Science.gov

Sample records for ether polymer maleic

  1. Improved lithographic performance for resists based on polymers having a vinyl ether-maleic anhydride (VEMA) backbone

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Woo; Choi, Sang-Jun; Jung, Dong-Won; Lee, Sook; Lee, Sung-Ho; Kang, Yool; Woo, Sang-Gyun; Moon, Joo-Tae; Kavanagh, Robert J.; Barclay, George G.; Orsula, George W.; Mattia, Joe; Caporale, Stefan; Adams, Timothy G.; Tanaka, Tsutomu; Kang, Doris

    2001-08-01

    ArF lithography, in combination with chemically amplified resists, has been investigated as one of the most promising technologies for producing patterns below 100 nm. In considering the polymer matrix for 193 nm photoresist applications, factors such as sensitivity, transparency to 193 nm radiation, adhesion to substrate, dry etch resistance, ease of synthesis, and availability of monomers are very critical. In these respects, remarkable progress has been made in development of ArF resist material. Polymers of acrylic and methacrylic esters show good imaging performance at 193 nm, but have insufficient dry-etch resistance under oxide or nitride etch condition. On the other hand, cyclic olefin-maleic anhydride (COMA) alternating copolymers exhibit good dry etch resistance, but have poor resolution capability. We previously reported a new platform, based on a vinyl ether-maleic anhydride (VEMA) alternating polymer system, that demonstrated both good resolution and high dry etch resistance. In this paper, VEMA systems with improved lithographic performance are presented. The new platform (VEMA) showed good performance in resolution, depth of focus (DOF), iso-dense bias, and post-etch roughness. With conventional illumination (NA=0.6, sigma=0.7), 120 nm dense line/space patterns with 0.4 (mu) M DOF were resolved. And 90 nm L/S patterns 0.6 (mu) M DOF were resolved with off-axis illumination (NA=0.63). Another important factor to be considered for the dry-etch process is post-etch roughness. In the case of VEMA system a clean surface was observed after etch under oxide, nitride, and poly conditions. The VEMA resist system is regarded as one of the most production-worthy material for real device manufacture.

  2. 40 CFR 721.10316 - Dicyclopentadiene polymer with maleic anhydride and alkyl alcohols (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Dicyclopentadiene polymer with maleic... Significant New Uses for Specific Chemical Substances § 721.10316 Dicyclopentadiene polymer with maleic.... (1) The chemical substance identified generically as dicyclopentadiene polymer with maleic anhydride...

  3. 40 CFR 721.10316 - Dicyclopentadiene polymer with maleic anhydride and alkyl alcohols (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Dicyclopentadiene polymer with maleic... Significant New Uses for Specific Chemical Substances § 721.10316 Dicyclopentadiene polymer with maleic.... (1) The chemical substance identified generically as dicyclopentadiene polymer with maleic anhydride...

  4. 40 CFR 721.10316 - Dicyclopentadiene polymer with maleic anhydride and alkyl alcohols (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Dicyclopentadiene polymer with maleic... Significant New Uses for Specific Chemical Substances § 721.10316 Dicyclopentadiene polymer with maleic.... (1) The chemical substance identified generically as dicyclopentadiene polymer with maleic anhydride...

  5. Separator Membrane from Crosslinked Poly(Vinyl Alcohol) and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride)

    PubMed Central

    Rohatgi, Charu Vashisth; Dutta, Naba K.; Choudhury, Namita Roy

    2015-01-01

    In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA) with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-MA). Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity), thermal and electrochemical properties using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermo-gravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications. PMID:28347019

  6. Poly(methyl vinyl ether-alt-maleic acid)-functionalized porous silicon nanoparticles for enhanced stability and cellular internalization.

    PubMed

    Shahbazi, Mohammad-Ali; Almeida, Patrick V; Mäkilä, Ermei; Correia, Alexandra; Ferreira, Mónica P A; Kaasalainen, Martti; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A

    2014-03-01

    Currently, developing a stable nanocarrier with high cellular internalization and low toxicity is a key bottleneck in nanomedicine. Here, we have developed a successful method to covalently conjugate poly(methyl vinyl ether-co-maleic acid) (PMVE-MA) copolymer on the surface of (3-aminopropyl)triethoxysilane-functionalized thermally carbonized porous silicon nanoparticles (APSTCPSi NPs), forming a surface negatively charged nanovehicle with unique properties. This polymer conjugated NPs could modify surface smoothness, charge, and hydrophilicity of the developed NPs, leading to considerable improvement in the colloidal and plasma stabilities via enhanced suspensibility and charge repulsion. Furthermore, despite the surface negative charge of the polymer-conjugated NPs, the cellular internalization was increased in both MDA-MB-231 and MCF-7 breast cancer cells. These results provide a proof-of-concept evidence that such polymer-based PSi nanocomposite can be extensively used as a promising candidate for intracellular drug delivery. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 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...

  8. 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...

  9. Ecologically benign polymers: the case of maleic polyelectrolytes.

    PubMed

    Chitanu, Gabrielle Charlotte; Carpov, Adrian

    2002-04-15

    The paper discusses a series of results that evidence the favorable effect of maleic polyelectrolytes in different fields in which a protective action of the environment is attained: (i) the exploitation of geothermal water, which is a cleaner source of energy; (ii) the improvement or preservation of the structure of agricultural soils; (iii) the substitution of phosphates in detergents; and (iv) the reduction of chromium load of effluents from tanning plants.

  10. Self-healing pH-sensitive poly[(methyl vinyl ether)-alt-(maleic acid)]-based supramolecular hydrogels formed by inclusion complexation between cyclodextrin and adamantane.

    PubMed

    Ma, Xiaoe; Zhou, Naizhen; Zhang, Tianzhu; Hu, Wanjun; Gu, Ning

    2017-04-01

    Self-healing materials are of interest for drug delivery, cell and gene therapy, tissue engineering, and other biomedical applications. In this work, on the base of biocompatible polymer poly(methyl vinyl ether-alt-maleic acid) (P(MVE-alt-MA)), host polymer β-cyclodextrin-grafted P(MVE-alt-MA) (P(MVE-alt-MA)-g-β-CD) and guest polymer adamantane-grafted P(MVE-alt-MA) (P(MVE-alt-MA)-g-Ad) were first prepared. Then through taking advantage of the traditional host-guest interaction of β-cyclodextrin and adamantane, a novel self-healing pH-sensitive physical P(MVE-alt-MA)-g-β-CD/P(MVE-alt-MA)-g-Ad supramolecular hydrogels were obtained after simply mixing the aqueous solution of host polymer and guest polymer. This kind of supramolecular hydrogels not only possess pH-sensitivity, but also possess the ability to repair themselves after being damaged. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Luteinizing hormone-releasing hormone targeted poly(methyl vinyl ether maleic acid) nanoparticles for doxorubicin delivery to MCF-7 breast cancer cells.

    PubMed

    Varshosaz, Jaleh; Jahanian-Najafabadi, Ali; Ghazzavi, Jila

    2016-08-01

    The purpose of this study was to design a targeted anti-cancer drug delivery system for breast cancer. Therefore, doxorubicin (DOX) loaded poly(methyl vinyl ether maleic acid) nanoparticles (NPs) were prepared by ionic cross-linking method using Zn(2+) ions. To optimise the effect of DOX/polymer ratio, Zn/polymer ratio, and stirrer rate a full factorial design was used and their effects on particle size, zeta potential, loading efficiency (LE, %), and release efficiency in 72 h (RE72, %) were studied. Targeted NPs were prepared by chemical coating of tiptorelin/polyallylamin conjugate on the surface of NPs by using 1-ethyl-3-(3-dimethylaminopropyl) carboiimid HCl as cross-linking agent. Conjugation efficiency was measured by Bradford assay. Conjugated triptorelin and targeted NPs were studied by Fourier-transform infrared spectroscopy (FTIR). The cytotoxicity of DOX loaded in targeted NPs and non-targeted ones were studied on MCF-7 cells which overexpress luteinizing hormone-releasing hormone (LHRH) receptors and SKOV3 cells as negative LHRH receptors using Thiazolyl blue tetrazolium bromide assay. The best results obtained from NPs prepared by DOX/polymer ratio of 5%, Zn/polymer ratio of 50%, and stirrer rate of 960 rpm. FTIR spectrum confirmed successful conjugation of triptorelin to NPs. The conjugation efficiency was about 70%. The targeted NPs showed significantly less IC50 for MCF-7 cells compared to free DOX and non-targeted NPs.

  12. 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.

  13. Prolonged Hypocalcemic Effect by Pulmonary Delivery of Calcitonin Loaded Poly(Methyl Vinyl Ether Maleic Acid) Bioadhesive Nanoparticles

    PubMed Central

    Varshosaz, J.; Minaiyan, M.; Forghanian, M.

    2014-01-01

    The purpose of the present study was to design a pulmonary controlled release system of salmon calcitonin (sCT). Therefore, poly(methyl vinyl ether maleic acid) [P(MVEMA)] nanoparticles were prepared by ionic cross-linking method using Fe2+ and Zn2+ ions. Physicochemical properties of nanoparticles were studied in vitro. The stability of sCT in the optimized nanoparticles was studied by electrophoretic gel method. Plasma calcium levels until 48 h were determined in rats as pulmonary-free sCT solution or nanoparticles (25 μg·kg−1), iv solution of sCT (5 μg·kg−1), and pulmonary blank nanoparticles. The drug remained stable during fabrication and tests on nanoparticles. The optimized nanoparticles showed proper physicochemical properties. Normalized reduction of plasma calcium levels was at least 2.76 times higher in pulmonary sCT nanoparticles compared to free solution. The duration of hypocalcemic effect of pulmonary sCT nanoparticles was 24 h, while it was just 1 h for the iv solution. There was not any significant difference between normalized blood calcium levels reduction in pulmonary drug solution and iv injection. Pharmacological activity of nanoparticles after pulmonary delivery was 65% of the iv route. Pulmonary delivery of P(MVEMA) nanoparticles of sCT enhanced and prolonged the hypocalcemic effect of the drug significantly. PMID:24701588

  14. Role of Cellulose Nanocrystals on the Microstructure of Maleic Anhydride Plasma Polymer Thin Films.

    PubMed

    Brioude, Michel M; Roucoules, Vincent; Haidara, Hamidou; Vonna, Laurent; Laborie, Marie-Pierre

    2015-07-01

    Recently, it was shown that the microstructure of a maleic anhydride plasma polymer (MAPP) could be tailored ab initio by adjusting the plasma process parameters. In this work, we aim to investigate the ability of cellulose nanocrystals (CNCs) to induce topographical structuration. Thus, a new approach was designed based on the deposition of MAPP on CNCs model surfaces. The nanocellulosic surfaces were produced by spin-coating the CNC suspension on a silicon wafer substrate and on a hydrophobic silicon wafer substrate patterned with circular hydrophilic microsized domains (diameter of 86.9 ± 4.9 μm), resulting in different degrees of CNC aggregation. By depositing the MAPP over these surfaces, it was possible to observe that the surface fraction of nanostructures increased from 20% to 35%. This observation suggests that CNCs can act as nucleation points resulting in more structures, although a critical density of the CNCs is required.

  15. Membrane protein extraction and purification using styrene-maleic acid (SMA) copolymer: effect of variations in polymer structure.

    PubMed

    Morrison, Kerrie A; Akram, Aneel; Mathews, Ashlyn; Khan, Zoeya A; Patel, Jaimin H; Zhou, Chumin; Hardy, David J; Moore-Kelly, Charles; Patel, Roshani; Odiba, Victor; Knowles, Tim J; Javed, Masood-Ul-Hassan; Chmel, Nikola P; Dafforn, Timothy R; Rothnie, Alice J

    2016-12-01

    The use of styrene-maleic acid (SMA) copolymers to extract and purify transmembrane proteins, while retaining their native bilayer environment, overcomes many of the disadvantages associated with conventional detergent-based procedures. This approach has huge potential for the future of membrane protein structural and functional studies. In this investigation, we have systematically tested a range of commercially available SMA polymers, varying in both the ratio of styrene and maleic acid and in total size, for the ability to extract, purify and stabilise transmembrane proteins. Three different membrane proteins (BmrA, LeuT and ZipA), which vary in size and shape, were used. Our results show that several polymers, can be used to extract membrane proteins, comparably to conventional detergents. A styrene:maleic acid ratio of either 2:1 or 3:1, combined with a relatively small average molecular mass (7.5-10 kDa), is optimal for membrane extraction, and this appears to be independent of the protein size, shape or expression system. A subset of polymers were taken forward for purification, functional and stability tests. Following a one-step affinity purification, SMA 2000 was found to be the best choice for yield, purity and function. However, the other polymers offer subtle differences in size and sensitivity to divalent cations that may be useful for a variety of downstream applications. © 2016 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  16. Poly(2-vinylnaphthalene-alt-maleic acid)-graft polystyrene as a photoactive polymer micelle and stabilizer for polystyrene latexes

    SciTech Connect

    Cao, T.; Yin, W.; Webber, S.E. )

    1994-12-05

    Polymerization of maleic anhydride and 2-vinylnaphthalene produces alternating polymers. Imidization of the polymer with amino-terminated polystyrene yields different loadings of an alternating polymer with polystyrene combs''. Upton rigorous hydrolysis one obtains poly(2-vinylnaphthalene-alt-maleic acid)-graft-polystyrene (P2VNMA-PS), which is a fluorescent polymer with unusual solution properties and with significant surface activity. P2VNMA-PS forms a small micelle structure in solution or can be used as a surfactant for an emulsion polymerization of polystyrene (no cosurfactant is required), producing monodisperse latex particles which are stable for pH > 3.9. Centrifugation shows that >90% of the P2VNMA-PS is associated with the latex particles. Fluorescence quenching studies of the naphthalene excimer with Tl[sup +] indicate that approximately 84% and 77% of the naphthalene groups remain exposed to the aqueous phase when this polymer is micellized or incorporated onto a latex particle, respectively. These data imply that the P2VNMA-PS polymer is permanently associated with the exterior of the latex particle, as one would expect given the amphiphilic nature of this polymer.

  17. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... maleic anhydride monomer content. Residual maleic anhydride monomer content shall be determined by a gas chromatographic method titled “Determination of Residual Maleic Anhydride in Polymers by Gas...

  18. New polymers for 193-nm single-layer resists based on substituted cycloolefins/maleic anhydride resins

    NASA Astrophysics Data System (ADS)

    Rushkin, Ilya L.; Houlihan, Francis M.; Kometani, Janet M.; Hutton, Richard S.; Timko, Allen G.; Reichmanis, Elsa; Nalamasu, Omkaram; Gabor, Allen H.; Medina, Arturo N.; Slater, Sydney G.; Neisser, Mark O.

    1999-06-01

    A series of new polymers for 193 nm single layer resist based on maleic anhydride/cycloolefin systems with minimum amount of acrylate units were synthesized. In order to minimize the acrylate content, the cycloolefin moiety of the polymers was functionalized with side groups designed to either promotes adhesion to silicon substrate and/or impart the imaging functionality. All polymers were prepared by free-radical polymerization in moderate to high yields and were characterized by variety of techniques. The initial lithographic evaluation of the new resists was carried out. It was found that acrylates can be successfully replaced with appropriately substituted cycloolefins to provide good resolution. The etch resistance of the new materials generally improves with increase in cycloolefin content. The Onishi and Kunz type plots will be discussed.

  19. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  20. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  1. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  2. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  3. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted phenol...

  4. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted phenol...

  5. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs P...

  6. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted phenol...

  7. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs P...

  8. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs P...

  9. Analysis physical properties of composites polymer from cocofiber and polypropylene plastic waste with maleic anhydrate as crosslinking agent

    NASA Astrophysics Data System (ADS)

    Pelita, E.; Hidayani, T. R.; Akbar, A.

    2017-07-01

    This research was conducted with the aim to produce composites polymer with polypropylene plastic waste materials and cocofiber which aims to produce wood replacement material in the home furnishings industry. This research was conducted with several stages. The first stage is the process of soaking coco fiber with detergent to remove oil and 2% NaOH. The second stage is to combine the polypropylene plastic waste with cocofiber is a chemical bond, modification by adding maleic anhydride as a crosslinking agent and benzoyl peroxide as an initiator each as much as 1%. Mixing materials done by reflux method using xylene solvent. In this study, carried out a wide range of weight variation of coco fiber are added to the 10, 20, 30, 40 and 50%. The third stage is a polymer composite molding process using hot press at a temperature of 158°C. The results of polymer composites Showed optimum condition on the addition of 40% cocofiber with supple tensile strength value of 90.800 kgf /cm2 and value of elongation break at 3.6726 x 104 (kgf/cm2), melting point at 160.02°C, burning point 463.43°C, residue of TGA is 19%, the density of 0.84 g/mL. From these data, conclude that the resulting polymer composites meet the SNI 03-2105-2006 about ordinary composite polymer and polymer composite structural type 8 regular types from 17.5 to 10.5.

  10. Cationic Poly(benzyl ether)s as Self-Immolative Antimicrobial Polymers.

    PubMed

    Ergene, Cansu; Palermo, Edmund F

    2017-10-09

    Self-immolative polymers (SIMPs) are macromolecules that spontaneously undergo depolymerization into small molecules when triggered by specific external stimuli. We report here the first examples of antimicrobial SIMPs with potent, rapid, and broad-spectrum bactericidal activity. Their antibacterial and hemolytic activities were examined as a function of cationic functionality. Polymers bearing primary ammonium cationic groups showed more potent bactericidal activity against Escherichia coli, relative to tertiary and quaternary ammonium counterparts, whereas the quaternary ammonium polymers showed the lowest hemolytic toxicity. These antibacterial polycations undergo end-to-end depolymerization when triggered by an externally applied stimulus. Specifically, poly(benzyl ether)s end-capped with a silyl ether group and bearing pendant allyl side chains were converted to polycations by photoinitiated thiol-ene radical addition using cysteamine HCl. The intact polycations are stable in solution, but they spontaneously unzip into their component monomers upon exposure to fluoride ions, with excellent sensitivity and selectivity. Upon triggered depolymerization, the antibacterial potency was largely retained but the hemolytic toxicity was substantially reduced. Thus, we reveal the first example of a self-immolative antibacterial polymer platform that will enable antibacterial materials to spontaneously unzip into biologically active small molecules upon the introduction of a specifically designed stimulus.

  11. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted oxirane, formaldehyde-phenol polymer glycidyl ether, substituted proplyamine and...-phenol polymer glycidyl ether, substituted proplyamine and polyethylenepolyamines (generic). (a) Chemical... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  12. Aluminum-phthalocyanine chloride associated to poly(methyl vinyl ether-co-maleic anhydride) nanoparticles as a new third-generation photosensitizer for anticancer photodynamic therapy.

    PubMed

    Muehlmann, Luis Alexandre; Ma, Beatriz Chiyin; Longo, João Paulo Figueiró; Almeida Santos, Maria de Fátima Menezes; Azevedo, Ricardo Bentes

    2014-01-01

    Photodynamic therapy is generally considered to be safer than conventional anticancer therapies, and it is effective against different kinds of cancer. However, its clinical application has been significantly limited by the hydrophobicity of photosensitizers. In this work, a system composed of the hydrophobic photosensitizer aluminum-phthalocyanine chloride (AlPc) associated with water dispersible poly(methyl vinyl ether-co-maleic anhydride) nanoparticles is described. AlPc was associated with nanoparticles produced by a method of solvent displacement. This system was analyzed for its physicochemical characteristics, and for its photodynamic activity in vitro in cancerous (murine mammary carcinoma cell lineage 4T1, and human mammary adenocarcinoma cells MCF-7) and noncancerous (murine fibroblast cell lineage NIH/3T3, and human mammary epithelial cell lineage MCF-10A) cell lines. Cell viability and the elicited mechanisms of cell death were evaluated after the application of photodynamic therapy. This system showed improved photophysical and photochemical properties in aqueous media in comparison to the free photosensitizer, and it was effective against cancerous cells in vitro.

  13. Aluminum–phthalocyanine chloride associated to poly(methyl vinyl ether-co-maleic anhydride) nanoparticles as a new third-generation photosensitizer for anticancer photodynamic therapy

    PubMed Central

    Muehlmann, Luis Alexandre; Ma, Beatriz Chiyin; Longo, João Paulo Figueiró; Almeida Santos, Maria de Fátima Menezes; Azevedo, Ricardo Bentes

    2014-01-01

    Photodynamic therapy is generally considered to be safer than conventional anticancer therapies, and it is effective against different kinds of cancer. However, its clinical application has been significantly limited by the hydrophobicity of photosensitizers. In this work, a system composed of the hydrophobic photosensitizer aluminum–phthalocyanine chloride (AlPc) associated with water dispersible poly(methyl vinyl ether-co-maleic anhydride) nanoparticles is described. AlPc was associated with nanoparticles produced by a method of solvent displacement. This system was analyzed for its physicochemical characteristics, and for its photodynamic activity in vitro in cancerous (murine mammary carcinoma cell lineage 4T1, and human mammary adenocarcinoma cells MCF-7) and noncancerous (murine fibroblast cell lineage NIH/3T3, and human mammary epithelial cell lineage MCF-10A) cell lines. Cell viability and the elicited mechanisms of cell death were evaluated after the application of photodynamic therapy. This system showed improved photophysical and photochemical properties in aqueous media in comparison to the free photosensitizer, and it was effective against cancerous cells in vitro. PMID:24634582

  14. Crosslinking Chemistry for Fluorocarbon Ether Bibenzoxazole Polymers

    DTIC Science & Technology

    1979-11-01

    soluble amber- colored gums which exhibited inherent viscosities in the range of 0.26 to 0.51 dl/g were obtained in yields of up to 90 percent. N -CF ) CH...dissolved to permit the formation of a viscous, amber- colored solution. The resultant gum exhibited an inherent viscosity of 0.20 dl/g. 3. POLYMER...reaction vessel. The excess copper and cuprous salts were filtered off, the organic layer separated, and the aqueous layer extracted with more

  15. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide...

  16. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide...

  17. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide (P-91...

  18. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide (P-91...

  19. 40 CFR 721.10605 - Polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyoxyalkylene ether, polymer with..., polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic). (a) Chemical substance and... polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (PMN P-11-485) is subject...

  20. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide (P-91...

  1. 40 CFR 721.10605 - Polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyoxyalkylene ether, polymer with..., polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic). (a) Chemical substance and... polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (PMN P-11-485) is subject...

  2. Effects of Secondary Polymer Covalently Attached to Monodisperse, Poly(maleic anhydride-styrene)-Modified Colloidal Silica on Dispersibility in Organic Solvent.

    PubMed

    Yoshinaga; Shimada; Nishida; Komatsu

    1999-06-15

    Effects of surface-grafted polymer on the dispersibility of polymer-silica composite particles in ethyl acetate-methanol cosolvent were investigated. The composite particles were prepared by a two-step modification of monodisperse colloidal silica (120 nm in diameter). Modifications were carried out by first reacting the surface silanol of the colloidal silica with maleic anhydride-styrene copolymer silane coupling agent to prevent aggregation and then grafting, in acetone or tetrahydrofuran, amino group-terminated poly(methyl acrylate), poly(methyl methacrylate), or polystyrene to the maleic anhydride moiety on the surface. For poly(methyl acrylate) and poly(methyl methacrylate) graftings, composite particles with long polymer chains aggregated in methanol-rich cosolvent due to insoluble secondary polymer chain interaction among the particles. Particles with a small amount of relatively low-molecular-weight secondary polymer were dispersible in the methanol content range from 0 to 90 vol%. Polystyrene-modified particles never aggregated, even in 90 vol% methanol solution. An ESR study of the suspension in ethyl acetate-hexane cosolvent suggested that the dispersibility of these composite particles in ethyl acetate-rich solution is attributable to steric repulsion between solvated and expanded secondary polymer chains among the particles. The dispersibility of the composite particles in methanol-rich solution was controlled by a delicate balance between the electrostatic repulsion and the interparticle attraction due to the desolvated and insoluble polymer chain interaction among the particles. Copyright 1999 Academic Press.

  3. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... maleic anhydride monomer content shall be determined by a gas chromatographic method titled “Determination of Residual Maleic Anhydride in Polymers by Gas Chromatography,” which is incorporated...

  4. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... maleic anhydride monomer content shall be determined by a gas chromatographic method titled “Determination of Residual Maleic Anhydride in Polymers by Gas Chromatography,” which is incorporated...

  5. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... maleic anhydride monomer content shall be determined by a gas chromatographic method titled “Determination of Residual Maleic Anhydride in Polymers by Gas Chromatography,” which is incorporated...

  6. Maleic hydrazide

    Integrated Risk Information System (IRIS)

    Maleic hydrazide ; CASRN 123 - 33 - 1 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

  7. 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

  8. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  9. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  10. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  11. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  12. 75 FR 4288 - Oxirane, 2-Methyl-, Polymer with Oxirane, Dimethyl Ether; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... AGENCY 40 CFR Part 180 Oxirane, 2-Methyl-, Polymer with Oxirane, Dimethyl Ether; Tolerance Exemption... an exemption from the requirement of a tolerance for residues of oxirane, 2-methyl-,polymer with... eliminates the need to establish a maximum permissible level for residues of oxirane, 2-methyl-, polymer...

  13. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  14. Effect of maleic anhydride pretreatment on tensile bond strength of a silicone soft liner to a denture base polymer.

    PubMed

    Demir, Hakan; Soygun, Koray; Dogan, Arife; Keskin, Selda; Dogan, Orhan Murat; Bolayir, Giray

    2011-10-01

    To determine the effect of resin surface treatment with dissolved maleic anhydride in butanone added into primer on the tensile bond strength between an acrylic denture base resin and a silicone soft liner. To test tensile bond strength, standard dumbbell-shaped acrylic specimens were prepared. Five experimental groups, including the control, were tested (n = 5). Maleic anhydride solutions prepared in butanone at concentrations of 1%, 5%, 10% or 20% were then mixed with 1 ml of Primo adhesive and the mixtures were applied onto the resin bonding surfaces. Silicone liner material was applied to resin surfaces in the conventional manner. Tensile bond strength of the specimens was measured in a universal testing machine. Fractured surfaces were observed under the scanning electron microscope, and resulting chemical changes with the solutions used were analyzed spectroscopically. The highest bond strength value was obtained for the group treated with 5% maleic anhydride (2.53 ± 0.48 MPa); the lowest value was for the group treated with 20% maleic anhydride (1.59 ± 0.29 MPa). Mixed failure was the dominant type seen in the experimental groups. Spectroscopic analysis showed the interaction of the anhydride carbonyl groups with the Primo primer. The treatment of resin surfaces with maleic anhydride added to Primo adhesive effectively increased bond strength between silicone soft liner and denture base resin.

  15. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (generic). 721.10518 Section... Substances § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (PMN P-11-48) is subject...

  16. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (generic). 721.10518 Section... Substances § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (PMN P-11-48) is subject...

  17. Transparent Films from CO2‐Based Polyunsaturated Poly(ether carbonate)s: A Novel Synthesis Strategy and Fast Curing

    PubMed Central

    Subhani, Muhammad Afzal; Köhler, Burkhard; Gürtler, Christoph; Leitner, Walter

    2016-01-01

    Abstract Transparent films were prepared by cross‐linking polyunsaturated poly(ether carbonate)s obtained by the multicomponent polymerization of CO2, propylene oxide, maleic anhydride, and allyl glycidyl ether. Poly(ether carbonate)s with ABXBA multiblock structures were obtained by sequential addition of mixtures of propylene oxide/maleic anhydride and propylene oxide/allyl glycidyl ether during the polymerization. The simultaneous addition of both monomer mixtures provided poly(ether carbonate)s with AXA triblock structures. Both types of polyunsaturated poly(ether carbonate)s are characterized by diverse functional groups, that is, terminal hydroxy groups, maleate moieties along the polymer backbone, and pendant allyl groups that allow for versatile polymer chemistry. The combination of double bonds substituted with electron‐acceptor and electron‐donor groups enables particularly facile UV‐ or redox‐initiated free‐radical curing. The resulting materials are transparent and highly interesting for coating applications. PMID:27028458

  18. Glycol ether/siloxane polymer penetrating and lubricating composition

    SciTech Connect

    MacIntosh, D.H.

    1981-02-03

    A penetrating and lubricating composition consists of a silicone lubricant dissolved in a glycol ether carrier having a very low surface tension. The glycol ether gives the composition the ability to penetrate into the cracks between two seized or corroded elements and dissolve any rust or corrosion present. The glycol ether then volitalizes leaving a coating of silicone on the parts to serve as a lubricant and prevent further corrosion.

