conditions were simulated to show sensitivity of production behavior to rock-fluid properties.

  10. Low-melt Viscosity Polyimide Resins for Resin Transfer Molding (RTM) II

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.

    2007-01-01

    A series of polyimide resins with low-melt viscosities in the range of 10-30 poise and high glass transition temperatures (Tg s) of 330-370 C were developed for resin transfer molding (RTM) applications. These polyimide resins were formulated from 2,3,3 ,4 -biphenyltetracarboxylic dianhydride (a-BPDA) with 4-phenylethynylphthalic anhydride endcaps along with either 3,4 - oxyaniline (3,4 -ODA), 3,4 -methylenedianiline, (3,4 -MDA) or 3,3 -methylenedianiline (3,3 -MDA). These polyimides had pot lives of 30-60 minutes at 260-280 C, enabling the successful fabrication of T650-35 carbon fiber reinforced composites via RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed.

  11. High Temperature Transfer Molding Resins: Preliminary Composite Properties of PETI-375

    NASA Technical Reports Server (NTRS)

    Connell, J. W.; Smith, J. G., Jr.; Hergenrother, P. M.; Criss, J. M., Jr.

    2004-01-01

    As part of an ongoing effort to develop materials for resin transfer molding (RTM) of high performance/high temperature composites, a new phenylethynyl containing imide designated as PETI-375 has been under evaluation. PETI-375 was prepared using 2,3,3 ,4 - biphenyltetracarboxylic dianhydride (a-BPDA), 1,3-bis(4-aminophenoxy)benzene and 2,2 - bis(trifluoromethyl)benzidine and endcapped with 4-phenylethynylphthalic anhydride. This material exhibited a stable melt viscosity of 0.1-0.4 Pa sec at 280 C. High quality, void-free laminates were fabricated by high temperature RTM using unsized T-650 carbon fabric and evaluated. After curing for 1 hour at 371 C, the laminates exhibited a glass transition temperature of approx. 375 C by thermomechanical analysis. The laminates were essentially void and microcrack free as evidenced by optical microscopic examination. The chemistry, physical, and composite properties of PETI-375 will be discussed.

  12. Adhesive and Composite Properties of a New Phenylethynyl Terminated Imide

    NASA Technical Reports Server (NTRS)

    Thompson, C. M.; Connell, J. W.; Hergenrother, P. M.

    2002-01-01

    A relatively new phenylethynyl terminated imide oligomer (PETI) from the reaction of 2,3,',4'- biphenyltetracarboxylic dianhydride, 4,4'-oxydianiline and endcapped with 4- phenylethynylphthalic anhydride at a calculated number average molecular weight of 5000 g/mole was evaluated as an adhesive and composite matrix. The asymmetric dianhydride imparts a low melt viscosity to the oligomer and a high glass transition temperature to the cured resin. Preliminary adhesive work with titanium (6Al-4V) adherend gave good room temperature (RT) tensile shear strengths and excellent retention of RT strength at 260 C. Preliminary composite work using unsized IM7 carbon fiber provided moderate to high mechanical properties. The chemistry, mechanical, and physical properties of the new PETI in neat resin, adhesive and composite form are presented.

  13. Novel 4-arm poly(ethylene glycol)-block-poly(anhydride-esters) amphiphilic copolymer micelles loading curcumin: preparation, characterization, and in vitro evaluation.

    PubMed

    Lv, Li; Shen, Yuanyuan; Li, Min; Xu, Xiaofen; Li, Mingna; Guo, Shengrong; Huang, Shengtang

    2013-01-01

    A novel 4-arm poly(ethylene glycol)-block-poly(anhydride-esters) amphiphilic copolymer (4-arm PEG-b-PAE) was synthesized by esterization of 4-arm poly(ethylene glycol) and poly(anhydride-esters) which was obtained by melt polycondensation of α -, ω -acetic anhydride terminated poly(L-lactic acid). The obtained 4-arm PEG-b-PAE was characterized by (1)H-NMR and gel permeation chromatography. The critical micelle concentration of 4-arm PEG-b-PAE was 2.38 μg/mL. The curcumin-loaded 4-arm PEG-b-PAE micelles were prepared by a solid dispersion method and the drug loading content and encapsulation efficiency of the micelles were 7.0% and 85.2%, respectively. The curcumin-loaded micelles were spherical with a hydrodynamic diameter of 151.9 nm. Curcumin was encapsulated within 4-arm PEG-b-PAE micelles amorphously and released from the micelles, faster in pH 5.0 than pH 7.4, presenting one biphasic drug release pattern with rapid release at the initial stage and slow release later. The hemolysis rate of the curcumin-loaded 4-arm PEG-b-PAE micelles was 3.18%, which was below 5%. The IC50 value of the curcumin-loaded micelles against Hela cells was 10.21 μg/mL, lower than the one of free curcumin (25.90 μg/mL). The cellular uptake of the curcumin-loaded micelles in Hela cell increased in a time-dependent manner. The curcumin-loaded micelles could induce G2/M phase cell cycle arrest and apoptosis of Hela cells.

  14. Kinetic resolution of racemic 2-hydroxy-γ-butyrolactones by asymmetric esterification using diphenylacetic acid with pivalic anhydride and a chiral acyl-transfer catalyst.

    PubMed

    Nakata, Kenya; Gotoh, Kouya; Ono, Keisuke; Futami, Kengo; Shiina, Isamu

    2013-03-15

    Various optically active 2-hydroxy-γ-butyrolactone derivatives are produced via the kinetic resolution of racemic 2-hydroxy-γ-butyrolactones with diphenylacetic acid using pivalic anhydride and (R)-benzotetramisole ((R)-BTM), a chiral acyl-transfer catalyst. Importantly, the substrate scope of this novel protocol is fairly broad (12 examples, s-value; up to over 1000). In addition, we succeeded in disclosing the reaction mechanism to afford high enantioselectivity using theoretical calculations and expounded on the substituent effects at the C-3 positions in 2-hydroxylactones.

  15. Poly(anhydride-ester) and poly(N-vinyl-2-pyrrolidone) blends: salicylic acid-releasing blends with hydrogel-like properties that reduce inflammation.

    PubMed

    Ouimet, Michelle A; Fogaça, Renata; Snyder, Sabrina S; Sathaye, Sameer; Catalani, Luiz H; Pochan, Darrin J; Uhrich, Kathryn E

    2015-03-01

    Polymers such as poly(N-vinyl-2-pyrrolidone) (PVP) have been used to prepare hydrogels for wound dressing applications but are not inherently bioactive. For enhanced healing, PVP was blended with salicylic acid-based poly(anhydride-esters) (SAPAE) and shown to exhibit hydrogel properties upon swelling. In vitro release studies demonstrated that the chemically incorporated drug (SA) was released from the polymer blends over 3-4 d in contrast to 3 h, and that blends of higher PVP content displayed greater swelling values and faster SA release. The polymer blends significantly the inflammatory cytokine, TNF-α, in vitro without negative effects. PMID:25333420

  16. Effect of O sub 2 concentration on selective and complete oxidation of 1,3-butadiene, furan, and maleic anhydride over MnMoO sub 4 /MoO sub 3 catalysts

    SciTech Connect

    Ozkan, U.S.; Smith, M.R.; Driscoll, S.A. )

    1990-05-01

    Oxidation experiments of 1,3-butadiene, furan, and maleic anhydride have been performed over MnMoO{sub 4}/MoO{sub 3} catalysts and their pure-phase constituents. The effect of oxygen concentration on catalytic activity and selectivity of these catalyst has been investigated. MoO{sub 3} catalysts containing MnMoO{sub 4} as a coexisting phase have been found to be active and selective for maleic anhydride formation for all feed materials and over a wide range of oxygen concentrations. The activity of the molybdenum trioxide catalyst has been found to be least affected by the concentration of gas-phase oxygen. Partial conversion of maleic anhydride to CO{sub 2} has been observed over all three catalysts with MnMoO{sub 4} showing the highest activity for complete oxidation. 20 refs.

  17. Supplementation with difructose anhydride III promotes passive calcium absorption in the small intestine immediately after calving in dairy cows.

    PubMed

    Teramura, M; Wynn, S; Reshalaitihan, M; Kyuno, W; Sato, T; Ohtani, M; Kawashima, C; Hanada, M

    2015-12-01

    The incidence of hypocalcemia increases in high-parity dairy cows because resorption of bone Ca is delayed in these animals, and they appear to have a reduced ability to absorb Ca from the intestine during the early postpartum period. Difructose anhydride (DFA) III has been shown to promote the absorption of intestinal Ca via a paracellular pathway. However, past studies have not reported this effect in peripartum dairy cows. Therefore, we investigated the effect of DFA III supplementation on Ca metabolism during the peripartum period to determine whether DFA III promotes intestinal Ca absorption via this route. Seventy-four multiparous Holstein cows were separated into DFA and control groups based on their parity and body weight. The feed of the DFA group was supplemented with 40g/d of DFA III from -14 to 6d relative to calving. The control group did not receive DFA III. At calving (0h relative to calving), serum Ca declined below 9mg/dL in both groups. However, serum Ca concentrations were greater in the DFA group than in the control group at 6, 12, 24, and 48h relative to calving, and the time required for serum Ca to recover to 9mg/dL during the postpartum period was shorter in the high-parity cows in the DFA group than in those in the control group. Parathyroid hormone concentrations increased immediately after calving in both groups and were greater in the control group than in the DFA group at 12 and 24h relative to calving. Serum 1,25-dihydroxyvitamin D concentrations increased at 0 and 12h relative to calving in both groups and were higher in the control group than in the DFA group at 72h relative to calving. Serum concentrations of the bone-resorption marker cross-linked N-telopeptide of type I collagen (NTX) were not different between the groups during peripartum period, and serum NTX in all cows was lower at 0, 6, 12, 24, 48, and 72h relative to calving than at -21, 4, and 5d relative to calving. Thus, DFA treatment induced faster recovery of serum Ca

  18. MoO sub 3 catalysts promoted by MnMoO sub 4 I. Synthesis, characterization, and selectivity in oxidation of 1-butene and 1,3-butadiene to maleic anhydride

    SciTech Connect

    Ozkan, U.; Gill, R.C.; Smith, M.R. )

    1989-03-01

    MoO{sub 3} catalysts impregnated with MnMoO{sub 4} are active for the selective oxidation of C{sub 4} hydrocarbons to maleic anhydride. Presence of MnMoO{sub 4} creates a significant promoter effect in catalytic behavior of MoO{sub 3}. The pure phases and the impregnated catalysts have been characterized during various stages of their life history using characterization techniques such as X-ray diffraction, laser Raman spectroscopy, scanning electron microscopy, and BET surface area measurements, and their catalytic activity and selectivity in selective oxidation of 1-butene and 1,3-butadiene to maleic anhydride have been studied.

  19. Synthesis of densely phosphorylated bis-1,5-diphospho-myo-inositol tetrakisphosphate and its enantiomer by bidirectional P-anhydride formation.

    PubMed

    Capolicchio, Samanta; Wang, Huanchen; Thakor, Divyeshsinh T; Shears, Stephen B; Jessen, Henning J

    2014-09-01

    The ubiquitous mammalian signaling molecule bis-diphosphoinositol tetrakisphosphate (1,5-(PP)2 -myo-InsP4 , or InsP8 ) displays the most congested three-dimensional array of phosphate groups found in nature. The high charge density, the accumulation of unstable P-anhydrides and P-esters, the lack of UV absorbance, and low levels of optical rotation constitute severe obstacles to its synthesis, characterization, and purification. Herein, we describe the first procedure for the synthesis of enantiopure 1,5-(PP)2 -myo-InsP4 and 3,5-(PP)2 -myo-InsP4 utilizing a C2 -symmetric P-amidite for desymmetrization and concomitant phosphitylation followed by a one-pot bidirectional P-anhydride-forming reaction that combines sixteen chemical transformations with high efficiency. The configuration of these materials is unambiguously shown by subsequent X-ray analyses of both enantiomers after being individually soaked into crystals of the kinase domain of human diphosphoinositol pentakisphosphate kinase 2.

  20. A new approach to quantification of DTPA incorporation into monoclonal antibodies (MoAbs) labeled by the cyclic anhydride DTPA method

    SciTech Connect

    Wang, T.S.T.; Ng, A.K.; Fawwaz, R.A.; Alsedairy, S.; Alderson, P.O.

    1985-05-01

    A method for determining the ratio of DTPA molecules attached per molecule of Ab was developed and used to examine the immunoreactivity of different Abs as a function of the amount of incorporated DTPA. The bicyclic anhydride of DTPA(2-C-14)acetic acid (BADTPA-C-14) was synthesized by reacting DTPA(2-C-14)acetic acid (1mCi/mmo1) and acetic anhydride. BADTPA-C-14 then was reacted with a MoAb to a melanoma associated antigen (MA) and to a MoAb to human HLA class II antigen (HLA) at 2mg/m1 of MoAb concentration, at MoAb to BADTPA-C-14 ratios (mmo1/mmo1) of l:1, 1:10, 1:00, l:200. The conjugate was dialyzed exhaustively against HEPES at pH 7.0. The MoAb concentration was measured at 280mm of uv; the DTPA/MoAb ratio was calculated based on the specific activity of BADTPA-C-14, and the immunoreactivity was assessed by direct cell-binding to melanoma, the HLA antigen and control (lymphoma) cells. Percent binding to the lymphoid cell line was less than 3%. The authors' results demonstrated a method for directly determining the number of DTPA molecules attached to a MOAb, and demonstrated variations in immunoreactivity as the number of DTPA groups per MoAb is altered.

  1. Determination of the energy storage capacity of the Diels-Alder reaction between methylfuran and maleic anhydride as applied to storing solar energy

    SciTech Connect

    Sparks, B.G.

    1981-01-01

    The heat storage capacity of the Diels-Alder reaction between 2-methylfuran and maleic anhydride is calculated using reaction parameters obtained from solution calorimetry. An equilibrium constant of .614 1/mol and a heat of reaction of 14.33 kcal/mole were obtained from experiments at 45/sup 0/C. A reaction ..delta..C/sub p/ of -21.8 cal/mole was calculated from heat capacity information at 25/sup 0/C. From these parameters, a solution initially seven molar in methylfuran and maleic anhydride was found to have a maximum apparent volumetric heat capacity of about 1.85 times that of water. This maximum occurs at about 335/sup 0/K. Typical active solar energy schemes operate between 300 and 400/sup 0/K. When cycled between these temperatures, this system has an overall apparent heat capacity about 1.5 times that of water. The apparent heat capacity increases as the temperature range is narrowed.

  2. Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride.

    PubMed

    Moriguchi, K; Mitamura, Y; Iwami, J; Hasegawa, Y; Higuchi, N; Murakami, Y; Maeda, H; Yoshimura, F; Nakamura, H; Ohno, N

    2012-11-01

    Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3'-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface.

  3. Butanediol via maleic anhydride

    SciTech Connect

    Harris, N.; Tuck, M.W. )

    1990-05-01

    A new butanediol process offers the opportunity for new producers to enter a growth market previously dominated by a very few major companies. Butanediol (BDO) and its derivatives compete with alternative products on a cost basis in their end use applications. The ability of the new route to produce BDO at a lower cost than established technology will lead to further market penetration and an expansion of the uses for the product. The feedstock, n-butane, is widely available and likely to fall in cost relative to the cost of the feedstocks used by competing processes. The process is environmentally acceptable and less hazardous than competing technologies.

  4. Evaluation of RTM370 Polyimide Composites by Resin Film Infusion (RFI)

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Yip, Thomas A.; Kollmansberger, Ronald B.; Tsotsis, Thomas K.

    2014-01-01

    RTM370 imide oligomer based on 2,3,3',4'-biphenyl dianhydride (a-BPDA), 3,4'-oxydianiline (3,4'-ODA) and terminated with the 4-phenylethynylphthalic (PEPA) endcap has been shown to exhibit a low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h and a high cured glass-transition temperature (Tg) of 370 C. RTM370 resin has been successfully infused into fiberglass-stitched T650-35 carbon-fabric preforms (ranged from 3- to 6-mm thick) by resin film infusion (RFI). The resulting composite panels were inspected by ultrasonic C-scan and by photomicrographs before and after post-curing as a quality control. Mechanical tests such as unnotched compression (UNC), open-hole compression (OHC), and short-beam shear strength (SBS) at ambient and elevated temperatures were performed before and after isothermal aging at 288 C for 1000 h to assess high-temperature performance. Thermal cycling of RTM370 stitched composites was also conducted from -54 C to 288 C for up to 1600 cycles to evaluate the microcrack resistance of RTM370 polyimide composites fabricated by RFI.

  5. Microwave-assisted synthesis and biological evaluation of 3,4-diaryl maleic anhydride/N-substituted maleimide derivatives as combretastatin A-4 analogues.

    PubMed

    Guan, Qi; Zuo, Daiying; Jiang, Nan; Qi, Huan; Zhai, Yanpeng; Bai, Zhaoshi; Feng, Dongjie; Yang, Lei; Jiang, Mingyang; Bao, Kai; Li, Chang; Wu, Yingliang; Zhang, Weige

    2015-02-01

    A series of new CA-4 analogues bearing maleic anhydride/N-substituted maleimide moiety were synthesized via a microwave-assisted process. They were evaluated for the anti-proliferative activities against three tumor cell lines (SGC-7901, HT-1080 and KB). Most compounds showed moderate potencies in micromolar range, with the most promising analogue 6f showing active at submicromolar concentration against HT-1080 cancer cells which was selected to investigate the antitumor mechanisms. In addition, molecular docking studies within the colchicine binding site of tubulin were also in good agreement with the tubulin polymerization inhibitory data and provided a basis for further structure-guided design of novel CA-4 analogues. PMID:25529737

  6. Effect of pre-irradiation PPO-grafted maleic anhydride on structure and properties of PPO-g-MAH/PA66 blends

    NASA Astrophysics Data System (ADS)

    Li, Wenfei; Yao, Zhanhai; Yao, Ruixiang; Li, Xuan; Liu, Shumei

    2014-04-01

    The pre-irradiation polyphenylene oxide (PPO)-graft-maleic anhydride (PPO-g-MAH) was carried out by reactive extrusion. The chemical structure of PPO-g-MAH was characterized by means of Fourier-transform infrared spectroscopy. The wettability of PPO-g-MAH was characterized by the contact angle method. The blends of PPO-g-MAH/polyamide 66 (PA66) were prepared. Compared with the PPO/PA66 blends, mechanical properties of PPO-g-MAH/PA66 blends were distinctly improved. Smaller dispersed particle sizes with narrower distribution were found in PPO-g-MAH/PA66 blends, via field-emitted scanning electron microscopy. Rheological properties of PPO-g-MAH/PA66 blends were studied with a rotational rheometer.

  7. Microwave-assisted synthesis and biological evaluation of 3,4-diaryl maleic anhydride/N-substituted maleimide derivatives as combretastatin A-4 analogues.

    PubMed

    Guan, Qi; Zuo, Daiying; Jiang, Nan; Qi, Huan; Zhai, Yanpeng; Bai, Zhaoshi; Feng, Dongjie; Yang, Lei; Jiang, Mingyang; Bao, Kai; Li, Chang; Wu, Yingliang; Zhang, Weige

    2015-02-01

    A series of new CA-4 analogues bearing maleic anhydride/N-substituted maleimide moiety were synthesized via a microwave-assisted process. They were evaluated for the anti-proliferative activities against three tumor cell lines (SGC-7901, HT-1080 and KB). Most compounds showed moderate potencies in micromolar range, with the most promising analogue 6f showing active at submicromolar concentration against HT-1080 cancer cells which was selected to investigate the antitumor mechanisms. In addition, molecular docking studies within the colchicine binding site of tubulin were also in good agreement with the tubulin polymerization inhibitory data and provided a basis for further structure-guided design of novel CA-4 analogues.

  8. Effect of temperature and duration of post-cure on in vitro wear and quantity of remaining double bonds of resins containing carboxylic anhydride.

    PubMed

    Peutzfeldt, A

    1995-08-01

    The present study determined the effect of post-cure temperature and duration on in vitro wear resistance and quantity of remaining double bonds of anhydride-containing resins. Temperatures were varied between 37 degrees C and 225 degrees C, and durations were varied between 0 and 24 h. The quantity of remaining double bonds could not be established for post-cure temperatures of 200 degrees C or more due to melting of the polymer. A temperature of approximately 120 degrees C had optimal effect on wear resistance. Quantity of remaining double bonds and wear were found to decrease with increasing duration of post-cure. Low quantities of remaining double bonds were generally associated with low in vitro wear.

  9. Characterization of the alcoholic fraction of vegetable oils by derivatization with diphenic anhydride followed by high-performance liquid chromatography with spectrophotometric and mass spectrometric detection.

    PubMed

    Lerma-García, M J; Ramis-Ramos, G; Herrero-Martínez, J M; Gimeno-Adelantado, J V; Simó-Alfonso, E F

    2009-01-01

    Aliphatic and triterpene alcohols present in vegetable oils have been identified and determined by HPLC using UV-vis and MS detection after previous derivatization with diphenic anhydride. The alcoholic fraction was obtained by saponification, extraction and TLC (according to the European Union official procedure). Derivatization was performed in tetrahydrofuran in the presence of suspended grinded urea, which increases the reaction rate and yield. Derivatized extracts were chromatographed on a C8 column using gradient elution with acetonitrile/water mixtures containing 0.1% acetic acid, with UV-vis followed by negative-ion mode MS detection. Using linear discriminant analysis of the HPLC-MS data (extracted ion chromatograms), oil samples belonging to seven botanical origins (hazelnut, sunflower, corn, extra virgin olive, soybean, peanut and grapeseed) were correctly classified with excellent resolution among all the categories.

  10. Poly(anhydride-ester) and Poly(N-vinyl-2-pyrrolidone) Blends: Salicylic acid-releasing blends with hydrogel-like properties that reduce inflammation

    PubMed Central

    Ouimet, Michelle A.; Fogaça, Renata; Snyder, Sabrina S.; Sathaye, Sameer; Catalani, Luiz H.; Pochan, Darrin J.

    2015-01-01

    Polymers such as poly(N-vinyl-2-pyrrolidone) (PVP) have been used to prepare hydrogels for wound dressing applications but are not inherently bioactive. For enhanced healing, the release of physically admixed therapeutics from hydrogels has been evaluated, but with limited control over drug release profiles. To overcome these limitations, PVP was blended with salicylic acid-based poly(anhydride-esters) (SAPAE) and shown to exhibit hydrogel properties upon swelling. In vitro release studies demonstrated that the chemically incorporated drug (SA) was released from the polymer blends over 3–4 days in contrast to 3 hours, as observed with diffusion-controlled hydrogels. Generally, blends of higher PVP content displayed greater swelling values and faster SA release. The polymer blends significantly reduce the inflammatory cytokine, TNF-α, in vitro without cytotoxic or anti-proliferative effects, further demonstrating their potential as a wound dressing with enhanced healing and decreased scar tissue formation. PMID:25333420

  11. Process for improving phosphorus-vanadium oxide and phosphorus vanadium-co-metal oxide catalysts in the oxidation of -butane to maleic anhydride

    SciTech Connect

    Edwards, R.C.

    1989-03-07

    This patent describes a process for the manufacture of maleic anhydride in which a feedstock comprising butane and a gas containing molecular oxygen are contacted with a phosphorus-vanadium-oxygen catalyst on a catalyst bed having a portion thereof containing an initial exotherm of reaction. The improvement comprises: treating the catalyst by adding to the gaseous feed stream water and a phosphorus compound in an amount sufficient to (a) initiate deactivation of the portion of the catalyst bed containing the initial exotherm, and (b) initiate formation of a new exotherm downstream in the catalyst bed from the initial exotherm, and thereafter reducing or discontinuing application of the phosphorus compound at a point in time when the initial exotherm portion of the catalyst is still undergoing deactivation, thereby allowing the partially deactivated exotherm portion to reactivate producing a more isothermal catalyst bed.

  12. Characterization of the alcoholic fraction of vegetable oils by derivatization with diphenic anhydride followed by high-performance liquid chromatography with spectrophotometric and mass spectrometric detection.

    PubMed

    Lerma-García, M J; Ramis-Ramos, G; Herrero-Martínez, J M; Gimeno-Adelantado, J V; Simó-Alfonso, E F

    2009-01-01

    Aliphatic and triterpene alcohols present in vegetable oils have been identified and determined by HPLC using UV-vis and MS detection after previous derivatization with diphenic anhydride. The alcoholic fraction was obtained by saponification, extraction and TLC (according to the European Union official procedure). Derivatization was performed in tetrahydrofuran in the presence of suspended grinded urea, which increases the reaction rate and yield. Derivatized extracts were chromatographed on a C8 column using gradient elution with acetonitrile/water mixtures containing 0.1% acetic acid, with UV-vis followed by negative-ion mode MS detection. Using linear discriminant analysis of the HPLC-MS data (extracted ion chromatograms), oil samples belonging to seven botanical origins (hazelnut, sunflower, corn, extra virgin olive, soybean, peanut and grapeseed) were correctly classified with excellent resolution among all the categories. PMID:19081103

  13. Enhancement of mechanical and thermal properties of oil palm empty fruit bunch fiber poly(butylene adipate-co-terephtalate) biocomposites by matrix esterification using succinic anhydride.