  19. 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.

  20. 40 CFR 721.10381 - Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether, hydroxy substituted alkane and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether, hydroxy substituted alkane and carboxylic acid anhydride, methacrylate terminated... Specific Chemical Substances § 721.10381 Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether...

  1. 40 CFR 721.10381 - Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether, hydroxy substituted alkane and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether, hydroxy substituted alkane and carboxylic acid anhydride, methacrylate terminated... Specific Chemical Substances § 721.10381 Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether...

  2. 40 CFR 721.10381 - Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether, hydroxy substituted alkane and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether, hydroxy substituted alkane and carboxylic acid anhydride, methacrylate terminated... Specific Chemical Substances § 721.10381 Cyclic carboxylic acid, polymer with dihydroxy dialkyl ether...

  3. Carbon-13 cross-polarization magic-angle-spinning nuclear magnetic resonance investigation of the interactions between maleic anhydride grafted polypropylene and wood polymers.

    PubMed

    Rude, Erica; Laborie, Marie-Pierre G

    2008-05-01

    The chemical interactions between maleic anhydride grafted polypropylene (MAPP) and wood were studied with solid-state carbon-13 cross-polarization magic-angle-spinning nuclear magnetic resonance ((13)C CPMAS NMR) spectroscopy. MAPP was synthesized with 100% (13)C enrichment at the C(1) and C(4) carbons to allow detection of the [1,4-(13)C(2)]MAPP functional groups and was melt blended with cellulose, lignin, and maple wood. In the cellulose/MAPP blend, changes in (13)C CPMAS NMR corrected signal intensities for the anhydride and dicarboxylic maleic acid functionalities suggested that esterification may have occurred predominantly from the more numerous diacid carbons. A single proton longitudinal relaxation in the rotating frame, (H)T(1rho), for the MAPP and the cellulose carbons in the blend suggested that they were spin coupled, i.e., homogeneous on a 10-200 Angstrom scale. Esterification was also suggested in the lignin/MAPP blend. Furthermore, the more significant changes in the intensities of the carbonyl signals and (H)T(1rho) values suggested that lignin may be more reactive to MAPP than cellulose. Finally, when maple was melt blended with MAPP, the same trends in the (13)C CP-MAS NMR spectra and (H)T(1rho) behavior were observed as when MAPP was blended with cellulose or lignin. This study therefore clarifies that during melt compounding of wood with MAPP, esterification occurs with wood polymers, preferentially with lignin. Understanding the interactions of MAPP with wood is of significance for the development of natural-fiber-reinforced thermoplastic composites.

  4. Poly(ether ester) Ionomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes.

    PubMed

    Pekkanen, Allison M; Zawaski, Callie; Stevenson, André T; Dickerman, Ross; Whittington, Abby R; Williams, Christopher B; Long, Timothy E

    2017-04-12

    Water-soluble polymers as sacrificial supports for additive manufacturing (AM) facilitate complex features in printed objects. Few water-soluble polymers beyond poly(vinyl alcohol) enable material extrusion AM. In this work, charged poly(ether ester)s with tailored rheological and mechanical properties serve as novel materials for extrusion-based AM at low temperatures. Melt transesterification of poly(ethylene glycol) (PEG, 8k) and dimethyl 5-sulfoisophthalate afforded poly(ether ester)s of sufficient molecular weight to impart mechanical integrity. Quantitative ion exchange provided a library of poly(ether ester)s with varying counterions, including both monovalent and divalent cations. Dynamic mechanical and tensile analysis revealed an insignificant difference in mechanical properties for these polymers below the melting temperature, suggesting an insignificant change in final part properties. Rheological analysis, however, revealed the advantageous effect of divalent countercations (Ca(2+), Mg(2+), and Zn(2+)) in the melt state and exhibited an increase in viscosity of two orders of magnitude. Furthermore, time-temperature superposition identified an elevation in modulus, melt viscosity, and flow activation energy, suggesting intramolecular interactions between polymer chains and a higher apparent molecular weight. In particular, extrusion of poly(PEG8k-co-CaSIP) revealed vast opportunities for extrusion AM of well-defined parts. The unique melt rheological properties highlighted these poly(ether ester) ionomers as ideal candidates for low-temperature material extrusion additive manufacturing of water-soluble parts.

  5. Accelerated simulations of aromatic polymers: application to polyether ether ketone (PEEK)

    NASA Astrophysics Data System (ADS)

    Broadbent, Richard J.; Spencer, James S.; Mostofi, Arash A.; Sutton, Adrian P.

    2014-10-01

    For aromatic polymers, the out-of-plane oscillations of aromatic groups limit the maximum accessible time step in a molecular dynamics simulation. We present a systematic approach to removing such high-frequency oscillations from planar groups along aromatic polymer backbones, while preserving the dynamical properties of the system. We consider, as an example, the industrially important polymer, polyether ether ketone (PEEK), and show that this coarse graining technique maintains excellent agreement with the fully flexible all-atom and all-atom rigid bond models whilst allowing the time step to increase fivefold to 5 fs.

  6. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN...

  7. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dimer acids, polymer with polyalkylene... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  8. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN...

  9. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN...

  10. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Dimer acids, polymer with polyalkylene... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  11. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN P...

  12. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN P...

  13. Potential of polymethacrylate pseudo crown ethers as solid state polymer electrolytes.

    PubMed

    Moins, S; Martins, J C; Krumpmann, A; Lemaur, V; Cornil, J; Delbosc, N; Decroly, A; Dubois, Ph; Lazzaroni, R; Gohy, J-F; Coulembier, O

    2017-06-22

    The association of kinetic studies, DFT calculations and (1)H-(7)Li NMR analyses allowed the control of the cyclo-ATRP of PEG9DMA and the production of polymethacrylate pseudo crown-ethers of various molar masses. Their potential to act as a solid-state polymer electrolyte in Li-ion batteries has been highlighted and may come from the supramolecular organization of the cyclo-PEG forming a Li(+) diffusion channel.

  14. Novel polymer electrolyte from poly(carbonate-ether) and lithium tetrafluoroborate for lithium-oxygen battery

    NASA Astrophysics Data System (ADS)

    Lu, Qi; Gao, Yonggang; Zhao, Qiang; Li, Ji; Wang, Xianhong; Wang, Fosong

    2013-11-01

    Novel polymer electrolyte based on low-molecular weight poly(carbonate-ether) and lithium tetrafluoroborate has been prepared and used in lithium-oxygen battery for the first time, the electrolyte with approximate 17% of LiBF4 showed ionic conductivity of 1.57 mS cm-1. Infrared spectra analysis indicates that obvious interaction between the lithium ions and partial oxygen atoms in the host polymer exists, and the lithium salt and the host polymer have good miscibility. The lithium-oxygen battery from this polymer electrolyte shows similar cyclic stability to traditional liquid electrolyte observed by FT-IR, AFM and electrochemical measurements, which may provide a new choice for fabrication of all-solid-state high-capacity rechargeable lithium-oxygen battery with better safety.

  15. Coating carbon nanotubes with polymer in supercritical carbon dioxide.

    PubMed

    Wang, Jiawei; Khlobystov, Andrei N; Wang, Wenxin; Howdle, Steven M; Poliakoff, Martyn

    2006-04-21

    A facile and efficient method has been developed for coating MWNTs with solvent resistant polymer in scCO2, which permits the selective deposition of high molecular weight fluorinated graft poly(methyl vinyl ether-alt-maleic anhydride) polymer onto MWNTs in scCO2 under 100-170 bar at 40 degrees C and forms quasi one-dimensional nanostructures with conducting cores and insulating surfaces.

  16. 40 CFR 721.7260 - Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether. 721.7260 Section 721.7260 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.7260 Polymer of poly-ethylene-polyamine and...

  17. Phenylethynyl Terminated Arylene Ether Oxadiazole and Triazole Oligomers and Their Cured Polymers

    NASA Technical Reports Server (NTRS)

    Thompson, C. M.; Hergenrother, P. M.

    2001-01-01

    Several novel phenylethynyl terminated arylene ether oligomers containing oxadiazole and triazole rings were prepared as part of an effort to develop high performance polymers with an attractive combination of properties (e.g. processability and mechanical performance) for future NASA applications. The oligomers displayed low melt viscosities and good solubilities. Thin films cast from solutions of the oligomers and cured for one hour at 350 C in air gave good tensile properties. Titanium to titanium (6Al-4V) tensile shear specimens were readily fabricated and provided moderate strengths. The chemistry and properties of these new materials are discussed.

  18. Toughening of BIS maleimide resins: Synthesis and characterization of maleimide terminated poly(arylene ether) oligomers and polymers

    NASA Technical Reports Server (NTRS)

    Mcgrath, J. E.; Lyle, G. D.; Jurek, M. J.; Mohanty, D.; Hedrick, J. C.

    1986-01-01

    Amine functional poly(arylene ether) sulfones were previously reported. Herein, the chemistry was extended to amorphous poly(arylene ether) ketones because of their higher fracture toughness values, relative to the polysulfones. It was demonstrated that the amino functional oligomers undergo a self-crosslinking reaction at temperatures above about 220 C. This produces an insoluble, but ductile network that has excellent resistance. A ketamine structure hypothesis was proposed and verified using solid state magic angle NMR. In most cases, the water generated upon ketamine formation is too low to produce porosity and solid networks are obtained. The stability of the ketamine networks towards hydrolysis is excellent. The chemistry was further demonstrated to be able to crosslink preformed nonfunctional poly(arylene ether) ketones if a difunctional amine was utilized. This concept has the possibility of greatly improving the creep resistance of thermoplastics. Also, a new technique was developed for converting the amine functional oligomers cleanly into maleimide structures. This method involves reacting maleic anhydride with monomeric aminophenols in the presence of solvent mixtures.

  19. Evaluation of polymer inclusion membranes containing crown ethers for selective cesium separation from nuclear waste solution.

    PubMed

    Mohapatra, P K; Lakshmi, D S; Bhattacharyya, A; Manchanda, V K

    2009-09-30

    Transport behaviour of (137)Cs from nitric acid feed was investigated using cellulose triacetate plasticized polymer inclusion membrane (PIM) containing several crown ether carriers viz. di-benzo-18-crown-6 (DB18C6), di-benzo-21-crown-7 (DB21C7) and di-tert-butylbenzo-18-crown-6 (DTBB18C6). The PIM was prepared from cellulose triacetate (CTA) with various crown ethers and plasticizers. DTBB18C6 and tri-n-butyl phosphate (TBP) were found to give higher transport rate for (137)Cs as compared to other carriers and plasticizers. Effect of crown ether concentration, nitric acid concentration, plasticizer and CTA concentration on the transport rate of Cs was also studied. The Cs selectivity with respect to various fission products obtained from an irradiated natural uranium target was found to be heavily dependent on the nature of the plasticizer. The present work shows that by choosing a proper plasticizer, one can get either good transport efficiency or selectivity. Though TBP plasticized membranes showed good transport efficiency, it displayed poor selectivities. On the other hand, an entirely opposite separation behaviour was observed with 2-nitrophenyloctylether (NPOE) plasticized membranes suggesting the possible application of the later membranes for the removal of bulk (137)Cs from the nuclear waste. The stability of the membrane was tested by carrying out transport runs for nearly 25 days.

  20. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

  1. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

  2. Characterisation of water behaviour in cellulose ether polymers using low frequency dielectric spectroscopy.

    PubMed

    McCrystal, C B; Ford, J L; He, R; Craig, D Q M; Rajabi-Siahboomi, A R

    2002-08-28

    The behaviour of water in hydroxypropylmethylcellulose (HPMC) K100LV, K4M, K15M, K100M, E4M, F4M and HPC polymers was characterised using low frequency dielectric spectroscopy (LFDS). Dielectric responses of 25% (w/w) HPMC K15M gels and deionised water were found to be similar at +22 and 0 degrees C. However, at -30 degrees C, a dielectric response typical of a solid was apparent. The melting of frozen water within gels was detected as increases in the magnitude of the dielectric response with increase in temperature. More than one phase transition was visible in the majority of gels studied which may be related to the presence of different states of water melting at different temperatures. In addition to polymer concentration, both polymer molecular weight and substitution level influenced the nature of the transitions. The magnitude of the dielectric response was increased in all HPMC gel systems in comparison to the response seen in deionised water. Drug addition affected the transitions occurring during the melting of ice in the gels. This may be related to the presence of ionic species in the systems. LFDS studies on cellulose ether gels have provided some interesting evidence for the existence of more than one state of water within such gel systems. The results are in good agreement with thermal analysis findings in similar gel systems.

  3. Amorphous phase separation in crystallizable polymer blends based on poly (aryl ether ketones) and poly (ether imide)

    SciTech Connect

    Kalika, D.S.; Bristow, J.F.

    1996-12-31

    The morphology of a series of miscible crystallizable blends based on poly (aryl ether ketones) [PAEK] and poly (ether imide) [PEI] has been investigated as a function of blend composition and crystallization condition by dielectric relaxation spectroscopy. For blends of poly (ether ether ketone) [PEEK] and PEI, dielectric scans of the crystallized samples reveal two glass-rubber relaxations corresponding to the coexistence of a mixed interlamellar amorphous phase, and a pure PEI phase located in interfibrillar/interspherulitic regions. The exclusion of a significant fraction of PEI outside of the crystal lamellae reflects a fundamental change in the nature of interaction between the interlamellar PEEK segments and the PEI chains owing to the constraints imposed on the PEEK segments by the crystal surfaces. The degree of PEI exclusion is dependent upon kinetic factors, i.e. the rate of PEEK crystallization relative to the rate of PEI diffusion away from the advancing crystal front. As a result, lower crystallization temperatures lead to an increase in the amount of PEI trapped in the interlamellar regions. In this work, the morphological characteristics of the PEEK/PEI blends are compared with those of blends comprised of poly (ether ketone ketone) [PEKK] and PEI. The introduction of the {open_quotes}kinked{close_quote} isophthalate moiety in the PEKK backbone has been shown to disrupt the persistence of order at the crystal-amorphous interface, and thereby leads to a reduction in the degree of constraint imposed by the crystal lamellae on the amorphous (interlamellar) PEKK segments. The impact of this reduction in crystalline constraint on the nature of the PEKK/PEI intersegmental interactions and the corresponding PEI segregation is discussed.

  4. Poly(arylene ether)s containing pendent ethynyl groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Jensen, Brian J. (Inventor)

    1996-01-01

    Poly(arylene ether)s containing pendent ethynyl and substituted ethynyl groups and poly(arylene ether) copolymers containing pendent ethynyl and substituted ethynyl groups are readily prepared from bisphenols containing ethynyl and substituted ethynyl groups. The resulting polymers are cured up to 350.degree. C. to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus.

  5. Synthesis and characterization of sulfonated poly(ether sulfone)s containing mesonaphthobifluorene for polymer electrolyte membrane fuel cell.

    PubMed

    Lim, Youngdon; Seo, Dongwan; Lee, Soonho; Hossain, Md Awlad; Lim, Jinseong; Lee, Sangyoung; Hong, Taehoon; Kim, Whangi

    2014-10-01

    The novel sulfonated poly(ether sulfone)s containing mesonaphthobifluorene (MNF) moiety were synthesized and characterized their properties. The prepared polymers have highly conjugated aromatic structure due to the MNF group which is an allotrope of carbon and one atom thick planar sheets of sp2-bonded carbon atoms. Poly(ether sulfone)s bearing tetraphenylethylene on polymer backbone were synthesized by polycondensation and followed intra-cyclization from tetraphenylethylene to form MNF by Friedel-craft reaction with Lewis acid (FeCl3). The sulfonation was performed selectively on MNF units with conc. sulfuric acid. The structural properties of the sulfonated polymers were investigated by 1H-NMR spectroscopy. The membranes were studied by ion exchange capacity (IEC), water uptake, and proton conductivity. The synthesized polymer electrolyte membranes showed better thermal and dimensional stabilities owing to the inducted highly conjugated aromatic structure in the polymer backbone. The water uptake of the synthesized membranes ranged from 23-52%, compared with 32.13% for Nafion 211 at 80 degrees C. The synthesized membranes exhibited proton conductivities (80 degrees C, RH 90%) of 74.6-100.4 mS/cm, compared with 102.7 mS/cm for Nafion 211.

  6. Study of improved resins for advanced supersonic technology composites. Part 1: Heteroaromatic polymers containing ether groups. Part 2: Curing chemistry of aromatic polymers and composite studies

    NASA Technical Reports Server (NTRS)

    Takekoshi, T.; Hillig, W. B.; Mellinger, G. A.

    1975-01-01

    Fourteen ether-containing, aromatic dianhydrides have been synthesized from N-phenyl-3 or 4-nitrophthalimide and various bisphenols. The process involves nucleophilic displacement of activated nitro groups with bisphenolate ions. Ether-containing dianhydrides were indefinitely stable in the presence of atmospheric moisture. One-step, high temperature solution polymerization of the ether-containing dianhydrides with m-phenylene diamine, 4,4'-oxydianiline and 1, 3-bis(4-aminophenoxy)benzene afforded 42 polyetherimides. The polyetherimides were all soluble in m-cresol except two which were found to be crystalline. The glass transition temperatures of the polyetherimides ranged from 178 to 277 C. Soluble polybenzimidazopyrrolones containing ether groups were also prepared from the same ether-containing dianhydrides and aromatic tetraamines by one-step solution polymerization. Using low molecular weight polyetherimides, various thermoset resin systems were developed and tested as matrices for fiber-reinforced composites. The curing chemistry involving reaction of the phthalonitrile group and the o-diaminophenyl group was found to be generally applicable to crosslinking various aromatic polymers other than polyimides.

  7. A new strategy for designing high-performance sulfonated poly(ether ether ketone) polymer electrolyte membranes using inorganic proton conductor-functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Gong, Chunli; Zheng, Xuan; Liu, Hai; Wang, Guangjin; Cheng, Fan; Zheng, Genwen; Wen, Sheng; Law, Wing-Cheung; Tsui, Chi-Pong; Tang, Chak-Yin

    2016-09-01

    Remarkable progress has been made on the use of polymer electrolyte membranes (PEMs) for renewable-energy-related research. In particular, carbon nanotubes (CNTs) have emerged as versatile nanomaterials to modify PEMs. However, the inert ionic conduction ability and possible short-circuiting risk are the two major obstacles to their further development. In this work, CNTs are firstly functionalized with an inorganic proton conductor, boron phosphate (BPO4), using a facile polydopamine-assisted sol-gel method to yield BPO4@CNTs. This new additive is then used to modify sulfonated poly(ether ether ketone) (SPEEK). Polydopamine coating layer can act as an extraordinary glue to homogeneously adhere BPO4 nanoparticles on CNTs, thereby not only reducing the risk of short-circuiting, but also fabricating new proton-conducting pathways in the composite membranes. A comprehensive characterization reveals that the thermal stability, tensile properties, and dimensional stability of PEMs are significantly improved. Compared with pure SPEEK, the proton conductivity of SPEEK/BPO4@CNTs-2 is improved by 45% and 150% at 20 °C and at 80 °C, respectively. Furthermore, the H2/O2 cell performance of SPEEK/BPO4@CNTs-2 membrane exhibits a peak power density of 340.7 mW cm-2 at 70 °C, which is significantly better than that of pure SPEEK (254.2 mW cm-2), demonstrating the great potential of proton conductors-functionalized CNTs in PEMs.

  8. Preparation and characterization of polymer blend based on sulfonated poly (ether ether ketone) and polyetherimide (SPEEK/PEI) as proton exchange membranes for fuel cells

    SciTech Connect

    Hashim, Nordiana; Ali, Ab Malik Marwan; Lepit, Ajis; Rasmidi, Rosfayanti; Subban, Ri Hanum Yahaya; Yahya, Muhd Zu Azhan

    2015-08-28

    Blends of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios using N-methyl-2-pyrrolidone (NMP) as solvent by the solution cast technique. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d{sub 6}) solution of the purified polymer using {sup 1}H NMR method. The properties studied in the present investigation includes conductivity, water uptake, thermal stability and structure analysis of pure SPEEK as well as SPEEK-PEI polymer blend membranes. The experimental results show that the conductivity of the membranes increased with increase in temperature from 30 to 80°C, except for that of pure SPEEK membrane which increased with temperature from 30 to 60°C while its conductivity decreased with increasing temperature from 60 to 80°C. The conductivity of 70wt.%SPEEK-30wt.%PEI blend membrane at 80% relative humidity (RH) is found to be 1.361 × 10{sup −3} Scm{sup −1} at 30°C and 3.383 × 10{sup −3} Scm{sup −1} at 80°C respectively. It was also found that water uptake and thermal stability of the membranes slightly improved upon blending with PEI. Structure analysis was carried out using Fourier Transform Infrared (FTIR) spectroscopy which revealed considerable interactions between sulfonic acid group of SPEEK and imide groups of PEI. Modification of SPEEK by blending with PEI shows good potential for improving the electrical and physical properties of proton exchange membranes.

  9. Preparation and characterization of polymer blend based on sulfonated poly (ether ether ketone) and polyetherimide (SPEEK/PEI) as proton exchange membranes for fuel cells

    NASA Astrophysics Data System (ADS)

    Hashim, Nordiana; Ali, Ab Malik Marwan; Lepit, Ajis; Rasmidi, Rosfayanti; Subban, Ri Hanum Yahaya; Yahya, Muhd Zu Azhan

    2015-08-01

    Blends of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios using N-methyl-2-pyrrolidone (NMP) as solvent by the solution cast technique. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d6) solution of the purified polymer using 1H NMR method. The properties studied in the present investigation includes conductivity, water uptake, thermal stability and structure analysis of pure SPEEK as well as SPEEK-PEI polymer blend membranes. The experimental results show that the conductivity of the membranes increased with increase in temperature from 30 to 80°C, except for that of pure SPEEK membrane which increased with temperature from 30 to 60°C while its conductivity decreased with increasing temperature from 60 to 80°C. The conductivity of 70wt.%SPEEK-30wt.%PEI blend membrane at 80% relative humidity (RH) is found to be 1.361 × 10-3 Scm-1 at 30°C and 3.383 × 10-3 Scm-1 at 80°C respectively. It was also found that water uptake and thermal stability of the membranes slightly improved upon blending with PEI. Structure analysis was carried out using Fourier Transform Infrared (FTIR) spectroscopy which revealed considerable interactions between sulfonic acid group of SPEEK and imide groups of PEI. Modification of SPEEK by blending with PEI shows good potential for improving the electrical and physical properties of proton exchange membranes.

  10. Characterization of sulfonated poly(ether ether ketone)/silane nanocomposite membrane for high temperature polymer electrolyte membrane fuel cells.

    PubMed

    Ghil, Lee-Jin; Kim, Chang-Kyeom; Park, Na-Ri; Rhee, Hee-Woo

    2011-01-01

    The perfluorosulfonic acid polymer membrane is most widely used in PEMFCs. However, its some major drawbacks like high cost and performance limitation at high temperature are obstacles of its commercialization. The goal of this study was to develop low cost membranes which have good conductivity in the range of PEMFCs operating temperature. We fabricated new sPEEK/3-APTES nanocomposite membrane where inorganic particles were chemically bonded to sulfuric acid group of sPEEK. PEEK is a thermally stable, mechanically tough and very cheap polymer. And the addition of 3-APTES and phosphorous acid increased the proton conductivity of composite membranes at high temperatures. This nanocomposite membranes maintained good conductivity at 110 degrees C.

  11. In Situ Formation of Polysulfonamide Supported Poly(ethylene glycol) Divinyl Ether Based Polymer Electrolyte toward Monolithic Sodium Ion Batteries.

    PubMed

    Zhang, Jianjun; Wen, Huijie; Yue, Liping; Chai, Jingchao; Ma, Jun; Hu, Pu; Ding, Guoliang; Wang, Qingfu; Liu, Zhihong; Cui, Guanglei; Chen, Liquan

    2017-01-01

    Sodium ion battery is one of the promising rechargeable batteries due to the low-cost and abundant sodium sources. In this work, a monolithic sodium ion battery based on a Na3 V2 (PO4 )3 cathode, MoS2 layered anode, and polyether-based polymer electrolyte is reported. In addition, a new kind of polysulfonamide-supported poly(ethylene glycol) divinyl ether based polymer electrolyte is also demonstrated for monolithic sodium ion battery via in situ preparation. The resultant polymer electrolyte exhibits relatively high ionic conductivity (1.2 mS cm(-1) ) at ambient temperature, wide electrochemical window (4.7 V), and favorable mechanical strength (25 MPa). Moreover, such a monolithic Na3 V2 (PO4 )3 /MoS2 sodium ion battery using this polymer electrolyte delivers outstanding rate capability (up to 10 C) and superior cyclic stability (84%) after 1000 cycles at 0.5 C. What is more essential, such a polymer electrolyte based soft-package monolithic sodium ion cell can still power a red light emitting diode lamp and run finite times without suffering from any internal short-circuit failures, even in the case of a bended and wrinkled state. Considering these aspects, this work no doubt provides a new approach for the design of a high-performance polymer electrolyte toward monolithic sodium ion battery with exceptional rate capability and high safety. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Evaluation of thermal gelation behavior of different cellulose ether polymers by rheology

    NASA Astrophysics Data System (ADS)

    Balaghi, S.; Edelby, Y.; Senge, B.

    2014-05-01

    Hydroxypropylmethylcellulose (HPMC) and Methylcellulose (MC) are cellulose ethers which can be dispersed in water and used as thickeners, emulsifiers, binders, film formers, and water-retention agents due to their hydrophilic and hydrophobic characteristics. In this study, various types of HPMCs, in comparison with two types of MCs were examined. The formed gels of the different cellulose ethers showed specific and various structural formation and network properties. The degree of methylation (Meth.) and hydroxypropylation (HyPr.) affected drastically the heat-induced gelation of the examined cellulose ethers.

  13. Functional films of maleic anhydride copolymers under physiological conditions.

    PubMed

    Pompe, Tilo; Renner, Lars; Grimmer, Milauscha; Herold, Nicole; Werner, Carsten

    2005-09-16

    Reactivity and swelling of nanometer films of alternating maleic anhydride copolymers were investigated in dependence on the kind of comonomer and molar mass of copolymer in aqueous solution at pH 7.4 and pH 3.0 in order to reveal their characteristics under physiological conditions. Fully hydrolyzed (maleic acid) chains of the copolymers with styrene, propene, and ethylene comonomers covalently bound to SiO2 substrates showed a "mushroom" swelling behavior at pH 7.4 with a layer thickness scaling of N3/5. Decreasing the environmental pH was found to induce a comonomer-dependent shrinking or collapse of the immobilized polymers due to the change in ionization. From the swelling kinetics of non-hydrolyzed chains, the time constants and characteristics of swelling and anhydride hydrolysis were determined and found to depend on the type of comonomer. The short- and long-term swelling kinetics [l approximately t and approximately ln(t)1/2] were found to be in agreement with theoretical models of polymer swelling, while at intermediate time scales enhanced swelling was observed due to hydrolysis reaction of maleic anhydride groups. The findings elucidate the variety of properties of maleic anhydride copolymer films under physiological conditions, which can advantageously be applied for biofunctionalization of different templates.

  14. Anhydrous state proton and lithium ion conducting solid polymer electrolytes based on sulfonated bisphenol-A-poly(arylene ethers)

    NASA Astrophysics Data System (ADS)

    Guha Thakurta, Soma

    Sulfonated polymer based solid polymer electrolytes (SPEs) have received considerable interest in recent years because of their wide variety of applications particularly in fuel cells, batteries, supercapacitors, and electrochromic devices. The present research was focused on three interrelated subtopics. First, two different bisphenol-A-poly(arylene ethers), polyetherimide (PEI) and polysulfone (PSU) were sulfonated by a post sulfonation method to various degrees of sulfonation, and their thermal and mechanical properties were examined. The effects of poly(arylene ether) chemical structure, reaction time, concentration, and types of sulfonating agents on sulfonation reaction were investigated. It was found that deactivation of bisphenol A unit caused by the electron withdrawing imide, retarded the sulfonation of PEI compared to PSU. Sulfonation conducted with a high concentration of sulfonating agent and/or prolonged reaction time exhibited evidence of degradation at the isopropylidene unit. The degradation occurred through the same mechanistic pathway with the two different sulfonating agents, chlorosulfonic acid (CSA) and trimethylsilyl chlorosulfonate (TMSCS). The degradation was faster with CSA than its silyl ester, TMSCS, and was evident even at low acid concentration. Second, novel anhydrous proton conducting solid polymer electrolytes (SPEs) were prepared by the incorporation of 1H-1,2,4-triazole (Taz) as a proton solvent in sulfonated polyetherimide (SPEI) matrix. The size, shape, and state of dispersion (crystal morphology) of triazole crystals in SPEI were examined as a function of degree of sulfonation and triazole concentration. Increasing sulfonic acid content caused reduction of triazole crystallite size, hence the depression of melting temperature and their uniform distribution throughout the sulfonated polymer matrix. The increased rate of structure diffusion within the smaller size crystals due to the improved molecular mobility contributed

  15. 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.

  16. Generation of a Focused Poly(amino ether) Library: Polymer-mediated Transgene Delivery and Gold-Nanorod based Theranostic Systems

    PubMed Central

    Vu, Lucas; Ramos, James; Potta, Thrimoorthy; Rege, Kaushal

    2012-01-01

    A focused library of twenty-one cationic poly(amino ethers) was synthesized following ring-opening polymerization of two diglycidyl ethers by different oligoamines. The polymers were screened in parallel for plasmid DNA (pDNA) delivery, and transgene expression efficacies of individual polymers were compared to those of 25 kDa polyethylenimine (PEI), a current standard for polymer-mediated transgene delivery. Seven lead polymers that demonstrated higher transgene expression than PEI in pancreatic and prostate cancer cells lines were identified from the screen. All seven lead polymers showed highest transgene expression at a polymer:pDNA weight ratio of 5:1 in the MIA PaCa-2 pancreatic cancer cell line. Among the conditions studied, transgene expression efficacy correlated with minimal polymer cytotoxicity but not polyplex sizes. In addition, this study indicated that methylene spacing between amine centers in the monomers, amine content, and molecular weight of the polymers are all significant factors and should be considered when designing polymers for transgene delivery. A lead effective polymer was employed for coating gold nanorods, leading to theranostic nanoassemblies that possess combined transgene delivery and optical imaging capabilities, leading to potential theranostic systems. PMID:23382773

  17. 40 CFR 721.10220 - Phosphoric acid, polymer with cycloaliphatic diglycidyl ether, alkylethers (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphoric acid, polymer with... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10220 Phosphoric acid, polymer with... to reporting. (1) The chemical substance identified generically as phosphoric acid, polymer with...

  18. 40 CFR 721.10220 - Phosphoric acid, polymer with cycloaliphatic diglycidyl ether, alkylethers (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phosphoric acid, polymer with... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10220 Phosphoric acid, polymer with... to reporting. (1) The chemical substance identified generically as phosphoric acid, polymer...

  19. 40 CFR 721.10220 - Phosphoric acid, polymer with cycloaliphatic diglycidyl ether, alkylethers (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, polymer with... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10220 Phosphoric acid, polymer with... to reporting. (1) The chemical substance identified generically as phosphoric acid, polymer with...

  20. 40 CFR 721.10220 - Phosphoric acid, polymer with cycloaliphatic diglycidyl ether, alkylethers (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid, polymer with... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10220 Phosphoric acid, polymer with... to reporting. (1) The chemical substance identified generically as phosphoric acid, polymer with...

  1. EXAFS investigations of strontium complexation by a polymer-supported crown ether.

    SciTech Connect

    Dietz, M. L.; Jensen, M. P.; Chemistry

    2004-01-09

    Extended X-ray absorption fine-structure (EXAFS) measurements have been used to probe the coordination environment of strontium ion sorbed from aqueous nitric acid solutions on an extraction chromatographic resin comprising a macrocyclic polyether dispersed on a polymeric support. The strontium EXAFS of the metal ions sorbed onto the resin are consistent with a 1:1:2 strontium:crown ether:nitrate stoichiometry in which the strontium is enveloped in the crown ether ring and both nitrate anions are coordinated to the strontium as bidentate ligands. This is the same structure and stoichiometry observed for complexes in liquid-liquid extraction when the macrocyclic polyether is dissolved in a diluent with low water miscibility like 1-octanol.

  2. Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

    DOEpatents

    Hofmann, Michael A.

    2006-11-14

    The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

  3. Thermodynamic analysis of alkali metal complex formation of polymer-bonded crown ether.

    PubMed

    Bey, Alexandra; Dreyer, Oliver; Abetz, Volker

    2017-06-21

    The complex formation of two crown ethers with colored alkali metal salts was investigated by UV/Vis spectroscopy. Complexation was accomplished with free benzo-15-crown-5 (B15C5) and 15-crown-5 bonded to a diblock copolymer (Poly15C5). The diblock copolymer was synthesized by two controlled polymerization techniques and copper(i)-catalyzed azide-alkyne cycloaddition. Depending on the inserted cation, 1 : 1- or 1 : 2-complexes are formed. A significant difference of the stability constants was determined by concentration dependence solvent extraction with sodium or potassium salt. For Poly15C5 the stability constants increase for both salts compared to the stability constants of B15C5, which suggests a more effective complexation. Evaluation of the thermodynamics (ΔH, ΔS, ΔG) of cation complexation was achieved by temperature dependence phase extraction on the basis of established thermodynamic equations. Remarkably, in all cases the entropic gain seems to be the major propulsion facilitating the complexation between alkali metal salts and crown ethers. Indeed, by using Poly15C5 a more pronounced dependency of enthalpy and entropy on the complex formation is calculated.

  4. Ammonium-crown ether supramolecular cation-templated assembly of an unprecedented heterobicluster-metal coordination polymer with enhanced NLO properties.

    PubMed

    Zhang, Jinfang; Jia, Ding; Humphrey, Mark G; Meng, Suci; Zaworotko, Michael J; Cifuentes, Marie P; Zhang, Chi

    2016-03-07

    An ammonium-crown ether host-guest supramolecular cation-templated synthetic methodology has been developed to construct a structurally unprecedented heterobicluster-metal coordination polymer (HCM-CP 1) based on tetranuclear clusters [WS4Cu3](+) with different connection environments, pentanuclear clusters [WS4Cu4](2+), and Cu(+) building metal ions. HCM-CP 1 exhibits enhanced NLO properties, which may be ascribed to the incorporation of diverse building cluster components.

  5. Performance of vapor-fed direct dimethyl ether fuel cell utilizing high temperature polybenzimidazole polymer electrolyte membrane

    NASA Astrophysics Data System (ADS)

    Neutzler, Jay; Qian, Guoqing; Huang, Kevin; Benicewicz, Brian

    2012-10-01

    There is increasing interest in dimethyl ether (DME) as a synthetic fuel. It has present-day relevance and introduces an effective path forward as an energy-dense, low-pressure hydrogen carrier/storage fuel for fuel cells with applications in transportation, stationary, and portable power. Direct reaction DME fuel cells have particular relevance to portable power. This study presents the performance of the vapor-fed direct reaction of DME using high temperature Polybenzimidazole (PBI) Polymer Electrolyte Membrane (PEM). Catalyzed PBI membrane utilized a Pt/Ru black anode and a Pt/C supported cathode. Performance was evaluated from temperatures of 180 °C-210 °C and at pressures from 100 kPa to 300 kPa. A strong performance correlation was observed in this study for these temperatures and pressures. A peak power density of 50 mW cm-2 was achieved at 180 °C without back pressure, whereas, an increase to 129 mW cm-2 was achieved at 210 °C at 300 kPa pressure. The performance of high temperature PBI PEMFCs with direct vapor-fed DME are investigated with emphasis on the critical variables of cell operation; temperature, back pressure, and humidity.

  6. Drug release from interpenetrating polymer networks based on poly(ethylene glycol) methyl ether acrylate and gelatin.

    PubMed

    Ding, Frank; Hsu, S-H; Wu, D-H; Chiang, W-Y

    2009-01-01

    In order to develop new materials for biomedical and pharmaceutical applications, interpenetrating polymer networks (IPNs) based on poly(ethylene glycol) methyl ether acrylate (PEGMEA) and gelatin were synthesized. These two materials were cross-linked sequentially using N,N'-methylene bisacrylamide (NMBA) and glutaraldehyde (Glu). Two series of IPNs gels were synthesized by applying different amounts of PEGMEA and gelatin in the initial feed. Sequential IPNs were prepared by polymerizing and cross-linking PEGMEA in the presence of gelatin using redox initiators (e.g., ammonium peroxydisulfate (APS) and N,N,N',N'-tetramethyl ethylenediamine (TEMED)), as well as NMBA as the cross-linking agent. Gelatin in firm gel was then cross-linked with 1% glutaraldehyde. The swelling kinetics, mechanical properties and drug-release behavior of these IPNs were analyzed. The surface properties were examined by scanning electron microscopy. The results indicated that the swelling ratio decreased with an increase in the content of both PEGMEA and gelatin in the IPNs. PEGMEA/gelatin-based full-IPNs had a significantly higher shear modulus (G) and cross-linking density (rho) when the content of PEGMEA was increased. The drug loading was very high due to the full-IPN structure. The drug-release velocity was mainly affected by the content of PEGMEA.

  7. Chemical grafting of poly(ethylene glycol) methyl ether methacrylate onto polymer surfaces by atmospheric pressure plasma processing.

    PubMed

    D'Sa, Raechelle A; Meenan, Brian J

    2010-02-02

    This article reports the use of atmospheric pressure plasma processing to induce chemical grafting of poly(ethylene glycol) methyl ether methacrylate (PEGMA) onto polystyrene (PS) and poly(methyl methacrylate) (PMMA) surfaces with the aim of attaining an adlayer conformation which is resistant to protein adsorption. The plasma treatment was carried out using a dielectric barrier discharge (DBD) reactor with PEGMA of molecular weights (MW) 1000 and 2000, PEGMA(1000) and PEGMA(2000), being grafted in a two step procedure: (1) reactive groups are generated on the polymer surface followed by (2) radical addition reactions with the PEGMA. The surface chemistry, coherency, and topography of the resulting PEGMA grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and atomic force microscopy (AFM), respectively. The most coherently grafted PEGMA layers were observed for the 2000 MW PEGMA macromolecule, DBD processed at an energy dose of 105.0 J/cm(2) as indicated by ToF-SIMS images. The effect of the chemisorbed PEGMA layer on protein adsorption was assessed by evaluating the surface response to bovine serum albumin (BSA) using XPS. BSA was used as a model protein to determine the grafted macromolecular conformation of the PEGMA layer. Whereas the PEGMA(1000) surfaces showed some protein adsorption, the PEGMA(2000) surfaces appeared to absorb no measurable amount of protein, confirming the optimum surface conformation for a nonfouling surface.

  8. Synthesis of ethylene maleic anhydride copolymer containing fungicides and evaluation of their effect for wood decay resistance

    Treesearch

    George C. Chen

    2008-01-01

    The aim of the present study was to combat wood decay based on the approach controlled-release biocides from polymers. The possibility of introducing polymer-bonded fungicides into the cell lumens was investigated. The synthesis of ethylene maleic anhydride copolymer containing pentachlorophenol (penta) and 8-hydroxy quinoline (8HQ) in N, N dimethyl formamide is...

  9. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ether, and alkylenepolyols polyglycidyl ethers (PMN P-86-628) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new...) , and (c). (ii) Hazard communication program. Requirements as specified in § 721.72 (b)(2), (c), (d), (e...

  10. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ether, and alkylenepolyols polyglycidyl ethers (PMN P-86-628) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new...) , and (c). (ii) Hazard communication program. Requirements as specified in § 721.72 (b)(2), (c), (d), (e...

  11. Sulfonated poly(ether ether ketone)/polypyrrole core-shell nanofibers: a novel polymeric adsorbent/conducting polymer nanostructures for ultrasensitive gas sensors.

    PubMed

    Wang, Wei; Li, Zhenyu; Jiang, Tingting; Zhao, Zhiwei; Li, Ye; Wang, Zhaojie; Wang, Ce

    2012-11-01

    Conducting polymers-based gas sensors have attracted increasing research attention these years. The introduction of inorganic sensitizers (noble metals or inorganic semiconductors) within the conducting polymers-based gas sensors has been regarded as the generally effective route for further enhanced sensors. Here we demonstrate a novel route for highly-efficient conducting polymers-based gas sensors by introduction of polymeric sensitizers (polymeric adsorbent) within the conducting polymeric nanostructures to form one-dimensional polymeric adsorbent/conducting polymer core-shell nanocomposites, via electrospinning and solution-phase polymerization. The adsorption effect of the SPEEK toward NH₃ can facilitate the mass diffusion of NH₃ through the PPy layers, resulting in the enhanced sensing signals. On the basis of the SPEEK/PPy nanofibers, the sensors exhibit large gas responses, even when exposed to very low concentration of NH₃ (20 ppb) at room temperature.

  12. Dual cross-linked organic-inorganic hybrid polymer electrolyte membranes based on quaternized poly(ether ether ketone) and (3-aminopropyl)triethoxysilane

    NASA Astrophysics Data System (ADS)

    Zhang, Na; Wang, Baolong; Zhao, Chengji; Zhang, Yurong; Bu, Fanzhe; Cui, Ying; Li, Xuefeng; Na, Hui

    2015-02-01

    Quaternized poly(ether ether ketone)s (QPEEKs) are synthesized to absorb phosphoric acid (PA) and used as high temperature proton exchange membranes (HTPEMs). In order to improve their oxidative and mechanical stability without sacrificing proton conductivities, a series of dual cross-linked organic-inorganic hybrid membranes are prepared using (3-aminopropyl)triethoxysilane (APTES) as a cross-linker. The amine of APTES reacts with two benzyl bromide groups to build the primary cross-linking network. The Si-O-Si network generated by the hydrolysis of triethoxysilane in APTES is the secondary cross-linking network. The dual cross-linking hybrid networks improve the mechanical and oxidative stability of PA doped membranes. They can endure up to 15.3 h in 3 wt.% H2O2, 4 ppm Fe2+ Fenton solution at 80 °C. During the hydrolysis of triethoxysilane, the release of small molecules (H2O and C2H5OH) forms many pores in surfaces and interior of membranes. These pores and the resulted Si-OH groups corporately enhance the PA absorbing ability and proton conductivity. The highest proton conductivity is 61.7 mS cm-1 for PA-QPEEK-10%APTES at 200 °C under anhydrous condition. These membranes show great potential to be used in HTPEM fuel cell.

  13. Interaction and release of catechin from anhydride maleic-grafted polypropylene films.

    PubMed

    López de Dicastillo, Carol; Castro-López, Maria Del Mar; Lasagabaster, Aurora; López-Vilariño, Jose M; González-Rodríguez, M Victoria

    2013-04-24

    In this paper, investigations were carried out on catechin-loaded maleic anhydride (MAH)-modified polypropylenes (PP). Two maleic-modified polypropylenes (PPMAH) with different maleic concentrations have been blended with PP and catechin to obtain composites of improved catechin retention with the aim of studying the possible interactions between these grafted polymers with antioxidants, and a secondary interest in developing an active antioxidant packaging. Composite physicochemical properties were measured by thermal analysis (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and oxidation induction time (OIT)) and infrared spectroscopy studies. Catechin release profiles into food simulants were obtained by HPLC-PDA-QqQ, following European legislation. Antiradical activity of composites was analyzed by the ABTS and DPPH method. The formation of intermolecular hydrogen bonds between catechin and functionalized PP has been confirmed by Fourier transform infrared (FTIR) studies. Besides, a small fraction of ester bonds, formed as a result of a chemical reaction between a fraction of the hydrolyzed anhydride and the catechin hydroxyl groups, is not discarded. OIT results also showed an increase in antioxidant effectiveness caused by the presence of catechin- and maleic-modified PPMAH in the blend formulations. Incorporation of MAH-grafted PP increased substantially the retention rate of catechin, being dependent on the MAH content of the grafted polypropylene. The described interactions between catechin and maleic groups, together with changes in PP morphology in comparison with reference PP explained lower antioxidant release. Besides formulation, antioxidant release was dependent on the type of food, the temperature, and the time.

  14. Polyphenylene ethers with imide linking groups

    NASA Technical Reports Server (NTRS)

    St.clair, T. L.; Burks, H. D. (Inventor)

    1984-01-01

    Novel polyphenylene ethers with imide linking units are disclosed. These polymers incorporate the solvent and thermal resistance of polyimides and the processability of polyphenylene ethers. Improved physical properties over those of the prior art are obtained by incorporating meta linked ethers and/or polyphenylene oxides into the polymer backbone. A novel process for making polymers of this type is also disclosed. The process is unique in that the expected need of high process temperatures and/or special atmospheres are eliminated.

  15. Controlling Styrene Maleic acid lipid particles through RAFT.

    PubMed

    Smith, Anton A A; Autzen, Henriette Elisabeth; Laursen, Tomas; Wu, Vincent; Yen, Max; Hall, Aaron; Hansen, Scott D; Cheng, Yifan; Xu, Ting

    2017-09-21

    The ability of styrene maleic acid copolymers to dissolve lipid membranes into nanosized lipid particles is a facile method of obtaining membrane proteins in solubilized lipid discs while conserving part of its native lipid environment. While the currently used copolymers can readily extract membrane proteins in native nanodiscs, their highly disperse composition is likely to influence the dispersity of the discs as well as the extraction efficiency. In this study, reversible addition fragmentation chain transfer was used to control the polymer architecture and dispersity of molecular weights with a high-precision. Based on Monte Carlo simulations of the polymerizations, the monomer composition was predicted and allowed a structure-function analysis of the polymer architecture in relation to their ability to assemble into lipid nanoparticles. We show that a higher degree of control of the polymer architecture may lead to homogeneous samples. We hypothesize that low dispersity copolymers with control of polymer architecture are an ideal frame-work for the rational design of polymers for customized isolation and characterization of integral membrane proteins in native lipid bilayer systems.

  16. 40 CFR 721.522 - Oxirane, methyl-, polymer with oxirane, mono(3,5,5,-trimethylhexyl) ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Oxirane, methyl-, polymer with oxirane... Significant New Uses for Specific Chemical Substances § 721.522 Oxirane, methyl-, polymer with oxirane, mono(3...) The chemical substance identified as oxirane, methyl-, polymer with oxirane,...

  17. 40 CFR 721.7260 - Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of poly-ethylene-polyamine and... New Uses for Specific Chemical Substances § 721.7260 Polymer of poly-ethylene-polyamine and alkanediol... chemical substance identified generically as polymer of polyethylenepolyamine and alkanediol...

  18. 40 CFR 721.522 - Oxirane, methyl-, polymer with oxirane, mono(3,5,5,-trimethylhexyl) ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Oxirane, methyl-, polymer with oxirane... Significant New Uses for Specific Chemical Substances § 721.522 Oxirane, methyl-, polymer with oxirane, mono(3...) The chemical substance identified as oxirane, methyl-, polymer with oxirane,...

  19. 40 CFR 721.7260 - Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polymer of poly-ethylene-polyamine and... New Uses for Specific Chemical Substances § 721.7260 Polymer of poly-ethylene-polyamine and alkanediol... chemical substance identified generically as polymer of polyethylenepolyamine and alkanediol...

  20. 40 CFR 721.7260 - Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polymer of poly-ethylene-polyamine and... New Uses for Specific Chemical Substances § 721.7260 Polymer of poly-ethylene-polyamine and alkanediol... chemical substance identified generically as polymer of polyethylenepolyamine and alkanediol diglycidyl...

  1. 40 CFR 721.522 - Oxirane, methyl-, polymer with oxirane, mono(3,5,5,-trimethylhexyl) ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Oxirane, methyl-, polymer with oxirane... Significant New Uses for Specific Chemical Substances § 721.522 Oxirane, methyl-, polymer with oxirane, mono(3...) The chemical substance identified as oxirane, methyl-, polymer with oxirane, mono(3,5,5...

  2. 40 CFR 721.522 - Oxirane, methyl-, polymer with oxirane, mono(3,5,5,-trimethylhexyl) ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxirane, methyl-, polymer with oxirane... Significant New Uses for Specific Chemical Substances § 721.522 Oxirane, methyl-, polymer with oxirane, mono(3...) The chemical substance identified as oxirane, methyl-, polymer with oxirane, mono(3,5,5...

  3. 40 CFR 721.7260 - Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polymer of poly-ethylene-polyamine and... New Uses for Specific Chemical Substances § 721.7260 Polymer of poly-ethylene-polyamine and alkanediol... chemical substance identified generically as polymer of polyethylenepolyamine and alkanediol diglycidyl...

  4. 40 CFR 721.522 - Oxirane, methyl-, polymer with oxirane, mono(3,5,5,-trimethylhexyl) ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Oxirane, methyl-, polymer with oxirane... Significant New Uses for Specific Chemical Substances § 721.522 Oxirane, methyl-, polymer with oxirane, mono(3...) The chemical substance identified as oxirane, methyl-, polymer with oxirane, mono(3,5,5...

  5. 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... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1820 Styrene-maleic anhydride copolymers. Styrene-maleic anhydride copolymers identified in paragraph (a) of this section may be...

  6. Langmuir and Langmuir-Blodgett films of a maleic anhydride derivative: effect of subphase divalent cations.

    PubMed

    Martín-García, B; Velázquez, M Mercedes; Pérez-Hernández, J A; Hernández-Toro, J

    2010-09-21

    We report the study of the equilibrium and dynamic properties of Langmuir monolayers of poly(styrene-co-maleic anhydride) partial 2-buthoxyethyl ester cumene terminated polymer and the effect of the Mg(NO(3))(2) addition in the water subphase on the film properties. Results show that the polymer monolayer becomes more expanded when the electrolyte concentration in the subphase increases. Dense polymer films aggregate at the interface. The aggregates are transferred onto silicon wafers using the Langmuir-Blodgett methodology and the morphology is observed by AFM. The structure of aggregates depends on the subphase composition of the Langmuir film transferred onto the silicon wafer.

  7. Maleic anhydride-g-low density polyethylene: Modification of LDPE molecular structure by γ-irradiation

    NASA Astrophysics Data System (ADS)

    Sheeja, Manaf, O.; Sujith, A.

    2017-06-01

    Polymer modification by radiation grafting of monomers onto polymers has received much attention recently. In the current study, γ-irradiation technique was used to achieve graft copolymerization of maleic anhydride (MA) onto low-density polyethylene (LDPE). To optimize, the process was performed at different γ-irradiation doses and MA concentration. The microstructure of grafted polymer film has been characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, field emission-scanning electron microscopy, and atomic force microscopy. The studies performed made possible the selection of experimental protocols adequate for the production of new copolymeric materials with high grafting yield.

  8. Biomaterial properties evaluation of poly(vinyl acetate- alt-maleic anhydride)/chitosan nanocapsules

    NASA Astrophysics Data System (ADS)

    Raţă, Delia Mihaela; Popa, Marcel; Chailan, Jean-François; Zamfir, Carmen Lăcrămioara; Peptu, Cătălina Anişoara

    2014-08-01

    Nanocapsules with diameter around 100 nm based on a natural polymer (chitosan) and a synthetic polymer poly(vinyl acetate- alt-maleic anhydride) [poly(MAVA)] by interfacial condensation method were prepared. The present study proposes a new type of biocompatible nanocapsules based on poly(vinyl acetate- alt-maleic anhydride-chitosan) (MCS) able to become a reliable support for inclusion and release of drugs. The spherical shape of the nanocapsules was evidenced by scanning electron microscopy. Nanocapsules presented a good Norfloxacin loading and release capacity. Haemocompatibility tests have demonstrated that the nanocapsules present a low toxicity and a good compatibility with sanguine medium. The biocompatibility properties of the nanocapsules after their intraperitoneal administration in rats were evidenced by histopathological examination of different organs (brain, liver, kidney, and lung). The results are encouraging and the nanocapsules can be used as controlled drug delivery systems.

  9. Evidence of glass transition in thin films of maleic anhydride derivatives: Effect of the surfactant coadsorption

    NASA Astrophysics Data System (ADS)

    López-Dıaz, D.; Velázquez, M. M.

    2008-08-01

    The glass transition temperature of poly (maleic anhydride-alt-1-octadecen) and poly (styrene-co-maleic anhydride) cumene-terminated thin films has been measured by mechanical relaxation of Langmuir films of these polymers. The dynamical properties show glass-like features (non-Arrhenius relaxation times and non-Debye mechanical response) interpreted by the coupling model. The glass transition temperature values determined by a mechanical relaxation experiment (step-compression) agree very well with those obtained by surface potential measurements. It is found that the glass transition temperature values in thin films decrease by about 100K as compared with those corresponding to the bulk polymers. The coadsorption of the water-insoluble surfactant DODAB decreases the glass transition temperature.

  10. Cytotoxic effects of maleic hydrazide.

    PubMed

    Swietlińska, Z; Zuk, J

    1978-01-01

    Since 1950, maleic hydrazide (MH) has been introduced into agriculture as a major commercial herbicide and a depressant of plant growth in numerous circumstances such as suppression of sprouting of vegetables and stored food crops, control of sucker growth on tobacco plants, ratardation of flowering and prolongation of dormancy period. Since 1951 MH has been known as an effective chromosome-breaking agent in higher plants, in sharp contrast with its low effect on the chromosomes and general health of tested mammals. The selectivity of action of MH in plants and animals was obviously the main reason of low interest devoted to the chemical by people working the field of environmental mutagenesis. In early works the inhibitory effects of MH on plant growth were mainly considered to result from the suppression of plant metabolism (inhibition of enzymic activity) and interference of the compound with plant hormones and growth regulators. More recently, numerous experiments performed with various plant species have shown that MH acts as an inhibitor of the synthesis of nucleic acids and proteins. Similar results have been obtained with animal tumour cells. The chromosome-breaking effect of MH on plant chromosomes resembles very closely the chromosome-breaking properties of alkylating agents and other mutagenic compounds such as mitomycin C. MH-induced chromosomal aberrations have also been recorded in grasshoppers, fish and mice, although tests with some mammalian cell lines gave negative results. Among higher plants, selective sensitivity to the toxic effects of MH is well proved. This phenomenon seems to be due to the differential ability of various plant species to detoxicate the chemical. Plants can break down MH into several products, one of which, hydrazine, is a well-known mutagen and carcinogen. MH does not seem to be toxic to bacteria and fungi. The compound is degraded by soil microflora and hence can be utilized as a source of nitrogen nutrition. MH proved to

  11. 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.

  12. Inorganic-organic polymer electrolytes based on poly(vinyl alcohol) and borane/poly(ethylene glycol) monomethyl ether for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Aydın, Hamide; Şenel, Mehmet; Erdemi, Hamit; Baykal, Abdülhadi; Tülü, Metin; Ata, Ali; Bozkurt, Ayhan

    In this study, poly(vinyl alcohol) (PVA) was modified with poly(ethylene glycol) monomethyl ether (PEGME) using borane-tetrahydrofuran (BH 3/THF) complex. Molecular weights of both PVA and PEGME were varied prior to reaction. Boron containing comb-branched copolymers were produced and abbreviated as PVA1PEGMEX and PVA2PEGMEX. Then polymer electrolytes were successfully prepared by doping of the host matrix with CF 3SO 3Li at several stoichiomeric ratios with respect to EO to Li. The materials were characterized via nuclear magnetic resonance (1H NMR and 11B NMR), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG) and differential scanning calorimeter (DSC). The ionic conductivity of these novel polymer electrolytes were studied by dielectric-impedance spectroscopy. Li-ion conductivity of these polymer electrolytes depends on the length of the side units as well as the doping ratio. Such electrolytes possess satisfactory ambient temperature ionic conductivity (>10 -4 S cm -1). Cyclic voltammetry results illustrated that the electrochemical stability domain extends over 4 V.

  13. 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.

  14. Polyhedral Oligomeric Silsesquioxane-Functionalized Perfluorocyclobutyl Aryl Ether Polymers: An Overview of the Synthesis and Properties of Polyhedral Oligomeric Silsesquioxanes (POSS) Functionalized with Perfluorocyclobutyl (PFCB) Aryl Ether Polymer Blends and Copolymers (Preprint)

    DTIC Science & Technology

    2007-10-17

    Polymer Blends Fluorinated POSS (F-POSS) compounds were blended into PFCB polymer poly5 (Man = 22000 , PDI = 2.2; GPC in CHCl3 using PS as standard) by...transition temperature (Tg) with POSS copolymers. The decrease was most noticeable for copolymers with iso -butyl groups (R = i-Bu) and further...Surface Analysis. Copolymers with up to 20 wt% iso -butyl functionalized POSS produced solution processable, optically transparent, semi-flexible films

  15. Adjustable degradation and drug release of a thermosensitive hydrogel based on a pendant cyclic ether modified poly(ε-caprolactone) and poly(ethylene glycol)co-polymer.