    PubMed

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Bin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex™), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite. PMID:22343368

  14. Enhancement of mechanical and thermal properties of oil palm empty fruit bunch fiber poly(butylene adipate-co-terephtalate) biocomposites by matrix esterification using succinic anhydride.

    PubMed

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Bin Wan; Rahman, Mohamad Zaki Ab

    2012-02-16

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex™), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite.

  15. Base-stimulated 1,2-, 1,4-, and 1,6-eliminations in suitably substituted alkylidenesuccinates leading to natural and unnatural conjugated alkenyl(methyl)maleic anhydrides.

    PubMed

    Deore, Prashant S; Argade, Narshinha P

    2014-03-21

    With dimethyl maleate as the starting material, facile stereoselective syntheses of natural and unnatural conjugated alkenyl(methyl)maleic anhydrides have been described. The key reactions were base-endorsed novel 1,2-, 1,4-, and 1,6-eliminations in the corresponding alkylidenesuccinate derivatives. The 1,2-eliminations in cyclic carbonate and sulfite by regioselective abstraction of methine protons with the respective release of CO2 and SO2 provided a conjugated ketone product. The characteristic 1,4- and 1,6-elimination reactions with respective release of acetone and mesylate furnished the corresponding unsaturated alcohols. The obtained allylic alcohols were transformed into conjugated alkenyl(methyl)maleic anhydrides via oxidation followed by a Horner-Wadsworth-Emmons reaction pathway in very good yields. The mechanistic aspects involved in these significant elimination reactions have also been described in brief. PMID:24593305

  16. (1S*,2R*,3S*,4R*,5R*)-5-Tetra­decyloxy­methyl-7-oxabicyclo­[2.2.1]heptane-2,3-dicarb­oxy­lic anhydride

    PubMed Central

    Kelly, Colin N.; Sulon, Sarah M.; Pham, Lam N.; Xiang, Kang Rui; Sykora, Richard E.; Forbes, David C.

    2012-01-01

    In the title compound, C23H38O5, the oxabicyclo­[2.2.1]heptane-2,3-dicarb­oxy­lic anhydride unit has a normal geometry and the tetra­decoxymethyl side chain is fully extended. In the crystal, mol­ecules are linked head-to-head by C—H⋯O hydrogen bonds, forming two-dimensional networks propagating along the a and c-axis directions. PMID:23476206

  17. Regioselective Syntheses of [13C]4-Labelled Sodium 1-Carboxy-2-(2-ethylhexyloxycarbonyl)ethanesulfonate and Sodium 2-Carboxy-1-(2-ethylhexyloxycarbonyl)ethanesulfonate from [13C]4-Maleic Anhydride

    PubMed Central

    Barsamian, Adam L.; Perkins, Matt J.; Field, Jennifer A.; Blakemore, Paul R.

    2014-01-01

    The entitled monohydrolysis products, also known as α- and β-ethylhexyl sulfosuccinate ('EHSS'), of the surfactant diisooctyl sulfosuccinate ('DOSS') were synthesized in stable isotope labelled form from [13C]4-maleic anhydride. Sodium [13C]4-1-carboxy-2-(2-ethylhexyloxycarbonyl)ethanesulfonate (α-EHSS) was prepared by the method of Larpent by reaction of 2-ethylhexan-1-ol with [13C]4-maleic anhydride followed by regioselective conjugate addition of sodium bisulfite to the resulting monoester (38% overall yield). The regiochemical outcome of bisulfite addition was confirmed by a combination of 13C/13C (INADEQUATE) and 1H/13C (HMBC) NMR spectral correlation experiments. Sodium [13C]4-2-carboxy-1-(2-ethylhexyloxycarbonyl)ethanesulfonate (β-EHSS) was prepared in four steps by reaction of 4-methoxybenzyl alcohol (PMBOH) with [13C]4-maleic anhydride, regioselective sodium bisulfite addition, DCC mediated esterification with 2-ethylhexan-1-ol, and PMB ester deprotection with trifluoroacetic acid (13% overall yield). The regiochemical outcome of the second synthesis was confirmed by a combination of 1JCC scalar coupling constant analysis and 1H/13C (HMBC) NMR spectral correlation. The materials prepared are required as internal standards for the LC-MS/MS trace analysis of the degradation products of DOSS, the anionic surfactant found in Corexit, the oil dispersant used during emergency response efforts connected to the Deepwater Horizon oil spill of April 2010. PMID:24700711

  18. Treatment with Succinic Anhydride Improves the Immunogenicity of Shigella flexneri Type 2a O-Specific Polysaccharide–Protein Conjugates in Mice

    PubMed Central

    Pavliakova, Danka; Chu, Chiayung; Bystricky, Slavomir; Tolson, Nathaniel W.; Shiloach, Joseph; Kaufman, Jeanne B.; Bryla, Dolores A.; Robbins, John B.; Schneerson, Rachel

    1999-01-01

    Seroepidemiological data and a clinical trial with a Shigella sonnei O-specific polysaccharide (O-SP)–Pseudomonas aeruginosa recombinant exoprotein A (rEPA) conjugate provide evidence that a critical level of immunoglobulin G (IgG) lipopolysaccharide (LPS) antibodies in serum confers protection against shigellosis. We evaluated the immunogenicity of conjugates whose carrier proteins and O-SPs were treated with succinic anhydride (SA), which reacts with amino groups at neutral pH to form amide-linked carboxyls (succinylation). Conjugates were synthesized with either of two genetically inactivated medically useful toxins, the diphtheria protein CRM9 or rEPA, bound to the O-SP of Shigella flexneri type 2a. Conjugates composed of the succinylated protein, succinylated O-SP, or both succinylated components were administered to mice by a clinically relevant scheme, and their levels of serum IgG anti-LPS and anti-proteins were assayed 7 days after the second and third injections. CRM9 served as a more immunogenic carrier than rEPA. Conjugates composed of succinylated components were more immunogenic than the conjugates composed of the native components. SA treatment of both the carrier protein and the O-SP did not confer an advantage over the succinylated protein alone. Conjugates prepared with native proteins, in general, elicited slightly higher levels of IgG protein antibodies than conjugates composed of the SA-treated proteins. PMID:10496944

  19. Encapsulation and stabilization of indocyanine green within poly(styrene-alt-maleic anhydride) block-poly(styrene) micelles for near-infrared imaging.

    PubMed

    Rodriguez, Victoria B; Henry, Scott M; Hoffman, Allan S; Stayton, Patrick S; Li, Xingde; Pun, Suzie H

    2008-01-01

    Indocyanine green (ICG) is a Federal Drug Administration-approved near-infrared imaging agent susceptible to chemical degradation, nonspecific binding to blood proteins, and rapid clearance from the body. In this study, we describe the encapsulation of ICG within polymeric micelles formed from poly(styrene-alt-maleic anhydride)-block-poly(styrene) (PSMA-b-PSTY) diblock copolymers to stabilize ICG for applications in near-infrared diagnostic imaging. In aqueous solution, the diblock copolymers self-assemble to form highly stable micelles approximately 55 nm in diameter with a critical micelle concentration (CMC) of approximately 1 mg/L. Hydrophobic ICG salts readily partition into the PSTY core of these micelles with high efficiency, and produce no change in micelle morphology or CMC. Once loaded in the micelle core, ICG is protected from aqueous and thermal degradation, with no significant decrease in fluorescence emission over 14 days at room temperature and retaining 63% of its original emission at 37 degrees C. Free ICG does not release rapidly from the micelle core, with only 11% release over 24 h. The ICG-loaded micelles do not exhibit significant cell toxicity. This system has the potential to greatly improve near-infrared imaging in breast cancer detection by increasing the stability of ICG for formulation/administration, and by providing a means to target ICG to tumor tissue.

  20. Anionic polymer, poly(methyl vinyl ether-maleic anhydride)-coated beads-based capture of human influenza A and B virus.

    PubMed

    Sakudo, Akikazu; Baba, Koichi; Tsukamoto, Megumi; Sugimoto, Atsuko; Okada, Takashi; Kobayashi, Takanori; Kawashita, Norihito; Takagi, Tatsuya; Ikuta, Kazuyoshi

    2009-01-15

    An anionic magnetic beads-based method was developed for the capture of human influenza A and B viruses from nasal aspirates, allantoic fluid and culture medium. A polymer, poly(methyl vinyl ether-maleic anhydride) [poly(MVE-MA)], was used to endow magnetic beads with a negative charge and bioadhesive properties. After incubation with samples containing human influenza virus, the beads were separated from supernatants by applying a magnetic field. The adsorption [corrected] of the virus by the beads was confirmed by hemagglutinin assay, immunochromatography, Western blotting, egg infection, and cell infection. Successful capture was proved using 5 H1N1 influenza A viruses, 10 H3N2 influenza A viruses, and 6 influenza B viruses. Furthermore, the infectivity in chicken embryonated eggs and Madin-Darby canine kidney (MDCK) cells of the captured human influenza virus was similar to that of the total viral quantity of starting materials. Therefore, this method of capture using magnetic beads coated with poly(MVE-MA) can be broadly used for the recovery of infectious human influenza viruses.

  1. 2, 3-Dimethylmaleic anhydride (3, 4-Dimethyl-2, 5-furandione): A plant derived insecticidal molecule from Colocasia esculenta var. esculenta (L.) Schott

    PubMed Central

    Rajashekar, Yallappa; Tonsing, Ngaihlun; Shantibala, Tourangbam; Manjunath, Javagal R.

    2016-01-01

    The phasing out of methyl bromide as a fumigant, resistance problems with phosphine and other fumigants in stored product beetles, and serious concern with human health and environmental safety have triggered the search for alternative biofumigants of plant origin. Despite the identification of a large number of plants that show insecticidal activity, and the diversity of natural products with inherent eco-friendly nature, newer biofumigants of plant origin have eluded discovery. Using a bioassay driven protocol, we have now isolated a bioactive molecule from the root stock of Colocasia esculenta (L.) and characterized it as 2, 3-dimethylmaleic anhydride (3, 4-dimethyl-2, 5-furandione) based on various physico-chemical and spectroscopic techniques (IR, 1H NMR, 13C NMR and Mass). The molecule proved to be an efficient biofumigant which is highly toxic to insect pests for stored grains even at very low concentration, but has no adverse effect on seed germination. We finally address the potential for this molecule to become a, effective biofumigant. PMID:26837840

  2. Femtosecond-picosecond laser photolysis studies on the dynamics of excited charge-transfer complexes: Aromatic hydrocarbon-acid anhydride, -tetracyanoethylene, and -tetracyanoquinodimethane systems in acetonitrile solutions

    SciTech Connect

    Asahi, Tsuyoshi; Mataga, Noboru )

    1991-03-07

    Formation processes of contact ion pairs (CIP) from the excited Franck-Condon (FC) state of charge-transfer (CT) complexes of aromatic hydrocarbons with acid anhydride as well as cyano compound acceptors in acetonitrile solution and charge recombination (CR) rates (k{sub CR}{sup CIP}) of produced CIP states have been investigated by femtosecond and picosecond laser phototlysis and time-resolved absorption spectral measurements covering a wide range of free energy gap-{Delta}G{degree}{sub ip} between the ion pair and the ground state. It has been confirmed that the CIP formation becomes faster and k{sub CR}{sup CIP} of the produced CIP increases with increase of the strengths of the electron donor (D) and acceptor (A) in the complex, i.e., with decrease of the {minus}{Delta}G{degree}{sub ip} value. This peculiar energy gap dependence of k{sub CR}{sup CIP}, quite different from the bell-shaped one observed in the case of the solvent-separated ion pairs (SSIP) or loose ion pairs (LIP) formed by encounter between fluorescer and quencher in the fluoresence quenching reaction, has been interpreted by assuming the change of electronic and geometrical structures of CIP depending on the strengths of D and A.

  3. 2, 3-Dimethylmaleic anhydride (3, 4-Dimethyl-2, 5-furandione): A plant derived insecticidal molecule from Colocasia esculenta var. esculenta (L.) Schott.

    PubMed

    Rajashekar, Yallappa; Tonsing, Ngaihlun; Shantibala, Tourangbam; Manjunath, Javagal R

    2016-01-01

    The phasing out of methyl bromide as a fumigant, resistance problems with phosphine and other fumigants in stored product beetles, and serious concern with human health and environmental safety have triggered the search for alternative biofumigants of plant origin. Despite the identification of a large number of plants that show insecticidal activity, and the diversity of natural products with inherent eco-friendly nature, newer biofumigants of plant origin have eluded discovery. Using a bioassay driven protocol, we have now isolated a bioactive molecule from the root stock of Colocasia esculenta (L.) and characterized it as 2, 3-dimethylmaleic anhydride (3, 4-dimethyl-2, 5-furandione) based on various physico-chemical and spectroscopic techniques (IR, (1)H NMR, (13)C NMR and Mass). The molecule proved to be an efficient biofumigant which is highly toxic to insect pests for stored grains even at very low concentration, but has no adverse effect on seed germination. We finally address the potential for this molecule to become a, effective biofumigant.

  4. Molecular conformational analysis, vibrational spectra, NBO, NLO analysis and molecular docking study of bis[(E)-anthranyl-9-acrylic]anhydride based on density functional theory calculations.

    PubMed

    Mary, Y Sheena; Panicker, C Yohannan; Thiemann, Thies; Al-Azani, Mariam; Al-Saadi, Abdulaziz A; Van Alsenoy, C; Raju, K; War, Javeed Ahmad; Srivastava, S K

    2015-01-01

    FT-IR and FT-Raman spectra of bis[(E)-anthranyl-9-acrylic]anhydride were recorded and analyzed. The conformational behavior is also investigated. The vibrational wave numbers were calculated using density functional theory (DFT) quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in Infrared and Raman spectra. Potential energy distribution was done using GAR2PED program. The geometrical parameters are compared with related structures. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using Natural Bonding Orbital (NBO) analysis. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) analysis are used to determine the charge transfer within the molecule. Molecular Electrostatic Potential (MEP) was performed by the DFT method. The calculated first hyperpolarizability of the title compound is comparable with the reported values of similar derivatives and is 4.23 times that of the standard nonlinear optical (NLO) material urea and the title compound and its derivatives are an attractive object for future studies of nonlinear optical properties. To evaluate the in silico antitumor activity of the title compound molecular docking studies were carried out against protein Bcl-xL. The (1)H-NMR spectrum is also reported. PMID:26143327

  5. Uptake and phytotoxicity of the herbicide metsulfuron methyl in corn root tissue in the presence of the safener 1,8-naphthalic anhydride. [Zea mays L

    SciTech Connect

    Milhomme, H.; Bastide, J. )

    1990-06-01

    Growth of Zea mays L. cv Potro roots was inhibited by the herbicide metsulfuron methyl (MSM) at the lowest concentration tested: 5 nanomoles per liter. Pretreatment of corn seeds with commercial 1,8-naphthalic anhydride (NA) at 1% (w/w) partially reversed MSM-induced root growth inhibition. MSM at a concentration of 52 nanomoles per liter was taken up rapidly by roots and accumulated in the corn tissue to concentrations three times those in the external medium; the safener NA increased MSM uptake up to 48 hours. The protective effect of NA was related to the ability of the safener to increase the metabolism of MSM; ten-fold increases in the metabolic rates of MSM were observed in NA-pretreated corn seedlings grown for 48 hours on 52 nanomolar ({sup 14}C)MSM solution. DNA synthesis determined by measurement of ({sup 3}H)thymidine incorporation into DNA was inhibited by root MSM applications; after a 6-hour application period, 13 nanomolar MSM solution reduced DNA synthesis by 64%, and the same reduction was also observed with NA-treated seedlings. Pretreatment of corn seeds with safener NA did not increase the acetolactate synthase activity in the roots and did not change, up to 13 micromoles per liter, the in vitro sensitivity of roots to MSM.

  6. Preparation and characterization of mucoadhesive nanoparticles of poly (methyl vinyl ether-co-maleic anhydride) containing glycyrrhizic acid intended for vaginal administration.

    PubMed

    Aguilar-Rosas, Irene; Alcalá-Alcalá, Sergio; Llera-Rojas, Viridiana; Ganem-Rondero, Adriana

    2015-01-01

    Traditional vaginal preparations reside in the vaginal cavity for relatively a short period of time, requiring multiple doses in order to attain the desired therapeutic effect. Therefore, mucoadhesive systems appear to be appropriate to prolong the residence time in the vaginal cavity. In the current study, mucoadhesive nanoparticles based on poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA) intended for vaginal delivery of glycyrrhizic acid (GA) (a drug with well-known antiviral properties) were prepared and characterized. Nanoparticles were generated by a solvent displacement method. Incorporation of GA was performed during nanoprecipitation, followed by adsorption of drug once nanoparticles were formed. The prepared nanoparticles were characterized in terms of size, Z-potential, morphology, drug loading, interaction of GA with PVM/MA (by differential scanning calorimetry) and the in vitro interaction of nanoparticles with pig mucin (at two pH values, 3.6 and 5; with and without GA adsorbed). The preparation method led to nanoparticles of a mean diameter of 198.5 ± 24.3 nm, zeta potential of -44.8 ± 2.8 mV and drug loading of 15.07 ± 0.86 µg/mg polymer. The highest mucin interaction resulted at pH 3.6 for nanoparticles without GA adsorbed. The data obtained suggest the promise of using mucoadhesive nanoparticles of PVM/MA for intravaginal delivery of GA.

  7. Preparation and characterization of single and dual propylene oxide and octenyl succinic anhydride modified starch carriers for the microencapsulation of essential oils.

    PubMed

    Baranauskienė, Renata; Rutkaitė, Ramunė; Pečiulytė, Laura; Kazernavičiūtė, Rita; Venskutonis, Petras Rimantas

    2016-08-10

    Hydroxypropylation with propylene oxide followed by esterification with octenyl succinic anhydride (OSA) was used to produce modified potato starch derivatives suitable for the encapsulation of essential oils. Caraway essential oil (EO) was encapsulated by spray-drying into enzymatically hydrolyzed dual/single modified and native starches. The EO microencapsulation efficiency in different modified starches, the retention of volatile aroma compounds, the emulsion particle size and the microstructure of the spray-dried encapsulated powdered products, as well as the compositional aroma changes taking place during the processing and storage for up to 8 months have been estimated. The increase of OSA content from 0.97 to 2.52% in the P-native structure and from 0.91% to 2.66% in P-HP resulted in the significant increase in the encapsulating capacity, evaluated as a percentage of the total EO retained, from 61.6 to 88.0% and 73.8% to 84.0%, respectively. However, the compositional changes of the microencapsulated caraway EO constituents were not remarkable. Additionally, the effect of pure and encapsulated caraway EO products on the oxidative stability of commercial rapeseed oil and mayonnaise was evaluated using the instrumental Oxipres method and it was shown that they were more effective in emulsion type products by the up to 1.8-fold increase in the oxidative stability of mayonnaise. PMID:27465989

  8. 2, 3-Dimethylmaleic anhydride (3, 4-Dimethyl-2, 5-furandione): A plant derived insecticidal molecule from Colocasia esculenta var. esculenta (L.) Schott.

    PubMed

    Rajashekar, Yallappa; Tonsing, Ngaihlun; Shantibala, Tourangbam; Manjunath, Javagal R

    2016-01-01

    The phasing out of methyl bromide as a fumigant, resistance problems with phosphine and other fumigants in stored product beetles, and serious concern with human health and environmental safety have triggered the search for alternative biofumigants of plant origin. Despite the identification of a large number of plants that show insecticidal activity, and the diversity of natural products with inherent eco-friendly nature, newer biofumigants of plant origin have eluded discovery. Using a bioassay driven protocol, we have now isolated a bioactive molecule from the root stock of Colocasia esculenta (L.) and characterized it as 2, 3-dimethylmaleic anhydride (3, 4-dimethyl-2, 5-furandione) based on various physico-chemical and spectroscopic techniques (IR, (1)H NMR, (13)C NMR and Mass). The molecule proved to be an efficient biofumigant which is highly toxic to insect pests for stored grains even at very low concentration, but has no adverse effect on seed germination. We finally address the potential for this molecule to become a, effective biofumigant. PMID:26837840

  9. Rheological Analysis of Polymer Interactions and Ageing of Poly(Methylvinylether-Co-Maleic Anhydride)/Poly(Vinyl Alcohol) Binary Networks and Their Effects on Mucoadhesion.

    PubMed

    Andrews, Gavin P; Laverty, Thomas P; Jones, David S

    2015-12-01

    Polymer blends of poly(vinylalcohol, PVA) and poly(methylvinylether-co-maleic anhydride, PMVE/MA) were formulated and their viscoelastic and mucoadhesive properties characterised. The viscoelastic and mucoadhesive properties were dependent on polymer concentration, molecular weight of PVA and PVA:PMVE/MA ratio. Alteration of these properties allowed platforms to be designed to offer defined rheological and mucoadhesive properties, properties that could not be achieved using monopolymeric platforms. A strong correlation was noted between the modulus of the polymeric blends and mucoadhesion. After storage, the polymeric blends underwent rheological structuring (ageing) with an attendant enhancement of mucoadhesion. In certain blends containing the highest molecular weight of PVA (146-186 kDa), storage ultimately resulted in an increase and then a significant decrease in the rheological and mucoadhesive properties, the latter phenomenon being accredited to polymer recrystallisation. Ageing of the rheological and mucoadhesive properties was modelled using an exponential growth model, allowing predictions of the storage period associated with the maxima in viscoelastic and mucoadhesive properties. These observations highlight the possible implications whenever interactive polymeric blends are employed in drug delivery. Caution is therefore urged whenever a formulation strategy based on interactive polymer blends is employed to ensure that ageing is fully understood and mathematically characterised. PMID:26502109

  10. Preparation and characterization of poly(methyl methacrylate) and poly(maleic anhydride-co-diallyl phthalate) grafted carbon black through γ-ray irradiation

    NASA Astrophysics Data System (ADS)

    Bo, Yang; Cui, Jiayang; Cai, Yangben; Xu, Shiai

    2016-02-01

    In this study, the grafting polymerization of methyl methacrylate (MMA) monomer and maleic anhydride/diallyl phthalate (MAH/DAP) co-monomer onto the surface of carbon black (CB) were carried out at room temperature and normal pressure by γ-ray irradiation. The surface chemistry of grafted CBs were characterized by infrared spectroscopy (IR), thermo-gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The results show that there are some remanent polymers on the surface of modified CBs after extract for 48 h, indicating that poly(methyl methacrylate) (PMMA) and poly(MAH-co-DAP) have been successfully grafted onto the surface of CB without using initiator due to the high energy of γ-ray irradiation. Dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) reveal that the grafted CBs have smaller average aggregate size and better dispersibility than that of CB in absolute ethanol. In addition, it was found that the amount of oxygen groups and the irradiation doses/dose rates have little effect on the grafting degree of CB.

  11. Investigation of the formation of benzoyl peroxide, benzoic anhydride, and other potential aerosol products from gas-phase reactions of benzoylperoxy radicals

    NASA Astrophysics Data System (ADS)

    Strollo, Christen M.; Ziemann, Paul J.

    2016-04-01

    The secondary organic aerosol (SOA) products of the reaction of benzaldehyde with Cl atoms and with OH radicals in air in the absence of NOx were investigated in an environmental chamber in order to better understand the possible role of organic peroxy radical self-reactions in SOA formation. SOA products and authentic standards were analyzed using mass spectrometry and liquid chromatography, and results show that the yields of benzoyl peroxide (C6H5C(O)OO(O)CC6H5) and benzoic anhydride (C6H5C(O)O(O)CC6H5), two potential products from the gas-phase self-reaction of benzoylperoxy radicals (C6H5C(O)OO·), were less than 0.1%. This is in contrast to results of recent studies that have shown that the gas-phase self-reactions of β-nitrooxyperoxy radicals formed from reactions of isoprene with NO3 radicals form dialkyl peroxides that contribute significantly to gas-phase and SOA products. Such reactions have also been proposed to explain the gas-phase formation of extremely low volatility dimers from autooxidation of terpenes. The results obtained here indicate that, at least for benzoylperoxy radicals, the self-reactions form only benzoyloxy radicals. Analyses of SOA composition and volatility were inconclusive, but it appears that the SOA may consist primarily of oligomers formed through heterogeneous/multiphase reactions possibly involving some combination of phenol, benzaldehyde, benzoic acid, and peroxybenzoic acid.