    PubMed

    Wang, Weiwei; Deng, Liandong; Liu, Shasha; Li, Xu; Zhao, Xiumei; Hu, Renjie; Zhang, Jianhua; Han, Haijie; Dong, Anjie

    2012-11-01

    The convenient and precise fabrication of drug-hydrogel formulations with satisfactory degradability and a well-controlled drug release profile are crucial factors for injectable hydrogel formulations in clinical applications. Here a new injectable thermosensitive hydrogel formed from poly(ε-caprolactone) (PCL)-poly(ethylene glycol)-poly(ε-caprolactone) amphiphilicco-polymers with 1,4,8-trioxa[4.6]spiro-9-undecanone (TOSUO) moieties incorporated in the poly(ε-caprolactone) (PCL)block (PECT) was constructed to provide a route to tailor the degradation and drug release behavior. The effect of hydrophilic cyclic ether moieties on the degradation of and drug release by PECT hydrogels were evaluated in vitro and in vivo. The results indicated that a freeze-dried powder of paclitaxel-loaded PECT nanoparticles rapidly dissolved in water at ambient temperature with slightly shaking and formed a stable injectable in situ drug-hydrogel formulation at body temperature, which is convenient for clinical operations because it avoids the need for pre-quenching or long-term incubation. The paclitaxel distribution was also more quantitative and homogeneous on entrapping paclitaxel in PECT nanoparticles. Further, the small number of pendant cyclic ether groups in PCL could decrease the cystallinity and hydrophobicity and, as a result, the in vitro and in vivo retention time of PECT hydrogels and the release of entrapped paclitaxel could be tuned from a few weeks to months by varying the amount of PTOSUO in the hydrophobic block. Significantly, paclitaxel-loaded PECT nanoparticles and free paclitaxel could be simultaneously released during the in vitro paclitaxel release from PECT hydrogels. A histopathological evaluation indicated that in vivo injected PECT hydrogels produced only a modest inflammatory response. Thus pendant cyclic ether modification of PCL could be an effective way to achieve the desired degradation and drug release profiles of amphiphilicco-polymer

  16. Ring-opening copolymerization of maleic anhydride with epoxides: a chain-growth approach to unsaturated polyesters.

    PubMed

    DiCiccio, Angela M; Coates, Geoffrey W

    2011-07-20

    We report the ring-opening copolymerization of maleic anhydride with a variety of epoxides catalyzed by a chromium(III) salen complex. Quantitative isomerization of the cis-maleate form of all polymers affords the trans-fumarate analogues. Addition of chain transfer reagents yields low M(n), narrow PDI polymer samples. This method provides access to a range of new unsaturated polyesters with versatile functionality, as well as the first synthesis of high molecular weight poly(propylene fumarate).

  17. Antimocrobial Polymer

    DOEpatents

    McDonald, William F.; Huang, Zhi-Heng; Wright, Stacy C.

    2005-09-06

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A)3P wherein A is hydroxyalkyl; and the antimicrobial agent is chlorhexidine, dimethylchlorophenol, cetyl pyridinium chloride, gentian violet, triclosan, thymol, iodine, and mixtures thereof.

  18. Antimicrobial Polymer

    DOEpatents

    McDonald, William F.; Wright, Stacy C.; Taylor, Andrew C.

    2004-09-28

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The polymeric composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from metals, metal alloys, metal salts, metal complexes and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one example embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A).sub.3 P wherein A is hydroxyalkyl; and the metallic antimicrobial agent is selected from chelated silver ions, silver metal, chelated copper ions, copper metal, chelated zinc ions, zinc metal and mixtures thereof.

  19. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  20. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  1. 40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... products with (butoxymethyl) oxirane formaldehyde-phenol polymer glycidyl ether, morpholinepropanamine...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N... products with (butoxymethyl) oxirane formaldehyde-phenol polymer glycidyl ether,...

  2. Ring-polymer molecular dynamics studies on the rate coefficient of the abstraction channel of hydrogen plus ethane, propane, and dimethyl ether

    NASA Astrophysics Data System (ADS)

    Meng, Qingyong; Chen, Jun

    2017-01-01

    To accurately compute the rates of the abstraction channels of hydrogen plus ethane (Et), propane (Pr), and dimethyl ether (DME), ring-polymer molecular dynamics (RPMD) method is used in conjunction with the recently constructed local permutation invariant polynomial neural-networks potential energy surface of the parent H + CH4 system [Q. Meng et al., J. Chem. Phys. 144, 154312 (2016)]. For H + Et, one of the H atoms in CH4 of the parent system is replaced by a methyl group, while for the H + DME reaction, it is replaced by the methoxyl group. For the H + Pr reaction, replacing one of the H atoms in CH4 by an ethyl group, the terminal channel is built, meanwhile the middle channel is considered through replacing two H atoms in CH4 by two methyl groups. Since the potential energy barriers of the title reactions must differ from the H + CH4 barrier, the corrections have to be made by computing the ratio of free-energy barriers between H + CH4 and the title reactions at coupled cluster with a full treatment singles and doubles (where the triples contribution is calculated by perturbation theory, that is, CCSD(T)) level. Comparing the present RPMD rates with the previous theoretical and experimental results, good agreement can be found. Moreover, probable reasons for the deviation between the present RPMD rates and the previous experimental ones are discussed.

  3. On-site polymer-coated hollow fiber membrane microextraction and gas chromatography--mass spectrometry of polychlorinated biphenyls and polybrominated diphenyl ethers.

    PubMed

    Basheer, Chanbasha; Vetrichelvan, Muthalagu; Valiyaveettil, Suresh; Lee, Hian Kee

    2007-01-19

    Porous polypropylene hollow fiber membrane coated with a conjugated polymer was used as an on-site sampling device for the extraction of polychlorinated biphenyls and polybrominated biphenyl ethers from coastal sea water samples. The coated hollow fiber membrane was placed in a vial containing the sample, and the target compounds extracted via manual shaking of the vials at the site of sample collection. For each extraction, two fibers were used. After extraction, the fibers with the adsorbed analytes were brought back to the laboratory for further processing. Care was taken to preserve the integrity of the analytes and to avoid contamination during transport; after extraction, the fibers were carefully removed and placed in air-tight crimper vials which were stored in an ice-box. The analytes were desorbed by solvent in the laboratory and analyses were carried out using gas chromatography/mass spectrometry. This method was highly reproducible with relative standard deviations in the range of 1-9%. Recoveries from spiked water samples ranged from 83% to 98%. Low limits of detections between 0.04 and 0.21ngl(-1) were achieved. The extraction efficiency was compared with solid-phase microextraction.

  4. Chemical modification of wheat protein-based natural polymers: grafting and cross-linking reactions with poly(ethylene oxide) diglycidyl ether and ethyl diamine.

    PubMed

    Kurniawan, Lusiana; Qiao, Greg G; Zhang, Xiaoqing

    2007-09-01

    Mobile poly(ethylene oxide) diglycidyl ether (PEODGE) segments were chemically grafted onto a soluble wheat protein (WP), and different network structures were formed via coupling reactions with ethyl diamine (EDA) in different PEODGE/EDA (PE) ratios. When the PE ratio was 1:1, linear PEs were the predominant segments grafted onto WP chains and the whole WP-PEODGE-EDA (WPE) system was still soluble with an increased molecular weight. Reducing the amount of EDA in the systems produced insoluble cross-linked WPE networks. The broad distribution of network structures and chain mobility resulted in a broad glass transition for the WPE materials. However, the glass transition started at lower temperatures, and the materials became flexible at room temperature. The PE segments were present in all rigid, intermediate, and mobile phases in WPE networks, while the proportion of mobile WP chains was increased as a result of the plasticization effect from the mobile PE segments. The mobility of the most mobile component lipid was also restricted to some extent when forming the cross-linked WPE networks. The study demonstrated that the formation of different network structures with PE segments could significantly improve the flexibility of WP materials, vary the solubility, and modify the mechanical performance of WP-based natural polymer materials.

  5. Effects of 12-crown-4 ether on the electrochemical performance of CoO2 and TiS2 cathodes in Li polymer electrolyte cells

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Attia, Alan I.; Halpert, G.

    1992-01-01

    The effect of adding 12-crown-4 ether (12Cr4) to the polyethylene oxide (PEO) electrolyte on the electrochemical properties of cells with Li(x)CoO2 or TiS2 as the cathode was investigated. The polymer electrolyte films were: (1) PEO, LiBF4; (2) PEO, LiBF4 with 12Cr4; (3) Li(x)CoO2, PEO, and LiBF4; and (4) Li(x)CoO2, PEO, LiBF4, and 12Cr4. It was found that, although 12Cr4 improved the cell performance over cells without 12Cr4 in the shallow c/d cycles (cyclic voltammetric behavior), it did not seem to prolong the active life of the cell. The cells with CoO2 as the cathode failed after a few c/d cycles, while similar cells with TiS2 did not fail even after 12 c/d cycles. The probable cause of failure in the case of CoO2 is ascribed to the instability of the CoO2 cathode.

  6. Interface Properties between Lithium Metal and a Composite Polymer Electrolyte of PEO18Li(CF3SO2)2N-Tetraethylene Glycol Dimethyl Ether

    PubMed Central

    Wang, Hui; Matsui, Masaki; Takeda, Yasuo; Yamamoto, Osamu; Im, Dongmin; Lee, Dongjoon; Imanishi, Nobuyuki

    2013-01-01

    The electrochemical properties of a composite solid polymer electrolyte, consisting of poly(ethylene oxide) (PEO)-lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and tetraethylene glycol dimethyl ether (TEGDME) was examined as a protective layer between lithium metal and a water-stable lithium ion-conducting glass ceramic of Li1+x+y(Ti,Ge)2−xAlxP3−ySiyO12 (LTAP). The lithium ion conductivity and salt diffusion coefficient of PEO18LiTFSI were dramatically enhanced by the addition of TEGDME. The water-stable lithium electrode with PEO18LiTFSI-2TEGDME, as the protective layer, exhibited a low and stable electrode resistance of 85 Ω·cm2 at 60 °C, after 28 days, and low overpotentials of 0.3 V for lithium plating and 0.4 V for lithium stripping at 4.0 mA·cm−2 and 60 °C. A Li/PEO18LiTFSI-2TEGDME/LTAP/saturated LiCl aqueous solution/Pt, air cell showed excellent cyclability up to 100 cycles at 2.0 mAh·cm−2. PMID:24957059

  7. Plasma Polymerisation of Maleic Anhydride: Just what are the right deposition conditions?

    PubMed Central

    Mishra, Gautam; McArthur, Sally L.

    2010-01-01

    Maleic anhydride plasma polymers enable amine containing biomolecules and polymers to be covalently coupled to a surface from an aqueous solution without any intermediate chemistry. The challenge in developing these functionally active plasma polymers lies in determining the optimal deposition conditions for producing a stable, highly active film. Unlike many previous studies that explore highly varied pulsed and continuous wave (CW) deposition conditions, this paper focuses on the comparison of films deposited under the same low nominal power conditions (1 W) and compares a range of CW, ms and µs pulsing parameters that can be used to produce this power condition. The use of attenuated total reflectance – Fourier transform infra red spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) has enabled the quantitative examination of the effects of processing parameters on the chemical functionality of the films. For the first time, the molecular specificity, surface sensitivity and high mass resolution of time-of-flight static secondary ion mass spectrometry (ToF-SSIMS) has been exploited to compare these films and multivariate analysis techniques used to explore the relationships between plasma processing parameters and surface chemistry. The results of the studies clearly demonstrate that a range of conditions can produce maleic anhydride films, with optimal functionality seen under µs pulsing regimes. Critically, the study demonstrates that the tight control and monitoring of the deposition parameters is critical if these films are to be manufactured with optimal functionality, stability and minimum processing time. PMID:20443591

  8. Ultrathin, flexible, and transparent polymer multilayer composites for the protection of silver surfaces.

    PubMed

    Langecker, Jens; Ritter, Helene; Fichini, Audrey; Rupper, Patrick; Faller, Markus; Hanselmann, Barbara

    2012-02-01

    Silver coatings at the nanoscale became of high interest for the integration of electronic functionalities on all kinds of objects for daily use. In these thin coatings, corrosion is a big problem as it destroys these thin layers and leads to a loss of conductivity due to missing bulk material. For protection of thin silver coatings against H(2)S induced corrosion, we developed nanocoatings based on the covalent layer-by-layer technique. We prepared composites by subsequent deposition of polyamines like polyethylenimine (PEI) or polyallylamine (PAAm) and polyanhydrides like poly(maleic anhydride-alt-methyl vinyl ether) (Gantrez) or poly(styrene-co-maleic anhydride) (PSMA). For the tuning of the hydrophobicity, the layers were terminated by reaction with palmitoylic acid derivatives. Reflectivity measurements, contact angle measurements, and AFM measurements were made to investigate how the coatings affect the surface properties. All coatings show a lower reflectivity below 450 nm compared to pure silver, depending on the number of layers deposited. The addition of a palmitoylic derivative to the surface increases the hydrophobicity, but only in case of the Gantrez-PVAm-composite, this approach leads to real hydrophobicity, reaching contact angles above 90°. AFM measurements show a decrease of the roughness of the polymer coated surfaces compared to the pure metal surfaces. Corrosion tests in a H(2)S atmosphere show a good protective effect of the palmitoyl-terminated composites. Martindale abrasion tests on coated textiles reveal a good stability of the prepared polymer composites.

  9. 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.

  10. Toxic metal ion separation by cellulose acetate/sulfonated poly(ether imide) blend membranes: effect of polymer composition and additive.

    PubMed

    Nagendran, A; Vijayalakshmi, A; Arockiasamy, D Lawrence; Shobana, K H; Mohan, D

    2008-07-15

    Toxic heavy metal ion removal from industrial effluents are gaining increased visibility owing to environmental concern and saving precious materials. In this work, an attempt has been made to remove the valuable metal ions using modified ultrafiltration (UF) blend membranes based on cellulose acetate (CA) and sulfonated poly(ether imide) (SPEI) were prepared in the presence and absence of additive, poly(ethylene glycol) 600 (PEG600) in various compositions. Prepared membranes were characterized in terms of pure water flux (PWF), water content and membrane hydraulic resistance. High flux UF membranes were obtained in the range of 15-25 wt% SPEI and 2.5-10 wt% PEG600 in the polymer blend. The molecular weight cut-off (MWCO) of the blend membranes were determined using protein separation studies found to vary from 20 to greater than 69 kDa. Surface morphology of the blend membranes were analysed with scanning electron microscopy. Studies were carried out to find the rejection and permeate flux of metal ions such as Cu(II), Ni(II), Zn(II) and Cd(II) using polyethyleneimine as the chelating ligand. On increasing the composition of SPEI and PEG600, the rejection of metal ions is decreasing while the permeate flux has an increasing trend. These effects are due to the increased pore formation in the CA/SPEI blend membranes because of the hydrophilic SPEI and polymeric additive PEG600. In general, it was found that CA/SPEI blend membranes displayed higher permeate flux and lower rejection compared to pure CA membranes. The extent of separation of metal ions depends on the affinity of metal ions to polyethyleneimine to form macromolecular complexes and the stability of the formed complexes.

  11. Influence of lipid bilayer properties on nanodisc formation mediated by styrene/maleic acid copolymers.

    PubMed

    Cuevas Arenas, Rodrigo; Klingler, Johannes; Vargas, Carolyn; Keller, Sandro

    2016-08-11

    Copolymers of styrene and maleic acid (SMA) have gained great attention as alternatives to conventional detergents, as they offer decisive advantages for studying membrane proteins and lipids in vitro. These polymers self-insert into artificial and biological membranes and, at sufficiently high concentrations, solubilise them into disc-shaped nanostructures containing a lipid bilayer core surrounded by a polymer belt. We have used (31)P nuclear magnetic resonance spectroscopy and dynamic light scattering to systematically study the solubilisation of vesicles composed of saturated or unsaturated phospholipids by an SMA copolymer with a 3 : 1 styrene/maleic acid molar ratio at different temperatures. Solubilisation was thermodynamically rationalised in terms of a three-stage model that treats various lipid/polymer aggregates as pseudophases. The solubilising capacity of SMA(3 : 1) towards a saturated lipid is higher in the gel than in the liquid-crystalline state of the membrane even though solubilisation is slower. Although the solubilisation of mixed fluid membranes is non-selective, the presence of a non-bilayer phospholipid lowers the threshold at which the membrane becomes saturated with SMA(3 : 1) but raises the polymer concentration required for complete solubilisation. Both of these trends can be explained by considering the vesicle-to-nanodisc transfer free energies of the lipid and the polymer. On the basis of the phase diagrams thus obtained, re-association of polymer-solubilised lipids with vesicles is possible under mild conditions, which has implications for the reconstitution of proteins and lipids from nanodiscs into vesicular membranes. Finally, the phase diagrams provide evidence for the absence of free SMA(3 : 1) in vesicular lipid suspensions.

  12. LaRC-ITPI/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J.; Working, Dennis C.

    1991-01-01

    As part of an effort to develop high performance structural resins for aerospace applications, work has continued on block copolymers containing imide and arylene ether segments. The arylene ether block used in this study contains a bulky fluorene group in the polymer backbone while the imide block contains an arylene ketone segment similar to that in the arylene ether block and has been named LaRC-ITPI. A series of imide/arylene ether block and segmented copolymers were prepared and characterized. Films were prepared from these copolymers and mechanical properties were measured.

  13. Nonabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Nonabromodiphenyl ether ; CASRN 63936 - 56 - 1 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 Noncarc

  14. Pentabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Pentabromodiphenyl ether ; CASRN 32534 - 81 - 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 Noncar

  15. Octabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Octabromodiphenyl ether ; CASRN 32536 - 52 - 0 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 Noncarc

  16. Tribromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Tribromodiphenyl ether ; CASRN 49690 - 94 - 0 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 Noncarci

  17. Hexabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Hexabromodiphenyl ether ; CASRN 36483 - 60 - 0 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 Noncarc

  18. Ethyl ether

    Integrated Risk Information System (IRIS)

    Ethyl ether ; CASRN 60 - 29 - 7 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 Effect

  19. Tetrabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Tetrabromodiphenyl ether ; CASRN 40088 - 47 - 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 Noncar

  20. Diclofenac sodium (DS) loaded bioerodible polymer based constructs

    NASA Astrophysics Data System (ADS)

    Piras, M.; Chiellini, F.; Nikkola, L.; Ashammakhi, N.; Chiellini, E.

    2008-02-01

    Pain is a prevalent problem that can raise morbidity of patients. Pain killer releasing biodegradable materials have been developed by using different techniques and biomaterials. The objective of the current study is to evaluate the use of a new bioerodible polymer for release of diclofenac sodium (DS). 1-butanol hemiester poly(maleic anhydride-alt-2-methoxyethyl vinyl ether) (PAM14) was prepared in the university of Pisa and selected as polymer of choice for the study. Polymer solutions of 5-10% (in ethanol or in acetic acid) were prepared, half of them containing 2% DS. The solutions were then electrospun to produce nanomats that were subsequently characterized using SEM. Fiber diameter was 160 nm 1 μm. Increasing polymer concentration increased the size of the fibers but reduced the number of beads (with or without DS). In the specimens obtained from acetic acid solution, the addition of DS resulted in a reduction in fiber diameter and an increase in the inter-bead distance. Corresponding ethanol solutions gave more homogeneous specimens than did acetic acid, having a lower number of beads. With the addition of DS a reduction in fiber diameter was observed for the acetic acid specimens. However, in ethanol, adding DS resulted in increased fiber diameter. Accordingly, it can be concluded that it is feasible to develop electrospun diclofenac releasing bioerodible nanostructures that have potential use in pain management. Their further evaluation is however, needed both in vitro and in vivo.

  1. Solubilization of Membrane Proteins into Functional Lipid-Bilayer Nanodiscs Using a Diisobutylene/Maleic Acid Copolymer.

    PubMed

    Oluwole, Abraham Olusegun; Danielczak, Bartholomäus; Meister, Annette; Babalola, Jonathan Oyebamiji; Vargas, Carolyn; Keller, Sandro

    2017-02-06

    Once removed from their natural environment, membrane proteins depend on membrane-mimetic systems to retain their native structures and functions. To this end, lipid-bilayer nanodiscs that are bounded by scaffold proteins or amphiphilic polymers such as styrene/maleic acid (SMA) copolymers have been introduced as alternatives to detergent micelles and liposomes for in vitro membrane-protein research. Herein, we show that an alternating diisobutylene/maleic acid (DIBMA) copolymer shows equal performance to SMA in solubilizing phospholipids, stabilizes an integral membrane enzyme in functional bilayer nanodiscs, and extracts proteins of various sizes directly from cellular membranes. Unlike aromatic SMA, aliphatic DIBMA has only a mild effect on lipid acyl-chain order, does not interfere with optical spectroscopy in the far-UV range, and does not precipitate in the presence of low millimolar concentrations of divalent cations. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  2. Solubilization of Membrane Proteins into Functional Lipid‐Bilayer Nanodiscs Using a Diisobutylene/Maleic Acid Copolymer

    PubMed Central

    Oluwole, Abraham Olusegun; Danielczak, Bartholomäus; Meister, Annette; Babalola, Jonathan Oyebamiji; Vargas, Carolyn

    2017-01-01

    Abstract Once removed from their natural environment, membrane proteins depend on membrane‐mimetic systems to retain their native structures and functions. To this end, lipid‐bilayer nanodiscs that are bounded by scaffold proteins or amphiphilic polymers such as styrene/maleic acid (SMA) copolymers have been introduced as alternatives to detergent micelles and liposomes for in vitro membrane‐protein research. Herein, we show that an alternating diisobutylene/maleic acid (DIBMA) copolymer shows equal performance to SMA in solubilizing phospholipids, stabilizes an integral membrane enzyme in functional bilayer nanodiscs, and extracts proteins of various sizes directly from cellular membranes. Unlike aromatic SMA, aliphatic DIBMA has only a mild effect on lipid acyl‐chain order, does not interfere with optical spectroscopy in the far‐UV range, and does not precipitate in the presence of low millimolar concentrations of divalent cations. PMID:28079955

  3. Optimization of the dilute maleic acid pretreatment of wheat straw

    PubMed Central

    2009-01-01

    Background In this study, the dilute maleic acid pretreatment of wheat straw is optimized, using pretreatment time, temperature and maleic acid concentration as design variables. A central composite design was applied to the experimental set up. The response factors used in this study are: (1) glucose benefits from improved enzymatic digestibility of wheat straw solids; (2) xylose benefits from the solubilization of xylan to the liquid phase during the pretreatment; (3) maleic acid replenishment costs; (4) neutralization costs of pretreated material; (5) costs due to furfural production; and (6) heating costs of the input materials. For each response factor, experimental data were fitted mathematically. After data translation to €/Mg dry straw, determining the relative contribution of each response factor, an economic optimization was calculated within the limits of the design variables. Results When costs are disregarded, an almost complete glucan conversion to glucose can be reached (90% from solids, 7%-10% in liquid), after enzymatic hydrolysis. During the pretreatment, up to 90% of all xylan is converted to monomeric xylose. Taking cost factors into account, the optimal process conditions are: 50 min at 170°C, with 46 mM maleic acid, resulting in a yield of 65 €/Mg (megagram = metric ton) dry straw, consisting of 68 €/Mg glucose benefits (from solids: 85% of all glucan), 17 €/Mg xylose benefits (from liquid: 80% of all xylan), 17 €/Mg maleic acid costs, 2.0 €/Mg heating costs and 0.68 €/Mg NaOH costs. In all but the most severe of the studied conditions, furfural formation was so limited that associated costs are considered negligible. Conclusions After the dilute maleic acid pretreatment and subsequent enzymatic hydrolysis, almost complete conversion of wheat straw glucan and xylan is possible. Taking maleic acid replenishment, heating, neutralization and furfural formation into account, the optimum in the dilute maleic acid pretreatment of

  4. Controlled delivery of paclitaxel from stent coatings using novel styrene maleic anhydride copolymer formulations.

    PubMed

    Richard, Robert; Schwarz, Marlene; Chan, Ken; Teigen, Nikolai; Boden, Mark

    2009-08-01

    The controlled release of paclitaxel (PTx) from stent coatings comprising an elastomeric polymer blended with a styrene maleic anhydride (SMA) copolymer is described. The coated stents were characterized for morphology by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and for drug release using high-performance liquid chromatography (HPLC). Differential scanning calorimetry (DSC) was used to measure the extent of interaction between the PTx and polymers in the formulation. Coronary stents were coated with blends of poly(b-styrene-b-isobutylene-b-styrene) (SIBS) and SMA containing 7% or 14% maleic anhydride (MA) by weight. SEM examination of the stents showed that the coating did not crack or delaminate either before or after stent expansion. Examination of the coating surface via AFM after elution of the drug indicated that PTx resides primarily in the SMA phase and provided information about the mechanism of PTx release. The addition of SMA altered the release profile of PTx from the base elastomer coatings. In addition, the presence of the SMA enabled tunable release of PTx from the elastomeric stent coatings, while preserving mechanical properties. Thermal analysis reveled no shift in the glass transition temperatures for any of the polymers at all drug loadings studied, indicating that the PTx is not miscible with any component of the polymer blend. An in vivo evaluation indicated that biocompatibility and vascular response results for SMA/SIBS-coated stents (without PTx) are similar to results for SIBS-only-coated and bare stainless steel control stents when implanted in the non-injured coronary arteries of common swine for 30 and 90 days.

  5. 40 CFR 721.6900 - Polymer of bisphenol A di-glyc-i-dal ether, substituted al-kenes, and but-a-diene.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of bisphenol A di-glyc-i-dal... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6900 Polymer of bisphenol A di-glyc-i... subject to reporting. (1) The chemical substances identified generically as polymer of bisphenol...

  6. 40 CFR 721.6900 - Polymer of bisphenol A di-glyc-i-dal ether, substituted al-kenes, and but-a-diene.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polymer of bisphenol A di-glyc-i-dal... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6900 Polymer of bisphenol A di-glyc-i... subject to reporting. (1) The chemical substances identified generically as polymer of bisphenol...

  7. 40 CFR 721.6900 - Polymer of bisphenol A di-glyc-i-dal ether, substituted al-kenes, and but-a-diene.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polymer of bisphenol A di-glyc-i-dal... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6900 Polymer of bisphenol A di-glyc-i... subject to reporting. (1) The chemical substances identified generically as polymer of bisphenol A...

  8. 40 CFR 721.6900 - Polymer of bisphenol A di-glyc-i-dal ether, substituted al-kenes, and but-a-diene.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polymer of bisphenol A di-glyc-i-dal... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6900 Polymer of bisphenol A di-glyc-i... subject to reporting. (1) The chemical substances identified generically as polymer of bisphenol A...

  9. 40 CFR 721.10400 - Oxirane, 2-ethyl-, polymer with oxirane, mono-C12-14-sec-alkyl ethers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxirane, 2-ethyl-, polymer with... Significant New Uses for Specific Chemical Substances § 721.10400 Oxirane, 2-ethyl-, polymer with oxirane...) The chemical substance identified as oxirane, 2-ethyl-, polymer with oxirane, mono-C12-14-sec-alkyl...

  10. 40 CFR 721.10401 - Oxirane, 2-ethyl-, polymer with oxirane, mono-C11-15-sec-alkyl ethers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxirane, 2-ethyl-, polymer with... Significant New Uses for Specific Chemical Substances § 721.10401 Oxirane, 2-ethyl-, polymer with oxirane...) The chemical substance identified as oxirane, 2-ethyl-, polymer with oxirane, mono C11-15-sec-alkyl...

  11. 40 CFR 721.6900 - Polymer of bisphenol A di-glyc-i-dal ether, substituted al-kenes, and but-a-diene.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polymer of bisphenol A di-glyc-i-dal... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6900 Polymer of bisphenol A di-glyc-i... subject to reporting. (1) The chemical substances identified generically as polymer of bisphenol A...

  12. Synthesis and characterizations of electrospun sulfonated poly (ether ether ketone) SPEEK nanofiber membrane

    NASA Astrophysics Data System (ADS)

    Hasbullah, N.; Sekak, K. A.; Ibrahim, I.

    2016-07-01

    A novel electrospun polymer electrolyte membrane (PEM) based on Sulfonated Poly (ether ether ketone) were prepared and characterized. The poly (ether ether ketone) PEEK was sulfonated using concentrated sulfuric acid at room temperature for 60 hours reaction time. The degree sulfonation (DS) of the SPEEK are 58% was determined by H1 NMR using area under the peak of the hydrogen shielding at aromatic ring of the SPEEK. Then, the functional group of the SPEEK was determined using Fourier transfer infrared (FTIR) showed O-H vibration at 3433 cm-1 of the sulfonated group (SO2-OH). The effect of the solvent and polymer concentration toward the electrospinning process was investigated which, the DMAc has electrospun ability compared to the DMSO. While, at 20 wt.% of the polymer concentration able to form a fine and uniform nanofiber, this was confirmed by FESEM that shown electrospun fiber mat SPEEK surface at nano scale diameter.

  13. 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.

  14. Effect of maleic anhydride treatment on the mechanical properties of sansevieria fiber/vinyl ester composites

    NASA Astrophysics Data System (ADS)

    Pradipta, Rangga; Mardiyati, Steven, Purnomo, Ikhsan

    2017-03-01

    Sanseviera trifasciata commonly called mother-in-law tongue also known as snake plant is native to Indonesia, India and Africa. Sansevieria is a new fiber in composite research and has showed promising properties as reinforcement material in polymer matrix composites. Chemical treatment on reinforcing fiber is crucial to reduce hydrophilic tendency and thus improve compatibility with the matrix. In this study, effect of maleic anhydride as chemical treatment on the mechanical properties of Sansevieria fiber/vinyl ester composite was investigated. Sansevieria fibers were immersed by using NaOH 3% for two hours at 100°C and then treated by using maleic anhydrate for two hours at 120°C. Composites were prepared by solution casting with various volume fractions of fiber; 0%, 2.5%, 5%, 7.5% and 10%. Actual density, volume fraction of void and mechanical properties of composite were conducted according to ASTM standard testing methods D792, D3171 and D3039. It was found that mechanical properties of composites increased as volume fractions of fiber was increased. The highest tensile strength and modulus of elasticity of composites were 57.45 MPa and 3.47 GPa respectively, obtained from composites with volume fraction of fiber 10%.

  15. Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketone)s and Linear Poly(ether ketone)s.

    PubMed

    Morikawa, Atsushi

    2016-02-16

    Poly(ether ether ketone) dendrimers and hyperbranched polymers were prepared from 3,5-dimethoxy-4'-(4-fluorobenzoyl)diphenyl ether and 3,5-dihydroxy-4'-(4-fluorobenzoyl)diphenyl ether through aromatic nucleophilic substitution reactions. 1-(tert-Butyldimethylsiloxy)-3,5-bis(4-fluorobenzoyl)benzene was polycondensed with bisphenols, followed by cleavage of the protective group to form linear poly(ether ketone)s having the same hydroxyl groups in the side chains as the chain ends of the dendrimer and hyperbranched polymers. Their properties, such as solubilities, reduced viscosities, and thermal properties, were compared with one another. Similar comparisons were also carried out among the corresponding methoxy group polymers, and the size of the molecules was shown to affect the properties.

  16. 40 CFR 721.10512 - Fatty acid maleic acid amides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid maleic acid amides (generic... Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical substance... fatty acid maleic acid amides (PMNs P-07-563 and P-07-564) are subject to reporting under this section...

  17. 40 CFR 721.10512 - Fatty acid maleic acid amides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid maleic acid amides (generic... Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical substance... fatty acid maleic acid amides (PMNs P-07-563 and P-07-564) are subject to reporting under this section...

  18. Thermoset epoxy polymers from renewable resources

    DOEpatents

    East, Anthony; Jaffe, Michael; Zhang, Yi; Catalani, Luiz H

    2009-11-17

    Novel thermoset epoxy polymers using the bisglycidyl ethers of anhydrosugars, such as isosorbide, isomannide, and isoidide, are disclosed. The bisglycidyl ethers are useful as substitutes for bisphenol A in the manufacture of thermoset epoxy ethers. The anhydrosugars are derived from renewable sources and the bisglycidyl ethers are not xenoestrogenic and the thermoset curing agents are likewise derived form renewable resources.

  19. Chemistry and adhesive properties of poly(arylene ether)s containing heterocyclic units

    NASA Technical Reports Server (NTRS)

    Connell, John W.

    1991-01-01

    Novel poly(arylene ether)s containing heterocyclic units were prepared, characterized, and evaluated as adhesives and composite matrices. The polymers were prepared by reacting a heterocyclic bisphenol with an activated aromatic dihalide in a polar aprotic solvent, using potassium carbonate. The polymerizations were generally carried out in N,N-dimethylacetamide at 155 C. In some cases, where the polymers were semicrystalline, higher temperatures and thus higher boiling solvents were necessary to keep the polymers in solution. Heterocyclic rings incorporated into the poly(arylene ether) backbone include phenylquinoxaline, phenylimidazole, benzimidazole, benzoxazole, 1,3,4-oxadiazole, and 1,2,4-triazole. The polymers were characterized by differential scanning calorimetry, solution viscosity, X-ray diffraction, thin film, and adhesive and (in some cases) composite properties. The glass transition temperatures, crystalline melt temperature, solubility, and mechanical properties varied depending upon the heterocyclic ring. The chemistry and properties of these materials are discussed.

  20. Simultaneous separation of chlorinated/brominated dioxins, polychlorinated biphenyls, polybrominated diphenyl ethers and their methoxylated derivatives from hydroxylated analogues on molecularly imprinted polymers prior to gas/liquid chromatography and mass spectrometry.

    PubMed

    Roszko, Marek; Szymczyk, Krystyna; Jędrzejczak, Renata

    2015-11-01

    Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are important contaminants in the environment. In recent years also polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) have been reported as emerging environmental stressors. It has been suggested that hydroxylated polybrominated biphenyl ethers (OH-BDEs) are important - may be even the most important - precursors of brominated dioxins/furans. The aim of this study was to develop a robust, time-saving analytical procedure to collectively separate in animal tissues such compounds prior to determination of individual substances with a gas/liquid chromatograph coupled to an ion trap/time-of-flight mass spectrometer (GC/IT-MS or UPLC/TOF-MS). Two OH-CB/BDE separation methods including alkaline extraction and molecularly imprinted polymers (MIP) were compared. Performance of both methods was validated: absolute recovery values were in the 47-90% range depending on the compound, while recovery relative standard deviation was below 20% in most cases. Levels of the studied compounds have been assessed in some real life samples.

  1. Preparation of extruded polyethylene/chitosan blends compatibilized with polyethylene-graft-maleic anhydride.

    PubMed

    Quiroz-Castillo, J M; Rodríguez-Félix, D E; Grijalva-Monteverde, H; Del Castillo-Castro, T; Plascencia-Jatomea, M; Rodríguez-Félix, F; Herrera-Franco, P J

    2014-01-30

    Novel films of polyethylene and chitosan were obtained using extrusion. These polymers have interesting properties, and processing them with methods that are of high use in the industry, such as the extrusion method, can have a significant effect on the potential applications of these materials. The individual materials were thermally characterized; after this, extruded films of low density polyethylene and chitosan mixtures were prepared with the addition of polyethylene-graft-maleic anhydride as a compatibilizer for the blends, and glycerol, as a plasticizer for chitosan. The use of compatibilizer and plasticizer agents improved the processability and compatibility of the mixtures, as well as their mechanical properties, as revealed by mechanical property measurements and scanning electron microscopy. It was possible to prepare blends with a maximum chitosan content of 20 wt%. The material stiffness increased with the increase of chitosan in the sample. FTIR studies revealed the existence of an interaction between the compatibilizer and chitosan.

  2. Maleic acid treatment of biologically detoxified corn stover liquor

    USDA-ARS?s Scientific Manuscript database

    Elimination of microbial and/or enzyme inhibitors from pretreated lignocellulose is critical for effective cellulose conversion and yeast fermentation of liquid hot-water (LHW) pretreated corn stover. In this study, xylan oligomers were hydrolyzed using either maleic acid or hemicellulases. Other so...

  3. 40 CFR 180.175 - Maleic hydrazide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...) The label of the pesticide formulation containing the food additive conforms to labeling registered by... (2) A food additive known as maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) may be present in...

  4. 40 CFR 180.175 - Maleic hydrazide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...) The label of the pesticide formulation containing the food additive conforms to labeling registered by... (2) A food additive known as maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) may be present in...

  5. 40 CFR 180.175 - Maleic hydrazide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...) The label of the pesticide formulation containing the food additive conforms to labeling registered by... (2) A food additive known as maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) may be present in...

  6. 40 CFR 180.175 - Maleic hydrazide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...) The label of the pesticide formulation containing the food additive conforms to labeling registered by... (2) A food additive known as maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) may be present in...

  7. 40 CFR 180.175 - Maleic hydrazide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...) The label of the pesticide formulation containing the food additive conforms to labeling registered by... (2) A food additive known as maleic hydrazide (1,2-dihydro-3,6-pyridazinedione) may be present in...

  8. [Simple analysis of maleic hydrazide in agricultural products by HPLC].

    PubMed

    Kobayashi, Maki; Nagayama, Toshihiro; Takano, Ichiro; Tamura, Yasuhiro; Tateishi, Yukinari; Tomizawa, Sanae; Kimura, Naoko; Kitayama, Kyoko; Saito, Kazuo

    2002-12-01

    A simplified HPLC determination method for maleic hydrazide in agricultural products was developed, and commercial agricultural crops were investigated. The homogenate of agricultural products was extracted with water. The crude extract was purified on an ACCUCAT Bond Elut extraction cartridge using water. Maleic hydrazide was analyzed by HPLC with UV detection (303 nm). The HPLC separation was performed on a ZORBAX SB-Aq column with acetonitrile-water-phosphoric acid(5:95:0.01) as the mobile phase. Recoveries of maleic hydrazide from 15 agricultural products fortified at 1.0 and 10 micrograms/g were in the ranges of 92.6-104.9% and 94.2-101.3%, respectively. The limit of detection was 0.5 microgram/g in samples. The proposed method was applied to the determination of 242 commercial vegetables and fruits. Maleic hydrazide was detected in 2 samples of imported onion at the levels of 4.9 and 7.2 micrograms/g.

  9. Polymers.

    ERIC Educational Resources Information Center

    Tucker, David C.

    1986-01-01

    Presents an open-ended experiment which has students exploring polymer chemistry and reverse osmosis. This activity involves construction of a polymer membrane, use of it in a simple osmosis experiment, and application of its principles in solving a science-technology-society problem. (ML)

  10. Polymers.

    ERIC Educational Resources Information Center

    Tucker, David C.

    1986-01-01

    Presents an open-ended experiment which has students exploring polymer chemistry and reverse osmosis. This activity involves construction of a polymer membrane, use of it in a simple osmosis experiment, and application of its principles in solving a science-technology-society problem. (ML)

  11. Polybrominated diphenyl ethers listed as Stockholm Convention POPs, other brominated flame retardants and heavy metals in e-waste polymers in Nigeria.

    PubMed

    Sindiku, Omotayo; Babayemi, Joshua; Osibanjo, Oladele; Schlummer, Martin; Schluep, Mathias; Watson, Alan; Weber, Roland

    2015-10-01

    Polybrominated diphenyl ethers (PBDEs) were the first brominated persistent organic pollutants (POPs) listed in the Stockholm Convention. Parties to the convention are currently establishing inventories for developing action plans for the environmentally sound management of PBDE-containing materials. The major use of commercial octabromodiphenyl ether (c-OctaBDE) has been in casings from cathode ray tube (CRT) TVs and computer monitors. Large quantities of used e-waste and electronic equipment have been exported to developing countries with Nigeria being a major importer in Africa. The casings from 382 TVs and computers imported from major world regions to Nigeria were sampled in backyards and waste dumps. The samples were screened with X-ray flourescence (XRF) for bromine and analysed by gas chromatography/ electron capture detection (GC/ECD) for brominated flame retardants (BFRs). A high proportion of the CRT casings (61 %) contained more than 10,000 ppm bromine from BFRs. Decabromodiphenyl ether (DecaBDE) was the major flame retardant used in TV sets and tetrabromobisphenol A (TBBPA) for computer CRTs.The screening suggests that average PBDE levels (of c-OctaBDE + DecaBDE) in Nigerian-stockpiled CRT casings were 1.1 % for TV and 0.13 % for PC CRTs. These are above the Restriction of Hazardous Substances (RoHS) limit and should be separated for RoHS compliant recycling. The Nigerian e-waste inventory of 237,000 t of CRT plastic would therefore contain approx. 594 t c-OctaBDE and 1,880 t of DecaBDE. In Nigeria, as for most developing countries, there is currently no adequate e-waste management, plastic separation or destruction capacity. The data highlight the urgent need to develop environmentally sound management for this large material flow.

  12. High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water insoluble Zirconium Fillers

    SciTech Connect

    McGrath, James E.; Baird, Donald G.

    2010-06-03

    Our research group has been engaged in the past few years in the synthesis of biphenol based partially disulfonated poly(arylene ether sulfone) random copolymers as potential PEMs. This series of polymers are named as BPSH-xx, where BP stands for biphenol, S stands for sulfonated, H stands for acidified and xx represents the degree of disulfonation. All of these sulfonated copolymers phase separate to form nano scale hydrophilic and hydrophobic morphological domains. The hydrophilic phase containing the sulfonic acid moieties causes the copolymer to absorb water. Water confined in hydrophilic pores in concert with the sulfonic acid groups serve the critical function of proton (ion) conduction and water transport in these systems. Both Nafion and BPSH show high proton conductivity at fully hydrated conditions. However proton transport is especially limited at low hydration level for the BPSH random copolymer. It has been observed that the diffusion coefficients of both water and protons change with the water content of the pore. This change in proton and water transport mechanisms with hydration level has been attributed to the solvation of the acid groups and the amount of bound and bulk-like water within a pore. At low hydration levels most of the water is tightly associated with sulfonic groups and has a low diffusion coefficient. This tends to encourage isolated domain morphology. Thus, although there may be significant concentrations of protons, the transport is limited by the discontinuous morphological structure. Hence the challenge lies in how to modify the chemistry of the polymers to obtain significant protonic conductivity at low hydration levels. This may be possible if one can alter the chemical structure to synthesize nanophase separated ion containing block copolymers. Unlike the BPSH copolymers, where the sulfonic acid groups are randomly distributed along the chain, the multiblock copolymers will feature an ordered sequence of hydrophilic and

  13. Anaerobic biodegradation of ether compounds by ether bond-cleaving bacteria and methanogenic consortia

    SciTech Connect

    Dwyer, D.F.

    1989-01-01

    Ether compounds are manufactured for use in nonionic detergents, plastics, pesticides and other products and occur as toxic organic compounds, the most famous being tetrachlorodibenzo-p-dioxin. Ether compounds were considered recalcitrant to anaerobic biodegradation due to the lack of an appropriate oxidant for ether bond-cleavage in reducing environments. Many of these compounds reside in anaerobic environments or are exposed to anaerobic waste treatment processes. Thus, it is of interest to identify: (i) whether ether compounds are anaerobically biodegradable, (ii) the anaerobic microorganisms able to degrade these compounds, and (iii) the mechanism(s) of anaerobic ether bond-cleavage. The ether bonds of polyethylene glycol (PEG; HO-(CH{sub 2}CH{sub 2}-O-){sub n}H), phenyl ether ((C{sub 6}H{sub 5}){sub 2}O), and dibenzo-p-dioxin ((C{sub 6}H{sub 4}){sub 2}O{sub 2}) were shown to be degraded in methanogenic consortia enriched with these compounds and polyethoxylate (nonionic) surfactants as substrates. Two anaerobic microorganisms which used PEGs as sole substrates were isolated and characterized. Desulfovibrio desulfuricans strain DG2 degraded the monomer ethylene glycol and oligomers up to tetraethylene glycol (HO-(CH{sub 2}CH{sub 2}-O-){sub 4}H) in length. Bacteroides sp. strain PG1 degraded diethylene glycol and all other polymer lengths of PEG. PEGs were degraded by Bacteroides sp. strain PG1 via an external depolymerization which was either a hydrolytic or a reductive cleavage of the ether bond. The ether bond of diaryl ethers was apparently cleaved by a reductive mechanism which produced benzene and phenol as products from phenyl ether degradation and benzene and, by indirect analysis, catechol from dibenzo-dioxin.

  14. Particleboard made from waste paper treated with maleic anhydride.

    PubMed

    Nourbakhsh, Amir; Ashori, Alireza

    2010-01-01

    This study evaluates the usage of waste newspaper as a supplement raw material for laboratory-made single-layer particle-boards. The boards were made of various ratios (75/25, 50/50, 25/75 and 0/100) of waste paper flakes to wood particles mixtures (wt/wt). The effects of press temperature and maleic anhydride on the properties of the boards were determined. Evaluated properties were modulus of rupture, modulus of elasticity, internal bonding strength, and thickness swelling. Panels made from waste newspaper satisfied the modulus of rupture, modulus of elasticity and internal bonding strength requirements of European Norms standards. Performing a statistical analysis of the results, press temperature and maleic anhydride content were found to be positively effective on the mechanical properties at a 95% confidence level. The results from this study indicated that technically waste paper could be a potential substitute material for particleboard manufacture.

  15. Purification of aqueous cellulose ethers

    SciTech Connect

    Bartscherer, K.A.; de Pablo, J.J.; Bonnin, M.C.; Prausnitz, J.M.

    1990-07-01

    Manufacture of cellulose ethers usually involves high amounts of salt by-products. For application of the product, salt must be removed. In this work, we have studied the injection of high-pressure CO{sub 2} into an aqueous polymer-salt solution; we find that upon addition of isopropanol in addition to CO{sub 2}, the solution separates into two phases. One phase is rich in polymer and water, and the other phase contains mostly isopropanol, water and CO{sub 2}. The salt distributes between the two phases, thereby offering interesting possibilities for development of a new purification process for water-soluble polymers. This work presents experimental phase-equilibrium data for hydroxyethyl cellulose and sodium carboxymethyl cellulose with sodium acetate and potassium sulfate, respectively, in the region 40{degree}C and 30 to 80 bar. Based on these data, we suggest a process for the manufacture and purification of water-soluble cellulose ethers. 15 refs., 14 figs., 9 tabs.

  16. Effect of bioadhesive polymers, sodium salicylate, polyoxyethylene-9-lauryl ether, and method of preparation on the relative hypoglycemia produced by insulin enteric-coated capsules in diabetic beagle dogs.

    PubMed

    Hosny, E A; al-Shora, H I; Elmazar, M M A

    2002-05-01

    The hypoglycemic effect of oral insulin capsules coated with pH-dependent Eudragit S100 and containing various absorption promoters was studied in hyperglycemic beagle dogs. The absorption enhancers used were bioadhesive polymers, sodium salicylate, and non-ionic surfactants. A comparative study of the bioadhesive polymers, polycarbophil (PC), hydroxypropyl methylcellulose (HPMC), and carbopol 934 in insulin-coated capsules revealed no significant difference between the insulin capsules containing these polymers, giving relative hypoglycemia (RH) values ranging from 4.3 +/- 2.3% to 6.5 +/- 5.1%. It was also found that the method of preparation of the mixture of the bioadhesive polymer with insulin either by physical mixing or freeze-drying did not affect the RH values obtained. Sodium salicylate, when used in insulin enteric-coated capsules (50 mg) mixed with insulin as a physical mixture, or prepared by wet granulation using 10% polyvinyl pyrollidone (PVP), or by freeze-drying, produced RH values ranging from 7.3 +/- 2.9% to 9.4 +/- 3.7%. When sodium salicylate (100 mg) was used with insulin in freeze-dried granules an RH value of 10 +/- 2.6% was produced. As the dose of insulin increased from 6 to 9 U/kg, the area under curve (AUC) of the enteric-coated capsules containing 50 mg sodium salicylate increased from 73.2 +/- 27.8% to 121.4 +/- 102.7% reduction, but the RH did not change significantly. Insulin capsules containing polyoxyethylene-9-lauryl ether (POELE) used in its optimum concentration (2%), found in these experiments, produced RH of 9.5 +/- 6.8% when prepared as granules by wetting with a few drops of absolute alcohol in the presence of PC (50 mg). Insulin capsules containing lower (1%) or higher (3%) concentrations of POELE and prepared with PC, 50 mg by wet granulation produced lower RH of about 6%. The enteric-coated oral insulin capsules containing insulin (6 or 9 U/kg) and sodium salicylate (50 mg) as an absorption promoter, together with the

  17. Effect of bio-adhesive polymers, sodium salicylate, polyoxyethylene-9-lauryl ether and method of preparation on the relative hypoglycemia produced by insulin enteric coated capsules in diabetic beagle dogs.

    PubMed

    Hosny, E A; al-Shora, H I; el-mazar, M M A

    2002-01-01

    The hypoglycemic effect of oral insulin capsules coated with pH-dependent Eudragit S100 and containing various absorption promoters was studied in hyperglycemic beagle dogs. The absorption enhancers used were bio-adhesive polymers, sodium salicylate and non-ionic surfactants. A comparative study of the bio-adhesive polymers, polycarbophil (PC), hydroxypropyl methylcellulose (HPMC) and carbopol 934 in insulin coated capsules, revealed no significant difference between the insulin capsules containing these polymers giving a relative hypoglycemia (RH) values ranged from 4.3 +/- 2.3% to 6.5 +/- 5.1%. It was also found that the method of preparation of the mixture of the bio-adhesive polymer with insulin either by physical mixing or freeze-drying did not affect the RH values obtained. Sodium salicylate, when used in insulin enteric coated capsules (50 mg) mixed with insulin as a physical mixture or prepared by wet granulation using 10% polyvinyl pyrollidone (PVP) or by freeze drying, produced RH values ranged from 7.3 +/- 2.9 to 9.4 +/- 3.7%. When sodium salicylate (100 mg) was used with insulin in freeze-dried granules an RH value of 10 +/- 2.6% was produced. As the dose of insulin increased from 6 to 9 U/kg, the AUC of the enteric coated capsules containing 50 mg sodium salicylate increased from 73.2 +/- 27.8 to 121.4 +/- 102.7% reduction but the RH id not significantly change. Insulin capsules containing polyoxyethylene-9-lauryl ether (POELE) used in its optimum concentration (2%), found in these experiments, produced a RH of 9.5 +/- 6.8% when prepared as granules by wetting with few drops of absolute alcohol in presence of PC (50 mg). Insulin capsules containing lower (1%) or higher (3%) concentrations of POELE and prepared with PC, 50 mg by wet granulation produced lower RH of about 6%. The enteric coated oral insulin capsules containing insulin (6 or 9 U/kg) and sodium salicylate (50 mg) as an absorption promoter together with the bioadhesive polymer polycarbophil

  18. Design of cycloolefin-maleic-anhydride resist for ArF lithography

    NASA Astrophysics Data System (ADS)

    Jung, Jae Chang; Bok, Cheol-Kyu; Baik, Ki-Ho

    1998-06-01

    Recently reported ArF positive photoresists can be classified into three groups: derivative methacrylate copolymers (methacrylate resist), methacrylate copolymers functionalized with pendant alicyclic moieties (alicyclic resist), and cycloolefin-maleic anhydride copolymers (cycloolefin resist). Each system has its own advantages and drawbacks from the viewpoint of lithographic properties. Methacrylate resist has been used for the assessment of ArF lens performance. However, it is hard to apply them in real device process because of its low plasma-etch resistance. Previous studies have reported that alicyclic resists possess adequate etch resistance with the help of cyclic carbon units, however these resists show poor adhesion and seldom dissolve in 2.38% TMAH developer. The cycloolefin resists will be good candidate for addressing the trade-off between etch resistance and requisite material properties for lithographic performance because these resists, unlike methacrylate-based resists, contain large quantities of alicyclic structures directly in the polymer backbone and such properties as dissolution, adhesion can be readily controlled by incorporation of -COOH and -OH functional groups into cycloolefin structures. We have synthesized poly(2-hydroxylethyl 5-norbornene-2-carboxylate/t-butyl 5- norbornene-2-carboxylate/5-norbornene-2-carboxylic acid/maleic anhydride; HNC/BNC/NC/MA) resists with a variety of functional groups and obtained lithographic performance using ArF stepper (0.6 NA). In this paper, we will describe the basic idea for designing of the novel olefin resist and demonstrate lithographic capabilities, especially in terms of process window for 130 nm feature. We believe that both off-axis illumination and bottom anti-reflective technologies should be applied in order to obtain wider process window.

  19. Advanced hybrid fluoropolymers from the cycloaddition of aryl trifluorovinyl ethers

    NASA Astrophysics Data System (ADS)

    Ligon, S. Clark, Jr.

    This dissertation discusses the synthesis of aryl trifluorovinyl ethers and their cycloaddition polymerization to give perfluorocyclobutyl (PFCB) polymers. To explore the stereochemistry of these polymers, simple monomfunctional aryl trifluorovinyl ethers were dimerized and the resultant cis and trans isomers were separated. Differences in structure help to improve understanding of the amorphous nature of the bulk PFCB polymeric material. To apply this knowledge, crown ether containing perfluorocyclobutyl (PFCB) polymers were synthesized for use in lithium ion battery applications. While poor solubility has hindered further development of these materials, slight modifications to structure may provide a solution. Also described is a fluorinated aryl vinyl ether and its attempted copolymerization with chlorotrifluoroethylene. While this copolymerization did not yield the desired materials, novel semifluorinated phenol precursors have been utilized in reactions with carboxylic acids to give polyesters and most recently with phosgene like species to give polycarbonates. Next, PFCB polymers were post functionalized with fluoroalkyl tethers to improve oleophobicity and hydrophobicity without decreasing thermal stability or optical clarity. In addition, various silica nanostructures were functionalized with aryl trifluorovinyl ethers. This includes the reaction of aryl silanes to give trifluorovinyl ether functional POSS and their polymerization to provide PFCB hybrid materials. Silane coupling agents were also used to functionalize colloidal silica and fumed silica nanoparticles. These procedures allow excellent dispersion of the silica nanoparticles throughout the fluoropolymer matrix. Finally, the reaction of aryl trifluorovinyl ether with nonfluorinated alkenes and alkynes was explored. In these reactions, the fluorinated olefin adds with the hydrocarbon olefin to give semifluorinated cyclobutanes (SFCB) and with the alkyne to give semifluorinated cyclobutene. The

  20. Profiling transcriptomes of human SH-SY5Y neuroblastoma cells exposed to maleic acid

    PubMed Central

    Wang, Chia-Chi; Lin, Yin-Chi; Cheng, Yin-Hua

    2017-01-01

    Background Maleic acid is a multi-functional chemical widely used in the field of industrial chemistry for producing food additives and food contact materials. As maleic acid may contaminate food by the release from food packages or intentional addition, it raises the concern about the effects of excessive dietary exposure to maleic acid on human health. However, the influence of maleic acid on human health has not been thoroughly studied. In silico toxicogenomics approaches have found the association between maleic acid and nervous system disease in human. The aim of this study is to experimentally explore the effects of maleic acid on human neuronal cells. Methods A microarray-based transcriptome profiling was performed to offer a better understanding of the effects of maleic acid on human health. Gene expression profiles of human neuroblastoma SH-SY5Y cells exposed to three concentrations of maleic acid (10, 50, and 100 μM) for 24 h were analyzed. Genes which were differentially expressed in dose-dependent manners were identified and further analyzed with an enrichment analysis. The expression profile of selected genes related to the inferred functional changes was validated using quantitative polymerase chain reaction (qPCR). Specific fluorescence probes were applied to observe the inferred functional changes in maleic acid-treated neuronal cells. Results A total of 316 differentially expressed genes (141 upregulated and 175 downregulated) were identified in response to the treatment of maleic acid. The enrichment analysis showed that DNA binding and metal ion binding were the significant molecular functions (MFs) of the neuronal cells affected by maleic acid. Maleic acid exposure decreased the expression of genes associated with calcium and thiol levels of the cells in a dose-dependent manner. The levels of intracellular calcium and thiol levels were also affected by maleic acid dose-dependent. Discussion The exposure to maleic acid is found to decrease the

  1. Poly(arlyene ether sulfone) based semi-interpenetrating polymer network membranes containing cross-linked poly(vinyl phosphonic acid) chains for fuel cell applications at high temperature and low humidity conditions

    NASA Astrophysics Data System (ADS)

    Kim, Kihyun; Heo, Pilwon; Ko, Taeyun; Kim, Ki-hyun; Kim, Sung-Kon; Pak, Chanho; Lee, Jong-Chan

    2015-10-01

    Semi-interpenetrating polymer network (semi-IPN) membranes are prepared by in-situ casting and thermal-initiated radical polymerization of vinyl phosphonic acid (VPA) and bis(2-(methacryloyloxy)ethyl) phosphate (BMAEP) in N,N-dimethylacetamide solutions of sulfonated poly(arylene ether sulfone) (SPAES). The incorporation of VPA units into the SPAES membranes improves proton conductivity especially at high temperature and low humidity conditions. In addition the cross-linker, BMAEP, prevents the decrease of the mechanical and chemical stabilities by the aliphatic linear poly(vinyl phosphonic acid) chains in the semi-IPN membranes, and furthermore the phosphonic acid group in BMAEP can prevent the decrease of the proton conductivity by the formation of cross-linked structures. Therefore, the resulting semi-IPN membranes show high proton conductivities up to 15 mS cm-1 at 120 °C and 40% RH. The fuel cell performance (187 mW cm-2 at 120 °C and 40% RH) of membrane-electrode assembly (MEA) from the semi-IPN membrane is found to be superior to that (145 mW cm-2 at 120 °C and 40% RH) of MEA from the SPAES membrane. The durability test result at the operating conditions indicates that the semi-IPN membrane is electrochemically very stable maintaining the low hydrogen cross-over and high power densities.