  12. Kinetic and spectrophotometric investigation of the diels-alder reaction between maleic anhydride derivatives and substituted anthracenes in the presence of gallium and aluminum chlorides

    SciTech Connect

    Kiselev, V.D.; Konovalov, A.I.; Shakirov, I.M.

    1986-10-01

    A comparison was made of the kinetic data for the normal Diels-Alder reaction of para-substituted N-arylmaleimides and substituted maleic anhydrides with meso-substituted anthracenes and of the reaction catalyzed by gallium and aluminum chlorides. The largely constant effects of gallium chloride (10/sup 4/) and aluminum chloride (10/sup 5/) in the acceleration of the reactions between the various pairs were demonstrated. The energies of charge transfer in the complexes between hexamethylbenzene and the dienophiles in the presence and absence of Lewis acids were determined by spectrophotometry. A significant decrease (to 1.2 eV) of the charge-transfer energy was found in the ..pi.., ..pi..-complexes and was attributed to the stabilization of the LUMO of the dienophile. From analysis of the obtained data it was concluded that the observed catalytic effect in the presence of Lewis acids can be explained by the approach of the frontier orbital levels and by a favorable change in the coefficients at the atomic orbitals responsible for the reaction.

  13. In situ FTIR spectroscopy of 1-butene and 1,3-butadiene selective oxidation to maleic anhydride on V-P-O catalysts

    SciTech Connect

    Wenig, R.W.; Schrader, G.L.

    1987-03-26

    The selective oxidation of 1-butene and 1,3-butadiene was studied by transmission infrared spectroscopy. Vanadium-phosphorus-oxygen catalysts prepared by the reaction of V/sub 2/O/sub 5/ with H/sub 3/PO/sub 4/ in alcohol solution were used. Infrared spectra were collected in situ during the flow of 75 cm/sup 3/ of 1.5% hydrocarbon-in-air mixtures over catalysts having P-to-V ratios of 0.9, 1.0, and 1.1. Reaction temperatures from 300 to 400 /sup 0/C were investigated with 1-butene feeds, whereas the highly reactive 1,3-butadiene was studied only at 300 /sup 0/C. An adsorbed butadiene species, maleic acid, and maleic anhydride were observed during both olefin partial oxidation studies. Evidence was obtained for a second olefin species which had been previously observed for in situ n-butane selective oxidation studies. Concentrations of adsorbed species were found to vary with catalyst phosphorus loading, reaction temperature, and time of exposure to reaction conditions.

  14. Molecular conformational analysis, vibrational spectra, NBO, NLO analysis and molecular docking study of bis[(E)-anthranyl-9-acrylic]anhydride based on density functional theory calculations.

    PubMed

    Mary, Y Sheena; Panicker, C Yohannan; Thiemann, Thies; Al-Azani, Mariam; Al-Saadi, Abdulaziz A; Van Alsenoy, C; Raju, K; War, Javeed Ahmad; Srivastava, S K

    2015-01-01

    FT-IR and FT-Raman spectra of bis[(E)-anthranyl-9-acrylic]anhydride were recorded and analyzed. The conformational behavior is also investigated. The vibrational wave numbers were calculated using density functional theory (DFT) quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in Infrared and Raman spectra. Potential energy distribution was done using GAR2PED program. The geometrical parameters are compared with related structures. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using Natural Bonding Orbital (NBO) analysis. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) analysis are used to determine the charge transfer within the molecule. Molecular Electrostatic Potential (MEP) was performed by the DFT method. The calculated first hyperpolarizability of the title compound is comparable with the reported values of similar derivatives and is 4.23 times that of the standard nonlinear optical (NLO) material urea and the title compound and its derivatives are an attractive object for future studies of nonlinear optical properties. To evaluate the in silico antitumor activity of the title compound molecular docking studies were carried out against protein Bcl-xL. The (1)H-NMR spectrum is also reported.

  15. Optimization and Simultaneous Determination of Alkyl Phenol Ethoxylates and Brominated Flame Retardants in Water after SPE and Heptafluorobutyric Anhydride Derivatization followed by GC/MS.

    PubMed

    Chokwe, Tlou B; Okonkwo, Jonathan O; Sibali, Linda L; Ncube, Esper J

    2012-10-01

    A gas chromatography-mass spectrometry (GC-MS) method was investigated for the simultaneous analysis of two types of endocrine disrupting compounds (EDCs), i.e., alkylphenol ethoxylates and brominated flame retardants (BFRs), by extraction and derivatization followed by GC-MS. Different solid phase extraction (SPE) cartridges (Cleanert PestiCarb, C18, Cleanert-SAX and Florosil), solvents (toluene, tetrahydrofuran, acetone, acetonitrile and ethyl acetate) and bases (NaHCO3, triethylamine and pyridine) were tested and the best chromatographic analysis was achieved by extraction with Strata-X (33 μm, Reverse Phase) cartridge and derivatization with heptafluorobutyric anhydride at 55 °C under Na2CO3 base in hexane. It was observed that APE together with lower substituted PBBs (PBB1, PBB10, PBB18 and PBB49), HBCD and TBBPA can be determined simultaneously under the same GC conditions. This simple and reliable analytical method was applied to determining trace amounts of these compounds from wastewater treatment plant samples. The recoveries of the target compounds from simulated water were above 60 %. The limit of detection ranged from 0.01 to 0.15 μg L(-1) and the limit of quantification ranged from 0.05 to 0.66 μg L(-1). There were no appreciable differences between filtered and unfiltered wastewater samples from Leeuwkil treatment plant although concentration of target analytes in filtered influent was slightly lower than the concentration of target analytes in unfiltered influent water. The concentrations of the target compounds from the wastewater treatment were determined from LOQ upwards. PMID:23864736

  16. Simultaneous efficient adsorption of Pb2+ and MnO4- ions by MCM-41 functionalized with amine and nitrilotriacetic acid anhydride

    NASA Astrophysics Data System (ADS)

    Chen, Feiyun; Hong, Mingzhu; You, Weijie; Li, Chong; Yu, Yan

    2015-12-01

    A novel adsorbent NH2/MCM-41/NTAA, capable of simultaneous adsorption of cations and anions from aqueous solution, was prepared by immobilization of amine and nitrilotriacetic acid anhydride (NTAA) onto MCM-41. The structures and properties before and after surface modification were systematically investigated through X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM), nitrogen adsorption-desorption, and infrared spectroscopy (FTIR), thermogravimetry (TGA) and X-ray photoelectron spectroscopy (XPS). They together confirm that the amine and NTAA group were chemically bonded to the internal surface of the mesoporous. The NH2/MCM-41/NTAA were used to adsorb Pb2+ and MnO4- in an aqueous solution in a batch system, and the maximum adsorption efficiency was found to occur at pH 5.0 and 3.0, respectively. NH2/MCM-41/NTAA exhibit preferable removal of Pb2+ through electrostatic interactions and chelation, whereas it captures MnO4- by means of electrostatic interactions. The experimental data are fitted the Langmuir isotherm model reasonably well, with the maximum adsorption capacity of 147 mg/g for Pb2+ and of 156 mg/g for MnO4-. The adsorption rates of both Pb2+ and MnO4- are found to follow the pseudo-second order kinetics. Furthermore, the NH2/MCM-41/NTAA adsorbent performs good recyclability and reusability for 5 cycles use. This study indicates a potential applicability of NH2/MCM-41/NTAA as new absorbents for effective simultaneous adsorption of hazardous metal ions and anions from wastewater.

  17. Enhancement of mechanical properties, microstructure, and antimicrobial activities of zein films cross-linked using succinic anhydride, eugenol, and citric Acid.

    PubMed

    Khalil, Ashraf A; Deraz, Sahar F; Elrahman, Somia Abd; El-Fawal, Gomaa

    2015-08-18

    Zein constitutes about half of the endosperm proteins in corn. Recently, attempts have been made to utilize zein for food coatings and biodegradable materials, which require better physical properties, using chemical modification of zein. In this study, zein proteins were modified using citric acid, succinic anhydride, and eugenol as natural cross-linking agents in the wet state. The cross-linkers were added either separately or combined in increment concentrations (0.1, 0.2, 0.3, and 0.4%). The effects of those agents on the mechanical properties, microstructure, optical properties, infrared (IR) spectroscopy, and antibacterial activities of zein were investigated. The addition of cross-linking agents promoted changes in the arrangement of groups in zein film-forming particles. Regarding the film properties, incorporation of cross-linking agents into zein films prepared in ethanol resulted in two- to three-fold increases in tensile strength (TS) values. According to the Fourier-transform infrared (FTIR) spectra and Hunter parameters there were no remarkable changes in the structure and color of zein films. Transparency of zein films was decreased differentially according to the type and cross-linker concentration. The mechanical and optical properties of zein films were closely related to their microstructure. All cross-linked films showed remarkable antibacterial activities against Bacillus cereus ATCC 49064 and Salmonella enterica ATCC 25566. Food spoilage and pathogenic bacteria were affected in a film-dependent manner. Our experimental results show that even with partial cross-linking the mechanical properties and antipathogen activities of zein films were significantly improved, which would be useful for various industrial applications.

  18. Synthesis, characterisation, and evaluation of a cross-linked disulphide amide-anhydride-containing polymer based on cysteine for colonic drug delivery.

    PubMed

    Lim, Vuanghao; Peh, Kok Khiang; Sahudin, Shariza

    2013-12-18

    The use of disulphide polymers, a low redox potential responsive delivery, is one strategy for targeting drugs to the colon so that they are specifically released there. The objective of this study was to synthesise a new cross-linked disulphide-containing polymer based on the amino acid cysteine as a colon drug delivery system and to evaluate the efficiency of the polymers for colon targeted drug delivery under the condition of a low redox potential. The disulphide cross-linked polymers were synthesised via air oxidation of 1,2-ethanedithiol and 3-mercapto-N-2-(3-mercaptopropionamide)-3-mercapto propionic anhydride (trithiol monomers) using different ratio combinations. Four types of polymers were synthesised: P10, P11, P151, and P15. All compounds synthesised were characterised by NMR, IR, LC-MS, CHNS analysis, Raman spectrometry, SEM-EDX, and elemental mapping. The synthesised polymers were evaluated in chemical reduction studies that were performed in zinc/acetic acid solution. The suitability of each polymer for use in colon-targeted drug delivery was investigated in vitro using simulated conditions. Chemical reduction studies showed that all polymers were reduced after 0.5-1.0 h, but different polymers had different thiol concentrations. The bacterial degradation studies showed that the polymers were biodegraded in the anaerobic colonic bacterial medium. Degradation was most pronounced for polymer P15. This result complements the general consensus that biodegradability depends on the swellability of polymers in an aqueous environment. Overall, these results suggest that the cross-linked disulphide-containing polymers described herein could be used as coatings for drugs delivered to the colon.

  19. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

    PubMed Central

    Jeon, Jong Yeob; Eo, Seong Chan; Varghese, Jobi Kodiyan

    2014-01-01

    Summary The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (M w/M n, 1.05–1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (M n up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (f PA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C). PMID:25161738

  20. Curing chemistry of phenylethynyl-terminated imide oligomers: Model compounds, carbon-13 labeling and cure analysis

    NASA Astrophysics Data System (ADS)

    Roberts, Christopher Chad

    1998-11-01

    Phenylethynyl-terminated imide oligomers (PETI) are currently considered the state-of-the-art high performance resins for aerospace applications. The processing of these resins is more facile because of their low molecular weight, but PETI's cure to form a tough, solvent-resistant material. However, the final cure structure was a complete mystery. Hence, the present study was set forth with three essential goals. The determination of the final structure of the crosslinked polymer is of obvious importance. Second, the crosslinking mechanism and controlling factors is also of interest. Lastly, the final structure of the crosslinked polymers was correlated with mechanical and thermal properties, thereby helping to establish the structure-processing-properties relationships for PETI resins. These goals were accomplished by using a combination of synthesis of model compounds synthesis and proposed cure products, sp{13}C labeling of the ethynyl endgroup in PETI's, monitoring of the thermal cure using solid state sp{13}C NMR and ESR and molecular modeling techniques. Phenylethynyl endcapping agents, 4-(phenylethynyl)phthalic anhydride (PEPA) and 3-(phenylethynyl)aniline (3PEA), were synthesized via the palladium-catalyzed coupling of phenylacetylene with 4-bromophthalic anhydride or 3-iodonitrobenzene followed by reduction to 3PEA, respectively. Isolated yields of 41 and 86% for 3PEA and PEPA were obtained, respectively. Model compounds were synthesized from 3PEA and PEPA by reacting with them the appropriate aniline or phthalic anhydride derivative. Model compounds included N-pentafluorophenyl-4-(phenylethynyl)phthalimide (PEPA/F5An), N-(4-trifluoromethyl-phenyl)4-(phenylethynyl)phthalimide (PEPA/F3CAn), N-lbrack 3-(phenylethynyl)phenylrbrack\\ phthalimide (3PEA/PA), N-phenyl-4-(phenylethynyl)phthalimide (PEPA/An), N-(4-phenoxyphenyl)4-(phenylethynyl)phthalimide (PEPA/POAn), and N-(1-naphthyl)-4-(phenylethynyl)phthalimide (PEPA/Anaph). Proposed cure products such as

  1. On the role of the VO(H{sub 2}PO{sub 4}){sub 2} precursor for n-butane oxidation into maleic anhydride

    SciTech Connect

    Sananes, M.T. |; Hutchings, G.J.; Volta, J.C.

    1995-07-01

    The catalytic role of VO(H{sub 2}PO{sub 4}){sub 2}, the precursor of the VO(PO{sub 3}){sub 2} phase, has been studied for N-butane oxidation to maleic anhydride. By comparison with the activated VPO catalyst, derived from the VOHPO{sub 4} {center_dot} 0.5H{sub 2}O precursor phase, VO(H{sub 2}PO{sub 4}){sub 2} gives a highly selective final catalyst. The total oxidation products CO and CO{sub 2} are not observed under any of the conditions examined, a result confirmed by extensive catalyst testing and carbon mass balances. The final catalyst derived from VO(H{sub 2}PO{sub 4}){sub 2} has a low surface area, ca. 1 m{sup 2}/g, and consequently demonstrates low specific activity on the basis of n-butane conversion per unit mass. However, the intrinsic activity (activity per unit surface area) is found to be higher than that for catalysts derived from VOHPO{sub 4}{center_dot}0.5H{sub 2}O. Since some VO(H{sub 2}PO{sub 4}){sub 2} is present in VOHPO{sub 4}{center_dot}0.5H{sub 2}O, which is the precursor of the industrial catalyst, the results of this study complicate the simple model in which the (VO){sub 2}O{sub 7} phase derived from VOHPO{sub 4} {center_dot}0.5H{sub 2}O is responsible for the selective oxidation of n-butane. The observation that the precursor VO(H{sub 2}PO{sub 4}){sub 2} can generate catalysts of high specific activity and of total selectivity to partial oxidation products might provide a useful insight into the design of a new series of high activity and high selectivity partial oxidation catalysts. 36 refs., 12 figs., 2 tabs.

  2. Effect of difructose anhydride III supplementation on passive immunoglobulin G transfer and serum immunoglobulin G concentration in newborn Holstein calves fed pooled colostrum.

    PubMed

    Htun, A; Sato, T; Hanada, M

    2016-07-01

    Difructose anhydride (DFA) III acts on intestinal epithelial tight junctions and promotes calcium absorption through the paracellular pathway in dairy cows. This trial was done to investigate the effects of DFA III supplementation on passive IgG transfer and serum IgG concentration in calves. Twenty-four newborn Holstein male calves were grouped as 12 pairs, with each pair receiving a separate batch of pooled colostrum (PC) from the first 2 milkings. One calf from each pair was allocated to the treatment group (n=12) and received 18g of DFA III in each feeding; the other calf was assigned to the control group (n=12) and did not receive DFA III. All calves were fed 2 L of PC per feeding at 1, 10, and 24 h after birth. Prefeeding blood samples taken at 0 h, 10 h, 24 h, 36 h, 4 d, and 7 d were analyzed for serum IgG concentration. Apparent efficiency of IgG absorption in the treatment group was higher compared to that in the control group. Serum IgG concentration of calves in the treatment group was higher for all sampling time points except for 0 h of age. Mean serum IgG concentrations in the treatment and control groups at 36 h of age were 22.3 and 17.7 g/L, respectively. Serum IgG concentration at 36 h of age was positively related with the IgG concentration in the PC in both groups, and it was higher in the treatment group than in the control group at the same IgG concentration in the PC. These results indicate that absorption of ingested IgG by endocytosis as well as a nonselected concentration gradient process of the paracellular pathway of the intestinal epithelium could be enhanced by DFA III supplementation. Supplementation of DFA III in PC containing various IgG concentrations could improve IgG absorption as well as calf serum IgG concentration.

  3. Multifunctional Poly(methyl vinyl ether-co-maleic anhydride)-graft-hydroxypropyl-β-cyclodextrin Amphiphilic Copolymer as an Oral High-Performance Delivery Carrier of Tacrolimus.

    PubMed

    Zhang, Dong; Pan, Xiaolei; Wang, Shang; Zhai, Yinglei; Guan, Jibin; Fu, Qiang; Hao, Xiaoli; Qi, Wanpeng; Wang, Yingli; Lian, He; Liu, Xiaohong; Wang, Yongjun; Sun, Yinghua; He, Zhonggui; Sun, Jin

    2015-07-01

    In order to improve oral bioavailability of tacrolimus (FK506), a novel poly(methyl vinyl ether-co-maleic anhydride)-graft-hydroxypropyl-β-cyclodextrin amphiphilic copolymer (CD-PVM/MA) is developed, combining the bioadhesiveness of PVM/MA, P-glycoprotein (P-gp), and cytochrome P450-inhibitory effect of CD into one. The FK506-loaded nanoparticles (CD-PVM/MA-NPs) were obtained by solvent evaporation method. The physiochemical properties and intestinal absorption mechanism of FK506-loaded CD-PVM/MA-NPs were characterized, and the pharmacokinetic behavior was investigated in rats. FK506-loaded CD-PVM/MA-NPs exhibited nanometer-sized particles of 273.7 nm, with encapsulation efficiency as high as 73.3%. FK506-loaded CD-PVM/MA-NPs maintained structural stability in the simulated gastric fluid, and about 80% FK506 was released within 24 h in the simulated intestinal fluid. The permeability of FK506 was improved dramatically by CD-PVM/MA-NPs compared to its solution, probably due to the synergistic inhibition effect of P-gp and cytochrome P450 3A (CYP3A). The intestinal biodistribution of fluorescence-labeled CD-PVM/MA-NPs confirmed its good bioadhesion to the rat intestinal wall. Two endocytosis pathways, clathrin- and caveolae-mediated endocytosis, were involved in the cellular uptake of CD-PVM/MA-NPs. The important role of lymphatic transport in nanoparticles' access to the systemic circulation, about half of the contribution to oral bioavailability, was observed in mesenteric lymph duct ligated rats. The AUC0-24 of FK506 loaded in nanoparticles was enhanced up to 20-fold compared to FK506 solutions after oral administration. The present study suggested that the novel multifunctional CD-PVM/MA is a promising efficient oral delivery carrier for FK506, due to its ability in solubilization, inhibitory effects on both P-gp and CYP 3A, high bioadhesion, and sustained release capability. PMID:26024817

  4. Validation of an assay for the determination of levoglucosan and associated monosaccharide anhydrides for the quantification of wood smoke in atmospheric aerosol.

    PubMed

    Cordell, Rebecca L; White, Iain R; Monks, Paul S

    2014-09-01

    Biomass burning is becoming an increasing contributor to atmospheric particulate matter, and concern is increasing over the detrimental health effects of inhaling such particles. Levoglucosan and related monosaccharide anhydrides (MAs) can be used as tracers of the contribution of wood burning to total particulate matter. An improved gas chromatography-mass spectrometry method to quantify atmospheric levels of MAs has been developed and, for the first-time, fully validated. The method uses an optimised, low-volume methanol extraction, derivitisation by trimethylsilylation and analysis with high-throughput gas chromatography-mass spectrometry (GC-MS). Recovery of approximately 90 % for levoglucosan, and 70 % for the isomers galactosan and mannosan, was achieved using spiked blank filters estimates. The method was extensively validated to ensure that the precision of the method over five experimental replicates on five repeat experimental occasions was within 15 % for low, mid and high concentrations and accuracy between 85 and 115 %. The lower limit of quantification (LLOQ) was 0.21 and 1.05 ng m(-3) for levoglucosan and galactosan/mannosan, respectively, where the assay satisfied precisions of ≤20 % and accuracies 80-120 %. The limit of detection (LOD) for all analytes was 0.105 ng m(-3). The stability of the MAs, once deposited on aerosol filters, was high over the short term (4 weeks) at room temperature and over longer periods (3 months) when stored at -20 °C. The method was applied to determine atmospheric levels of MAs at an urban background site in Leicester (UK) for a month. Mean concentrations of levoglucosan over the month of May were 21.4 ± 18.3 ng m(-3), 7.5 ± 6.1 ng m(-3) mannosan and 1.8 ± 1.3 ng m(-3) galactosan. PMID:24948096

  5. Changes of Serum Calcium Concentration, Frequency of Ruminal Contraction and Feed Intake Soon after Parturition of Dairy Cows Fed Difructose Anhydride III

    PubMed Central

    Wynn, S.; Teramura, M.; Sato, T.; Hanada, M.

    2015-01-01

    Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p<0.05). Time interval for recovery from decreased serum Ca to its normal range (>9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis (R2 = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition. PMID:25557676

  6. Changes of Serum Calcium Concentration, Frequency of Ruminal Contraction and Feed Intake Soon after Parturition of Dairy Cows Fed Difructose Anhydride III.

    PubMed

    Wynn, S; Teramura, M; Sato, T; Hanada, M

    2015-01-01

    Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p<0.05). Time interval for recovery from decreased serum Ca to its normal range (>9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis (R(2) = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition.

  7. MoO sub 3 catalysts promoted by MnMoO sub 4. II. Effect of O sub 2 concentration and temperature in selective oxidation of 1-butene to maleic anhydride

    SciTech Connect

    Gill, R.C.; Ozkan, U.S. )

    1990-04-01

    In a previous paper, the authors have reported the results of a study where they focused their attention on catalytic activity and selectivity of pure MoO{sub 3} and attempted to modify its catalytic behavior by bringing its surfaces into close contact with MnMoO{sub 4}. While their characterization experiments revealed the two-phase nature of the MnMoO{sub 4}/MoO{sub 3} catalyst, the activity studies showed a pronounced promoter effect in selective oxidation of both 1-butene and 1,3-butadiene to maleic anhydride, suggesting a possible synergy between the two phases. This note presents the results of their selective oxidation studies where the effect of temperature and oxygen partial pressure on catalytic behavior of the pure phases (MoO{sub 3} and MnMoO{sub 4}) as well as the two phase catalyst (MnMoO{sub 4}/MoO{sub 3}) has been investigated in conversion of 1-butene to maleic anhydride. All catalysts were characterized in detail using BET surface area measurement, x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, laser Raman spectroscopy and Raman microprobe techniques.

  8. A preliminary study on the dynamic-mechanical behaviour of compression moulded polypropylene/carbon fiber composites interfacially modified by a succinic anhydride grafted atactic polypropylene from polymer wastes

    NASA Astrophysics Data System (ADS)

    García-Martínez, Jesús María; Areso, Susana; Collar, Emilia P.

    2016-05-01

    Present communication is devoted to the study of the effect of a novel interfacial agent in polypropylene/carbon fibre composites. The interfacial agent used is a succinic anhydride grafted atactic polypropylene containing both succinic bridges and side grafts (aPP-SASA) and with 5.6% (5.6.10-4g/mol) of grafting content obtained at the GIP labs. The study considers the study dynamic-mechanical behaviour with temperature at a frequency of 1 hz to ascertain the differences in the interfacial activity. The samples were compression molded in order to isolate as far as possible the effect of the solely aPP-SASA in absence of those synergetic effects due to the preferential orientation of the fibres.

  9. Theoretical problems associated with the use of acetic anhydride as a co-solvent for the non-aqueous titration of hydrohalides of organic bases and quaternary ammonium salts.