  2. Tailoring polymer properties with layered silicates

    NASA Astrophysics Data System (ADS)

    Xu, Liang

    Polymer layered silicate nanocomposites have found widespread applications in areas such as plastics, oil and gas production, biomedical, automotive and information storage, but their successful commercialization critically depends on consistent control over issues such as complete dispersion of layered silicate into the host polymer and optimal interaction between the layered silicates and the polymers. Polypropylene is a commercially important polymer but usually forms intercalated structures with organically modified layered silicate upon mixing, even it is pre-treated with compatibilizing agent such as maleic anhydride. In this work, layered silicate is well dispersed in ammonium modified polypropylene but does not provide sufficient reinforcement to the host polymer due to poor interactions. On the other hand, interactions between maleic anhydride modified polypropylene and layered silicate are fine tuned by using a small amount of maleic anhydride and mechanical strength of the resultant nanocomposites are significantly enhanced. In particular, the melt rheological properties of layered silicate nanocomposites with maleic anhydride functionalized polypropylene are contrasted to those based on ammonium-terminated polypropylene. While the maleic anhydride treated polypropylene based nanocomposites exhibit solid-like linear dynamic behavior, consistent with the formation of a long-lived percolated nanoparticle network, the single-end ammonium functionalized polypropylene based nanocomposites demonstrated liquid-like behavior at comparable montmorillonite concentrations. The differences in the linear viscoelasticity are attributed to the presence of bridging interaction in maleic anhydride functionalized nanocomposites, which facilitates formation of a long-lived silicate network mediated by physisorbed polymer chains. Further, the transient shear stress of the maleic anhydride functionalized nanocomposites in start-up of steady shear is a function of the shear

  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. HematoPorphyrin Monomethyl Ether polymer contrast agent for ultrasound/photoacoustic dual-modality imaging-guided synergistic high intensity focused ultrasound (HIFU) therapy

    NASA Astrophysics Data System (ADS)

    Yan, Sijing; Lu, Min; Ding, Xiaoya; Chen, Fei; He, Xuemei; Xu, Chunyan; Zhou, Hang; Wang, Qi; Hao, Lan; Zou, Jianzhong

    2016-08-01

    This study is to prepare a hematoporphyrin monomethyl ether (HMME)-loaded poly(lactic-co-glycolic acid) (PLGA) microcapsules (HMME/PLGA), which could not only function as efficient contrast agent for ultrasound (US)/photoacoustic (PA) imaging, but also as a synergistic agent for high intensity focused ultrasound (HIFU) ablation. Sonosensitizer HMME nanoparticles were integrated into PLGA microcapsules with the double emulsion evaporation method. After characterization, the cell-killing and cell proliferation-inhibiting effects of HMME/PLGA microcapsules on ovarian cancer SKOV3 cells were assessed. The US/PA imaging-enhancing effects and synergistic effects on HIFU were evaluated both in vitro and in vivo. HMME/PLGA microcapsules were highly dispersed with well-defined spherical morphology (357 ± 0.72 nm in diameter, PDI = 0.932). Encapsulation efficiency and drug-loading efficiency were 58.33 ± 0.95% and 4.73 ± 0.15%, respectively. The HMME/PLGA microcapsules remarkably killed the SKOV3 cells and inhibited the cell proliferation, significantly enhanced the US/PA imaging results and greatly enhanced the HIFU ablation effects on ovarian cancer in nude mice by the HMME-mediated sono-dynamic chemistry therapy (SDT). HMME/PLGA microcapsules represent a potential multifunctional contrast agent for HIFU diagnosis and treatment, which might provide a novel strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy for cancers by SDT in clinic.

  6. HematoPorphyrin Monomethyl Ether polymer contrast agent for ultrasound/photoacoustic dual-modality imaging-guided synergistic high intensity focused ultrasound (HIFU) therapy

    PubMed Central

    Yan, Sijing; LU, Min; Ding, Xiaoya; Chen, Fei; He, Xuemei; Xu, Chunyan; Zhou, Hang; Wang, Qi; Hao, Lan; Zou, Jianzhong

    2016-01-01

    This study is to prepare a hematoporphyrin monomethyl ether (HMME)-loaded poly(lactic-co-glycolic acid) (PLGA) microcapsules (HMME/PLGA), which could not only function as efficient contrast agent for ultrasound (US)/photoacoustic (PA) imaging, but also as a synergistic agent for high intensity focused ultrasound (HIFU) ablation. Sonosensitizer HMME nanoparticles were integrated into PLGA microcapsules with the double emulsion evaporation method. After characterization, the cell-killing and cell proliferation-inhibiting effects of HMME/PLGA microcapsules on ovarian cancer SKOV3 cells were assessed. The US/PA imaging-enhancing effects and synergistic effects on HIFU were evaluated both in vitro and in vivo. HMME/PLGA microcapsules were highly dispersed with well-defined spherical morphology (357 ± 0.72 nm in diameter, PDI = 0.932). Encapsulation efficiency and drug-loading efficiency were 58.33 ± 0.95% and 4.73 ± 0.15%, respectively. The HMME/PLGA microcapsules remarkably killed the SKOV3 cells and inhibited the cell proliferation, significantly enhanced the US/PA imaging results and greatly enhanced the HIFU ablation effects on ovarian cancer in nude mice by the HMME-mediated sono-dynamic chemistry therapy (SDT). HMME/PLGA microcapsules represent a potential multifunctional contrast agent for HIFU diagnosis and treatment, which might provide a novel strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy for cancers by SDT in clinic. PMID:27535093

  7. 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.

  8. Removal of copper ions from aqueous solution by the sodium salt of the maleic acid-allylpropionate-styrene terpolymer.

    PubMed

    Akperov, Elchin; Akperov, Oktay; Jafarova, Elnara; Gafarova, Sabahiye

    2016-09-01

    The sodium salt of the maleic acid-allylpropionate-styrene terpolymer was used for recovery of copper ions from aqueous solution. Effects of contact time, sorbent weight and initial Cu(2+) ion concentrations on removal efficiency were tested. The maximum experimental sorption capacity of the sorbent for copper ions is 0.71 g g(-1). The sorption isotherm of copper ions onto a prepared polymer sorbent has been studied and the equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The adsorption isotherm data showed that copper ions adsorption on the sorbent was better fitted to the Langmuir isotherm model. The Lagergren pseudo-first- and pseudo-second-order kinetic models were applied to examine the kinetics of the copper ions sorption by the synthesized sorbent. The kinetic data are best described by the pseudo-second-order model. The calculated value of the maximum sorption capacity by the pseudo-second-order equation (0.62 g g(-1)) corresponds well with its experimentally found value (0.71 g g(-1)). Considering the obtained kinetic data, and the Fourier transform infrared spectroscopy (FT-IR) and UV-vis spectra of the sorbent after the sorption, it is possible to come to the conclusion that during the sorption process Cu(2+) ions enter a complex with the carboxylic groups of the maleic acid units of the sorbent.

  9. 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.

  10. Properties of styrene-maleic anhydride copolymers containing wood-based fillers

    Treesearch

    John Simonsen; Rodney Jacobson; Roger Rowell

    1998-01-01

    Recycled newsprint (ONP) and dry process aspen fiber were combined with styrene maleic anhydride (SMA) copolymers containing either 7 or 14 percent maleic anhydride. The fiber-filled SMA composites were equivalent or superior to unfilled SMA in strength, stiffness, and notched Izod impact strength. ONP performed surprisingly well as a filler. Unnotched Izod impact...

  11. Multiple functionalities of polyfluorene grafted with metal ion-intercalated crown ether as an electron transport layer for bulk-heterojunction polymer solar cells: optical interference, hole blocking, interfacial dipole, and electron conduction.

    PubMed

    Liao, Sih-Hao; Li, Yi-Lun; Jen, Tzu-Hao; Cheng, Yu-Shan; Chen, Show-An

    2012-09-05

    We present a novel electron transport (ET) polymer composed of polyfluorene grafted with a K(+)-intercalated crown ether involving six oxygen atoms (PFCn6:K(+)) for bulk-heterojunction polymer solar cells (PSCs) with regioregular poly(3-hexylthiophene) (P3HT) as the donor and indene-C(60) bisadduct (ICBA) or indene-[6,6]-phenyl-C(61)-butyric acid methyl ester (IPCBM) as the acceptor in the active layer and with Al or Ca/Al as the cathode. A remarkable improvement in the power conversion efficiency (PCE) (measured in air) was observed upon insertion of this ET layer, which increased the PCE from 5.78 to 7.5% for a PSC with ICBA and Ca/Al (5.53 to 6.63% with IPCBM) and from 3.87 to 6.88% for a PSC with ICBA and Al (3.06 to 6.21% with IPCBM). This ET layer provides multiple functionalities: (1) it generates an optical interference effect for redistribution of light intensity as an optical spacer; (2) it blocks electron-hole recombination at the interface with the cathode; (3) it forms an interfacial dipole that promotes the vacuum level of the cathode metal; and (4) it enhances electron conduction, as evidenced by (1) the increase in total absorption of 1:1 w/w P3HT:ICBA by a factor of 1.3; (2) the reduction in the hole-only current density profile by a factor of 3.3 at 2.0 × 10(5) V/cm; (3) the decrease of 0.81 eV in the work function of Al from 4.28 to 3.47 eV, as determined by UV photoelectron spectroscopy; and (4) the decrease in the series resistance of PSCs with ICBA and Al by a factor of 4.5, as determined by the current-voltage characteristic under dark conditions; respectively. The PSC of 7.5% is the highest among the reported values for PSC systems with the simplest donor polymer, P3HT.

  12. 21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section 872.3490 Food and Drugs... maleic acid calcium-sodium double salt denture adhesive. (a) Identification. A carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

  13. 21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section 872.3490 Food and Drugs... maleic acid calcium-sodium double salt denture adhesive. (a) Identification. A carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

  14. 21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section 872.3490 Food and Drugs... maleic acid calcium-sodium double salt denture adhesive. (a) Identification. A carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

  15. 21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section 872.3490 Food and Drugs... maleic acid calcium-sodium double salt denture adhesive. (a) Identification. A carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

  16. Molecular Engineering of Liquid Crystalline Polymers by Living Polymerization. 9. Living Cationic Polymerization of 5-((4-Cyano-4’-Biphenyl) oxy)pentyl Vinyl Ethers and 7-((4-Cyano-4’-Biphenyl)oxy)heptyl Vinyl Ether, and the Mesomorphic Behavior of the Resulting Polymers

    DTIC Science & Technology

    1990-10-16

    REPRODUCEDO A"? GOVERPNME14T EXPENSE AD 2979 T.pOCUMENTATION PiA,4j -* L E is RkEPoRT SC-R-Y CLA i.ATiO It lb RESTRiCTovE MARKiNGS 26 SECURITYr C...PROCuREMENT INSTRUMENT IDENTIFICATION NUMBER OGN IZAT7ION If picb & L . AZORE SS (Ciay, Sr, arad ZIP Coot) 10 SOURCE OF ’UNDING NUMBERS office of Naval...mesomorphic behavior of poly( L .-.) and poly(6-_7) is discussed and compared to that of 5-[(4-cyano-4’- biphenyl)oxy]pentyl ethyl ether (8)and 7-f (4-cyano

  17. Recent developments in high temperature organic polymers

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.

    1991-01-01

    Developments in high temperature organic polymers during the last 5 years with major emphasis on polyimides and poly(arylene ether)s are discussed. Specific polymers or series of polymers have been selected to demonstrate unique properties or the effect chemical structure has upon certain properties. This article is not intended to be a comprehensive review of high temperature polymer advancements during the last 5 years.

  18. Maleic acid treatment of biologically detoxified corn stover liquor.

    PubMed

    Kim, Daehwan; Ximenes, Eduardo A; Nichols, Nancy N; Cao, Guangli; Frazer, Sarah E; Ladisch, Michael R

    2016-09-01

    Elimination of microbial and enzyme inhibitors from pretreated lignocellulose is critical for effective cellulose conversion and yeast fermentation of liquid hot water (LHW) pretreated corn stover. In this study, xylan oligomers were hydrolyzed using either maleic acid or hemicellulases, and other soluble inhibitors were eliminated by biological detoxification. Corn stover at 20% (w/v) solids was LHW pretreated LHW (severity factor: 4.3). The 20% solids (w/v) pretreated corn stover derived liquor was recovered and biologically detoxified using the fungus Coniochaeta ligniaria NRRL30616. After maleic acid treatment, and using 5 filter paper units of cellulase/g glucan (8.3mg protein/g glucan), 73% higher cellulose conversion from corn stover was obtained for biodetoxified samples compared to undetoxified samples. This corresponded to 87% cellulose to glucose conversion. Ethanol production by yeast of pretreated corn stover solids hydrolysate was 1.4 times higher than undetoxified samples, with a reduction of 3h in the fermentation lag phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A simple and rapid approach to evaluate the in vitro in vivo role of release controlling agent ethyl cellulose ether derivative polymer.

    PubMed

    Akhlaq, Muhammad; Khan, Gul Majid; Jan, Syed Umer; Wahab, Abdul; Hussain, Abid; Nawaz, Asif; Abdelkader, Hamdy

    2014-11-01

    Diclofenac sodium (DCL-Na) conventional oral tablets exhibit serious side effects when given for a longer period leading to noncompliance. Controlled release matrix tablets of diclofenac sodium were formulated using simple blending (F-1), solvent evaporation (F-2) and co-precipitation techniques (F-3). Ethocel® Standard 7 FP Premium Polymer (15%) was used as a release controlling agent. Drug release study was conducted in 7.4 pH phosphate buffer solutions as dissolution medium in vitro. Pharmacokinetic parameters were evaluated using albino rabbits. Solvent evaporation technique was found to be the best release controlling technique thereby prolonging the release rate up to 24 hours. Accelerated stability studies of the optimized test formulation (F-2) did not show any significant change (p<0.05) in the physicochemical characteristics and release rate when stored for six months. A simple and rapid method was developed for DCL-Na active moiety using HPLC-UV at 276nm. The optimized test tablets (F-2) significantly (p<0.05) exhibited peaks plasma concentration (cmax=237.66±1.98) and extended the peak time (tmax=4.63±0.24). Good in-vitro in vivo correlation was found (R(2)=0.9883) against drug absorption and drug release. The study showed that once-daily controlled release matrix tablets of DCL-Na were successfully developed using Ethocel® Standard 7 FP Premium.

  20. Crown ethers in graphene

    DOE PAGES

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; ...

    2014-11-13

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basicmore » structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.« less

  1. Crown ethers in graphene

    SciTech Connect

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; Gallego, Nidia C.; Pantelides, Sokrates T.; Pennycook, Stephen J.; Moyer, Bruce A.; Chisholm, Matthew F.

    2014-11-13

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.

  2. Crown ethers in graphene.

    PubMed

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I; Gallego, Nidia C; Pantelides, Sokrates T; Pennycook, Stephen J; Moyer, Bruce A; Chisholm, Matthew F

    2014-11-13

    Crown ethers are at their most basic level rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted attention for their ability to selectively incorporate various atoms or molecules within the cavity formed by the ring. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity. Here we present atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar. First-principles calculations show that the close similarity of the structures should also extend to their selectivity towards specific metal cations. Crown ethers in graphene offer a simple environment that can be systematically tested and modelled. Thus, we expect that our finding will introduce a new wave of investigations and applications of chemically functionalized graphene.

  3. Nanoparticle self-assembly in mixtures of phospholipids with styrene/maleic acid copolymers or fluorinated surfactants

    NASA Astrophysics Data System (ADS)

    Vargas, Carolyn; Arenas, Rodrigo Cuevas; Frotscher, Erik; Keller, Sandro

    2015-12-01

    Self-assembling nanostructures in aqueous mixtures of bilayer-forming lipids and micelle-forming surfactants are relevant to in vitro studies on biological and synthetic membranes and membrane proteins. Considerable efforts are currently underway to replace conventional detergents by milder alternatives such as styrene/maleic acid (SMA) copolymers and fluorinated surfactants. However, these compounds and their nanosized assemblies remain poorly understood as regards their interactions with lipid membranes, particularly, the thermodynamics of membrane partitioning and solubilisation. Using 19F and 31P nuclear magnetic resonance spectroscopy, static and dynamic light scattering, and isothermal titration calorimetry, we have systematically investigated the aggregational state of a zwitterionic bilayer-forming phospholipid upon exposure to an SMA polymer with a styrene/maleic acid ratio of 3 : 1 or to a fluorinated octyl phosphocholine derivative called F6OPC. The lipid interactions of SMA(3 : 1) and F6OPC can be thermodynamically conceptualised within the framework of a three-stage model that treats bilayer vesicles, discoidal or micellar nanostructures, and the aqueous solution as distinct pseudophases. The exceptional solubilising power of SMA(3 : 1) is reflected in very low membrane-saturating and solubilising polymer/lipid molar ratios of 0.10 and 0.15, respectively. Although F6OPC saturates bilayers at an even lower molar ratio of 0.031, this nondetergent does not solubilise lipids even at >1000-fold molar excess, thus highlighting fundamental differences between these two types of mild membrane-mimetic systems. We rationalise these findings in terms of a new classification of surfactants based on bilayer-to-micelle transfer free energies and discuss practical implications for membrane-protein research.Self-assembling nanostructures in aqueous mixtures of bilayer-forming lipids and micelle-forming surfactants are relevant to in vitro studies on biological and

  4. Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride.

    PubMed

    Carrasco-Guigón, Fernando Javier; Rodríguez-Félix, Dora Evelia; Castillo-Ortega, María Mónica; Santacruz-Ortega, Hisila C; Burruel-Ibarra, Silvia E; Encinas-Encinas, Jose Carmelo; Plascencia-Jatomea, Maribel; Herrera-Franco, Pedro Jesus; Madera-Santana, Tomas Jesus

    2017-01-25

    The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA) as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP) matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films.

  5. Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride

    PubMed Central

    Carrasco-Guigón, Fernando Javier; Rodríguez-Félix, Dora Evelia; Castillo-Ortega, María Mónica; Santacruz-Ortega, Hisila C.; Burruel-Ibarra, Silvia E.; Encinas-Encinas, Jose Carmelo; Plascencia-Jatomea, Maribel; Herrera-Franco, Pedro Jesus; Madera-Santana, Tomas Jesus

    2017-01-01

    The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA) as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP) matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films. PMID:28772464

  6. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Morphological control of calcium oxalate particles in the presence of poly-(styrene-alt-maleic acid)

    NASA Astrophysics Data System (ADS)

    Yu, Jiaguo; Tang, Hua; Cheng, Bei; Zhao, Xiujian

    2004-10-01

    Calcium oxalate (CaOx) particles exhibiting different shapes and phase structures were fabricated by a simple precipitation reaction of sodium oxalate with calcium chloride in the absence and presence of poly-(styrene-alt-maleic acid) (PSMA) as a crystal modifier at room temperature. The as-obtained products were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of reaction conditions including pH, [Ca2+]/[C2O42-] ratio and concentration of PSMA and CaC2O4 on the crystal forms and morphologies of the as-obtained calcium oxalate were investigated. The results show that various crystal morphologies of calcium oxalate, such as parallelograms, plates, spheres, bipyramids etc. can be obtained depending on the experimental conditions. Higher polymer concentration favors formation of the metastable calcium oxalate dihydrate (COD) crystals. Lower pH is beneficial to the formation of plate-like CaOx crystals. Especially, the monodispersed parallelogram-like CaOx crystals can be produced by PSMA as an additive at pH 2. PSMA may act as a good inhibitor for urolithiasis since it induces the formation of COD and reduces the particle size of CaOx. This research may provide new insight into the morphological control of CaOx particles and the prevention of urolithiasis.

  8. Synthesis, structures, and magnetic behavior of a series of copper(II) azide polymers of Cu4 building clusters and isolation of a new hemiaminal ether as the metal complex.

    PubMed

    Mukherjee, Sandip; Gole, Bappaditya; Song, You; Mukherjee, Partha Sarathi

    2011-04-18

    Four new neutral copper azido polymers, [Cu(4)(N(3))(8)(L(1))(2)](n) (1), [Cu(4)(N(3))(8)(L(2))(2)](n) (2), [Cu(4)(N(3))(8)(L(3))(2)](n) (3), and [Cu(9)(N(3))(18)(L(4))(4)](n) (4) [L(1-4) are formed in situ by reacting pyridine-2-carboxaldehyde with 2-[2-(methylamino)ethyl]pyridine (mapy, L(1)), N,N-dimethylethylenediamine (N,N-dmen, L(2)), N,N-diethylethylenediamine (N,N-deen, L(3)), and N,N,2,2-tetramethylpropanediamine (N,N,2,2-tmpn, L(4))], have been synthesized by using 0.5 mol equiv of the chelating tridentate ligands with Cu(NO(3))(2)·3H(2)O and an excess of NaN(3). Single-crystal X-ray structures show that the basic unit of these complexes, especially 1-3, contains very similar Cu(II)(4) building blocks. The overall structure of 3 is two-dimensional, while the other three complexes are one-dimensional in nature. Complex 1 represents a unique example containing hemiaminal ether arrested by copper(II). Complexes 1 and 2 have a rare bridging azido pathway: both end-on and end-to-end bridging azides between a pair of Cu(II) centers. Cryomagnetic susceptibility measurements over a wide range of temperature exhibit dominant ferromagnetic behavior in all four complexes. Density functional theory calculations (B3LYP functional) have been performed on complexes 1-3 to provide a qualitative theoretical interpretation of their overall ferromagnetic behavior.

  9. New polymers for phase partitioning

    NASA Technical Reports Server (NTRS)

    Harris, J. M.

    1981-01-01

    The synthesizing of several polyethylene glycols having crown ethers attached is reported. This work led to the identification of three new polymer types which promise to be more effective at selectively binding specific cell types. Work was completed on identification of chemical properties of the new polymer crowns and on development of new techniques for determination of polymer-phase composition.

  10. Nanoparticle self-assembly in mixtures of phospholipids with styrene/maleic acid copolymers or fluorinated surfactants.

    PubMed

    Vargas, Carolyn; Arenas, Rodrigo Cuevas; Frotscher, Erik; Keller, Sandro

    2015-12-28

    Self-assembling nanostructures in aqueous mixtures of bilayer-forming lipids and micelle-forming surfactants are relevant to in vitro studies on biological and synthetic membranes and membrane proteins. Considerable efforts are currently underway to replace conventional detergents by milder alternatives such as styrene/maleic acid (SMA) copolymers and fluorinated surfactants. However, these compounds and their nanosized assemblies remain poorly understood as regards their interactions with lipid membranes, particularly, the thermodynamics of membrane partitioning and solubilisation. Using (19)F and (31)P nuclear magnetic resonance spectroscopy, static and dynamic light scattering, and isothermal titration calorimetry, we have systematically investigated the aggregational state of a zwitterionic bilayer-forming phospholipid upon exposure to an SMA polymer with a styrene/maleic acid ratio of 3 : 1 or to a fluorinated octyl phosphocholine derivative called F(6)OPC. The lipid interactions of SMA(3 : 1) and F(6)OPC can be thermodynamically conceptualised within the framework of a three-stage model that treats bilayer vesicles, discoidal or micellar nanostructures, and the aqueous solution as distinct pseudophases. The exceptional solubilising power of SMA(3 : 1) is reflected in very low membrane-saturating and solubilising polymer/lipid molar ratios of 0.10 and 0.15, respectively. Although F(6)OPC saturates bilayers at an even lower molar ratio of 0.031, this nondetergent does not solubilise lipids even at >1000-fold molar excess, thus highlighting fundamental differences between these two types of mild membrane-mimetic systems. We rationalise these findings in terms of a new classification of surfactants based on bilayer-to-micelle transfer free energies and discuss practical implications for membrane-protein research.

  11. 40 CFR 721.10072 - Benzene, 1,1′-methylenebis[4-isocyanato-, polymer with benzenedicarboxylic acid, butyl dialkyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....-hydro-.omega.-hydroxy-, oxirane, alkyl-, polymer with oxirane, ether with propanepolyol and Sartomer's... , .alpha.-hydro-.omega.-hydroxy-, oxirane, alkyl-, polymer with oxirane, ether with propanepolyol and... , .alpha.-hydro-.omega.-hydroxy-, oxirane, alkyl-, polymer with oxirane, ether with propanepolyol...

  12. Molecular Engineering of Liquid Crystalline Polymers by Living Polymerization. 8. Influence of Molecular Weight on the Phase Behavior pf Poly(Omega-((4-cyano-4’Biphenyl)oxy)alkyl Vinyl Ether)s with Ethyl, Propyl and Butyl Alkyl Groups

    DTIC Science & Technology

    1990-10-16

    diacetate l0 were synthesized as described previously. Methyl sulfide was refluxed over 9-borabicyclo[3,3, l ]nonane (crystalline, 98%, Aldrich) and then...LJ.I., poly(A-4) with different degrees of polynerization and narow molecular weight distribution was compared to that of L -1, U- and 6. and of 2.((4...vinyl ether I ( L ),, poy 3 [4-cyano-4’-biphenyl)oxy]propyl vinyl ether) &63) and poly (4-[4-cyano-4’- biphenyl)oxylbutyl vinyl ether) (6_-4). Their

  13. SMA-SH: Modified Styrene-Maleic Acid Copolymer for Functionalization of Lipid Nanodiscs.

    PubMed

    Lindhoud, Simon; Carvalho, Vanessa; Pronk, Joachim W; Aubin-Tam, Marie-Eve

    2016-04-11

    Challenges in purification and subsequent functionalization of membrane proteins often complicate their biochemical and biophysical characterization. Purification of membrane proteins generally involves replacing the lipids surrounding the protein with detergent molecules, which can affect protein structure and function. Recently, it was shown that styrene-maleic acid copolymers (SMA) can dissolve integral membrane proteins from biological membranes into nanosized discs. Within these nanoparticles, proteins are embedded in a patch of their native lipid bilayer that is stabilized in solution by the amphipathic polymer that wraps the disc like a bracelet. This approach for detergent-free purification of membrane proteins has the potential to greatly simplify purification but does not facilitate conjugation of functional compounds to the membrane proteins. Often, such functionalization involves laborious preparation of protein variants and optimization of labeling procedures to ensure only minimal perturbation of the protein. Here, we present a strategy that circumvents several of these complications through modifying SMA by grafting the polymer with cysteamine. The reaction results in SMA that has solvent-exposed sulfhydrils (SMA-SH) and allows tuning of the coverage with SH groups. Size exclusion chromatography, dynamic light scattering, and transmission electron microscopy demonstrate that SMA-SH dissolves lipid bilayer membranes into lipid nanodiscs, just like SMA. In addition, we demonstrate that, just like SMA, SMA-SH solubilizes proteoliposomes into protein-loaded nanodiscs. We covalently modify SMA-SH-lipid nanodiscs using thiol-reactive derivatives of Alexa Fluor 488 and biotin. Thus, SMA-SH promises to simultaneously tackle challenges in purification and functionalization of membrane proteins.

  14. Evaluation of copolymer conformation states of vinylchloride-maleic anhydride

    NASA Astrophysics Data System (ADS)

    Ivanov, A. A.