    PubMed

    Völgyi, Gergely; Béni, Szabolcs; Takács-Novák, Krisztina; Görög, Sándor

    2010-01-01

    A potentiometric titration study of organic base hydrohalides and quaternary ammonium salts using perchloric acid as the titrant and a mixture of acetic anhydride and acetic acid as the solvent was carried out and the titration mixture was analysed by NMR in order to clarify the chemistry of the reactions involved. It was found that in contrast to the general belief the formation of acetyl halides and titratable free acetate ion does not take place prior to the titration but NMR spectra proved the formation of acetyl halides in the course of the titration. This observation and the fact that the shape of the titration curves depends on the nature of the hydrohaloic acid bound to the base or of the anion in the quaternary ammonium salts led to the conclusion that the titrating agent is acetyl perchlorate formed in situ during the titration. Equations of the reactions involved in the titration process are shown in the paper.

  10. Processing and properties of fiber reinforced polymeric matrix composites: I. IM7/LARC(TM)-PETI-7 polyimide composites

    NASA Technical Reports Server (NTRS)

    Hou, Tan-Hung

    1995-01-01

    A phenylethynyl terminated imide oligomer formed from the reaction of benzophenone tetracarboxylic acid dianhydride, an 75:25 molar ratio of 4,4'-oxydianiline and meta-phenylenediamine and 4-phenylethynylphthalic anhydride as the endcapper at a theoretical number average molecular weight (Mn) of approximately 3,700 g/mol was evaluated as a composite resin matrix. A glass transition temperature (Tg) of 315 deg C was reached after 250 deg C/1 hr annealing of the matrix resin. Unidirectional prepreg was made by coating an N-methylpyrrolidinone solution of the amide acid oligomer onto unsized IM7 graphite fibers. The thermal and rheological properties and the solvent/volatile depletion rates of the amide acid/NMP system were determined. This information was used to successfully design a molding cycle for composite fabrication. Composites molded under 800 Psi at 371 C consistently yielded good consolidation as measured by C-scan and optical photomicrography. The composite's short beam shear strength (SBS), longitudinal and transverse flexural strengths and moduli were measured at various temperatures. These composites exhibited excellent room temperature (RT) longitudinal flexural strength and modulus and RT SBS strength retention at 177 C.

  11. Indirect enantioresolution of (R,S)-mexiletine by reversed-phase high-performance liquid chromatography via diastereomerization with [(S,S)-O,O'-di-p-toluoyl tartaric acid anhydride], (S)-naproxen and nine chiral reagents synthesized as variants of Marfey's reagent.

    PubMed

    Bhushan, R; Tanwar, Shivani; Dixit, Shuchi

    2011-03-01

    Eleven chiral derivatizing reagents (CDRs) were used for preparation of diastereomers of (R,S)-mexiletine containing a primary amino group in close proximity to the stereogenic center. One anhydride, namely [(S,S)-O,O'-di-p-toluoyl tartaric acid anhydride] was synthesized and (S)-naproxen was used as such as the chiral derivatizing reagent. The other nine CDRs were synthesized by substituting one of the fluorine atoms in 1,5-difluoro-2,4-dinitrobenzene with six amino acid amides and three amino acids. The diastereomers were separated by reversed-phase high-performance liquid chromatography. The method was validated for linearity, accuracy, limit of detection and limit of quantification. The limit of detection was found in the range of 10-30  pmol. PMID:20586109

  12. Study on thermal properties and crystallization behavior of electron beam irradiated ethylene vinyl acetate (EVA)/waste tyre dust (WTD) blends in the presence of polyethylene graft maleic anhydride (PEgMAH)

    SciTech Connect

    Ramli, Syuhada; Ahmad, S. H.; Ratnam, C. T.; Athirah, Nurul

    2013-11-27

    The aim of this article is to show the effects of the electron beam irradiation dose and presence of a compatibiliser on the thermal properties and crystallinity of EVA/WTD blends. The purpose of applying electron beam radiation with doses range 50 to 200 kGy and adding a compatibiliser was to enhance the compatibility of the studied blends and at the same time to investigate the possibility of using this technique in the process of recycling polymeric materials. As the compatibilisers, the polyethylene grafted maleic anhydride (PEgMAH) was utilized, they were added at the amounts of 1-5 phr respectively. The enhancement of thermal properties was accompanied by the following effects, discussed in this article: i) an irradiated EVA/WTD blend at 200kGy was found to improve the thermal properties of EVA, ii) the addition of PEgMAH in EVA/WTD blends and the subsequent irradiation allowed prevention of degradation mechanism. iii) the ΔH{sub f} and crystallinity percentage decrease at higher PEgMAH content.

  13. Disproportionation of bromous acid HOBrO by direct O-transfer and via anhydrides O(BrO)2 and BrO-BrO2. An ab initio study of the mechanism of a key step of the Belousov-Zhabotinsky oscillating reaction.

    PubMed

    Glaser, Rainer; Jost, Mary

    2012-08-16

    The results are reported of an ab initio study of the thermochemistry and of the kinetics of the HOBrO disproportionation reaction 2HOBrO (2) ⇄ HOBr (1) + HBrO(3) (3), reaction ( R4' ), in gas phase (MP2(full)/6-311G*) and aqueous solution (SMD(MP2(full)/6-311G*)). The reaction energy of bromous acid disproportionation is discussed in the context of the coupled reaction system R2-R4 of the FKN mechanism of the Belousov-Zhabotinsky reaction and considering the acidities of HBr and HOBrO(2). The structures were determined of ten dimeric aggregates 4 of bromous acid, (HOBrO)(2), of eight mixed aggregates 5 formed between the products of disproportionation, (HOBr)(HOBrO(2)), and of four transition states structures 6 for disproportionation by direct O-transfer. It was found that the condensation of two HOBrO molecules provides facile access to bromous acid anhydride 7, O(BrO)(2). A discussion of the potential energy surface of Br(2)O(3) shows that O(BrO)(2) is prone to isomerization to the mixed anhydride 8, BrO-BrO(2), and to dissociation to 9, BrO, and 10, BrO(2), and their radical pair 11. Hence, three possible paths from O(BrO)(2) to the products of disproportionation, HOBr and HOBrO(2), are discussed: (1) hydrolysis of O(BrO)(2) along a path that differs from its formation, (2) isomerization of O(BrO)(2) to BrO-BrO(2) followed by hydrolysis, and (3) O(BrO)(2) dissociation to BrO and BrO(2) and their reactions with water. The results of the potential energy surface analysis show that the rate-limiting step in the disproportionation of HOBrO consists of the formation of the hydrate 12a of bromous acid anhydride 7 via transition state structure 14a. The computed activation free enthalpy ΔG(act)(SMD) = 13.6 kcal/mol for the process 2·2a → [14a](‡) → 12a corresponds to the reaction rate constant k(4) = 667.5 M(-1) s(-1) and is in very good agreement with experimental measurements. The potential energy surface analysis further shows that anhydride 7 is

  14. Biodegradation of poly(anhydride-esters) into non-steroidal anti-inflammatory drugs and their effect on Pseudomonas aeruginosa biofilms in vitro and on the foreign-body response in vivo.

    PubMed

    Bryers, James D; Jarvis, Rebecca A; Lebo, Jason; Prudencio, Almudena; Kyriakides, Themis R; Uhrich, Kathryn

    2006-10-01

    The ability of poly(anhydride-esters) composed of non-steroidal anti-inflammatory drugs that biodegrade to salicylic acid (SA) and adipic acid to prevent colonization by Pseudomonas aeruginosa and their effects on the foreign-body response were studied in vitro and in vivo, respectively. Soluble SA in bacterial medium at concentrations up to 300 mg/L did not affect the growth rate or viability of P. aeruginosa, indicating that SA does not exhibit a direct toxicity effect on the bacterium. Batch degradation rates of the salicylate-based polymer in the presence of an actively growing bacterial culture only marginally (14%) increased relative to polymer degradation rates in sterile medium. Short-term (3h) bacterial adhesion studies in agitated batch systems indicated a 47% reduction in the rate of P. aeruginosa adhesion relative to a control polymer that does not release SA upon biodegradation. Long-term (3-day) biofilm accumulation studies indicated a dramatic reduction in biofilm formation on salicylate-based polymer versus controls. A recombinant P. aeruginosa pMHLAS, containing a fluorescent reporter gene prior to the las regulon, was employed to determine whether salicylate-based polymer prevents biofilm formation by the released SA inhibiting quorum sensing pathways. Long-term biofilm accumulation studies with P. aeruginosa pMHLAS insinuate that salicylate-based polymer prevents biofilm accumulation by inhibiting the las quorum sensing system. Furthermore, unlike control polymer, salicylate-based polymer implanted subcutaneously for a period of 4 weeks-resisted cell-mediated degradation and remained intact. Histological and immunohistochemical analysis indicated a reduction in overall encapsulation and paucity of macrophages in the area of the salicylate-based polymer implant.

  15. Bis(phenyl-phospho-nic) anhydride.

    PubMed

    Li, Yang; Hua, Guoxiong; Slawin, Alexandra M Z; Woollins, J Derek

    2009-10-03

    The asymmetric unit of the title compound, C(12)H(12)O(5)P(2), contains four independent mol-ecules, generating two dimers via pairs of inter-molecular O-H⋯O hydrogen bonds, forming R(2) (2)(8) rings. The two aryl rings of each mol-ecule form dihedral angles of 108.6 (1), 103.2 (1), 12.5 (2) and 8.1 (2)° in the four mol-ecules.

  16. DIMETHYLTHIOARSINIC ANHYDRIDE: A STANDARD FOR ARSENIC SPECIATION

    EPA Science Inventory

    Dimethylthioarsinic acid (DMTAV) has recently been identified in biological, dietary and environmental matrices. The relevance of this compound to the toxicity of arsenic in humans is unknown and further exposure assessment and metabolic studies are difficult to conduct because ...

  17. DIMETHYLITHIOARSINIC ANHYDRIDE: A STANDARD FOR ARSENIC SPECIATION

    EPA Science Inventory

    Recently, sulfar analogs of well know arsenicals have been identfied in biolgical, dietary and environmental matrices. These discoveries have generated a need for stable species-specific standards. This presentation will forcus on the isolation and characterization of a standar...

  18. High Temperature VARTM with LaRC Polyimides

    NASA Technical Reports Server (NTRS)

    Cano, Roberto J.; Grimsley, Brian W.; Jensen, Brian J.; Kellen, Charles B.

    2004-01-01

    Recent work at NASA Langley Research Center (LaRC) has concentrated on developing new polyimide resin systems for advanced aerospace applications that can be processed without the use of an autoclave. Polyimide composites are very attractive for applications that require a high strength to weight ratio and thermal stability. Vacuum assisted resin transfer molding (VARTM) has shown potential to reduce the manufacturing cost of composite structures. In VARTM, the fibrous preform is infiltrated on a rigid tool surface contained beneath a flexible vacuum bag. Both resin injection and fiber compaction are achieved under pressures of 101.3 KPa or less. Recent studies have demonstrated the feasibility of the VARTM process for fabrication of void free structures utilizing epoxy resin systems with fiber volume fractions approaching 60%. In this work, the VARTM process has been extended to the fabrication of composite panels from polyimide systems developed at the Langley Research Center. This work has focused on processing LARC(trademark) PETI-8 (Langley Research Center Phenylethynyl Terminated Imide- 8), an aromatic polyimide based on 3,3',4,4' -biphenyltetracarboxylic dianhydride, a 50:50 molar ratio of 3,4'-oxydianiline and 1,3-bis(3-aminophenoxy)benzene, with 4-phenylethynylphthalic anhydride as the endcapping agent. Various molecular weight versions were investigated to determine their feasibility of being processed by VARTM at elevated temperatures. An injection temperature of approximately 280 C was required to achieve the necessary viscosity (<5 Poise) for flow at VARTM pressures. Laminate quality and initial mechanical properties are presented for LARC(trademark) PETI-8 and 6k IM7 uniweave fabric.

  19. Method to Prepare Processable Polymides with Reactive Endgroups using 1,3-Bis (3-Aminophenoxy) Benzene

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor)

    2000-01-01

    Polyimide copolymers were obtained containing 1,3-bis(3-aminophenoxy)benzene (APB) and other diamines and dianhydrides and terminating with the appropriate amount of reactive endcapper. The reactive endcappers studied include but should not be limited to 4-phenylethynyl phthalic anhydride (PEPA ), 3-aminophenoxy- 4'-phenylethynylbenzophenone (3-APEB), maleic anhydride (MA) and nadic anhydride (5-norbomene-2,3-dicarboxylic anhydride, NA). Homopolymers containing only other diamines and dianhydrides which are not processable under conditions described previously can be made processable by incorporating various amounts of APB, depending on the chemical structures of the diamines and dianhydrides used. By simply changing the ratio of APB to the other diamine in the polyimide backbone, a material with a unique combination of solubility, Tg, Tm, melt viscosity, toughness and elevated temperature mechanical properties can be prepared. The copolymers that result from using APB to enhance processability have a unique combination of properties that include low pressure processing (200 psi and below), long term melt stability (several hours at 300 C. for the phenylethynyl terminated polymers), high toughness, improved solvent resistance, improved adhesive properties, and improved composite mechanical properties. These copolyimides are eminently suitable as adhesives, composite matrices, moldings, films and coatings.

  20. A new approach to reducing the flammability of layered double hydroxide (LDH)-based polymer composites: preparation and characterization of dye structure-intercalated LDH and its effect on the flammability of polypropylene-grafted maleic anhydride/d-LDH composites.

    PubMed

    Kang, Nian-Jun; Wang, De-Yi; Kutlu, Burak; Zhao, Peng-Cheng; Leuteritz, Andreas; Wagenknecht, Udo; Heinrich, Gert

    2013-09-25

    Dye structure-intercalated layered double hydroxide (d-LDH) was synthesized using a one-step method, and its intercalated behaviors have been characterized by Fourier transform infrared spectroscopy (FTIR), wide angle X-ray scattering (WAXS), scanning electron microscopy, thermogravimetric analysis (TGA), etc. As a novel functional potential fire-retarding nanofiller, it was used to prepare a polypropylene-grafted maleic anhydride (PP-g-MA)/d-LDH composite by refluxing the mixture of d-LDH and PP-g-MA in xylene, aiming to investigate its effect on the flammability of the PP-g-MA composite. The morphological properties, thermal stability, and flame retardant properties of the PP-g-MA/d-LDH composite were determined by FTIR, WAXS, transmission electron microscopy, TGA, and microscale combustion calorimetry. Compared with NO3-LDH (unmodified LDH) and LDH intercalated by sodium dodecylbenzenesulfonate (conventional organo-modified LDH), d-LDH can significantly decrease the heat release rate and the total heat release of the PP-g-MA composite, offering a new approach to imparting low flammability to LDH-based polymer composites.

  1. Polyimide Composites Based on Asymmetric Dianhydrides (a-ODPA vs a-BPDA)

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Criss, Jim M., Jr.; Mintz, Eric A.

    2009-01-01

    Two series of low-melt viscosity imide resins (2-15 poise at 260-280 C) were formulated from either asymmetric oxydiphthalic anhydride (a-ODPA) or asymmetric biphenyl dianhydride (a- BPDA) with 4-phenylethynyl endcap (PEPA), along with 3,4'-oxydianiline, 3,4 - methylenedianiline, 3,3 -methylenedianiline or 3,3 -diaminobenzophenone, using a solvent-free melt process. These low-melt viscosity imide resins were fabricated into polyimide/T650-35 carbon fabric composites by resin transfer molding (RTM). Composites from a-ODPA based resins display better open-hole compression strength and short beam shear strength from room temperature to 288 C than that of the corresponding a-BPDA based resins. However, due to the lower Tg s of a-ODPA based resins (265-330 C), their corresponding composites do not possess 315 C use capability while the a-BPDA based composites do. In essence, RTM 370 (T g = 370 C), derived from a-BPDA and 3,4 -ODA and PEPA, exhibits the best overall property performance at 315 C (600 F).

  2. [Acute poisoning from arsenous anhydride ingestion. A clinical case].

    PubMed

    Marcovigi, P; Calbi, G; Valtancoli, E; Calbi, P

    1993-06-01

    A clinical case of acute poisoning after ingestion of arsenic trioxide is reported. We have, in particular, underlined the importance of identification of arsenic in faeces and urine for diagnosis and therapy.

  3. [Arsenous anhydride poisoning. Peripheral neuropathy and changes in cognitive functions].

    PubMed

    Danan, M; Conso, F; Dally, S; Bertaux, L; Chouraki, L; Balme, R

    1985-01-01

    The authors report the evolution over an 11 months period of a case of subacute intoxication with arsenic in a 30 years old woman. In addition to the classical peripheral neuropathy, we observed impairment of the superior neurological functions which improved together with the neuropathy. These malfunctions are rarely described in the literature although arsenic seems to cross the blood-brain barrier easily. There is no other explanation, and we believe arsenic to be responsible for these disturbances. We suggest systematic testing of the superior neurological functions in cases of arsenic intoxication.

  4. PLA branching with anhydrides and tri-functional aziridine

    NASA Astrophysics Data System (ADS)

    Gu, Liangliang; Xu, Yuewen; Naredla, Rajasekhar; Hoye, Thomas; Macosko, Christopher

    Branched PLA was prepared by melt blending with tri-functional aziridine (T-Az) and pyromellitic dianhydride (PMDA). 1HNMR, gel permeation chromatography (GPC) and rheology were used to characterize the topological structures of branched PLA. Fast reaction between PLA carboxyl end group and T-Az resulted in 3-arm stars and increased the molecular weight. However, the 3-arm stars did not show strain hardening behavior under extensional flow. After modifying PLA hydroxyl end group with PMDA, PLA can react with T-Az on both chain ends and form long chain branched structure, which showed strain hardening in extension. It was found that that only 10% of the PLA hydroxyl end groups reacted with PMDA. This work is supported by Center for Sustainable Polymers.

  5. Physical insights into salicylic acid release from poly(anhydrides).

    PubMed

    Dasgupta, Queeny; Chatterjee, Kaushik; Madras, Giridhar

    2016-01-21

    Salicylic acid (SA) based biodegradable polyanhydrides (PAHs) are of great interest for drug delivery in a variety of diseases and disorders owing to the multi-utility of SA. There is a need for the design of SA-based PAHs for tunable drug release, optimized for the treatment of different diseases. In this study, we devised a simple strategy for tuning the release properties and erosion kinetics of a family of PAHs. PAHs incorporating SA were derived from related aliphatic diacids, varying only in the chain length, and prepared by simple melt condensation polymerization. Upon hydrolysis induced erosion, the polymer degrades into cytocompatible products, including the incorporated bioactive SA and diacid. The degradation follows first order kinetics with the rate constant varying by nearly 25 times between the PAH obtained with adipic acid and that with dodecanedioic acid. The release profiles have been tailored from 100% to 50% SA release in 7 days across the different PAHs. The release rate constants of these semi-crystalline, surface eroding PAHs decreased almost linearly with an increase in the diacid chain length, and varied by nearly 40 times between adipic acid and dodecanedioic acid PAH. The degradation products with SA concentration in the range of 30-350 ppm were used to assess cytocompatibility and showed no cytotoxicity to HeLa cells. This particular strategy is expected to (a) enable synthesis of application specific PAHs with tunable erosion and release profiles; (b) encompass a large number of drugs that may be incorporated into the PAH matrix. Such a strategy can potentially be extended to the controlled release of other drugs that may be incorporated into the PAH backbone and has important implications for the rational design of drug eluting bioactive polymers.

  6. Crystal structure of 2-methyl-3-nitro-benzoic anhydride.

    PubMed

    Moreno-Fuquen, Rodolfo; Azcárate, Alexis; Kennedy, Alan R

    2015-07-01

    The title mol-ecule, C16H12N2O7, lies on a twofold rotation axis which bis-ects the central O atom. The dihedral angle between two symmetry-related benzene rings is 48.54 (9)°. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds which generate C(13) chains running parallel to [31-1]. PMID:26279902

  7. Reactive extrusion of zein with glyoxal and polyethylene maleic anhydride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order for zein, a potentially significant co-product of the bio-ethanol industry, to be used in new markets, improved zein based products are needed. These products need to be produced by the most economical means possible. In the traditional plastics industry, extrusion techniques are the most e...

  8. Aminoacyl transfer from an adenylate anhydride to polyribonucleotides

    NASA Technical Reports Server (NTRS)

    Weber, A. L.; Lacey, J. C., Jr.

    1975-01-01

    Imidazole catalysis of phenylalanyl transfer from phenylalanine adenylate to hydroxyl groups of homopolyribonucleotides is studied as a possible chemical model of biochemical aminoacylation of transfer RNA (tRNA). The effect of pH on imidazole-catalyzed transfer of phenylalanyl residues to poly(U) and poly(A) double helix strands, the number of peptide linkages and their lability to base and neutral hydroxylamine, and the nature of adenylate condensation products are investigated. The chemical model entertained exhibits a constraint by not acylating the hydroxyl groups of polyribonucleotides in a double helix. The constraint is consistent with selective biochemical aminoacylation at the tRNA terminus. Interest in imidazole as a model of histidine residue in protoenzymes participating in prebiotic aminoacyl transfer to polyribonucleotides, and in rendering the tRNA a more efficient adaptor, is indicated.

  9. Comparative Emulsifying Properties of Octenyl Succinic Anhydride (OSA)-Modified Starch: Granular Form vs Dissolved State

    PubMed Central

    Marefati, Ali; Gutiérrez, Gemma; Wahlgren, Marie; Rayner, Marilyn

    2016-01-01

    The emulsifying ability of OSA-modified and native starch in the granular form, in the dissolved state and a combination of both was compared. This study aims to understand mixed systems of particles and dissolved starch with respect to what species dominates at droplet interfaces and how stability is affected by addition of one of the species to already formed emulsions. It was possible to create emulsions with OSA-modified starch isolated from Quinoa as sole emulsifier. Similar droplet sizes were obtained with emulsions prepared at 7% (w/w) oil content using OSA-modified starch in the granular form or molecularly dissolved but large differences were observed regarding stability. Pickering emulsions kept their droplet size constant after one month while emulsions formulated with OSA-modified starch dissolved exhibited coalescence. All emulsions stabilized combining OSA-modified starch in granular form and in solution showed larger mean droplet sizes with no significant differences with respect to the order of addition. These emulsions were unstable due to coalescence regarding presence of free oil. Similar results were obtained when emulsions were prepared by combining OSA-modified granules with native starch in solution. The degree of surface coverage of starch granules was much lower in presence of starch in solution which indicates that OSA-starch is more surface active in the dissolved state than in granular form, although it led to unstable systems compared to starch granule stabilized Pickering emulsions, which demonstrated to be extremely stable. PMID:27479315

  10. 40 CFR 721.524 - Alcohols, C6-12, ethoxylated, reaction product with maleic anhydride.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alcohols, C6-12, ethoxylated, reaction... New Uses for Specific Chemical Substances § 721.524 Alcohols, C6-12, ethoxylated, reaction product... chemical substance identified generically as alcohols, C6-12, ethoxylated, reaction product with...

  11. 40 CFR 721.524 - Alcohols, C6-12, ethoxylated, reaction product with maleic anhydride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alcohols, C6-12, ethoxylated, reaction... New Uses for Specific Chemical Substances § 721.524 Alcohols, C6-12, ethoxylated, reaction product... chemical substance identified generically as alcohols, C6-12, ethoxylated, reaction product with...

  12. 40 CFR 721.524 - Alcohols, C6-12, ethoxylated, reaction product with maleic anhydride.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alcohols, C6-12, ethoxylated, reaction... New Uses for Specific Chemical Substances § 721.524 Alcohols, C6-12, ethoxylated, reaction product... chemical substance identified generically as alcohols, C6-12, ethoxylated, reaction product with...

  13. 40 CFR 721.524 - Alcohols, C6-12, ethoxylated, reaction product with maleic anhydride.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alcohols, C6-12, ethoxylated, reaction... New Uses for Specific Chemical Substances § 721.524 Alcohols, C6-12, ethoxylated, reaction product... chemical substance identified generically as alcohols, C6-12, ethoxylated, reaction product with...

  14. 40 CFR 721.524 - Alcohols, C6-12, ethoxylated, reaction product with maleic anhydride.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alcohols, C6-12, ethoxylated, reaction... New Uses for Specific Chemical Substances § 721.524 Alcohols, C6-12, ethoxylated, reaction product... chemical substance identified generically as alcohols, C6-12, ethoxylated, reaction product with...

  15. Comparative Emulsifying Properties of Octenyl Succinic Anhydride (OSA)-Modified Starch: Granular Form vs Dissolved State.

    PubMed

    Matos, María; Marefati, Ali; Gutiérrez, Gemma; Wahlgren, Marie; Rayner, Marilyn

    2016-01-01

    The emulsifying ability of OSA-modified and native starch in the granular form, in the dissolved state and a combination of both was compared. This study aims to understand mixed systems of particles and dissolved starch with respect to what species dominates at droplet interfaces and how stability is affected by addition of one of the species to already formed emulsions. It was possible to create emulsions with OSA-modified starch isolated from Quinoa as sole emulsifier. Similar droplet sizes were obtained with emulsions prepared at 7% (w/w) oil content using OSA-modified starch in the granular form or molecularly dissolved but large differences were observed regarding stability. Pickering emulsions kept their droplet size constant after one month while emulsions formulated with OSA-modified starch dissolved exhibited coalescence. All emulsions stabilized combining OSA-modified starch in granular form and in solution showed larger mean droplet sizes with no significant differences with respect to the order of addition. These emulsions were unstable due to coalescence regarding presence of free oil. Similar results were obtained when emulsions were prepared by combining OSA-modified granules with native starch in solution. The degree of surface coverage of starch granules was much lower in presence of starch in solution which indicates that OSA-starch is more surface active in the dissolved state than in granular form, although it led to unstable systems compared to starch granule stabilized Pickering emulsions, which demonstrated to be extremely stable. PMID:27479315

  16. Participation of cationic intermediates in radical-induced homopolymerization of maleic anhydride

    SciTech Connect

    Gaylord, N.G.; Koo, J.Y.

    1981-03-01

    Since the failure to promote MAH polymerization in the presence of amine-containing redox catalyst systems suggested the presence of cationic intermediates, the radical-induced polymerization of MAH was carried out in the absence and in the presence of N,N-dimethylformamide (DMF) and N, N-dimethylaniline (DMA).

  17. 78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-18

    ... September 12, 2013 (78 FR 56185) (FRL- 9399-7), EPA issued a document pursuant to FFDCA section 408, 21 U.S... review under Executive Order 12866, entitled ``Regulatory Planning and Review'' (58 FR 51735, October 4... Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001) or Executive Order...

  18. A [4 pi+4 pi] intramolecular photocyclomer of 9-anthroic anhydride: 5,6,11,12-tetrahydro-5,12;6,11-di-o-benzenodibenzo[a,e]cyclooctene-5,6-dicarboxylic anhydride.

    PubMed

    Cicogna, Francesca; Ingrosso, Giovanni; Marchetti, Fabio

    2002-06-01

    The title compound, C(30)H(18)O(3), was obtained by light irradiation of a dichloroethane solution of 9-anthroyl chloride and 9-anthroic acid. The molecules, which possess approximately mm2 local symmetry, are packed in columns, the oxygenated moieties facing each other according to the symmetry of a monoclinic lattice. The space group of the crystal is P2(1)/c, with a whole molecule as the asymmetric unit. The structure is compared with those of similar dianthracene derivatives.

  19. Insights into the architecture and stoichiometry of Escherichia coli PepA*DNA complexes involved in transcriptional control and site-specific DNA recombination by atomic force microscopy.

    PubMed

    Minh, Phu Nguyen Le; Devroede, Neel; Massant, Jan; Maes, Dominique; Charlier, Daniel

    2009-04-01

    Multifunctional Aminopeptidase A (PepA) from Escherichia coli is involved in the control of two distinct DNA transaction processes: transcriptional repression of the carAB operon, encoding carbamoyl phosphate synthase and site-specific resolution of ColE1-type plasmid multimers. Both processes require communication at a distance along a DNA molecule and PepA is the major structural component of the nucleoprotein complexes that underlie this communication. Atomic Force Microscopy was used to analyze the architecture of PepA.carAB and PepA.cer site complexes. Contour length measurements, bending angle analyses and volume determinations demonstrate that the carP1 operator is foreshortened by approximately 235 bp through wrapping around one PepA hexamer. The highly deformed part of the operator extends from slightly upstream of the -35 hexamer of the carP1 promoter to just downstream of the IHF-binding site, and comprises the binding sites for the PurR and RutR transcriptional regulators. This extreme remodeling of the carP1 control region provides a straightforward explanation for the strict requirement of PepA in the establishment of pyrimidine and purine-specific repression of carAB transcription. We further provide a direct physical proof that PepA is able to synapse two cer sites in direct repeat in a large interwrapped nucleoprotein complex, likely comprising two PepA hexamers. PMID:19136463

  20. Converting a Staphylococcus aureus toxin into effective cyclic pseudopeptide antibiotics.

    PubMed

    Solecki, Olivia; Mosbah, Amor; Baudy Floc'h, Michèle; Felden, Brice

    2015-03-19

    Staphylococcus aureus produces peptide toxins that it uses to respond to environmental cues. We previously characterized PepA1, a peptide toxin from S. aureus, that induces lytic cell death of both bacterial and host cells. That led us to suggest that PepA1 has an antibacterial activity. Here, we demonstrate that exogenously provided PepA1 has activity against both Gram-positive and Gram-negative bacteria. We also see that PepA1 is significantly hemolytic, thus limiting its use as an antibacterial agent. To overcome these limitations, we converted PepA1 into nonhemolytic derivatives. Our most promising derivative is a cyclic heptapseudopeptide with inconsequential toxicity to human cells, enhanced stability in human sera, and sharp antibacterial activity. Mechanistically, linear and helical PepA1 derivatives form pores at the bacterial and erythrocyte surfaces, while the cyclic peptide induces bacterial envelope reorganization, with insignificant action on the erythrocytes. Our work demonstrates that bacterial toxins might be an attractive starting point for antibacterial drug development.

  1. Use of anionic polymer, poly(methyl vinyl ether-maleic anhydride)-coated beads for capture of respiratory syncytial virus.

    PubMed

    Sakudo, Akikazu; Baba, Koichi; Tsukamoto, Megumi; Ikuta, Kazuyoshi

    2009-08-01

    Respiratory syncytial virus (RSV) is the single most important cause of severe lower respiratory tract infections in infants and young children, and a major public health concern in pediatrics. However, current diagnostic methods for RSV are not sufficiently sensitive. In addition, there is no simple method for enhancing RSV detection. Here, a method for capturing RSV from nasal fluid has been developed using magnetic beads coated with an anionic polymer, poly(methyl vinyl ether-maleic anhydrate). The beads were incubated with RSV-infected nasal fluid, then separated from the supernatant by applying a magnet field and washed. The adsorption [corrected] of RSV by the beads was confirmed by immunochromatography, reverse transcription-polymerase chain reaction, Western blotting and an enzyme-linked immunosorbent assay, which indicated the presence of nucleocapsid protein, fusion protein, and the viral genome of RSV on the incubated beads. Therefore, this capture method will contribute to the improvement of RSV detection.

  2. Synthesis of Canthardin Sulfanilamides and Their Acid Anhydride Analogues via a Ring-Opening Reaction of Activated Aziridines and Their Associated Pharmacological Effects.

    PubMed

    Chiang, Ling-Ling; Tseng, Ing-Jy; Lin, Pen-Yuan; Sheu, Shiow-Yunn; Lin, Ching-Tung; Hsieh, Yun-Han; Lin, Yi-Jing; Chen, Hsiao-Ling; Lin, Mei-Hsiang

    2016-01-16

    The cantharidinimide derivatives, 5a-h, including sulfanilamides containing pyrimidyl, pyrazinyl, hydrogen, thiazolyl, and oxazolyl groups were synthesized. Modification of cantharidinimide by means of the reaction of activated aziridine ring opening led to the discovery of a novel class of antitumor compounds. The analogues 10i-k, 11l-n, 12o-p, and 16q-s were obtained from treating cantharidinimide 6 and analogues (7, 8, and 13) with activated aziridines, which produced a series of ring-opened products including normal and abnormal types. Some of these compounds showed cytotoxic effects in vitro against HL-60, Hep3B, MCF7, and MDA-MB-231 cancer cells. The most potent cytostatic compound, N-cantharidinimido-sulfamethazine (5a), exhibited anti-HL-60 and anti-Hep3B cell activities. Two compounds 5g and 5h displayed slight effects on the Hep3B cell line, while the other compounds produced no response in these four cell lines.

  3. Functional and Structural Insights of a Staphylococcus aureus Apoptotic-like Membrane Peptide from a Toxin-Antitoxin Module*

    PubMed Central

    Sayed, Nour; Nonin-Lecomte, Sylvie; Réty, Stéphane; Felden, Brice

    2012-01-01

    We report a functional type I toxin-antitoxin (TA) module expressed by a human pathogen, Staphylococcus aureus. TA systems consist of stable toxins and labile antitoxins encoded within small genetic modules widespread in eubacteria and archaea. TA genes provide stress adaptation and protection against DNA loss or invasion. The genes encoding the SprA1 toxic peptide (PepA1) and the SprA1AS RNA antitoxin are within a pathogenicity island on opposite strands and possess a 3′ overlap. To prevent peptide toxicity during S. aureus growth, PepA1 expression from stable (half-life > 3 h) SprA1 is repressed by elevated amounts of unstable (half-life = ∼10 mn) SprA1AS. In vivo, PepA1 localizes at the bacterial membrane and triggers S. aureus death. Based on NMR and CD data, its solution structure was solved and is a long bent, interrupted helix. Molecular dynamics simulations indicate that PepA1 compaction and helical content fluctuate in accordance with its cytoplasm or membrane location. When inserted into the S. aureus membrane, the PepA1 conformation switches to a ∼7-nm-long continuous helix, presumably forming pores to alter membrane integrity. PepA1 expression is induced upon acidic and oxidative stresses by reducing SprA1AS levels. As an altruistic behavior during infection, some cells may induce the expression of that toxin that would facilitate departure from the host immune cells for spreading. PMID:23129767

  4. Piquing Student Interest with Pharmacology: An Interdisciplinary Program Helps High School Students Learn Biology and Chemistry Principles

    ERIC Educational Resources Information Center

    Halpin, Myra J.; Hoeffler, Leanne; Schwartz-Bloom, Rochelle D.

    2005-01-01

    To help students learn science concepts, Pharmacology Education Partnership (PEP)--a science education program that incorporates relevant topics related to drugs and drug abuse into standard biology and chemistry curricula was developed. The interdisciplinary PEP curriculum provides six modules to teach biology and chemistry principles within the…

  5. Note on the Honduras Radio Schools (ACPH--Accion Cultural Popular Hondureno). IEC Discussion Paper. Appendix 4.

    ERIC Educational Resources Information Center

    Young, Michael

    This report on the radio schools in Honduras, Central America, includes (1) an account of an afternoon session of the radio school's Primary Equivalence Programme (PEPA), including a testimonial of a student and a statement regarding the importance of the monitors; (2) information on the social background of Honduras; (3) an historical account of…

  6. The effect of packaging material and storage period on microwave-dried potato (Solanum tuberosum L.) cubes.

    PubMed

    Shakouri, Shahrzad; Ziaolhagh, Hamid Reza; Sharifi-Rad, Javad; Heydari-Majd, Mojtaba; Tajali, Rohallah; Nezarat, Somayeh; Teixeira da Silva, Jaime A

    2015-06-01

    The effect of three packaging materials (transparent biaxially oriented polypropylene laminate (BOPP); semi-transparent BOPP; polyethylene-polyamide (PE-PA) laminate) in three packaging conditions (vacuum, N2, natural atmosphere) and in two temperature treatments (blanching in hot water; steam) on microwave-dried potato (Solanum tuberosum L.; Solanaceae) cubes was studied. After storage for 60 and 120 days, the amount of ascorbic acid (AA), shrinkage and rehydration were determined. Dried potato cubes packaged under N2 atmosphere had the highest rehydration value (3.142 %). Since there is a direct relationship between the amount of water loss and shrinkage, samples packaged in PE-PA laminate packages under vacuum showed 4.947 % less shrinkage than transparent BOPP or semi-transparent BOPP due to low permeability of these packages. Potatoes stored for 120 days resulted in 7.89 % more shrinkage than those stored for 60 days. The least loss in AA occurred in PE-PA laminate packaging. The shelf-life of potato cubes can be increased and their quantitative and qualitative characteristics can be best preserved by package-drying in PE-PA laminate under vacuum conditions. PMID:26028775

  7. The effect of packaging material and storage period on microwave-dried potato (Solanum tuberosum L.) cubes.

    PubMed

    Shakouri, Shahrzad; Ziaolhagh, Hamid Reza; Sharifi-Rad, Javad; Heydari-Majd, Mojtaba; Tajali, Rohallah; Nezarat, Somayeh; Teixeira da Silva, Jaime A

    2015-06-01

    The effect of three packaging materials (transparent biaxially oriented polypropylene laminate (BOPP); semi-transparent BOPP; polyethylene-polyamide (PE-PA) laminate) in three packaging conditions (vacuum, N2, natural atmosphere) and in two temperature treatments (blanching in hot water; steam) on microwave-dried potato (Solanum tuberosum L.; Solanaceae) cubes was studied. After storage for 60 and 120 days, the amount of ascorbic acid (AA), shrinkage and rehydration were determined. Dried potato cubes packaged under N2 atmosphere had the highest rehydration value (3.142 %). Since there is a direct relationship between the amount of water loss and shrinkage, samples packaged in PE-PA laminate packages under vacuum showed 4.947 % less shrinkage than transparent BOPP or semi-transparent BOPP due to low permeability of these packages. Potatoes stored for 120 days resulted in 7.89 % more shrinkage than those stored for 60 days. The least loss in AA occurred in PE-PA laminate packaging. The shelf-life of potato cubes can be increased and their quantitative and qualitative characteristics can be best preserved by package-drying in PE-PA laminate under vacuum conditions.

  8. 77 FR 33195 - Western Pacific Fishery Management Council; Public Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-05

    .... American Samoa Archipelago A. Motu Lipoti B. Fono Report C. Enforcement Issues D. Community Activities and... Discussion and Action 10. Marianas Archipelago A. Island Reports 1. Arongo Flaeey 2. Isla Informe B.... Hawaii Archipelago and PRIAs A. Moku Pepa B. Legislative Report C. Enforcement Report D. Bottomfish...

  9. 75 FR 56507 - Western Pacific Fishery Management Council; Public Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... Priorities F. National Marine Sanctuaries Program G. Public Comment 7. Marianas Archipelago A. Arongo flaeey.... Council Discussion and Action 8. American Samoa Archipelago A. Motu Lipoti B. Fono Report C. Enforcement... Wednesday, October 13, 2010, 8:30 a.m. - 5 p.m. 10. Hawaii Archipelago A. Moku Pepa B. Commercial...

  10. A Novel Glutamyl (Aspartyl)-Specific Aminopeptidase A from Lactobacillus delbrueckii with Promising Properties for Application

    PubMed Central

    Stressler, Timo; Ewert, Jacob; Merz, Michael; Funk, Joshua; Claaßen, Wolfgang; Lutz-Wahl, Sabine; Schmidt, Herbert; Kuhn, Andreas; Fischer, Lutz

    2016-01-01

    Lactic acid bacteria (LAB) are auxotrophic for a number of amino acids. Thus, LAB have one of the strongest proteolytic systems to acquit their amino acid requirements. One of the intracellular exopeptidases present in LAB is the glutamyl (aspartyl) specific aminopeptidase (PepA; EC 3.4.11.7). Most of the PepA enzymes characterized yet, belonged to Lactococcus lactis sp., but no PepA from a Lactobacillus sp. has been characterized so far. In this study, we cloned a putative pepA gene from Lb. delbrueckii ssp. lactis DSM 20072 and characterized it after purification. For comparison, we also cloned, purified and characterized PepA from Lc. lactis ssp. lactis DSM 20481. Due to the low homology between both enzymes (30%), differences between the biochemical characteristics were very likely. This was confirmed, for example, by the more acidic optimum pH value of 6.0 for Lb-PepA compared to pH 8.0 for Lc-PepA. In addition, although the optimum temperature is quite similar for both enzymes (Lb-PepA: 60°C; Lc-PepA: 65°C), the temperature stability after three days, 20°C below the optimum temperature, was higher for Lb-PepA (60% residual activity) than for Lc-PepA (2% residual activity). EDTA inhibited both enzymes and the strongest activation was found for CoCl2, indicating that both enzymes are metallopeptidases. In contrast to Lc-PepA, disulfide bond-reducing agents such as dithiothreitol did not inhibit Lb-PepA. Finally, Lb-PepA was not product-inhibited by L-Glu, whereas Lc-PepA showed an inhibition. PMID:27003449

  11. Polyimides Based on Asymmetric Dianhydrides (II) (a-BPDA vs a-BTDA) for Resin Transfer Molding (RTM)

    NASA Technical Reports Server (NTRS)

    Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.

    2010-01-01

    A new series of low-melt viscosity imide resins (10-20 poise at 280 C) were formulated from asymmetric 2,3,3',4' -benzophenone dianhydride (a-BTDA) and 4-phenylethynylphthalic endcaps, along with 3,4' -oxydianiline, 3,3' -methylenedianiline and 3,3'- diaminobenzophenone, using a solvent-free melt process. a-BTDA RTM resins exhibited higher glass transition temperatures (Tg's = 330-400 C) compared to those prepared by asymmetric 2,3,3',4' -biphenyl dianhydride, (a-BPDA, Tg's = 320-370 C). These low-melt viscosity imide resins were fabricated into polyimide/T650-35 carbon fiber composites by a RTM process. Composites properties of a-BTDA resins, such as open-hole compression and short-beam shear strength, are compared to those of composites made from a-BPDA based resin at room temperature, 288 C and 315 C. These novel, high temperature RTM imide resins exhibit outstanding properties beyond the performance of conventional RTM resins, such as epoxy and BMI resins which have use-temperatures around 177 C and 232 C for aerospace applications.

  12. 40 CFR 180.1035 - Pine oil; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... formulation with the bee repellent butanoic anhydride applied in an absorbent pad over the hive. Pine oil is... formulation with the bee repellent butanoic anhydride applied in an absorbent pad over the hive....

  13. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... resins are prepared by the reaction of trimellitic anhydride with 2,2-dimethyl-1,3-propanediol followed by reaction of the resin thus produced with phosphoric acid anhydride to produce a resin having...

  14. 40 CFR 180.1035 - Pine oil; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... formulation with the bee repellent butanoic anhydride applied in an absorbent pad over the hive. Pine oil is... formulation with the bee repellent butanoic anhydride applied in an absorbent pad over the hive....

  15. 40 CFR 180.1035 - Pine oil; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... formulation with the bee repellent butanoic anhydride applied in an absorbent pad over the hive. Pine oil is... formulation with the bee repellent butanoic anhydride applied in an absorbent pad over the hive....

  16. Maleic anhydride proton sponge as a novel MALDI matrix for the visualization of small molecules (<250 m/z) in brain tumors by routine MALDI ToF imaging mass spectrometry.

    PubMed

    Giampà, M; Lissel, M B; Patschkowski, T; Fuchser, J; Hans, V H; Gembruch, O; Bednarz, H; Niehaus, K

    2016-08-14

    A novel vacuum stable proton sponge, 4-maleicanhydridoproton sponge (MAPS), was prepared and applied as the matrix in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) of an aggressive brain tumor tissue (glioblastoma multiforme). Ionic maps of lactate, 2-hydroxyglutarate and chloride anions (m/z 89, 147, 35, respectively) were obtained using a routine MALDI ToF mass spectrometer. PMID:27419250

  17. New polymer systems: Chain extension by dianhydrides

    NASA Technical Reports Server (NTRS)

    Rhein, R. A.; Ingham, J. D.

    1974-01-01

    Three anhydrides provide effective chain extension of hydroxy-terminated polyalkylene oxides and polybutadienes. Novel feature of these anhydride reactants is that they are difunctional as anhydrides, but they are tetrafunctional if conditions are selected that lead to total esterification or reaction of all carboxyl groups.

  18. 21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... copolymerization of ethylene and vinyl acetate, followed by reaction with maleic anhydride. Such polymers shall... prior to reaction with maleic anhydride, and not more than 2 percent of grafted maleic anhydride by... ASTM method D 1238-82, “Standard Test Method for Flow Rates of Thermoplastics by Extrusion...

  19. Improved in vivo stability of actinium-225 macrocyclic complexes.

    PubMed

    Deal, K A; Davis, I A; Mirzadeh, S; Kennel, S J; Brechbiel, M W

    1999-07-29

    The favorable nuclear properties of actinium-225 ((225)Ac) have led to proposal of this isotope for use in radioimmunotherapy. In an effort to reduce the toxicity of free (225)Ac, a series of ligands were evaluated for stability in vivo. Loss of (225)Ac from acyclic chelating agents resulted in high liver uptake and poor whole body clearance. The macrocyclic ligands c-DOTA, PEPA, and HEHA were evaluated, and (225)Ac-HEHA showed exceptional stability in vivo. (225)Ac chelated with EDTA, DTPA, DOTA, or PEPA permitted substantial accumulation of the radionuclide to the liver, while the (225)Ac-HEHA complex was essentially excreted within minutes of administration. The preparation of the ligands and radiolabeled complexes and the biodistribution results will be discussed.

  20. Thermal stabilized vegetable oil extended diesel fuels

    SciTech Connect

    Sweeney, W.M.; Lachowicz, D.R.

    1986-03-11

    A middle distillate fuel composition is described comprising: (a) a major portion of a middle distillate containing a hydrocarbon boiling in the middle distillate boiling range; (b) an extending portion of a vegetable oil; and (c) an effective thermal-stabilizing amount of a nitrogen-containing polymer prepared by reacting an ethylene/propylene copolymer with maleic anhydride, thereby forming a succinic anhydride, reacting the succinic anhydride, with an alcohol, thereby forming a succinate ester while leaving a portion of the succinic anhydride unreacted, and, reacting the succinate ester and the unreacted succinic anhydride with dimethylaminopropylamine, thereby forming a nitrogen-containing polymer.

  1. Familial mental retardation in a family with an inherited chromosome rearrangement

    PubMed Central

    Chudley, A. E.; Bauder, F.; Ray, M.; McAlpine, Phyllis J.; Pena, S. D. J.; Hamerton, J. L.

    1974-01-01

    A family of three generations has been described with an insertional type of chromosome rearrangement involving chromosomes 11 and 18[46,XX or XY, ins(11;18)(p15;q11q21)] detected by G-banding using a trypsin digestion method. Four members of this family with clinical features of 18q− have inherited the der(18) from their father and are thus deficient for (18)(q11q21). Three other family members have inherited the der(11) and thus have a duplication of the same segment [(18)(q11q21)]. Genetic marker studies on this family, show no significant segregation of any of the markers studied with either the der(11) or der(18). Eight family members had the PepA8PepA1 genotype and four of these were carrying the der(18), indicating that the PepA locus which had been previously assigned to chromosome 18, does not lie in the segment q11→q21. Images PMID:4140909

  2. Activation of AMPA receptor in the infralimbic cortex facilitates extinction and attenuates the heroin-seeking behavior in rats.

    PubMed

    Chen, Weisheng; Wang, Yiqi; Sun, Anna; Zhou, Linyi; Xu, Wenjin; Zhu, Huaqiang; Zhuang, Dingding; Lai, Miaojun; Zhang, Fuqiang; Zhou, Wenhua; Liu, Huifen

    2016-01-26

    Infralimbic cortex (IL) is proposed to suppress cocaine seeking after extinction, but whether the IL regulates the extinction and reinstatement of heroin-seeking behavior is unknown. To address this issue, the male SD rats were trained to self-administer heroin under a FR1 schedule for consecutive 14 days, then the rats underwent 7 daily 2h extinction session in the operant chamber. The activation of IL by microinjection PEPA, an allosteric AMPA receptor potentiator into IL before each of extinction session facilitated the extinction responding after heroin self-administration, but did not alter the locomotor activity in an open field testing environment. Other rats were first trained under a FR1 schedule for heroin self-administration for 14 days, followed by 14 days of extinction training, and reinstatement of heroin-seeking induced by cues was measured for 2h. Intra-IL microinjecting of PEPA at 15min prior to test inhibited the reinstatement of heroin-seeking induced by cues. Moreover, the expression of GluR1 in the IL and NAc remarkably increased after treatment with PEPA during the reinstatement. These finding suggested that activation of glutamatergic projection from IL to NAc shell may be involved in the extinction and reinstatement of heroin-seeking. PMID:26639425

  3. Rosen’s (M,R) system in process algebra

    PubMed Central

    2013-01-01

    Background Robert Rosen’s Metabolism-Replacement, or (M,R), system can be represented as a compact network structure with a single source and three products derived from that source in three consecutive reactions. (M,R) has been claimed to be non-reducible to its components and algorithmically non-computable, in the sense of not being evaluable as a function by a Turing machine. If (M,R)-like structures are present in real biological networks, this suggests that many biological networks will be non-computable, with implications for those branches of systems biology that rely on in silico modelling for predictive purposes. Results We instantiate (M,R) using the process algebra Bio-PEPA, and discuss the extent to which our model represents a true realization of (M,R). We observe that under some starting conditions and parameter values, stable states can be achieved. Although formal demonstration of algorithmic computability remains elusive for (M,R), we discuss the extent to which our Bio-PEPA representation of (M,R) allows us to sidestep Rosen’s fundamental objections to computational systems biology. Conclusions We argue that the behaviour of (M,R) in Bio-PEPA shows life-like properties. PMID:24237684

  4. Activation of AMPA receptor in the infralimbic cortex facilitates extinction and attenuates the heroin-seeking behavior in rats.