    2016-11-01

    The quantum-chemical analysis and experimental study of alternating vinylchloride-maleic anhydride (VC-MA) copolymer macromolecules with polymerization degree 600 have been carried out. The VC-MA copolymer in solvents of different nature undergoes cycloanhydride-enol tautomerism and the macromolecules take the form of corrugated sticks according to viscometric measurements. The computer simulation has shown that the segment with polymerization degree n < 18 (model compound) is not a helix and rolls while if n = 18 the conformations get distorted. The model molecule optimal structure comprising a random sequence of alternating units of comonomers and their enol tautomers with minimal system total energy has been found by the semiempirical parametric method PM3.

  15. Catalytic oxidation of dimethyl ether

    SciTech Connect

    Zelenay, Piotr; Wu, Gang; Johnston, Christina M.; Li, Qing

    2016-05-10

    A composition for oxidizing dimethyl ether includes an alloy supported on carbon, the alloy being of platinum, ruthenium, and palladium. A process for oxidizing dimethyl ether involves exposing dimethyl ether to a carbon-supported alloy of platinum, ruthenium, and palladium under conditions sufficient to electrochemically oxidize the dimethyl ether.

  16. Tuning the size of styrene-maleic acid copolymer-lipid nanoparticles (SMALPs) using RAFT polymerization for biophysical studies.

    PubMed

    Craig, Andrew F; Clark, Emily E; Sahu, Indra D; Zhang, Rongfu; Frantz, Nick D; Al-Abdul-Wahid, M Sameer; Dabney-Smith, Carole; Konkolewicz, Dominik; Lorigan, Gary A

    2016-11-01

    Characterization of membrane proteins is challenging due to the difficulty in mimicking the native lipid bilayer with properly folded and functional membrane proteins. Recently, styrene-maleic acid (StMA) copolymers have been shown to facilitate the formation of disc-like lipid bilayer mimetics that maintain the structural and dynamic integrity of membrane proteins. Here we report the controlled synthesis and characterization of StMA containing block copolymers. StMA polymers with different compositions and molecular weights were synthesized and characterized by size exclusion chromatography (SEC). These polymers act as macromolecular surfactants for 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol (POPG) lipids, forming disc like structures of the lipids with the polymer wrapping around the hydrophobic lipid edge. A combination of dynamic light scattering (DLS), solid-state nuclear magnetic resonance (SSNMR) spectroscopy, and transmission electron microscopy (TEM) was used to characterize the size of the nanoparticles created using these StMA polymers. At a weight ratio of 1.25:1 StMA to lipid, the nanoparticle size created is 28+1nm for a 2:1 ratio, 10+1nm for a 3:1 StMA ratio and 32+1nm for a 4:1 StMA ratio independent of the molecular weight of the polymer. Due to the polymer acting as a surfactant that forms disc like nanoparticles, we term these StMA based block copolymers "RAFT SMALPs". RAFT SMALPs show promise as a new membrane mimetic with different nanoscale sizes, which can be used for a wide variety of biophysical studies of membrane proteins. Copyright © 2016. Published by Elsevier B.V.

  17. 40 CFR 180.960 - Polymers; exemptions from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...)-, polymer with ethenol and ethenyl acetate, sodium salt, minimum number average molecular weight (in amu...-84-0 Polyvinyl acetate, copolymer with maleic anhydride, partially hydrolyzed, sodium salt, minimum...-1-sulfonic acid sodium salt, polymer with ethenol and ethenyl acetate, number average molecular...

  18. 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) denture...

  19. 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) denture...

  20. 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) denture...

  1. 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. Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture...

  2. 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) denture...

  3. Triclosan antimicrobial polymers

    PubMed Central

    Petersen, Richard C.

    2016-01-01

    Triclosan antimicrobial molecular fluctuating energies of nonbonding electron pairs for the oxygen atom by ether bond rotations are reviewed with conformational computational chemistry analyses. Subsequent understanding of triclosan alternating ether bond rotations is able to help explain several material properties in Polymer Science. Unique bond rotation entanglements between triclosan and the polymer chains increase both the mechanical properties of polymer toughness and strength that are enhanced even better through secondary bonding relationships. Further, polymer blend compatibilization is considered due to similar molecular relationships and polarities. With compatibilization of triclosan in polymers a more uniform stability for nonpolar triclosan in the polymer solid state is retained by the antimicrobial for extremely low release with minimum solubility into aqueous solution. As a result, triclosan is projected for long extended lifetimes as an antimicrobial polymer additive. Further, triclosan rapid alternating ether bond rotations disrupt secondary bonding between chain monomers in the resin state to reduce viscosity and enhance polymer blending. Thus, triclosan is considered for a polymer additive with multiple properties to be an antimicrobial with additional benefits as a nonpolar toughening agent and a hydrophobic wetting agent. The triclosan material relationships with alternating ether bond rotations are described through a complete different form of medium by comparisons with known antimicrobial properties that upset bacterial cell membranes through rapid fluctuating mechanomolecular energies. Also, triclosan bond entanglements with secondary bonding can produce structural defects in weak bacterial lipid membranes requiring pliability that can then interfere with cell division. Regarding applications with polymers, triclosan can be incorporated by mixing into a resin system before cure, melt mixed with thermoplastic polymers that set on cooling

  4. Novel high T[sub g] high-strength poly(aryl ether)s

    SciTech Connect

    Banerjee, S.; Maier, G. . Lehrstuhl fuer Makromolekulare Stoffe)

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4[prime]-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 [times] 10[sup 5] g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T[sub g]) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl[sub 3], THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  5. Novel high T{sub g} high-strength poly(aryl ether)s

    SciTech Connect

    Banerjee, S.; Maier, G.

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4{prime}-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 {times} 10{sup 5} g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T{sub g}) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl{sub 3}, THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  6. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  7. Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

    SciTech Connect

    Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang; Boyer, François; Olivier, Philippe; Sapelkin, Andrei; King, Stephen; Heenan, Richard; Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri

    2014-06-21

    Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

  8. Vibrational spectroscopic study of pure and silica-doped sulfonated poly(ether ether ketone) membranes

    NASA Astrophysics Data System (ADS)

    Rangasamy, Vijay Shankar; Thayumanasundaram, Savitha; Seo, Jin Won; Locquet, Jean-Pierre

    2015-03-01

    We report the vibrational properties of sulfonated poly(ether ether ketone) (SPEEK) membranes, used as electrolytes in proton exchange membrane (PEM) fuel cells, studied by Fourier transform infrared (FTIR) spectroscopy. We discuss the changes in the vibrational modes of the functional groups present in the polymer arising due to the sulfonation process and the subsequent incorporation of silica particles functionalized with sulfonic acid group. From the infrared spectra, we confirm the incorporation of sulfonic acid group in the polymer chain as well as in the functionalized silica particles. We have also measured the variations in the peak area ratio of the characteristic out-of-plane vibrations of the aromatic rings in the PEEK polymer at 1280 cm-1 with respect to a reference peak at 1305 cm-1. These values were correlated to the crystallinity (XC) values experimentally determined by DSC technique, providing a non-destructive means to calculate the crystallinity of polymer membranes. The calculated XC values were in good agreement with the experimental values. The crystallinity was observed to decrease with increasing degree of sulfonation (DS), indicating the crystalline-to-amorphous phase modification of the polymer by sulfonation, which along with the enhanced ion-exchange capacity and water uptake, is responsible for the improved ionic conductivity at higher DS values.

  9. Molecular Model for the Solubilization of Membranes into Nanodisks by Styrene Maleic Acid Copolymers

    PubMed Central

    Scheidelaar, Stefan; Koorengevel, Martijn C.; Pardo, Juan Dominguez; Meeldijk, Johannes D.; Breukink, Eefjan; Killian, J. Antoinette

    2015-01-01

    A recent discovery in membrane research is the ability of styrene-maleic acid (SMA) copolymers to solubilize membranes in the form of nanodisks allowing extraction and purification of membrane proteins from their native environment in a single detergent-free step. This has important implications for membrane research because it allows isolation as well as characterization of proteins and lipids in a near-native environment. Here, we aimed to unravel the molecular mode of action of SMA copolymers by performing systematic studies using model membranes of varying compositions and employing complementary biophysical approaches. We found that the SMA copolymer is a highly efficient membrane-solubilizing agent and that lipid bilayer properties such as fluidity, thickness, lateral pressure profile, and charge density all play distinct roles in the kinetics of solubilization. More specifically, relatively thin membranes, decreased lateral chain pressure, low charge density at the membrane surface, and increased salt concentration promote the speed and yield of vesicle solubilization. Experiments using a native membrane lipid extract showed that the SMA copolymer does not discriminate between different lipids and thus retains the native lipid composition in the solubilized particles. A model is proposed for the mode of action of SMA copolymers in which membrane solubilization is mainly driven by the hydrophobic effect and is further favored by physical properties of the polymer such as its relatively small cross-sectional area and rigid pendant groups. These results may be helpful for development of novel applications for this new type of solubilizing agent, and for optimization of the SMA technology for solubilization of the wide variety of cell membranes found in nature. PMID:25606677

  10. Aqueous alkali metal hydroxide insoluble cellulose ether membrane

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1969-01-01

    A membrane that is insoluble in an aqueous alkali metal hydroxide medium is described. The membrane is a resin which is a water-soluble C2-C4 hydroxyalkyl cellulose ether polymer and an insolubilizing agent for controlled water sorption, a dialytic and electrodialytic membrane. It is particularly useful as a separator between electrodes or plates in an alkaline storage battery.

  11. Evaluation of Scotchbond Multipurpose and maleic acid as alternative methods of bonding orthodontic brackets.

    PubMed

    Olsen, M E; Bishara, S E; Damon, P; Jakobsen, J R

    1997-05-01

    Damage to the enamel surface during bonding and debonding of orthodontic brackets is a clinical concern. Alternative bonding methods that minimize enamel surface damage while maintaining a clinically useful bond strength is an aim of current research. The purpose of this study was to compare the effects on bond strength and bracket failure location of two adhesives (System 1+ and Scotchbond Multipurpose, 3M Dental Products Division) and two enamel conditioners (37% phosphoric acid and 10% maleic acid). Forty-eight freshly extracted human premolars were pumiced and divided into four groups of 12 teeth, and metal orthodontic brackets were attached to the enamel surface by one of four protocols: (1) System 1+ and phosphoric acid, (2) Scotchbond and phosphoric acid, (3) System 1+ and maleic acid, and (4) Scotchbond and maleic acid. After bracket attachment, the teeth were mounted in phenolic rings and stored in deionized water at 37 degrees C for 72 hours. A Zwick universal testing machine (Zwick GmbH & Co.) was used to determine shear bond strengths. The residual adhesive on the enamel surface was evaluated with the Adhesive Remnant Index. The analysis of variance was used to compare the four groups. Significance was predetermined at p < or = 0.05. The results indicated that there were no significant differences in bond strength among the four groups (p = 0.386). The results of the Chi square test, evaluating the residual adhesives on the enamel surfaces, revealed significant differences among the four groups (mean 2 = 0.005). A Duncan multiple range test revealed the difference occurred between the phosphoric acid and maleic acid groups, with maleic acid having bond failures at the enamel-adhesive interface. In conclusion, the use of Scotchbond Multipurpose and/or maleic acid does not significantly effect bond strength, however, the use of maleic acid resulted in an unfavorable bond failure location.

  12. Mechanistic study of maleic anhydride grafting onto fatty double bonds using mass spectrometry.

    PubMed

    Loutelier-Bourhis, Corinne; Zovi, Ornella; Lecamp, Laurence; Bunel, Claude; Hubert-Roux, Marie; Lange, Catherine M

    2012-06-15

    The grafting of maleic anhydride onto fatty C=C double bonds is a well-known and used method to functionalize triglyceride molecules. Nevertheless, grafted products are not actually structurally well defined. In this work, the thermal grafting of maleic anhydride onto (un)saturated fatty acid esters without the use of an initiator was characterized in order to determine the nature of the products formed during this reaction. Complementary spectrometric techniques, ESI-MS(n) (ion-trap mass spectrometer), IMS-MS(n) (Q-IMS-TOFMS) and GC/MS, were used to identify the grafted products which were prepared using either ethyl oleate (EtO) or methyl linoleate (MeL) as model molecules and maleic anhydride (MA). Lithiated adducts were investigated since they yield useful structural information when subjected to collision-induced dissociation (CID) in tandem mass spectrometry. A high number of products are formed during MA grafting and various reaction types could occur. Radical addition of maleic anhydride followed by combination or elimination reactions led to succinic and maleic anhydride grafting, respectively. The addition occurred with or without double-bond shift; the resulting derivatives showed succinic and maleic anhydride branching in the α-position relative to the double bond or onto the carbon atom of the initial double bond. Some structures obtained by radical addition and combination were also consistent with the Alder ene functionalization reaction. The Diels-Alder addition between di-unsaturated fatty acid chains and maleic anhydride could yield cyclic forms of MA-grafted derivatives. We have shown that ESI-MS(n) and IMS-MS(n) allow the identification of grafted products providing relevant structural information concerning isomers. These methods permit the rapid and direct analyses of 'crude reaction mixtures'. Copyright © 2012 John Wiley & Sons, Ltd.

  13. Augmented cellular trafficking and endosomal escape of porous silicon nanoparticles via zwitterionic bilayer polymer surface engineering.

    PubMed

    Shahbazi, Mohammad-Ali; Almeida, Patrick V; Mäkilä, Ermei M; Kaasalainen, Martti H; Salonen, Jarno J; Hirvonen, Jouni T; Santos, Hélder A

    2014-08-01

    The development of a stable vehicle with low toxicity, high cellular internalization, efficient endosomal escape, and optimal drug release profile is a key bottleneck in nanomedicine. To overcome all these problems, we have developed a successful layer-by-layer method to covalently conjugate polyethyleneimine (PEI) and poly(methyl vinyl ether-co-maleic acid) (PMVE-MA) copolymer on the surface of undecylenic acid functionalized thermally hydrocarbonized porous silicon nanoparticles (UnTHCPSi NPs), forming a bilayer zwitterionic nanocomposite containing free positive charge groups of hyper-branched PEI disguised by the PMVE-MA polymer. The surface smoothness, charge and hydrophilicity of the developed NPs considerably improved the colloidal and plasma stabilities via enhanced suspensibility and charge repulsion. Furthermore, despite the surface negative charge of the bilayer polymer-conjugated NPs, the cellular trafficking and endosomal escape were significantly increased in both MDA-MB-231 and MCF-7 breast cancer cells. Remarkably, we also showed that the conjugation of surface free amine groups of the highly toxic UnTHCPSi-PEI (Un-P) NPs to the carboxylic groups of PMVE-MA renders acceptable safety features to the system and preserves the endosomal escape properties via proton sponge mechanism of the free available amine groups located inside the hyper-branched PEI layer. Moreover, the double layer protection not only controlled the aggregation of the NPs and reduced the toxicity, but also sustained the drug release of an anticancer drug, methotrexate, with further improved cytotoxicity profile of the drug-loaded particles. These results provide a proof-of-concept evidence that such zwitterionic polymer-based PSi nanocomposites can be extensively used as a promising candidate for cytosolic drug delivery. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Polymer blend compositions and methods of preparation

    DOEpatents

    Naskar, Amit K.

    2016-09-27

    A polymer blend material comprising: (i) a first polymer containing hydrogen bond donating groups having at least one hydrogen atom bound to a heteroatom selected from oxygen, nitrogen, and sulfur, or an anionic version of said first polymer wherein at least a portion of hydrogen atoms bound to a heteroatom is absent and replaced with at least one electron pair; (ii) a second polymer containing hydrogen bond accepting groups selected from nitrile, halogen, and ether functional groups; and (iii) at least one modifying agent selected from carbon particles, ether-containing polymers, and Lewis acid compounds; wherein, if said second polymer contains ether functional groups, then said at least one modifying agent is selected from carbon particles and Lewis acid compounds. Methods for producing the polymer blend, molded forms thereof, and articles thereof, are also described.

  15. New developments in thermally stable polymers

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1991-01-01

    Advances in high-temperature polymers since 1985 are discussed with the emphasis on the chemistry. High-temperature polymers refer to materials that exhibit glass-transition temperatures greater than 200 C and have the chemical structure expected to provide high thermooxidative stability. Specific polymers or series of polymers were selected to show how the chemical structure influences certain properties. Poly(arylene ethers) and polyimides are the two principal families of polymers discussed. Recent work on poly(arylene ethers) has concentrated on incorporating heterocyclic units within the polymer backbone. Recent polyimide work has centered on the synthesis of new polymers from novel monomers, several containing the trifluoromethyl group strategically located on the molecule. Various members in each of these polymer families display a unique combination of properties, heretofore unattainable. Other families of polymers are also briefly discussed with a polymer from an AB maleimidobenzocyclobutene exhibiting an especially attractive combination of properties.

  16. Triethylene glycol monoethyl ether

    Integrated Risk Information System (IRIS)

    Triethylene glycol monoethyl ether ; CASRN 112 - 50 - 5 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 fo

  17. Triethylene glycol monobutyl ether

    Integrated Risk Information System (IRIS)

    Triethylene glycol monobutyl ether ; CASRN 143 - 22 - 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 fo

  18. p-Bromodiphenyl ether

    Integrated Risk Information System (IRIS)

    p - Bromodiphenyl ether ; CASRN 101 - 55 - 3 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 Noncarcin

  19. Propylene glycol monoethyl ether

    Integrated Risk Information System (IRIS)

    Propylene glycol monoethyl ether ; CASRN 52125 - 53 - 8 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 fo

  20. Chloromethyl methyl ether (CMME)

    Integrated Risk Information System (IRIS)

    Chloromethyl methyl ether ( CMME ) ; CASRN 107 - 30 - 2 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 fo

  1. Cytotoxic effects of etephon and maleic hydrazide in Vero, Hep2, HepG2 cells.

    PubMed

    Yurdakok, Begum; Baydan, Emine; Okur, Hamza; Gurcan, Ismayil Safa

    2014-10-01

    The toxicity of etephon and maleic hydrazide, used as plant growth regulators in agriculture, were reported as low in mammals in previous studies. However, in vitro cytotoxicity studies in mammalian cells are currently missing to understand their toxicity at molecular level. In the current study, the cytotoxicity of these compounds, were studied in Vero (African green monkey kidney epithelium), HepG2 (human hepatocellular carcinoma), Hep2 (human epidermoid cancer) cells by MTT ((3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromure) and LDH (lactate dehydrogenase) assays. Maleic hydrazide had lower IC50 values for all cell lines compared to ethephon. Least cytotoxic effect treated by ethephon were observed in Vero, followed by HepG2 and Hep2. Similarly maleic hydrazide also showed least cytotoxicity on Vero cells, followed by Hep2 and HepG2 cells (p < 0.05). IC50 values in general were found to be highest in Vero cells, followed by HepG2 and Hep2 cells (p < 0.05). LDH and MTT assays showed correllation and had close relation except HepG2-maleic hydrazide application with the correlation coefficient for all >0.868 (p < 0.05). This study is expected to be a basis to understand the cytotoxic effects of ethephon and maleic hydrazide in mammal cells to be supplemented by further studies.

  2. Kinetics of Maleic Acid and Aluminum Chloride Catalyzed Dehydration and Degradation of Glucose

    SciTech Connect

    Zhang, Ximing; Hewetson, Barron B.; Mosier, Nathan S.

    2015-04-16

    We report the positive effect of maleic acid, a dicarboxylic acid, on the selectivity of hexose dehydration to 5-hydroxymethyfurfural (HMF) and subsequent hydrolysis to levulinic and formic acids. We also describe the kinetic analysis of a Lewis acid (AlCl3) alone and in combination with HCl or maleic acid to catalyze the isomerization of glucose to fructose, dehydration of fructose to HMF, hydration of HMF to levulinic and formic acids, and degradation of these compounds to humins. The results show that AlCl3 significantly enhances the rate of glucose conversion to HMF and levulinic acid in the presence of both maleic acid and HCl. In addition, the degradation of HMF to humins, rather than levulinic and formic acids, is reduced by 50% in the presence of maleic acid and AlCl3 compared to HCl combined with AlCl3. The results suggest different reaction mechanisms for the dehydration of glucose and rehydration of HMF between maleic acid and HCl.

  3. Fluorinated Poly(Phenylene Ether Ketones)

    NASA Technical Reports Server (NTRS)

    St. Clair, Anne K.; Cassidy, Patrick E.; Tullos, Gordon L.

    1994-01-01

    Fluorinated poly(phenylene ether ketones) are colorless, transparent, low-dielectric-constant, highly thermally stable polymers. Particularly suitable for use as film and coating materials in electronic and thermal-control applications such as; passivant insulating coats and interlevel dielectrics in microelectronic circuits, or as protective transparent coats on solar cells or mirrors. Solubility and transparency of 12F-PEK along with its lower dielectric constant and other properties make it more useful as dielectric film and coating material in many applications.

  4. Propenyl ether monomers for photopolymerization

    DOEpatents

    Crivello, J.V.

    1996-10-22

    Propenyl ether monomers of formula A(OCH{double_bond}CHCH{sub 3}){sub n} wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of the above formula together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  5. Propenyl ether monomers for photopolymerization

    DOEpatents

    Crivello, James V.

    1996-01-01

    Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  6. High performance polymer development

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1991-01-01

    The term high performance as applied to polymers is generally associated with polymers that operate at high temperatures. High performance is used to describe polymers that perform at temperatures of 177 C or higher. In addition to temperature, other factors obviously influence the performance of polymers such as thermal cycling, stress level, and environmental effects. Some recent developments at NASA Langley in polyimides, poly(arylene ethers), and acetylenic terminated materials are discussed. The high performance/high temperature polymers discussed are representative of the type of work underway at NASA Langley Research Center. Further improvement in these materials as well as the development of new polymers will provide technology to help meet NASA future needs in high performance/high temperature applications. In addition, because of the combination of properties offered by many of these polymers, they should find use in many other applications.

  7. Glycol Ethers As Groundwater Contaminants

    NASA Astrophysics Data System (ADS)

    Ross, Benjamin; Johannson, Gunnar; Foster, Gregory D.; Eckel, William P.

    1992-01-01

    Ether derivatives of dihydroxy alcohols, which are formed from ethylene or propylene, comprise an important group of groundwater contaminants known as glycol ethers. Compounds in this group are used as solvents, cleaning agents, and emulsifiers in many chemical products and manufacturing operations. Glycol ethers have been associated with a variety of toxic effects, and some compounds in the group are relatively potent teratogens. The limited information available suggests that glycol ethers are contaminants in groundwater, especially in anaerobic plumes emanating from disposal of mixed industrial and household waste. Most methods used to analyze groundwater samples cannot adequately detect μg/? (ppb) concentrations of glycol ethers, and the existing methods perform worst for the most widely used and toxic species. A new method capable of analyzing μg/? concentrations of glycol ethers was recently developed, and its use is recommended for groundwater samples where glycol ethers are likely to be present.

  8. Chemistry and properties of new poly(arylene ether imidazoles)

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    As part of a program to develop high-temperature high-performance structural resins for aerospace applications, the chemistry and properties of new poly(arylene ether imidazoles) were investigated. The polymers were prepared by the nucleophilic displacement reaction of aromatic bis(imidazolephenols) with activated aromatic difluoro compounds. The amorphous thermoplastic polymers exhibited glass transition temperatures from 230 to 301 C, inherent viscosities from 0.46 to 1.46 dL/g, and number-average molecular weights as high as 59,300 g/mole. The polymers exhibit good toughness, adhesive, composite, and film properties. The chemical, physical, and mechanical properties of these materials are discussed.

  9. Chemistry and properties of new poly(arylene ether imidazoles)

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    As part of a program to develop high-temperature high-performance structural resins for aerospace applications, the chemistry and properties of new poly(arylene ether imidazoles) were investigated. The polymers were prepared by the nucleophilic displacement reaction of aromatic bis(imidazolephenols) with activated aromatic difluoro compounds. The amorphous thermoplastic polymers exhibited glass transition temperatures from 230 to 301 C, inherent viscosities from 0.46 to 1.46 dL/g, and number-average molecular weights as high as 59,300 g/mole. The polymers exhibit good toughness, adhesive, composite, and film properties. The chemical, physical, and mechanical properties of these materials are discussed.

  10. Determination of Physical and Chemical Structure of New High-Temperature Polymers

    DTIC Science & Technology

    thermal properties, and molecular weight. Several samples of the perfluoroalkyl bibenzoxazole polymers were examined. Considerable effort was directed...toward determination of the molecular weight of both perfluorosebacate and perfluoroalkyl ether-linked polymers. In addition, solubility, thermal...stability and subambient DTA of the perfluoroalkyl ether- linked polymers (elastomers) were investigated. Samples of the aromatic heterocyclic-ladder type

  11. 21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section 872.3490 Food and Drugs... DENTAL DEVICES Prosthetic Devices § 872.3490 Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. (a) Identification. A carboxymethylcellulose...

  12. 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.

  13. Crystal structure of 2,3-di-methyl-maleic anhydride: continuous chains of electrostatic attraction.

    PubMed

    Wiscons, Ren A; Zeller, Matthias; Rowsell, Jesse L C

    2015-08-01

    In the crystal structure of 2,3-di-methyl-maleic anhydride, C6H6O3, the closest non-bonding inter-molecular distances, between the carbonyl C and O atoms of neighboring mol-ecules, were measured as 2.9054 (11) and 3.0509 (11) Å, which are well below the sum of the van der Waals radii for these atoms. These close contacts, as well as packing motifs similar to that of the title compound, were also found in the crystal structure of maleic anhydride itself and other 2,3-disubstituted maleic anhydrides. Computational modeling suggests that this close contact is caused by strong electrostatic inter-actions between the carbonyl C and O atoms.

  14. Solid/Liquid phase diagram of the ammonium sulfate/maleic acid/water system.

    PubMed

    Beyer, Keith D; Schroeder, Jason R; Pearson, Christian S

    2011-12-01

    We have studied the low temperature phase diagram and water activities of the ammonium sulfate/maleic acid/water system using differential scanning calorimetry and infrared spectroscopy of thin films. Using the results from our experiments, we have mapped the solid/liquid ternary phase diagram, determined the water activities based on the freezing point depression, and determined the ice/maleic acid phase boundary as well as the ternary eutectic composition and temperature. We also compare our results to the predictions of the extended AIM aerosol thermodynamics model and find good agreement for the ice melting points in the ice primary phase field of this system; however significant differences were found with respect to phase boundaries, maleic acid dissolution, and ammonium sulfate dissolution.

  15. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    SciTech Connect

    Kim, Dae Sik; Kim, Yu Seung; Lee, Kwan - Soo; Boncella, James M; Kuiper, David; Guiver, Michael D

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  16. Cationic Polymerization of Vinyl Ethers Controlled by Visible Light.

    PubMed

    Kottisch, Veronika; Michaudel, Quentin; Fors, Brett P

    2016-12-07

    Photoinitiated cationic polymerizations are widely used in industrial processes; however, gaining photocontrol over chain growth would expand the utility of these methods and facilitate the design of novel complex architectures. We report herein a cationic polymerization regulated by visible light. This polymerization proceeds under mild conditions: a combination of a metal-free photocatalyst, a chain-transfer agent, and light irradiation enables the synthesis of various poly(vinyl ether)s with good control over molecular weight and dispersity as well as excellent chain-end fidelity. Significantly, photoreversible cation formation in this system enables efficient control over polymer chain growth with light.

  17. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, B.F.; Robison, T.W.; Gohdes, J.W.

    1999-04-06

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  18. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    2002-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  19. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    1999-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  20. Solvothermal process for grafting maleic anhydride onto poly(ethylene 1-octene)

    NASA Astrophysics Data System (ADS)

    Liu, Qiaochu; Qi, Rongrong; Shen, Yanhan; Zhou, Chixing

    2007-11-01

    Solvothermal process was developed to graft maleic anhydride (MAH) onto poly(ethylene 1-octene) (POE). Fourier transform infrared spectra (FT-IR) and 1H NMR spectra confirmed that maleic anhydride was successfully grafted onto the POE. The influences of MAH content, initiator concentration, POE concentration, reaction temperature, reaction time and solvents on the graft copolymerization were investigated through both of the grafting degree (GD) and gel content (GC). The results demonstrated that high grafting degree (up to 10.85%) could be obtained while the gel content was still low. Further studies revealed that POE-g-MAH could also be achieved in poor solvents of POE through this method.