    PubMed

    Chen, Weisheng; Wang, Yiqi; Sun, Anna; Zhou, Linyi; Xu, Wenjin; Zhu, Huaqiang; Zhuang, Dingding; Lai, Miaojun; Zhang, Fuqiang; Zhou, Wenhua; Liu, Huifen

    2016-01-26

    Infralimbic cortex (IL) is proposed to suppress cocaine seeking after extinction, but whether the IL regulates the extinction and reinstatement of heroin-seeking behavior is unknown. To address this issue, the male SD rats were trained to self-administer heroin under a FR1 schedule for consecutive 14 days, then the rats underwent 7 daily 2h extinction session in the operant chamber. The activation of IL by microinjection PEPA, an allosteric AMPA receptor potentiator into IL before each of extinction session facilitated the extinction responding after heroin self-administration, but did not alter the locomotor activity in an open field testing environment. Other rats were first trained under a FR1 schedule for heroin self-administration for 14 days, followed by 14 days of extinction training, and reinstatement of heroin-seeking induced by cues was measured for 2h. Intra-IL microinjecting of PEPA at 15min prior to test inhibited the reinstatement of heroin-seeking induced by cues. Moreover, the expression of GluR1 in the IL and NAc remarkably increased after treatment with PEPA during the reinstatement. These finding suggested that activation of glutamatergic projection from IL to NAc shell may be involved in the extinction and reinstatement of heroin-seeking.

  5. Theoretical investigation of the role of clay edges in prebiotic peptide bond formation. II - Structures and thermodynamics of the activated complex species

    NASA Technical Reports Server (NTRS)

    Collins, Jack R.; Loew, Gilda H.; Luke, Brian T.; White, David H.

    1988-01-01

    Molecular orbital calculations are used to study amino acid activation by anhydride formation in neutral phosphates and in tetrahedral silicate and aluminate sites on clay edges. The results agree with previous ab initio studies of Luke et al. (1984) on the reactant species. Relative heats of formation of the anhydrides indicate the extent of anhydride formation to be the greatest for Al and the least for phosphate, which is the same order as the stability of hydrolysis.

  6. 40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... + vegetable oil esters Dialkydithiocarbamates, metal salts/Dialkylamines + carbon disulfide Thiuram... polymerization of phthalic anhydride + glycerin + vegetable oil esters Benzene/By-product of styrene...

  7. 40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... + vegetable oil esters Dialkydithiocarbamates, metal salts/Dialkylamines + carbon disulfide Thiuram... polymerization of phthalic anhydride + glycerin + vegetable oil esters Benzene/By-product of styrene...

  8. 40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... + vegetable oil esters Dialkydithiocarbamates, metal salts/Dialkylamines + carbon disulfide Thiuram... polymerization of phthalic anhydride + glycerin + vegetable oil esters Benzene/By-product of styrene...

  9. 40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... + vegetable oil esters Dialkydithiocarbamates, metal salts/Dialkylamines + carbon disulfide Thiuram... polymerization of phthalic anhydride + glycerin + vegetable oil esters Benzene/By-product of styrene...

  10. 40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... + vegetable oil esters Dialkydithiocarbamates, metal salts/Dialkylamines + carbon disulfide Thiuram... polymerization of phthalic anhydride + glycerin + vegetable oil esters Benzene/By-product of styrene...

  11. Partial reversal of the acetaldehyde and butyraldehyde oxidation reactions catalysed by aldehyde dehydrogenases from sheep liver.

    PubMed Central

    Hart, G J; Dickinson, F M

    1978-01-01

    In the presence of acetic anhydride or butyric anhydride, liver aldehyde dehydrogenases catalyse the oxidation of NADH at pH 7.0 and 25 degrees C. The maximum velocities and Michaelis constants for NADH at saturating anhydride concentrations are independent of which anhydride is used, the values being V'max. = 12 min-1 and Km for NADH = 9 micrometer for the mitochondrial enzyme and V'max = 25 min-1 and Km for NADH = 20 micrometer for the cytoplasmic enzyme. Substitution of [4A-2H]NADH for NADH resulted in 2-fold and 4-fold decreases in rate for the mitochondrial and cytoplasmic enzymes respectively. PMID:217349

  12. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Hazardous Liquids Acetic Acid Acetic Anhydride Acetone Acrylonitrile Amyl Acetate Amyl Alcohol Benzene Butyl... Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas...

  13. 24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Hazardous Liquids Acetic Acid Acetic Anhydride Acetone Acrylonitrile Amyl Acetate Amyl Alcohol Benzene Butyl... Butane Ethene Ethylene Ethylene Oxide Hydrogen Liquefied Natural Gas (LNG) Liquefied Petroleum Gas...

  14. Preparation of poly(oxybutyleneoxymaleoyl) catalyzed by a proton exchanged montmorillonite clay.

    PubMed

    Ferrahi, Mohammed Issam; Belbachir, Mohammed

    2004-01-01

    The polycondensation of tetrahydrofuran with maleic anhydride catalyzed by Maghnite-H+ (Mag-H) was investigated. Maghnite is a montmorillonite sheet silicate clay that is exchanged with protons to produce Maghnite-H [1]. It was found that the polymerization in bulk is initiated by Mag-H in the presence of acetic anhydride at 40 degrees C. The effects of the amounts of Mag-H and acetic anhydride were studied. The polymerization yield increased as the proportions of catalyst and acetic anhydride were increased.

  15. Synthesis, characterization and nanocomposite formation of poly(glycerol succinate-co-maleate) with cellulose nanowhiskers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel biodegradable polymer based on glycerol, succinic anhydride and maleic anhydride, poly(glycerol succinate-co-maleate), poly(GlySAMA), was synthesized by melt polycondensation and tested as a matrix for composites with cellulose nanowhiskers. This glycerol-based polymer is thermally stable as...

  16. 21 CFR 172.828 - Acetylated monoglycerides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... molecular distillation or by steam stripping; or (2) The direct acetylation of edible monoglycerides with acetic anhydride without the use of catalyst or molecular distillation, and with the removal by vacuum distillation, if necessary, of the acetic acid, acetic anhydride, and triacetin. (b) The food additive has...

  17. 21 CFR 172.828 - Acetylated monoglycerides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... molecular distillation or by steam stripping; or (2) The direct acetylation of edible monoglycerides with acetic anhydride without the use of catalyst or molecular distillation, and with the removal by vacuum distillation, if necessary, of the acetic acid, acetic anhydride, and triacetin. (b) The food additive has...

  18. 21 CFR 172.828 - Acetylated monoglycerides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... molecular distillation or by steam stripping; or (2) The direct acetylation of edible monoglycerides with acetic anhydride without the use of catalyst or molecular distillation, and with the removal by vacuum distillation, if necessary, of the acetic acid, acetic anhydride, and triacetin. (b) The food additive has...

  19. 77 FR 22780 - Certain New Chemicals; Receipt and Status Information

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ..., sodium salt, hydrogen peroxide- and peroxydisulfuric acid ( 2O2) sodium salt (1:2)-initiated. P-12-0218... anhydride, maltodextrin, and methacrylic acid, ammonium salt, hydrogen peroxide- and peroxydisulfuric acid... additive. with acrylic acid and maleic anhydride, maltodextrin and methacrylic acid, sodium salt,...

  20. A Classroom Experiment on Phase Equilibria Involving Orientational Disordering in Crystals.

    ERIC Educational Resources Information Center

    Mjojo, C. C.

    1985-01-01

    Background information, procedures used, and results obtained are provided for an experiment in which a phase diagram is determined using a differential scanning calorimeter. Commercial samples of D-camphoric anhydride (Eastman Kodak) and D,L-camphoric anhydride (Aldrich) were used in the experiment. (JN)

  1. [Investigation of the intramolecular cyclization of the thiophene substituted cyclohexane skeleton gamma-oxocarboxylic acid and synthesis of some N-heteroaryl isoindole derivatives].

    PubMed

    Csende, Ferenc

    2011-01-01

    From thiophene and cis-hexahydrophthalic anhydride the corresponding gamma-oxocarboxylic acid was obtained by the Friedel-Crafts reaction, which resulted in new heterocycles with acetic anhydride, Lawesson reagent or urea by intramolecular cyclization. Saturated N-heteroaryl isoindoles were prepared directly by the fusion reaction of heteroaromatic amines with the oxocarboxylic acid. PMID:21800711

  2. Comparative kinetic study and microwaves non-thermal effects on the formation of poly(amic acid) 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 4,4'-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline (BAPHF). Reaction activated by microwave, ultrasound and conventional heating.

    PubMed

    Tellez, Hugo Mendoza; Alquisira, Joaquín Palacios; Alonso, Carlos Rius; Cortés, José Guadalupe López; Toledano, Cecilio Alvarez

    2011-01-01

    Green chemistry is the design of chemical processes that reduce or eliminate negative environmental impacts. The use and production of chemicals involve the reduction of waste products, non-toxic components, and improved efficiency. Green chemistry applies innovative scientific solutions in the use of new reagents, catalysts and non-classical modes of activation such as ultrasounds or microwaves. Kinetic behavior and non-thermal effect of poly(amic acid) synthesized from (6FDA) dianhydride and (BAPHF) diamine in a low microwave absorbing p-dioxane solvent at low temperature of 30, 50, 70 °C were studied, under conventional heating (CH), microwave (MW) and ultrasound irradiation (US). Results show that the polycondensation rate decreases (MW > US > CH) and that the increased rates observed with US and MW are due to decreased activation energies of the Arrhenius equation. Rate constant for a chemical process activated by conventional heating declines proportionally as the induction time increases, however, this behavior is not observed under microwave and ultrasound activation. We can say that in addition to the thermal microwave effect, a non-thermal microwave effect is present in the system.

  3. The C2H2-type transcription factor, FlbC, is involved in the transcriptional regulation of Aspergillus oryzae glucoamylase and protease genes specifically expressed in solid-state culture.

    PubMed

    Tanaka, Mizuki; Yoshimura, Midori; Ogawa, Masahiro; Koyama, Yasuji; Shintani, Takahiro; Gomi, Katsuya

    2016-07-01

    Aspergillus oryzae produces a large amount of secreted proteins in solid-state culture, and some proteins such as glucoamylase (GlaB) and acid protease (PepA) are specifically produced in solid-state culture, but rarely in submerged culture. From the disruption mutant library of A. oryzae transcriptional regulators, we successfully identified a disruption mutant showing an extremely low production level of GlaB but a normal level of α-amylase production. This strain was a disruption mutant of the C2H2-type transcription factor, FlbC, which is reported to be involved in the regulation of conidiospore development. Disruption mutants of other upstream regulators comprising a conidiation regulatory network had no apparent effect on GlaB production in solid-state culture. In addition to GlaB, the production of acid protease in solid-state culture was also markedly decreased by flbC disruption. Northern blot analyses revealed that transcripts of glaB and pepA were significantly decreased in the flbC disruption strain. These results suggested that FlbC is involved in the transcriptional regulation of genes specifically expressed under solid-state cultivation conditions, possibly independent of the conidiation regulatory network.

  4. Preparation of highly luminescent and color tunable carbon nanodots under visible light excitation for in vitro and in vivo bio-imaging

    SciTech Connect

    Zheng, Min; Li, Jing; Xie, Zhigang; Qu, Dan; Miao, Xiang; Jing, Xiabing; Sun, Zaicheng; Fan, Hongyou; Liu, Shi

    2015-11-10

    Carbon nanodots (CDs) have generated enormous excitement because of their superiority in water solubility, chemical inertness, low toxicity, ease of functionalization and resistance to photobleaching. Here we report a facile thermal pyrolysis route to prepare CDs with high quantum yield (QY) using citric acid as the carbon source and ethylene diamine derivatives (EDAs) including triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and polyene polyamine (PEPA) as the passivation agents. We find that the CDs prepared from EDAs, such as TETA, TEPA and PEPA, show relatively high photoluminescence (PL) QY (11.4, 10.6, and 9.8%, respectively) at 1ex of 465 nm. The cytotoxicity of the CDs has been investigated through in vitro and in vivo bio-imaging studies. The results indicate that these CDs possess low toxicity and good biocompatibility. As a result, the unique properties such as the high PL QY at large excitation wave length and the low toxicity of the resulting CDs make them promising fluorescent nanoprobes for applications in optical bio-imaging and biosensing.

  5. Preparation of highly luminescent and color tunable carbon nanodots under visible light excitation for in vitro and in vivo bio-imaging

    DOE PAGES

    Zheng, Min; Li, Jing; Xie, Zhigang; Qu, Dan; Miao, Xiang; Jing, Xiabing; Sun, Zaicheng; Fan, Hongyou; Liu, Shi

    2015-11-10

    Carbon nanodots (CDs) have generated enormous excitement because of their superiority in water solubility, chemical inertness, low toxicity, ease of functionalization and resistance to photobleaching. Here we report a facile thermal pyrolysis route to prepare CDs with high quantum yield (QY) using citric acid as the carbon source and ethylene diamine derivatives (EDAs) including triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and polyene polyamine (PEPA) as the passivation agents. We find that the CDs prepared from EDAs, such as TETA, TEPA and PEPA, show relatively high photoluminescence (PL) QY (11.4, 10.6, and 9.8%, respectively) at 1ex of 465 nm. The cytotoxicity of themore » CDs has been investigated through in vitro and in vivo bio-imaging studies. The results indicate that these CDs possess low toxicity and good biocompatibility. As a result, the unique properties such as the high PL QY at large excitation wave length and the low toxicity of the resulting CDs make them promising fluorescent nanoprobes for applications in optical bio-imaging and biosensing.« less

  6. Combining protein-shelled platinum nanoparticles with graphene to build a bionanohybrid capacitor.

    PubMed

    San, Boi Hoa; Kim, Jang Ah; Kulkarni, Atul; Moh, Sang Hyun; Dugasani, Sreekantha Reddy; Subramani, Vinod Kumar; Thorat, Nanasaheb D; Lee, Hyun Ho; Park, Sung Ha; Kim, Taesung; Kim, Kyeong Kyu

    2014-12-23

    The electronic properties of biomolecules and their hybrids with inorganic materials can be utilized for the fabrication of nanoelectronic devices. Here, we report the charge transport behavior of protein-shelled inorganic nanoparticles combined with graphene and demonstrate their possible application as a bionanohybrid capacitor. The conductivity of PepA, a bacterial aminopeptidase used as a protein shell (PS), and the platinum nanoparticles (PtNPs) encapsulated by PepA was measured using a field effect transistor (FET) and a graphene-based FET (GFET). Furthermore, we confirmed that the electronic properties of PepA-PtNPs were controlled by varying the size of the PtNPs. The use of two poly(methyl methacrylate) (PMMA)-coated graphene layers separated by PepA-PtNPs enabled us to build a bionanohybrid capacitor with tunable properties. The combination of bioinorganic nanohybrids with graphene is regarded as the cornerstone for developing flexible and biocompatible bionanoelectronic devices that can be integrated into bioelectric circuits for biomedical purposes. PMID:25426677

  7. Allozyme analysis of the temporal populations of Echinostoma revolutum collected from domestic ducks in Khon Kaen Province, Thailand.

    PubMed

    Saijuntha, Weerachai; Sithithaworn, Paiboon; Tantrawatpan, Chairat; Tapdara, Sumonta; Andrews, Ross H

    2011-01-01

    Four temporal populations of Echinostoma revolutum (ER1, ER2, ER3, ER4) were collected from domestic ducks in Khon Kaen Province, Thailand during February-October 2008. The ER1, ER2, ER3 and ER4 were collected in February, April, June and October, respectively. The 12 enzymes encoding 15 loci were examined. Two loci were found in each of 3 enzymes, namely glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and peptidase valine-leucine (PEPA). Of these, three loci, namely, G6pd-1, Me-1 and PepA-2, were polymorphic. Genotypes were assigned for the specific allelic profiles detected at these three polymorphic loci. Twenty-eight genotypes were observed in the 4 temporal populations of E. revolutum. Three genotypes, Er22, Er23 and Er25, were found in all populations. The Er6 genotype occurred had the highest frequency of all the populations. These 28 genotypes were clustered into 3 groups with genetic differences of 2-12% among the loci. A cluster of genotypes (Er1, Er3, Er9 and Er12) showed the greatest genetic difference among the genotypes (12% difference). These results show intraspecific variation exists in E. revolutum populations in domestic ducks from Khon Kaen Province, Thailand.

  8. Soy protein polymers: Enhancing the water stability property

    NASA Astrophysics Data System (ADS)

    Srinivasan, Gowrishankar

    Soy protein based plastics have been processed in the past by researchers for various short-term applications; however a common issue is the high water sensitivity of these plastics. This work concentrates on resolving this water sensitivity issue of soy protein polymers by employing chemical and mechanical interaction at the molecular level during extrusion. The primary chemical interactions employed were anhydride chemistries such as maleic anhydride (MA), phthalic anhydride (PTA), and butylated hydroxyanisole (BHA). These were respectively used in conjunction with glycerol as a plasticizer to produce relatively water stable soy protein based plastics. Formulations with varying additive levels of the chemistries were extruded and injection molded to form the samples for characterization. The additive levels of anhydrides were varied between 3-10% tw/tw (total mass). Results indicated that phthalic anhydride formulations resulted in highest water stability. Plastic formulations with concentration up to 10% phthalic anhydride were observed to have water absorption as low as 21.5% after 24 hrs of exposure to water with respect to 250% for the control formulation. Fourier transform infrared spectroscopy (FTIR) was utilized to characterize and confirm the fundamental mechanisms of water stability achieved by phthalic and maleic anhydride chemistries. In addition, the anhydride formulations were modified by inclusion of cotton fibers and pretreated cotton powder in order to improve mechanical properties. The incorporation of cotton fibers improved the dry strength by 18%, but did not significantly improve the wet state strength of the plastics. It was also observed that the butylated-hydroxy anisole (BHA) formulation exhibited high extension values in the dry state and had inferior water absorption properties in comparison with anhydride formulations.

  9. Hydrocarbon fuel detergent

    SciTech Connect

    Meyer, G.R.; Lyons, W.R.

    1990-01-23

    This patent describes a hydrocarbon fuel composition comprising: a hydrocarbon fuel; and a detergent amount of a detergent comprising an alkenylsuccinimide prepared by reacting an alkenylsuccinic acid or anhydride with a mixture of amines, wherein at least 90 weight percent of the alkenyl substituent is derived from an olefin having a carbon chain of from 10 to 30 carbons or mixtures thereof, and wherein the alkenylsuccinic acid or anhydride is reacted with the mixture of amines at a mole ratio of 0.8 to 1.5 moles of the amines per mole of the alkenylsuccinic acid or anhydride.

  10. Process for epoxy foam production

    DOEpatents

    Celina, Mathias C.

    2011-08-23

    An epoxy resin mixture with at least one epoxy resin of between approximately 60 wt % and 90 wt %, a maleic anhydride of between approximately 1 wt % and approximately 30 wt %, and an imidazole catalyst of less than approximately 2 wt % where the resin mixture is formed from at least one epoxy resin with a 1-30 wt % maleic anhydride compound and an imidazole catalyst at a temperature sufficient to keep the maleic anhydride compound molten, the resin mixture reacting to form a foaming resin which can then be cured at a temperature greater than 50.degree. C. to form an epoxy foam.

  11. Phosphorus-containing bisimide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1981-01-01

    The production of fire-resistant resins particularly useful for making laminates with inorganic fibers such as graphite fibers is discussed. The resins are by (1) condensation of an ethylenically unsaturated cyclic anhydride with a bis(diaminophenyl) phosphine oxide, and (2) by addition polymerization of the bisimide so obtained. Up to about 50%, on a molar basis, of benzophenonetetracarboxylic acid anhydride can be substituted for some of the cyclic anhydride to alter the properties of the products. Graphite cloth laminates made with these resins show 800 C char yields greater than 70% by weight in nitrogen. Limiting oxygen indexes of more than 100% are determined for these resins.

  12. Surfactant and process for enhanced oil recovery

    SciTech Connect

    Stapp, P. R.

    1984-12-11

    A novel surfactant is formed by reacting maleic anhydride with either a petroleum sulfonate or an alkaryl sulfonate. A surfactant system containing the above surfactant useful in enhanced oil recovery processes is also provided.

  13. Polyolefin-based aerogels

    NASA Technical Reports Server (NTRS)

    Lee, Je Kyun (Inventor); Gould, Gerogle L. (Inventor)

    2010-01-01

    The present invention relates to cross-linked polyolefin aerogels in simple and fiber-reinforced composite form. Of particular interest are polybutadiene aerogels. Especially aerogels derived from polybutadienes functionalized with anhydrides, amines, hydroxyls, thiols, epoxies, isocyanates or combinations thereof.

  14. Chiroptical spectroscopy of natural products: avoiding the aggregation effects of chiral carboxylic acids.

    PubMed

    Polavarapu, Prasad L; Donahue, Emily A; Hammer, Karissa C; Raghavan, Vijay; Shanmugam, Ganesh; Ibnusaud, Ibrahim; Nair, Divya S; Gopinath, Chithra; Habel, Deenamma

    2012-08-24

    Determination of the absolute configurations and predominant conformations of chiral natural products, occurring as carboxylic acids, using chiroptical spectroscopic methods becomes challenging due to the formation of solute aggregates (in the form of dimers, etc.) and/or solute-solvent complexes resulting from intermolecular hydrogen bonding with solvent. A hypothesis that such aggregation effects can be avoided by using corresponding sodium salts or acid anhydrides for chiroptical spectroscopic measurements has been tested. For this purpose, vibrational circular dichroism, electronic circular dichroism, and optical rotatory dispersion spectra for disodium salts of two natural products, hibiscus acid and garcinia acid, and the anhydride of acetylated garcinia acid have been measured. These experimental spectra are analyzed in combination with quantum chemical calculations of corresponding spectra. The spectral analysis for sodium salts and anhydride turned out to be simpler, suggesting that the conversion of carboxylic acids to corresponding salts or anhydride can be advantageous for the application of chiroptical spectroscopy. PMID:22877358

  15. Polymeric foams stable at high temperatures

    NASA Technical Reports Server (NTRS)

    Riccitiello, S. R.; Harrison, E. S.; Delano, C. B.

    1976-01-01

    Crosslinked poly(N-arylenebenzimidazoles) are stable up to 370 C. Polymers are made by mixing appropriate stoichiometric amounts of tetramine and aromatic dicarboxylic acid anhydride with phenol or alkyl-substituted phenol.

  16. Determination of the Absolute Stereochemistry of Secondary Alcohols: An Advanced Organic Chemistry Experiment for Undergraduate Students.

    ERIC Educational Resources Information Center

    Bandaranayake, Wickramasinghe M.

    1980-01-01

    Describes experiments which can be completed in five four-hour laboratory sessions, including two synthesis (alpha-phenylbutyric and alpha-phenylbutyric acid anhydride) and determining the absolute stereochemistry of secondary alcohols using the synthetic products. (JN)

  17. Catalytic actions of alkaline salts in reactions between 1,2,3,4-butanetetracarboxylic acid and cellulose: II. Esterification.

    PubMed

    Ji, Bolin; Tang, Peixin; Yan, Kelu; Sun, Gang

    2015-11-01

    1,2,3,4-Butanetetracarboxylic acid (BTCA) reacts with cellulose in two steps with catalysis of alkaline salts such as sodium hypophosphite: anhydride formation and esterification of anhydride with cellulose. The alkali metal ions were found effective in catalyzing formation of BTCA anhydride in a previous report. In this work, catalytic functions of the alkaline salts in the esterification reaction between BTCA anhydride and cellulose were investigated. Results revealed that acid anions play an important role in the esterification reaction by assisting removal of protons on intermediates and completion of the esterification between cellulose and BTCA. Besides, alkaline salts with lower pKa1 values of the corresponding acids are more effective ones for the reaction since addition of these salts could lead to lower pH values and higher acid anion concentrations in finishing baths. The mechanism explains the results of FTIR and wrinkle recovery angles of the fabrics cured under different temperatures and times.

  18. A Demonstration of Polymer Crosslinking and Gel Formation Without Heating

    ERIC Educational Resources Information Center

    Ross, Joseph H.

    1977-01-01

    Describes an undergraduate experiment in which Gantrez AN polymer chains are crosslinked at the anhydride groups by the addition of the hydroxyl groups of triethanolamine, which also acts as a basic catalyst. (MLH)

  19. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific... manufactured by treating molten phthalic anhydride with steam in the presence of a zinc oxide catalyst, by...

  20. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  1. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  2. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  3. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  4. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  5. 21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... additive is the reaction product of succinic anhydride, fully hydrogenated vegetable oil (predominantly C16... additive is used or intended for use as an emulsifier in or with shortenings and edible oils intended...

  6. 21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... additive is the reaction product of succinic anhydride, fully hydrogenated vegetable oil (predominantly C16... additive is used or intended for use as an emulsifier in or with shortenings and edible oils intended...

  7. 21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... additive is the reaction product of succinic anhydride, fully hydrogenated vegetable oil (predominantly C16... additive is used or intended for use as an emulsifier in or with shortenings and edible oils intended...

  8. 21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... additive is the reaction product of succinic anhydride, fully hydrogenated vegetable oil (predominantly C16... additive is used or intended for use as an emulsifier in or with shortenings and edible oils intended...

  9. New polymer systems: Chain extension by dianhydrides

    NASA Technical Reports Server (NTRS)

    Rhein, R. A.; Ingham, J. D.

    1972-01-01

    The results are presented for a systematic investigation on the use of anhydrides to prepare stable elastomeric materials for space use, under mild reaction conditions. The three anhydrides investigated were found to provide effective chain extension of hydroxy-terminated poly(alkylene oxides) and poly(butadienes). These were tetrahydrofuran tetracarboxylic dianhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic diahydride. The most effective catalyst investigated was ferric acetylacetonate, which resulted in chain extension at 333 K (60 C). One feature of these anhydride reactants is that they are difunctional as anhydrides, but tetrafunctional if conditions are selected that lead to reaction of all carboxyl groups. Therefore, chain extension can be effected and then followed by crosslinking via the residual carboxyl groups.

  10. My fifty years in catalysis: the Eugene J. Houdry Award Address

    SciTech Connect

    Farkas, A.

    1980-01-01

    A review of catalytic developments, with which Farkas was associated, covers hydrogen chemistry; the oxidation of hydrocarbons to hydroperoxides; vanadium catalyst for phthalic anhydride synthesis; and triethylenediamine catalysts for the polyurethane production.

  11. THE SYNTHESIS OF A TETRADECAPEPTIDE RENIN SUBSTRATE

    PubMed Central

    Skeggs, Leonard T.; Lentz, Kenneth E.; Kahn, Joseph R.; Shumway, Norman P.

    1958-01-01

    A tetradecapeptide renin substrate having a biological activity comparable to the natural product and similar chemical properties has been synthesized by means of the carbobenzyloxyl azide and mixed anhydride methods. PMID:13575666

  12. Organic and petroleum chemistry for nonchemists

    SciTech Connect

    Schmerling, L.

    1981-01-01

    A nontechnical book dealing with organic and petroleum chemistry is presented. The contents include: elements and compounds; hydrocarbons; equations; alcohols and phenols; aldehydes; ketones; carboxylic acids; esters; acid halides; amides, and anhydrides; petroleum; and a glossary of compounds. (JMT)

  13. TREATMENT OF AMMONIUM NITRATE SOLUTIONS

    DOEpatents

    Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.

    1958-06-10

    The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.

  14. Aminoacyl-nucleotide reactions - Studies related to the origin of the genetic code and protein synthesis

    NASA Technical Reports Server (NTRS)

    Mullins, D. W., Jr.; Senaratne, N.; Lacey, J. C., Jr.

    1984-01-01

    In the present paper, a report is presented on the effect of pH and carbonate on the hydrolysis rate constants of N-blocked and free aminoacyl adenylate anhydrides. Whereas the hydrolysis of free aminoacyl adenylates seems principally catalyzed by OH(-), the hydrolysis of the N-blocked species is also catalyzed by H(+), giving this compound a U-shaped hydrolysis vs. pH curve. Furthermore, at pH's less than 8, carbonate has an extreme catalytic effect on the hydrolysis of free aminoacyl-AMP anhydride, but essentially no effect on the hydrolysis of N-blocked aminoacyl-AMP anhydride. Furthermore, the N-blocked aminoacyl-AMP anhydride is a very efficient generator of peptides using free glycine as acceptor. The possible significance of the observations to prebiological peptide synthesis is discussed.

  15. Identification of a novel calcium binding motif based on the detection of sequence insertions in the animal peroxidase domain of bacterial proteins.

    PubMed

    Santamaría-Hernando, Saray; Krell, Tino; Ramos-González, María-Isabel

    2012-01-01

    Proteins of the animal heme peroxidase (ANP) superfamily differ greatly in size since they have either one or two catalytic domains that match profile PS50292. The orf PP_2561 of Pseudomonas putida KT2440 that we have called PepA encodes a two-domain ANP. The alignment of these domains with those of PepA homologues revealed a variable number of insertions with the consensus G-x-D-G-x-x-[GN]-[TN]-x-D-D. This motif has also been detected in the structure of pseudopilin (pdb 3G20), where it was found to be involved in Ca(2+) coordination although a sequence analysis did not reveal the presence of any known calcium binding motifs in this protein. Isothermal titration calorimetry revealed that a peptide containing this consensus motif bound specifically calcium ions with affinities ranging between 33-79 µM depending on the pH. Microcalorimetric titrations of the purified N-terminal ANP-like domain of PepA revealed Ca(2+) binding with a K(D) of 12 µM and stoichiometry of 1.25 calcium ions per protein monomer. This domain exhibited peroxidase activity after its reconstitution with heme. These data led to the definition of a novel calcium binding motif that we have termed PERCAL and which was abundantly present in animal peroxidase-like domains of bacterial proteins. Bacterial heme peroxidases thus possess two different types of calcium binding motifs, namely PERCAL and the related hemolysin type calcium binding motif, with the latter being located outside the catalytic domains and in their C-terminal end. A phylogenetic tree of ANP-like catalytic domains of bacterial proteins with PERCAL motifs, including single domain peroxidases, was divided into two major clusters, representing domains with and without PERCAL motif containing insertions. We have verified that the recently reported classification of bacterial heme peroxidases in two families (cd09819 and cd09821) is unrelated to these insertions. Sequences matching PERCAL were detected in all kingdoms of life. PMID

  16. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1984-01-01

    Flame-resistant reinforced bodies are disclosed which are composed of reinforcing fibers, filaments or fabrics in a cured body of bis- and tris-imide resins derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, or of addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride.

  17. Gamma-irradiation stability of saturated and unsaturated aliphatic polyanhydrides--ricinoleic acid based polymers.

    PubMed

    Teomim, D; Mäder, K; Bentolila, A; Magora, A; Domb, A J

    2001-01-01

    The effect of terminal sterilization by gamma-irradiation on several ricinoleic acid based polyanhydrides was investigated. The following polymers were used: poly(ricinoleic acid maleate) [P(RAM)], poly(ricinoleic acid succinate) [P(RAS)], poly(hydroxy stearic acid succinate) [P(HSAS)], poly(hydroxy stearic acid maleate) [P(HSAM)], and their copolymers with sebacic acid. The polymers were irradiated with an absorbed dose of 2.5 or 10 Mrad by means of a 60Co source under dry ice or at room temperature. No differences were found between samples irradiated under dry ice and at room temperature. Polymers prepared from monomers containing maleate residues, which contain double bonds adjusted to the anhydride linkage along the polymer chain, decreased in molecular weight, became insoluble, and showed fast hydrolytic degradation. For example, p(RAM), p(HSAM), and their copolymers with sebacic acid decreased in Mw from about 10,000 to about 2000, and from about 30,000 to about 5000, respectively, while polymers based on RAS and HSAS remained stable. This phenomenon was explained by an anhydride interchange-self-depolymerization process of the unsaturated anhydride bonds induced by gamma-irradiation. This explanation was supported by the depolymerization of another class of polymers having an anhydride bond between two double bonds, fumaric acid anhydride polymers. The anhydride bond that lies between two double bonds was found to be more sensitive to gamma-irradiation. This anhydride bond may be cleaved to form two radicals that further react with aliphatic anhydride bonds along the polymer chain to form inter- and/or intracyclization products. PMID:11710004

  18. Novel enzymatic synthesis of 4-O-cinnamoyl quinic and shikimic acid derivatives.

    PubMed

    Armesto, Nuria; Ferrero, Miguel; Fernández, Susana; Gotor, Vicente

    2003-07-11

    The first direct synthesis of 4-O-cinnamoyl derivatives of quinic and shikimic acids were accomplished by regioselective esterification with Candida antarctica lipase A. For hydrocinnamic esters, enzymatic transesterification with vinyl esters gave excellent yields. However, more reactive acylating agents such as anhydrides were used to synthesize cinnamic derivatives of both acids. An inhibitory effect was observed with this lipase for p-methoxy, p-hydroxy, and p-acetoxy vinyl ester and anhydride derivatives (coumarate and ferulate derivatives).

  19. Synthesis of 24-phenyl-24-oxo steroids derived from bile acids by palladium-catalyzed cross coupling with phenylboronic acid. NMR characterization and X-ray structures.

    PubMed

    Mayorquín-Torres, Martha C; Romero-Ávila, Margarita; Flores-Álamo, Marcos; Iglesias-Arteaga, Martin A

    2013-11-01

    Palladium-catalyzed cross coupling of phenyboronic acid with acetylated bile acids in which the carboxyl functions have been activated by formation of a mixed anhydride with pivalic anhydride afforded moderate to good yield of 24-phenyl-24-oxo-steroids. Unambiguous assignments of the NMR signals were made with the aid of combined 1D and 2D NMR techniques. X-ray diffraction studies confirmed the obtained structures.

  20. Sulfide-mediated dehydrative glycosylation.

    PubMed

    Nguyen, H M; Chen, Y; Duron, S G; Gin, D Y

    2001-09-12

    The development of a new method for glycosylation with 1-hydroxy glycosyl donors employing dialkyl sulfonium reagents is described. The process employs the reagent combination of a dialkyl sulfide and triflic anhydride to effect anomeric bond constructions. This controlled dehydrative coupling of various C(1)-hemiacetal glycosyl donors and nucleophilic acceptors proceeds by way of a sulfide-to-sulfoxide oxidation process in which triflic anhydride serves as the oxidant.

  1. Three new compounds from the stem bark of Juglans mandshurica.

    PubMed

    Lin, Hua; Zhang, Yu-Wei; Hua, Ying; Bao, Yong-Li; Wu, Yin; Sun, Lu-Guo; Yu, Chun-Lei; Huang, Yan-Xin; Wang, En-Bo; Jiang, Hong-Yu; Li, Yu-Xin

    2014-01-01

    Three new compounds, 3,6-dihydroxy-4,5-dimethoxy-1,8-naphalic anhydride (1), 3,4,5,6-tetrahydroxy-1,8-naphalic anhydride (2), and methyl (7E,9E)-6,11-dioxononadeca-7,9-dienoate (3), were isolated from the stem bark of Juglans mandshurica. Their structures were elucidated on the basis of spectroscopic evidence, including 1D and 2D NMR, HR-TOF-MS, and by comparison with the literature data.

  2. Hydrocarbon Processing`s petrochemical processes `97

    SciTech Connect

    1997-03-01

    The paper compiles information on numerous petrochemical processes, describing the application, the process, yields, economics, commercial plants, references, and licensor. Petrochemicals which are synthesized include: alkylbenzene, methylamines, ammonia, benzene, bisphenol-A, BTX aromatics, butadiene, butanediol, butyraldehyde, caprolactam, cumene, dimethyl terephthalate, ethanolamines, ethylbenzene, ethylene, ethylene glycols, ethylene oxide, formaldehyde, maleic anhydride, methanol, olefins, paraxylene, phenol, phthalic anhydride, polycaproamide, polyethylene, polyethylene terephthalate, polypropylene, PVC, styrene, terephthalic acid, urea, vinyl chloride, and xylene isomers.

  3. Comparison of methods of immobilization to enzyme-linked immunosorbent assay plates for the detection of sugar chains.

    PubMed

    Satoh, A; Fukui, E; Yoshino, S; Shinoda, M; Kojima, K; Matsumoto, I

    1999-11-15

    The immobilization of carbohydrates for solid-phase assays, including enzyme-linked immunosorbent assay (ELISA), is difficult because they are hydrophilic. We developed four new methods for the immobilization of oligosaccharides. ELISA plates were first coated with methyl vinyl ether-maleic anhydride copolymer (MMAC) and an excess of active anhydride groups was introduced. They were subsequently reacted, in four different ways, to bind oligosaccharides. In method 1, the anhydride groups were reacted with hydrazide groups, in the presence of adipic acid dihydrazide, and then coupled to the reducing ends of sugar chains by reductive amination. In method 2, the anhydride groups were reacted with p-aminophenyl glycoside obtained by reduction with p-nitrophenyl glycoside. In method 3, the anhydride groups were reacted with 1, 6-hexamethylenediamine. Aminooxy groups were coupled to the amino groups introduced and then aminooxyacetic acid with carbodiimide and ligated to oligosaccharides by oxime formation. In method 4, stereospecifically aminated oligosaccharides reacted with the anhydride groups. We compared, in solid-phase assays systems, the ability of lectins to detect oligosaccharides immobilized with either one of these four new methods or one of the two methods previously described. Detection of sugars with lectins is useful because, in most cases, they recognize sugars stereospecifically. The immobilization method should therefore be carefully selected to avoid changing the configuration and substitution in C-1. PMID:10552909

  4. Succinimide lubricating oil dispersant

    SciTech Connect

    Wisotsky, M.J.; Bloch, R.; Brownwell, D.W.; Chen, F.J.; Gutierrez, A.

    1987-08-11

    A lubricating oil composition is described exhibiting improved dispersancy in both gasoline and diesel engines comprising a major amount of lubricating oil and 0.5 to 10 weight percent of a dispersant, the dispersant being prepared in a sequential process comprising the steps of: (a) in a first step reacting an oil-soluble polyolefin succinic anhydride, the olefin being a C/sub 3/ or C/sub 4/ olefin and an alkylene polyamine of the formula H/sub 2/N(CH/sub 2/)/sub n/(NH(CH/sub 2/)/sub n/)/sub m/sup -// NH/sub 2/ wherein n is 2 or 3 and m is 0 to 10, in a molar ratio of about 1.0 to 2.2 moles of polyolefin succinic anhydride per mole of polyamine, and (b) reacting the product of step (a) with dicarboxylic acid anhydride selected from the group consisting of maleic anhydride and succinic anhydride in sufficient molar proportions to provide a total mole ratio of about 2,3 to 3.0 moles of anhydride compounds per mole of polyamine.

  5. A kinetic study of isoamyl acetate synthesis by immobilized lipase-catalyzed acetylation in n-hexane.

    PubMed

    Romero, M D; Calvo, L; Alba, C; Daneshfar, A

    2007-01-01

    The objective of this work was to propose a reaction mechanism and to develop a rate equation for the synthesis of isoamyl acetate by acylation of the corresponding alcohol with acetic anhydride using the lipase Novozym 435 in n-hexane. The reaction between isoamyl alcohol and acetic anhydride occurred at high rate in first place. Then, if excess alcohol was used, produced acetic acid further reacted with remaining alcohol, leading to yields higher than 100% (based on initial acetic anhydride content). This reaction was much slower and took place only when acetic anhydride had been totally consumed. Optimal pH for Novozym 435 was 7.7. Acetic acid strongly inactivated the enzyme but it was partially caused by the pH drop in the biocatalyst aqueous microenvironment. Acetic anhydride also showed an important inhibition effect. On the contrary, isoamyl alcohol and isoamyl acetate had no negative effect on the lipase. The analysis of the initial rate data showed that reaction followed a Ping-Pong Bi-Bi mechanism with inhibition by acetic anhydride. The kinetic constants were obtained by multiple regression analysis of experimental findings. Equation predictions and experimental reaction rate values matched very well at conditions where acetic acid concentration in the medium was low.

  6. An Experimental Study of a Pulsed Electromagnetic Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Eskridge, Richard; Lee, Mike; Smith, James; Martin, Adam; Markusic, Tom E.; Cassibry, Jason T.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Experiments are being performed on the NASA Marshall Space Flight Center (MSFC) pulsed electromagnetic plasma accelerator (PEPA-0). Data produced from the experiments provide an opportunity to further understand the plasma dynamics in these thrusters via detailed computational modeling. The detailed and accurate understanding of the plasma dynamics in these devices holds the key towards extending their capabilities in a number of applications, including their applications as high power (greater than 1 MW) thrusters, and their use for producing high-velocity, uniform plasma jets for experimental purposes. For this study, the 2-D MHD modeling code, MACH2, is used to provide detailed interpretation of the experimental data. At the same time, a 0-D physics model of the plasma initial phase is developed to guide our 2-D modeling studies.

  7. Comparison of 225actinium chelates: tissue distribution and radiotoxicity.

    PubMed

    Davis, I A; Glowienka, K A; Boll, R A; Deal, K A; Brechbiel, M W; Stabin, M; Bochsler, P N; Mirzadeh, S; Kennel, S J

    1999-07-01

    The biodistribution and tissue toxicity of intravenously administered 225-actinium (225Ac) complexed with acetate, ethylene diamine tetraacetic acid (EDTA), 1, 4, 7, 10, 13-pentaazacyclopentadecane-N, N', N", N"', N"-pentaacetic acid (PEPA), or the "a" isomer of cyclohexyl diethylenetriamine pentaacetic acid (CHX-DTPA), were examined. The percent of injected dose per organ and per gram of tissue for each chelate complex was determined. 225Ac-CHX-DTPA was evaluated further for radiotoxic effects. Mice receiving > or =185 kBq 225Ac-CHX-DTPA suffered 100% morbidity by 5 days and 100% mortality by 8 days postinjection, and all animals evaluated had significant organ damage. The in vivo instability of the 225Ac-CHX-DTPA complex likely allowed accumulation of free 225Ac in organs, which resulted in tissue pathology.

  8. Interactions between VTA orexin and glutamate in cue-induced reinstatement of cocaine seeking in rats

    PubMed Central

    Mahler, Stephen V.; Smith, Rachel J.

    2013-01-01

    Rationale Glutamate and orexin/hypocretin systems are involved in Pavlovian cue-triggered drug seeking. Objectives Here, we asked whether orexin and glutamate interact within ventral tegmental area (VTA) to promote reinstatement of extinguished cocaine seeking in a rat self-administration paradigm. Methods/results We first found that bilateral VTA micro-injections of the orexin 1 receptor (OX1R) antagonist SB-334867 (SB) or a cocktail of the AMPA and NMDA glutamate receptor antagonists CNQX/AP-5 reduced reinstatement of cocaine seeking elicited by cues. In contrast, neither of these microinjections nor systemic SB reduced cocaine-primed reinstatement. Additionally, unilateral VTA OX1R blockade combined with contralateral VTA glutamate blockade attenuated cue-induced reinstatement, indicating that VTA orexin and glutamate are simultaneously necessary for cue-induced reinstatement. We further probed the receptor specificity of glutamate actions in VTA, finding that CNQX, but not AP-5, dose-dependently attenuated cue-induced reinstatement, indicating that AMPA but not NMDA receptor transmission is required for this type of cocaine seeking. Given the necessary roles of both OX1 and AMPA receptors in VTA for cue-induced cocaine seeking, we hypothesized that these signaling pathways interact during this behavior. We found that PEPA, a positive allosteric modulator of AMPA receptors, completely reversed the SB-induced attenuation of reinstatement behavior. Intra-VTA PEPA alone did not alter cue-induced reinstatement, indicating that potentiating AMPA activity with this drug specifically compensates for OX1R blockade, rather than simply inducing or enhancing reinstatement itself. Conclusions These findings show that cue-induced, but not cocaine-primed, reinstatement of cocaine seeking is dependent upon orexin and AMPA receptor interactions in VTA. PMID:22411428

  9. TrpM, a Small Protein Modulating Tryptophan Biosynthesis and Morpho-Physiological Differentiation in Streptomyces coelicolor A3(2)

    PubMed Central

    Palazzotto, Emilia; Gallo, Giuseppe; Renzone, Giovanni; Giardina, Anna; Sutera, Alberto; Silva, Joohee; Vocat, Celinè; Botta, Luigi; Scaloni, Andrea; Puglia, Anna Maria

    2016-01-01

    In the model actinomycete Streptomyces coelicolor A3(2), small open reading frames encoding proteins with unknown functions were identified in several amino acid biosynthetic gene operons, such as SCO2038 (trpX) in the tryptophan trpCXBA locus. In this study, the role of the corresponding protein in tryptophan biosynthesis was investigated by combining phenotypic and molecular analyses. The 2038KO mutant strain was characterized by delayed growth, smaller aerial hyphae and reduced production of spores and actinorhodin antibiotic, with respect to the WT strain. The capability of this mutant to grow on minimal medium was rescued by tryptophan and tryptophan precursor (serine and/or indole) supplementation on minimal medium and by gene complementation, revealing the essential role of this protein, here named TrpM, as modulator of tryptophan biosynthesis. His-tag pull-down and bacterial adenylate cyclase-based two hybrid assays revealed TrpM interaction with a putative leucyl-aminopeptidase (PepA), highly conserved component among various Streptomyces spp. In silico analyses showed that PepA is involved in the metabolism of serine, glycine and cysteine through a network including GlyA, CysK and CysM enzymes. Proteomic experiments suggested a TrpM-dependent regulation of metabolic pathways and cellular processes that includes enzymes such as GlyA, which is required for the biosynthesis of tryptophan precursors and key proteins participating in the morpho-physiological differentiation program. Altogether, these findings reveal that TrpM controls tryptophan biosynthesis at the level of direct precursor availability and, therefore, it is able to exert a crucial effect on the morpho-physiological differentiation program in S. coelicolor A3(2). PMID:27669158

  10. A novel cell penetrating aspartic protease inhibitor blocks processing and presentation of tetanus toxoid more efficiently than pepstatin A.

    PubMed

    Zaidi, Nousheen; Burster, Timo; Sommandas, Vinod; Herrmann, Timo; Boehm, Bernhard O; Driessen, Christoph; Voelter, Wolfgang; Kalbacher, Hubert

    2007-12-14

    Selective inhibition of enzymes involved in antigen processing such as cathepsin E and cathepsin D is a valuable tool for investigating the roles of these enzymes in the processing pathway. However, the aspartic protease inhibitors, including the highly potent pepstatin A (PepA), are inefficiently transported across the cell membrane and thus have limited access to antigen processing compartments. Previously described mannose-pepstatin conjugates were efficiently taken up by the cells via receptor mediated uptake. However, cells without mannose receptors are unable to take up these conjugates efficiently. The aim of the present study was to synthesize new cell-permeable aspartic protease inhibitors by conjugating pepstatin A with well-known cell penetrating peptides (CPPs). To achieve this, the most commonly used CPPs namely pAntp(43-58) (penetratin), Tat(49-60), and 9-mer of l-arginine (R9), were synthesized and coupled to pepstatin. The enzyme inhibitory properties of these bioconjugates and their cellular uptake into MCF7 (human breast cancer cell line), Boleths (EBV-transformed B-cell line) and dendritic cells (DC) were the focus of our study. We found that the bioconjugate PepA-penetratin (PepA-P) was the most efficient cell-permeable aspartic protease inhibitor tested, and was more efficient than unconjugated PepA. Additionally, we found that PepA-P efficiently inhibited the tetanus toxoid C-fragment processing in peripheral blood mononuclear cells (PBMC), primary DC and in primary B cells. Therefore, PepA-P can be used in studying the role of intracellular aspartic proteases in the MHC class II antigen processing pathway. Moreover, inhibition of tetanus toxoid C-fragment processing by PepA-P clearly implicates the role of aspartic proteinases in antigen processing.

  11. New trends in ganglioside chemistry

    SciTech Connect

    Sonnino, S.; Ghidoni, R.; Gazzotti, G.; Acquotti, D.; Tettamanti, G.

    1988-01-01

    New methods have been developed for the preparation of highly purified gangliosides, homogeneous in the saccharide, long chain base, and fatty acid moieties and gangliosides carrying different kinds of labelled probes. Gangliosides, homogeneous in the oligosaccharide portion, were prepared by preparative normal phase HPLC on a Lichrosorb-NH-2 column, using a gradient of acetonitrile-phosphate buffer, pH 5.6, as solvent system. Each class of ganglioside (from monosialo- to tetrasialogangliosides) was then submitted to reversed phase HPLC on a preparative RP-8 column, using acetonitrile-5 mM phosphate buffer, pH 7, as solvent system, to obtain gangliosides homogeneous in the long chain base moiety. Gangliosides containing C18 and C20 sphinganine were prepared by catalytic hydrogenation of the corresponding unsaturated gangliosides. GM1 with homogeneous acyl chain was prepared by alkaline hydrolysis in the presence of tetramethylammonium hydroxide, followed by re-N-acylation, carried out in the presence of dimethylaminopropyl, ethylcarbodiimide and natural fatty acids, or of mixed anhydride of ethylchloroformate and 14C-stearic acid, and re-N-acetylation performed with acetic anhydride or labelled acetic anhydride. The GM1 derivative, de-acetylated at the level of sialic acid, also produced by alkaline treatment of GM1, was submitted to re-N-acetylation with 14C-acetic anhydride to produce specifically 14C-labelled GM1. Re-N-acylation was carried out a) in the presence of dimethylaminopropyl, ethylcarbodiimide and natural fatty acids, b) with mixed anhydride of ethylchloroformate and 14C-stearic acid. After re-N-acylations, re-N-acetylation was performed with acetic anhydride or labelled acetic anhydride. 53 references.

  12. Examination of the kinetic isotopic effect to the acetylation derivatization for the gas chromatographic-combustion-isotope ratio mass spectrometric doping control analysis of endogenous steroids.

    PubMed

    Angelis, Yiannis S; Kioussi, Maroula K; Kiousi, Polyxeni; Brenna, J Thomas; Georgakopoulos, Costas G

    2012-12-01

    In gas chromatographic-combustion-isotope ratio mass spectrometry (GC-C-IRMS) doping control analysis, endogenous androgenic anabolic steroids and their metabolites are commonly acetylated using acetic anhydride reagent, thus incorporating exogenous carbon that contributes to the measured isotope ratio. Comparison of the endogenous δ(13)C of free, mono-, and di-acetylated steroids requires application of corrections, typically through straightforward use of the mass balance equation. Variability in kinetic isotope effects (KIE) due to steroid structures could cause fractionation of endogenous steroid carbon, resulting in inaccurate results. To test for possible KIE influence on δ(13)C, acetic anhydride of graded isotope ratio within the natural abundance range was used under normal derivatization conditions to test for linearity. In all cases, plots of measured steroid acetate δ(13)C versus acetic anhydride δ(13)C were linear and slopes were not significantly different. Regression analysis of the Δδ(13)C of enriched acetic anhydrides versus Δδ(13)C of derivatized steroids shows that KIE are similar in all cases. We conclude that δ(13)C calculated from the mass balance equation is independent of the δ(13)C of the acetic anhydride reagent, and that net KIE under normal derivatization conditions do not bias the final reported steroid δ(13)C.

  13. Green route to modification of wood waste, cellulose and hemicellulose using reactive extrusion.

    PubMed

    Vaidya, Alankar A; Gaugler, Marc; Smith, Dawn A

    2016-01-20

    A large volume of wood waste is produced in timber processing industry which traditionally used in low value applications. Here, value addition to the wood waste (Sander dust) and cellulose, hemicellulose isolated thereof by functionalisation using cyclic anhydrides in a solvent-free and green reactive extrusion process is reported. The effect of extrusion temperature, catalyst and different weight ratios of Sander dust (SD):succinic anhydride (SA) on the esterification reaction is evaluated. The esterified products were characterised by the acid value, degree of substitution (DS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solid state (13)C NMR and thermo-gravimetric analysis (TGA). Under optimum extrusion conditions, mixed esters are formed, with highest acid value obtained for succinylation of cellulose (0.122 g/g at DS of 0.350) which is two times higher compared to succinylated SD (0.059 g/g at a weight gain of 0.452) and hemicellulose (0.043 g/g at DS of 0.290). The reactivity trend for individual anhydride was: (1) SA-Cellulose>SD>hemicellulose; (2) maleic anhydride (MA)-SD>hemicellulose>cellulose and (3) dodecenyl succinic anhydride (DDSA)-SD ≈ cellulose ≫ hemicellulose. The pendant free carboxyl groups generated through functionalisation of wood waste, cellulose and hemicellulose without the presence of polymeric carriers will allow more tailored or targeted modification of wood-plastic composites.

  14. Green route to modification of wood waste, cellulose and hemicellulose using reactive extrusion.

    PubMed

    Vaidya, Alankar A; Gaugler, Marc; Smith, Dawn A

    2016-01-20

    A large volume of wood waste is produced in timber processing industry which traditionally used in low value applications. Here, value addition to the wood waste (Sander dust) and cellulose, hemicellulose isolated thereof by functionalisation using cyclic anhydrides in a solvent-free and green reactive extrusion process is reported. The effect of extrusion temperature, catalyst and different weight ratios of Sander dust (SD):succinic anhydride (SA) on the esterification reaction is evaluated. The esterified products were characterised by the acid value, degree of substitution (DS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solid state (13)C NMR and thermo-gravimetric analysis (TGA). Under optimum extrusion conditions, mixed esters are formed, with highest acid value obtained for succinylation of cellulose (0.122 g/g at DS of 0.350) which is two times higher compared to succinylated SD (0.059 g/g at a weight gain of 0.452) and hemicellulose (0.043 g/g at DS of 0.290). The reactivity trend for individual anhydride was: (1) SA-Cellulose>SD>hemicellulose; (2) maleic anhydride (MA)-SD>hemicellulose>cellulose and (3) dodecenyl succinic anhydride (DDSA)-SD ≈ cellulose ≫ hemicellulose. The pendant free carboxyl groups generated through functionalisation of wood waste, cellulose and hemicellulose without the presence of polymeric carriers will allow more tailored or targeted modification of wood-plastic composites. PMID:26572467

  15. Studies on the oxidation of hexamethylbenzene 1: Oxidation of hexamethylbenzene with nitric acid

    NASA Technical Reports Server (NTRS)

    Chiba, K.; Tomura, S.; Mizuno, T.

    1986-01-01

    The oxidative reaction of hexamethylbenzene (HMB) with nitric acid was studied, and the hitherto unknown polymethylbenzenepolycarboxylic acids were isolated: tetramethylphthalic anhydride, tetramethylisophthalic acid, 1,3,5-, 1,2,4- and 1,2,3-trimethylbenzenetricarboxylic acids. When HMB was warmed with 50% nitric acid at about 80 C, tetramethylphthalic anhydride and tetramethylisophthalic acid were initially produced. The continued reaction led to the production of trimethylbenzenetricarboxylic acids, but only slight amounts of dimethylbenzenetetracarboxylic acids were detected in the reaction mixture. Whereas tetramethylphthalic anydride and tetramethylisophthalic acid were obtained, pentamethylbenzoic acid, a possible precursor of them, was scarcely produced. On the other hand, a yellow material extracted with ether from the initial reaction mixture contained bis-(nitromethyl)prehnitene (CH3)4C6(CH2NO2)2, which was easily converted into the phthalic anhydride.

  16. Tough soluble aromatic thermoplastic copolyimides

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor)

    2000-01-01

    Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. Alternatively, these copolyimides may be prepared by reacting 4,4'-oxydiphthalic anhydride with 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydiisocyanate. Also, the copolyimide may be prepared by reacting the corresponding tetra acid and ester precursors of 4,4'-oxydiphthalic anhydride and 3,4,3',4'-biphenyltetracarboxylic dianhydride with 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

  17. Solvent effects on the cinnamoylation of n-propyl alcohol catalyzed by N-methylimidazole and 4-dimethylaminopyridine.

    PubMed

    Connors, K A; Eboka, C J

    1983-04-01

    The kinetics of reaction of trans-cinnamic anhydride or trans-cinnamoyl chloride with n-propyl alcohol, catalyzed by N-methylimidazole or 4-dimethylaminopyridine, were studied spectrophotometrically at 25 degrees in methyl ethyl ketone, ethylene dichloride, methylene chloride, and toluene. The acid chloride reacted in all solvents via the intermediate formation of the N-acyl catalyst, which underwent reaction with the alcohol catalyzed by another molecule of the base. The anhydride did not form the intermediate in any of the solvents, but underwent direct general base catalysis. The rate of the anhydride reactions was not sensitive to solvent polarity, whereas the rate of the chloride reactions tended to increase as the solvent polarity decreased. A kinetic analysis is given of the effect of ion-pair formation on the kinetics of acyl transfer in systems where the charged N-acyl catalyst intermediate is formed.

  18. Allergic contact dermatitis to copolymers in cosmetics--case report and review of the literature.

    PubMed

    Quartier, Sarah; Garmyn, Marjan; Becart, Sophie; Goossens, An

    2006-11-01

    Copolymers or heteropolymers are large molecules with high molecular weights (>1000 D). They have been underestimated for a long time as to their sensitizing capacities. Allergic contact dermatitis to 6 copolymers in cosmetics and 1 in a medical dressing has been described; however, the nature of the hapten is still unknown. We report a case of allergic contact dermatitis to polyvinylpyrrolidone (PVP)/hexadecene copolymer in a purple-colored lipstick and review the literature on allergic contact dermatitis to 7 copolymers: PVP/hexadecene, PVP/eicosene, PVP/1-triacontene, methoxy polyethyleneglycol (PEG)-22/dodecyl glycols, methoxy PEG-17/dodecyl glycols, phthalic anhydride/trimellitic anhydride/glycols, and polyvinyl methyl/maleic acid anhydride. PMID:17026690

  19. Liquid Crystals Derived from 2-phenyl-isoindoles: Synthesis and Characterization

    NASA Technical Reports Server (NTRS)

    Jow, Kenny G.; Dingemans, Theo J.; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    2-Phenyl-isoindole was investigated as the rigid core unit in a series of asymmetric mesogenic molecules. When the 2-phenyl-isoindole core was terminated with a hexyl tail, no mesophase formation could be observed. When 4-n-(tridecafluorohexyl) was used, however, we observed both monotropic and enantiotropic phase behavior. We found that most functionalities at the anhydride 5-position results in the formation of smectic A (SmA) phases in the temperature range of 70-180 C. Functionalities at the anhydride 4-position suppress mesophase formation. Large substituents (-Br, -NO2) and symmetric substitution patterns (5,6-dichloro, 4,7-dichloro and 4,5,6,7-tetrachloro) on the anhydride moiety increase the melting point and destabilize the mesophase. Temperature dependent X-ray diffraction experiments suggest an interdigitated SmA packing for this family of compounds.

  20. Thermoplastic olefin/clay nanocomposites. Effect of matrix composition, and organoclay and compatibilizer structure on morphology/properties relationships.

    PubMed

    Silva, S M L; López-Manchado, M A; Arroyo, M

    2007-12-01

    The effect of different nanofillers and compatibilizers (maleic anhydride-grafted-polypropylene and maleic anhydride-grafted-ethylene propylene diene terpolymer rubber) on the morphology, mechanical, mechanodynamical and thermal characteristics of thermoplastic olefins based on polypropylene and ethylene propylene diene terpolymer rubber blends has been analysed. A better affinity with the matrix and a better dispersion of the nanoparticles is observed in rubber rich matrices. Organoclay, such as Cloisite C15A and Cloisite C20A, treated with a non-polar surfactant give rise to intercalated nanocomposites, and the lower the concentration of surfactant (C20A) the most noticeable increase in interlayer spacing and consequently better properties in the nanocomposites. The maleic anhydride-grafted-ethylene propylene diene terpolymer rubber is a better compatibilizer for organo-clay nanocomposites based on rubber rich matrices. PMID:18283828

  1. Product analysis for polyethylene degradation by radiation and thermal ageing

    NASA Astrophysics Data System (ADS)

    Sugimoto, Masaki; Shimada, Akihiko; Kudoh, Hisaaki; Tamura, Kiyotoshi; Seguchi, Tadao

    2013-01-01

    The oxidation products in crosslinked polyethylene for cable insulation formed during thermal and radiation ageing were analyzed by FTIR-ATR. The products were composed of carboxylic acid, carboxylic ester, and carboxylic anhydride for all ageing conditions. The relative yields of carboxylic ester and carboxylic anhydride increased with an increase of temperature for radiation and thermal ageing. The carboxylic acid was the primary oxidation product and the ester and anhydride were secondary products formed by the thermally induced reactions of the carboxylic acids. The carboxylic acid could be produced by chain scission at any temperature followed by the oxidation of the free radicals formed in the polyethylene. The results of the analysis led to formulation of a new oxidation mechanism which was different from the chain reactions via peroxy radicals and peroxides.

  2. Method for controlling corrosion using molybdate compositions

    SciTech Connect

    Boffardi, B.P.; Rey, S.P.

    1989-01-17

    A method is described for inhibiting corrosion in an aqueous system comprising adding to the system an effective amount of a corrosion inhibiting composition comprising: (a) a molybdate ion source; and (b) a water-soluble component selected from the group consisting of polymaleic anhydride; amine adducts of polymaleic anhydride; polymers prepared by polymerizing maleic anhydride with dimethyl diallyl ammonium chloride or homologs thereof; polymers prepared from 50-70%, by weight, acrylic acid or methacrylic acid, 10-40%, by weight, 2-acrylamido-2-methylpropyl sulfonic acid or 2-methyacrylamido-2-methylpropyl sulfonic acid and 10-30%, by weight, of a polyalkyleneoxide compound; salts of the above described polymers; phosphonates selected from the group consisting of 2-phosnphonobutane-1,2,4 tricarboxylic acid and hydroxyphosphono acetic acid; phosphino carboxylic acids; polyphosphoric acid and polyhydroxy esters of polyphosphoric acid; wherein the weight of (a):(b), on an active basis, ranges from about 10:1 to about 1:10.

  3. Catalytic oxidation of furan on a Mo-Ti-O catalyst. Infrared and thermodesorption study

    SciTech Connect

    Rivasseau, J.; Canesson, P.; Blanchard, M.

    1980-10-16

    The adsorption and oxidation of furan, an intermediate in the conversion of 1-butene to maleic anhydride, were studied on a catalyst containing 15.6% molybdenum as trioxide on titanium dioxide that yielded 53% maleic anhydride at 63% conversion. The results showed at furan adsorbed in two distinct modes, of which one was observed only on oxidized surface and the other was always present but depended on the degree of reduction. The adsorbed furan was oxidized in the presence of oxygen at temperatures above 235/sup 0/C, but it desorbed only above 320/sup 0/C. The Mo=O species did not seem to be important in the oxidation of furan to maleic anhydride.

  4. Polyimide analysis using diffuse reflectance-FTIR. [Fourier Transform IR Spectroscopy

    NASA Technical Reports Server (NTRS)

    Young, P. R.; Chang, A. C.

    1985-01-01

    The thermal imidization of a number of polyimide precursors in the form of powders, films, and prepregs was examined by an in situ diffuse reflectance-FTIR technique where infrared spectra were determined while the material was being heated. An analysis of these spectra revealed that, with the exception of one water soluble adhesive, each precursor developed an anhydride band around 1850 cm/cu during imidization. This band diminished in intensity during final stages of cure. Efforts were made to quantify the amount of anhydride in several samples. Evidence obtained could be interpreted to mean that poly(amic acid) resins undergo an initial reduction in molecular weight during imidization before recombining to achieve their ultimate molecular weights as polyimides. Several reports in the literature are cited to support this interpretation. This report serves both to document anhydride formation during imidization and to increase our fundamental understanding of how polyimides cure.

  5. Mechanistic Investigation into the Decarboxylation of Aromatic Carboxylic Acids

    SciTech Connect

    Britt, P F; Buchanan, III, A C; Eskay, T P; Mungall, W S

    1999-08-22

    It has been proposed that carboxylic acids and carboxylates are major contributors to cross-linking reactions in low-rank coals and inhibit its thermochemical processing. Therefore, the thermolysis of aromatic carboxylic acids was investigated to determine the mechanisms of decarboxylation at temperatures relevant to coal processing, and to determine if decarboxylation leads to cross-linking (i.e., formation of more refractory products). From the thcrmolysis of simple and polymeric coal model compounds containing aromatic carboxylic acids at 250-425 °C, decarboxylation was found to occur primarily by an acid promoted ionic pathway. Carboxylate salts were found to enhance the decarboxylation rate, which is consistent with the proposed cationic mechanism. Thermolysis of the acid in an aromatic solvent, such as naphthalene, produced a small amount of arylated products (~5 mol%)), which constitute a low-temperature cross-link. These arylated products were formed by the rapid decomposition of aromatic anhydrides, which are in equilibrium with the acid. These anhydrides decompose by a free radical induced decomposition pathway to form atyl radicals that can add to aromatic rings to form cross-links or abstract hydrogen. Large amounts of CO were formed in the thennolysis of the anhydrides which is consistent with the induced decomposition pathway. CO was also formed in the thermolysis of the carboxylic acids in aromatic solvents which is consistent with the formation and decomposition of the anhydride. The formation of anhydride linkages and cross-links was found to be very sensitive to the reactions conditions. Hydrogen donor solvents, such as tetralin, and water were found to decrease the formation of arylated products. Silar reaction pathways were also found in the thermolysis of a polymeric model that contained aromatic carboxylic acids. In this case, anhydride formation and decomposition produced an insoluble polymer, while the O-methylated polymer and the non

  6. 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives.

    PubMed

    Meyer, Adam G; Ryan, John H

    2016-01-01

    We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carboxyl systems, in particular isatoic anhydrides and phthalic anhydrides. Intramolecular cycloadditions with esters can also occur under certain circumstances. The oxazolidine cycloadducts undergo a range of reactions triggered by the ring-opening of the oxazolidine ring system. PMID:27455230

  7. Modification of microneedles using inkjet printing

    PubMed Central

    Boehm, R D; Miller, P R; Hayes, S L; Monteiro-Riviere, N A; Narayan, R J

    2011-01-01

    In this study, biodegradable acid anhydride copolymer microneedles containing quantum dots were fabricated by means of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing. Nanoindentation was performed to obtain the hardness and the Young's modulus of the biodegradable acid anhydride copolymer. Imaging of quantum dots within porcine skin was accomplished by means of multiphoton microscopy. Our results suggest that the combination of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing enables fabrication of solid biodegradable microneedles with a wide range of geometries as well as a wide range of pharmacologic agent compositions. PMID:22125759

  8. New methods for preparing n, n-dialkyltrifluoroacetamides

    NASA Technical Reports Server (NTRS)

    Hsu, L.

    1972-01-01

    The customary preparative methods for N,N-dialkyltrifluoroacetamides involve the acylation of an amine by trifluoroacetic acid or its derivatives. In this report the synthesis of N,N-dialkyltrifluoroacetamides by reacting trifluoroacetic anhydride or acid with disubstituted formamides and acetamides is discussed. These reactions are interpreted with the aid of gas chromatographic analysis. Different reaction mechanisms are proposed for the reactions of formamides and acetamides with trifluoroacetic anhydride or acid. The use of the proposed reaction mechanisms for the synthesis of other fluorinated compounds is discussed.

  9. New methods for preparing N,N-dialkyltrifluoroacetamides

    NASA Technical Reports Server (NTRS)

    Hsu, L.

    1972-01-01

    The customary preparative methods for N,N-dialkyltrifluoroacetamides involve the acylation of an amine by trifluoroacetic acid or its derivatives. The synthesis of N,N-dialkyltrifluoroacetamides by reacting trifluoroacetic anhydride or acid with disubstituted formamides and acetamides is discussed. These reactions were interpreted with the aid of gas chromatographic analysis. Different reaction mechanisms are proposed for the reactions of formamides and acetamides with trifluoroacetic anhydride or acid. The use of the proposed reaction mechanisms for the synthesis of other fluorinated compounds is discussed.

  10. Environmentally friendly synthesis of supportless Pt based nanoreactors in aqueous solution

    NASA Astrophysics Data System (ADS)

    Groves, Michael N.; Malardier-Jugroot, Cecile; Jugroot, Manish

    2014-09-01

    Using the amphiphilic alternating copolymer poly(styrene-alt-maleic anhydride), the hydrophobic salt PtCl2, is reduced into platinum nanoparticles that are less than 3 nm in an aqueous biocompatible environment. The nanoparticles are characterized by transmission electron microscopy and X-ray diffraction. The formation of unsupported nanoparticles embedded in the polymer nanotemplate take advantage of the confinement effect in reactions due to the dynamic formation of the poly(styrene-alt-maleic anhydride) nanotube. This enhanced catalytic effect is demonstrated with the polymerization of pyrrole.

  11. Pretreatment of solid carbonaceous material with dicarboxylic aromatic acids to prevent scale formation

    DOEpatents

    Brunson, Roy J.

    1982-01-01

    Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a pretreating agent selected from the group consisting of phthalic acid, phthalic anhydride, pyromellitic acid and pyromellitic anhydride. The pretreatment is believed to convert the scale-forming components to the corresponding phthalate and/or pyromellitate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 1 to about 2 atmospheres. Temperature during pretreatment will generally be within the range from about 5.degree. to about 80.degree. C.

  12. Regenerable solid imine sorbents

    DOEpatents

    Gray, McMahan; Champagne, Kenneth J.; Fauth, Daniel; Beckman, Eric

    2013-09-10

    Two new classes of amine-based sorbents are disclosed. The first class comprises new polymer-immobilized tertiary amine sorbents; the second class new polymer-bound amine sorbents. Both classes are tailored to facilitate removal of acid anhydrides, especially carbon dioxide (CO.sub.2), from effluent gases. The amines adsorb acid anhydrides in a 1:1 molar ratio. Both classes of amine sorbents adsorb in the temperature range from about 20.degree. C. upwards to 90.degree. C. and can be regenerated by heating upwards to 100.degree. C.

  13. Gas-Phase Partial Oxidation of Lignin to Carboxylic Acids over Vanadium Pyrophosphate and Aluminum-Vanadium-Molybdenum.

    PubMed

    Lotfi, Samira; Boffito, Daria C; Patience, Gregory S

    2015-10-26

    Lignin is a complex polymer that is a potential feedstock for aromatic compounds and carboxylic acids by cleaving the β-O-4 and 5-5' linkages. In this work, a syringe pump atomizes an alkaline solution of lignin into a catalytic fluidized bed operating above 600 K. The vanadium heterogeneous catalysts convert all the lignin into carboxylic acids (up to 25 % selectivity), coke, carbon oxides, and hydrogen. Aluminum-vanadium-molybdenum mostly produced lactic acid (together with formic acid, acrylic acid, and maleic anhydride), whereas the vanadium pyrophosphate catalyst produced more maleic anhydride.

  14. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1985-01-01

    Cured polymers of bis and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a monoimide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride prior to curing are disclosed and claimed. Such polymers are flame resistant. Also disclosed are an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst and fiber reinforced cured resin composites.

  15. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1983-01-01

    Bis- and tris-imides derived from tris (m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride. Such monomers or their oligomes may be used to impregnate fibers and fabrics which when cured, are flame resistant. Also an improved method of producing tris (m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst is described.

  16. Rational synthesis of AB-type N-substituted core-functionalized naphthalene diimides (cNDIs).

    PubMed

    Berezin, Andrey A; Sciutto, Andrea; Demitri, Nicola; Bonifazi, Davide

    2015-04-17

    Acid-mediated transformation of tetraethyl 2,6-diethoxynaphthalene-1,4,5,8-tetracarboxylate selectively affords the core-substituted naphthalene-anhydride-ester (cNAE) in quantitative yield. This anhydride can be selectively converted into hetero-N-substituted core-functionalized naphthalene diimides (cNDIs) through sequential condensation reactions in the presence of the precursor amine with very high isolated yields over four steps. The approach can be applied to prepare a large variety of heterocyclic, aromatic, and aliphatic heterodiimides.

  17. High temperature drilling fluids

    SciTech Connect

    Stong, R.E.; Walinsky, S.W.

    1986-01-28

    This patent describes an aqueous drilling fluid suitable for high-temperature use. This fluid is composed of a water base. Clay is suspended in the base and from about 0.01-25 pounds per barrel total composition of a hydrolyzed terpolymer of maleic anhydride, styrene and a third monomer selected from acrylamide, methacrylamide, acrylic acid and metacrylic acid. The molar ratio of maleic anhydride to styrene to the third monomer is from about 30:10:60 to 50:40:10, and the alkali metal, ammonium and lower aliphatic amine salts thereof, the weight-average molecular weight of the hydrolyzed terpolymer is from about 500-10,000.

  18. Aromatic cyclotriphosphazenes

    NASA Technical Reports Server (NTRS)

    Kamar, Devendra (Inventor); Fohlen, George M. (Inventor); Parker, John A. (Inventor)

    1988-01-01

    Four-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g., hexakis amino or trisaminophenoxy trisphenoxy cyclotrisphosphazenes), selection of molar porportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

  19. Fire and heat resistant laminating resins based on maleimido substituted aromatic cyclotriphosphazene polymer

    NASA Technical Reports Server (NTRS)

    Kumar, Devendra (Inventor); Fohlen, George M. (Inventor); Parker, John A. (Inventor)

    1987-01-01

    4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g., hexakis amino or trisaminophenoxy trisphenoxy cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

  20. Maleimido substituted aromatic cyclotriphosphazenes

    NASA Technical Reports Server (NTRS)

    Kumar, D.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1985-01-01

    4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g., hexakis amino or trisaminophenoxy-trisphenoxy-cyclo-triphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.