  1. Marchantin M trimethyl ether.

    PubMed

    Mombrú, A W; Suescun, L; Pandolfi, E; Seoane, G; López, G; Mariezcurrena, R

    2000-11-01

    The title macrocycle, C(31)H(30)O(5), is comprised of two bibenzyl ether moieties linked cyclically by spacers which each consist of two-carbon alkyl chains. The observed conformation of the macrocycle may be partly stabilized by intramolecular C-H.O close contacts. The packing appears to be directed by van der Waals forces. This work explains the occurrence of a signal found in the (1)H NMR spectra of both marchantinquinone and marchantin M trimethyl ether at delta = 5. 49 and 5.56 p.p.m., respectively. The shift in the position of the expected peak can be explained by the proximity of an H atom belonging to one of the aromatic rings to another ring in the same molecule.

  2. Determination of maleic hydrazide residues in garlic bulbs by HPLC.

    PubMed

    Mamani Moreno, Claudia; Stadler, Teodoro; da Silva, Antônio Alberto; Barbosa, Luiz C A; de Queiroz, Maria Eliana L R

    2012-01-30

    In recent years, the release of information about the preventative and curative properties of garlic on different diseases and their benefits to human health has led to an increase in the consumption of garlic. To meet the requirements of international markets and reach competitiveness and profitability, farmers seek to extend the offer period of fresh garlic by increasing post-harvest life. As a result, the use of maleic hydrazide (1,2-dihydropyridazine-3,6-dione) [MH], a plant growth regulator, has been widespread in various garlic growing regions of the world. The present work was undertaken to develop and validate a new analytical procedure based on MH extraction from garlic previously frozen by liquid nitrogen and submitted to low temperature clean-up. The applicability of the method by analysis of garlic samples from a commercial plantation was also demonstrated. The influence of certain factors on the performance of the analytical methodology were studied and optimized. The approach is an efficient extraction, clean-up and determination alternative for MH residue-quantification due to its specificity and sensitivity. The use of liquid nitrogen during the sample preparation prevents the degradation of the analyte due to oxidation reactions, a major limiting factor. Moreover, the method provides good linearity (r(2): 0.999), good intermediate precision (coefficient of variation (CV): 8.39%), and extracts were not affected by the matrix effect. Under optimized conditions, the limit of detection (LOD) (0.33 mg kg(-1)) was well below the maximum residue level (MRL) set internationally for garlic (15 mg kg(-1)), with excellent rates of recovery (over 95%), good repeatability and acceptable accuracy (CV averaged 5.74%), since garlic is a complex matrix. The analytical performance of the methodology presented was compared with other techniques already reported, with highly satisfactory results, lower LOD and higher recoveries rates. In addition, the extraction

  3. Thermally resistant polymers for fuel tank sealants

    NASA Technical Reports Server (NTRS)

    Webster, J. A.

    1973-01-01

    Imide-linked perfluoroalkylene ether polymers, that were developed for the high temperature fuel tank sealant application, are discussed. Modifications of polymer structure and properties were realized through use of a new aromatic dianhydride intermediate containing an ether-linked perfluoroalkylene segment. Tests of thermal, oxidative and hydrolytic stability, fuel resistance, and adhesion are discussed along with tensile strength and elongation results. Efforts to effect a low temperature condensation of amic acid prepolymer to form imide links inside are described.

  4. Synthesis and fluorescence properties of divalent europium-poly(methacrylate containing crown ether structure) complexes

    SciTech Connect

    Higashiyama, N.; Nakamura, H.; Mishima, T.; Shiokawa, J.; Adachi, G. )

    1991-02-01

    This paper reports on divalent europium complexes with poly(methacrylate containing crown ether structure)s, poly(crown ether)s, prepared and their fluorescence properties studied. The polymers used were poly(15-crown-5-methyl methacrylate) (PMA15C5), copoly(15- crown-5-methyl methacrylate-X) (copoly(MA15C5-X)); (X = MMA, EMA, BMA, 2-methoxyethyl methacrylate (MAGI) 3,6,9,12,15- pentaoxahexadecyl methacrylate (MAG5)), poly(18-crown-6- methyl methacrylate) (PMA18C6), and copoly(18-crown-6-methyl methacrylate-MMA) (copoly(MA18C6-MMA)), which were obtained by bulk polymerization. The fluorescence properties of Eu{sup 2+} polymers activated by complexing Eu{sup 2+} ions with crown ether groups were measured in powder form. The Eu{sup 2+}-poly (crown ether)s irradiated by UV light generally gave blue bright emission in the region of 420-465 nm. It was Eu{sup 2+}-copoly(Ma15C5-X); (X = MMA, EMA, and MAG1) that showed the largest emission intensity among the Eu{sup 2+} polymers, and its emission intensity was ca. 20% of that for CaWO{sub 4}:Pb (NBS1026) whose quantum efficiency is about 76%. The intensities of emission for the Eu{sup 2+} polymers containing 15-crown-5 were much larger than that for the ones containing 18-crown-6.

  5. Blending of Low-Density Polyethylene and Poly-Lactic Acid with Maleic Anhydride as A Compatibilizer for Better Environmentally Food-Packaging Material

    NASA Astrophysics Data System (ADS)

    Setiawan, A. H.; Aulia, F.

    2017-05-01

    The common conventional food packaging materialsare using a thin layer plastic or film, which is made of a synthetic polymer, such as Low-Density Poly Ethylene (LDPE). However, the use of these polymers hasan adverse impact on the environment, because the synthetic polymersare difficult to degrade naturally. Poly-Lactic Acid (PLA) is a biodegradable polymer that can be substituted to synthetic polymers. Since LDPE and PLA have a difference in polarity, therefore the first step of research is to graft them with maleic anhydride (MAH) for increasing the properties of its miscibility. The interaction between them is confirmed by FTIR; whereas the environment issueis characterized by the water adsorption and biodegradability. The FTIR spectra indicated that there had been an interaction between LDPE and MAH and LDPE/LDPE-g-MAH/PLA blend. Increasing PLA content in the blend affected to the increasing in their water absorption and biodegradable. Poly-blend with 20% PLA content was the optimum composition for environmentally food packaging.

  6. Synthesis and characterization of poly(silyl ether)s and modified poly(siloxane)s

    NASA Astrophysics Data System (ADS)

    Mabry, Joseph Mark

    Activated dihydridocarbonyltris(triphenylphosphine)ruthenium ( Ru) catalyzes the dehydrogenative silylation condensation copolymerization of ortho-quinones with alpha,o-dihydrido-oligodimethylsiloxanes to give high molecular weight copoly(arylene-1,2-dioxy/oligodimethylsiloxanylene)s in good chemical yield. The hydrosilylation polymerization of aliphatic o-dimethylsilyloxy ketones is also catalyzed by activated Ru to yield unsymmetrical poly(silyl ether)s. Likewise, Ru catalyzes the copolymerization of alpha,o-diketones with alpha,o-dihydrido-oligodimethylsiloxanes to yield symmetrical poly(silyl ether)s. A mechanism of the copolymerizations is proposed, in which beta-hydride elimination is favored over reductive elimination in the reaction of the ortho-quinones. Chiral centers affect the NMR spectra of the poly(silyl ether)s produced by hydrosilylation. The photoluminescence properties of the polymers were studied along with those of model compounds. The decrease in Tgs with increase in siloxane chain length as well as fluorescence spectra is discussed. RuH2(CO)(PPh3)3 (Ru), activated with a stoichiometric amount of styrene, catalyzes the anti-Markovnikov addition of an ortho C-H bond of benzophenone across the C-C double bonds of alpha,o-bis(trimethylsilyloxy)copoly(dimethylsiloxane/vinylmethylsiloxane), alpha,o-bis(vinyldimethsilyloxy)poly(dimethylsiloxane)s, and 1,3-divinyltetramethyldisiloxane to yield alpha,o-bis(trimethylsilyloxy)copoly[dimethylsiloxane/2-(2 '-benzophenonyl)ethylmethylsiloxane]s, alpha,o-bis[2-(2 '-benzophenonyl)ethyldimethylsilyloxy]poly(dimethylsiloxane)s, and 1,3-bis[2-(2'-benzophenonyl)ethyl]tetramethyldisiloxane, respectively. While the Mw/Mn and Tgs of the modified polysiloxanes are similar to those of the precursor polymers, an increase in molecular weight is observed upon heating. 1,3-bis[2-(2 '-Benzophenonyl)ethyl]tetramethyldisiloxane, a model compound, was utilized to test a mechanism for the increase in molecular weight. A

  7. Alcohol/ether separation by pervaporation. High performance membrane design

    SciTech Connect

    Roizard, D.; Jonquieres, A.; Leger, C.

    1999-02-01

    Several routes were investigated to design high performance membranes for the separation of tert-butyl ethers (octane enhancers) from alcohols by pervaporation. These routes aim at incorporating Lewis base groups into good film-forming polymers with different structures. The Lewis base groups showed a high affinity to alcohols in screening tests, thus imparting high pervaporation selectivity to the polymer materials. They led to several membranes able to extract pure ethanol out of the azeotropic mixture, but with very low permeation rates. Further modifications of the polymer structure allowed the authors to synthesize materials with greatly enhanced transfer rates and with acceptable selectivity for industrial applications. Structure-property relationships were derived from sorption and pervaporation data for a qualitative prediction of the effect of polymer structure on the flux and selectivity. For these solvent-polymer systems the diffusion phenomenon appears to further improve the pervaporation selectivity for alcohol compared with that given by the sorption process at the membrane face.

  8. Dual-responsive poly(styrene-alt-maleic acid)-graft-poly(N-isopropyl acrylamide) micelles as switchable emulsifiers.

    PubMed

    Yi, Chenglin; Liu, Na; Zheng, Junchao; Jiang, Jinqiang; Liu, Xiaoya

    2012-08-15

    Self-assembled polymeric micelles can be used as efficient particulate emulsifiers. To explore the relationship between micellar structure and emulsification performance, pH- and temperature-responsive self-assembled micelles were prepared and used as emulsifiers, based on a novel grafted polymer poly(styrene-alt-maleic acid)-graft-poly(N-isopropyl acrylamide) (PSMA-g-PNIPAm). Structure of PSMA-g-PNIPAm micelles varies in response to pH and temperature changes and can be classified into four typical states, including shrunken, moderately swollen, extremely swollen, and inverted states, confirmed by a combination of electrophoresis, dynamic light scattering (DLS), transmission electron microscopy (TEM), and (1)H NMR. This structural variation plays a key role in the emulsification performance of PSMA-g-PNIPAm micelles, according to the emulsifying characteristics of the four typical PSMA-g-PNIPAm micelles as well as the micellar morphologies on the surface of oil droplets as observed by SEM. Emulsions stabilised by micelles with moderately swollen structure are especially stable compared with either the shrunken micelles or the extremely swollen micelles, because the moderately swollen micelles combine the advantages of solid particulate emulsifiers and polymeric surfactants. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Preparation of High Density Polyethylene/Waste Polyurethane Blends Compatibilized with Polyethylene-Graft-Maleic Anhydride by Radiation

    PubMed Central

    Park, Jong-Seok; Lim, Youn-Mook; Nho, Young-Chang

    2015-01-01

    Polyurethane (PU) is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA). The PE-g-MA-grafted PU/high density polyethylene (HDPE) composite was prepared by melt-blending at various concentrations (0–10 phr) of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR), and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased. PMID:28788022

  10. Molecular sieve/sulfonated poly(ether ketone ether sulfone) composite membrane as proton exchange membrane

    NASA Astrophysics Data System (ADS)

    Changkhamchom, Sairung; Sirivat, Anuvat

    2012-02-01

    A proton exchange membrane (PEM) is an electrolyte membrane used in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFCs). Currently, PEMs typically used for PEMFCs are mainly the commercially available Nafion^ membranes, which is high cost and loss of proton conductivity at elevated temperature. In this work, the Sulfonated poly(ether ketone ether sulfone), (S-PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-dichlorobenzophenone, and followed by the sulfonation reaction with concentrated sulfuric acid. The molecular sieve was added in the S-PEKES matrix at various ratios to form composite membranes to be the candidate for PEM. Properties of both pure sulfonated polymer and composite membranes were compared with the commercial Nafion^ 117 membrane from Dupont. S-PEKES membranes cast from these materials were evaluated as a polymer electrolyte membrane for direct methanol fuel cells. The main properties investigated were the proton conductivity, methanol permeability, thermal, chemical, oxidative, and mechanical stabilities by using a LCR meter, Gas Chromatography, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, Fenton's reagent, and Universal Testing Machine. The addition of the molecular sieve helped to increase both the proton conductivity and the methanol stability. These composite membranes are shown as to be potential candidates for use as a Proton Exchange Membrane (PEM).

  11. A New Pathway to Aspartic Acid from Urea and Maleic Acid Affected by Ultraviolet Light

    NASA Astrophysics Data System (ADS)

    Terasaki, Masanori; Nomoto, Shinya; Mita, Hajime; Shimoyama, Akira

    2002-04-01

    The photochemistry of a mixture of urea and maleic acid, which are thought to have been widely present on the primitive Earth, was studied in order to examine a possibility of the formation of amino acids. When an aqueous solution of urea and maleic acid was irradiated with an ultraviolet light of wavelength 172 nm, urea was revealed to be rather resistant to photochemical decomposition. In contrast, maleic acid was completely decomposed within 4 h, reflecting the reactivity of a C-C double bond in the molecule. In the reaction mixture, 2-isoureidosuccinic acid was detected. The acid was considered to be formed by addition of an isoureido radical which had been produced from urea by the action of a hydroxyl radical, to a C-C double bond of maleic acid. The isoureido group of the product was revealed to undergo thermal rearrangement to afford 2-ureidosuccinic acid (N-carbamoylaspartic acid). The result suggested a novel pathway leading to the formation of aspartic acid from non-amino acid precursors, possibly effected by UV-light on the primitive Earth. The formation of ureidocarboxylic acids is of another significance, since they are capable of undergoing thermal polymerization, resulting in formation of polyamino acids.

  12. Maleic Hydrazide Unsuitable for Controlling Height Growth of Green Ash and Shumard Oak Seedlings

    Treesearch

    F. T. Bonner

    1965-01-01

    In southern nurseries, hardwood seedlings often grow so large that they are difficult to lift and plant. In a study at the Southern Hardwoods Laboratory, maleic hydrazide (MH) was tested as a means of halting height growth when seedlings reach suitable size.

  13. Shear bond strength of a resin composite to enamel etched with maleic or phosphoric acid.

    PubMed

    Hallett, K B; Garcia-Godoy, F; Trotter, A R

    1994-10-01

    The purpose of this study was to evaluate the effect of 10 per cent maleic and 37 per cent phosphoric acid on the shear bond strength of Z100 composite resin with Scotchbond Multi-Purpose adhesive to primary and permanent tooth enamel. Four groups of 20 teeth each were established: 1, permanent teeth, 10 per cent maleic acid etched for 15 seconds; 2, permanent teeth, 10 per cent maleic acid etched for 30 seconds; 3, permanent teeth, 37 per cent phosphoric acid etched for 15 seconds; 4, primary teeth, 10 per cent maleic acid etched for 15 seconds. Five teeth from each group were randomly assigned for SEM examination of the etched enamel surface. Scotchbond Multi-Purpose primer and adhesive were applied to the etched enamel surface of the remaining 15 teeth and cured following the manufacturer's instructions. Z100 composite resin was placed in a nylon cylinder and cured for two 40 second intervals. Following thermocycling, the specimens were sheared on an universal testing machine and debonded areas were examined visually with a stereo microscope and with SEM. The mean shear bond strengths in MPa were: 1, 17.00; 2, 14.58; 3, 14.66; 4, 11.18. ANOVA and Student-Newman-Keuls analyses revealed no statistically significant difference among the groups. SEM examination showed the majority of specimens fractured at the adhesive-resin interface.

  14. MALEIC ANHYDRIDE HYDROGENATION OF PD/AL2O3 CATALYST UNDER SUPERCRITICAL CO2 MEDIUM

    EPA Science Inventory

    Hydrogenation of maleic anhydride (MA) to either y-butyrolactone of succinic anhydride over simple Pd/Al2O3 impregnated catalyst in supercritical CO2 medium has been studied at different temperatures and pressures. A comparison of the supercritical CO2 medium reaction with the c...

  15. Catalytic Hydrogenation of Maleic Acid at Moderate Pressures: A Laboratory Demonstration

    ERIC Educational Resources Information Center

    Amoa, Kwesi

    2007-01-01

    Moderate-pressure catalytic hydrogenation is often overlooked as a classroom demonstration because of the awkwardness of the equipment and the time constraints required for the conversion of reactants to products. This article demonstrates the reduction of maleic acid in about 90 minutes. (Contains 1 table and 1 figure.)

  16. Catalytic Hydrogenation of Maleic Acid at Moderate Pressures: A Laboratory Demonstration

    ERIC Educational Resources Information Center

    Amoa, Kwesi

    2007-01-01

    Moderate-pressure catalytic hydrogenation is often overlooked as a classroom demonstration because of the awkwardness of the equipment and the time constraints required for the conversion of reactants to products. This article demonstrates the reduction of maleic acid in about 90 minutes. (Contains 1 table and 1 figure.)

  17. Aliphatic polycarbonates based on carbon dioxide, furfuryl glycidyl ether, and glycidyl methyl ether: reversible functionalization and cross-linking.

    PubMed

    Hilf, Jeannette; Scharfenberg, Markus; Poon, Jeffrey; Moers, Christian; Frey, Holger

    2015-01-01

    Well-defined poly((furfuryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((FGE-co-GME)C)) copolymers with varying furfuryl glycidyl ether (FGE) content in the range of 26% to 100% are prepared directly from CO2 and the respective epoxides in a solvent-free synthesis. All materials are characterized by size-exclusion chromatography (SEC), (1)H NMR spectroscopy, and differential scanning calorimetry (DSC). The furfuryl-functional samples exhibit monomodal molecular weight distributions with Mw/Mn in the range of 1.16 to 1.43 and molecular weights (Mn) between 2300 and 4300 g mol(-1). Thermal properties reflect the amorphous structure of the polymers. Both post-functionalization and cross-linking are performed via Diels-Alder chemistry using maleimide derivatives, leading to reversible network formation. This transformation is shown to be thermally reversible at 110 °C.

  18. Poly(arylene ether)s That Resist Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Hergenrother, Paul; Smith, Joseph G., Jr.

    1994-01-01

    Novel poly(arylene ether)s containing phosphine oxide (PAEPO's) made via aromatic nucleophilic displacement reactions of activated aromatic dihalides (or, in some cases, activated aromatic dinitro compounds) with new bisphenol monomers containing phosphine oxide. Exhibited favorable combination of physical and mechanical properties and resistance to monatomic oxygen in oxygen plasma environment. Useful as adhesives, coatings, films, membranes, moldings, and composite matrices.

  19. Structure-property study of keto-ether polyimides

    NASA Technical Reports Server (NTRS)

    Dezern, James F.; Croall, Catharine I.

    1991-01-01

    As part of an on-going effort to develop an understanding of how changes in the chemical structure affect polymer properties, an empirical study was performed on polyimides containing only ether and/or carbonyl connecting groups in the polymer backbone. During the past two decades the structure-property relationships in linear aromatic polyimides have been extensively investigated. More recently, work has been performed to study the effect of isomeric attachment of keto-ether polyimides on properties such as glass transition temperature and solubility. However, little work has been reported on the relation of polyimide structure to mechanical properties. The purpose of this study was to determine the effect of structural changes in the backbone of keto-ether polyimides on their mechanical properties, specifically, unoriented thin film tensile properties. This study was conducted in two stages. The purpose of the initial stage was to examine the physical and mechanical properties of a representative group (four) of polyimide systems to determine the optimum solvent and cure cycle requirements. These optimum conditions were then utilized in the second stage to prepare films of keto-ether polyimides which were evaluated for mechanical and physical properties. All of the polyimides were prepared using isomers of oxydianiline (ODA) and diaminobenzophenone (DABP) in combination with 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-oxydiphthalic anhydride (ODPA).

  20. Sorbents based on crown ethers: preparation and application for the sorption of strontium

    NASA Astrophysics Data System (ADS)

    Bezhin, N. A.; Dovhyi, I. I.

    2015-12-01

    The key approaches to the synthesis of crown ether-based sorbents, including immobilization both with and without covalent bonding, are reviewed. Examples of sorbent preparation using anodic oxidation, chemical modification of polymers, polycondensation reactions, chemical modification of inorganic supports and radiochemical synthesis for covalent bonding of crown ether moieties are considered. Immobilization methods without covalent bonding including support synthesis in the presence of crown ethers, impregnation of supports with a crown ether solution and the use of powdered crown ether as a sorbent are presented. The applications of sorbents for selective removal of strontium from solutions of radioactive waste and spent nuclear fuel, for radiochemical analysis (determination of strontium in water, soil and biological materials) and for separation of strontium and yttrium isotopes are discussed. The bibliography includes 114 references.

  1. Allene ether Nazarov cyclization.

    PubMed

    Tius, Marcus A

    2014-05-07

    The ease of synthesis and the exceptional reactivity of alkoxyallenes has led to their use in a large number of highly diverse applications. This Report describes their use in various versions of the allene ether Nazarov cyclization. Following a brief introduction to the Nazarov cyclization (Section 1), the oxidative cyclization of vinyl alkoxyallenes is discussed first (Section 2). Nazarov cyclizations of α-alkoxyallenyl vinyl ketones and of α-alkoxyallenyl vinyl tertiary carbinols are covered (Section 3). The discovery and the subsequent rational design of acetals that serve as chiral auxiliaries on the allene in highly enantioselective Nazarov cyclizations is explained (Section 4). Interrupted Nazarov cyclizations of alkoxyallenes that are generated in situ from the isomerization of propargyl ethers on solid supports are discussed, including the evolution of a highly diastereoselective, chiral auxiliary controlled version of the reaction. Some applications of the methodology to natural products total synthesis have been included so as to provide the reader with benchmarks with which to judge the utility of the methodology.

  2. Alkyl substituted cyclic ethers in 2,300 M yr old Transvaal algal stromatolite

    NASA Technical Reports Server (NTRS)

    Zumberge, J. E.; Nagy, B.

    1975-01-01

    Two cyclic ethers have been identified for the first time from insoluble polymer-like kerogen in a Precambrian rock by ozonolysis, gas chromatography, and mass spectrometry. The ethers are 2-n-propyl-3-methyltetrahydrofuran and 2-n-propyltetrahydropyran. These compounds could prove to be the oldest indigenous biochemical fossils. The sample was obtained 750 m stratigraphically above the base of the Transvaal Sequence from an outcrop approximately 315 km north-east of Johannesburg, South Africa.

  3. Alkyl substituted cyclic ethers in 2,300 M yr old Transvaal algal stromatolite

    NASA Technical Reports Server (NTRS)

    Zumberge, J. E.; Nagy, B.

    1975-01-01

    Two cyclic ethers have been identified for the first time from insoluble polymer-like kerogen in a Precambrian rock by ozonolysis, gas chromatography, and mass spectrometry. The ethers are 2-n-propyl-3-methyltetrahydrofuran and 2-n-propyltetrahydropyran. These compounds could prove to be the oldest indigenous biochemical fossils. The sample was obtained 750 m stratigraphically above the base of the Transvaal Sequence from an outcrop approximately 315 km north-east of Johannesburg, South Africa.

  4. Statistical modelling of the rheological and mucoadhesive properties of aqueous poly(methylvinylether-co-maleic acid) networks: Redefining biomedical applications and the relationship between viscoelasticity and mucoadhesion.

    PubMed

    Jones, David S; Laverty, Thomas P; Morris, Caoimhe; Andrews, Gavin P

    2016-08-01

    Poly(methylvinylether-co-maleic acid) (PMVE/MA) is commonly used as a component of pharmaceutical platforms, principally to enhance interactions with biological substrates (mucoadhesion). However, the limited knowledge on the rheological properties of this polymer and their relationships with mucoadhesion has negated the biomedical use of this polymer as a mono-component platform. This study presents a comprehensive study of the rheological properties of aqueous PMVE/MA platforms and defines their relationships with mucoadhesion using multiple regression analysis. Using dilute solution viscometry the intrinsic viscosities of un-neutralised PMVE/MA and PMVE/MA neutralised using NaOH or TEA were 22.32±0.89dLg(-1), 274.80±1.94dLg(-1) and 416.49±2.21dLg(-1) illustrating greater polymer chain expansion following neutralisation using Triethylamine (TEA). PMVE/MA platforms exhibited shear-thinning properties. Increasing polymer concentration increased the consistencies, zero shear rate (ZSR) viscosities (determined from flow rheometry), storage and loss moduli, dynamic viscosities (defined using oscillatory analysis) and mucoadhesive properties, yet decreased the loss tangents of the neutralised polymer platforms. TEA neutralised systems possessed significantly and substantially greater consistencies, ZSR and dynamic viscosities, storage and loss moduli, mucoadhesion and lower loss tangents than their NaOH counterparts. Multiple regression analysis enabled identification of the dominant role of polymer viscoelasticity on mucoadhesion (r>0.98). The mucoadhesive properties of PMVE/MA platforms were considerable and were greater than those of other platforms that have successfully been shown to enhance in vivo retention when applied to the oral cavity, indicating a positive role for PMVE/MA mono-component platforms for pharmaceutical and biomedical applications.

  5. pH-sensitive micelles self-assembled from multi-arm star triblock co-polymers poly(ε-caprolactone)-b-poly(2-(diethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) for controlled anticancer drug delivery.

    PubMed

    Yang, You Qiang; Zhao, Bin; Li, Zhen Dong; Lin, Wen Jing; Zhang, Can Yang; Guo, Xin Dong; Wang, Ju Fang; Zhang, Li Juan

    2013-08-01

    A series of amphiphilic 4- and 6-armed star triblock co-polymers poly(ε-caprolactone)-b-poly(2-(diethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) (4/6AS-PCL-b-PDEAEMA-b-PPEGMA) were developed by a combination of ring opening polymerization and continuous activators regenerated by electron transfer atom transfer radical polymerization. The critical micelle concentration values of the star co-polymers in aqueous solution were extremely low (2.2-4.0mgl(-1)), depending on the architecture of the co-polymers. The self-assembled blank and doxorubicin (DOX)-loaded three layer micelles were spherical in shape with an average size of 60-220nm determined by scanning electron microscopy and dynamic light scattering. The in vitro release behavior of DOX from the three layer micelles exhibited pH-dependent properties. The DOX release rate was significantly accelerated by decreasing the pH from 7.4 to 5.0, due to swelling of the micelles at lower pH values caused by the protonation of tertiary amine groups in DEAEMA in the middle layer of the micelles. The in vitro cytotoxicity of DOX-loaded micelles to HepG2 cells suggested that the 4/6AS-PCL-b-PDEAEMA-b-PPEGMA micelles could provide equivalent or even enhanced anticancer activity and bioavailability of DOX and thus a lower dosage is sufficient for the same therapeutic efficacy. The results demonstrate that the pH-sensitive multilayer micelles could have great potential application in delivering hydrophobic anticancer drugs for improved cancer therapy.

  6. Novel Ordered Crown Ether-Containing Polyimides for Ion Conduction

    NASA Technical Reports Server (NTRS)

    Irvin, Jennifer A.; Stasko, Daniel; Fallis, Stephen; Guenthner, Andrew J.; Webber, Cynthia; Blackwell, John; Chvalun, Sergei N.

    2003-01-01

    We report the synthesis and characterization of thermally-stable polyimides for use as battery and fuel cell electrolyte membranes. Dianhydrides used were 1,4,5,8- naphthalenetetracarboxylic dianhydride and/or 4,4'-(hexafluoroisopropylidene)diphthalic anhydride. Diamines used were anti-4,4-diaminodibenzo-l8-crown-6, 4,4'- diaminodibenzo-24-crown-8, 2,2-bis(4-aminophenyl)hexafluoropropane, and/or 2,5- diaminobenzenesulfonic acid. The polymers were characterized using electrochemical impedance spectroscopy (EIS), thermal analysis and X-ray diffraction. Polymers containing the hexafluoroisopropylidene (HFIP) group were soluble in common organic solvents, while polymers without the HFIP group were very poorly soluble. Sulfonation yields polymers that are sparingly soluble in aqueous base and/or methanol. Degree of sulfonation, determined by titration, was between one and three sulfonate groups per repeat unit. Proton conductivity was determined as a function of water content, with a maximum conductivity of l x 10(exp -2) per centimeter when fully hydrated. Crown ether-containing polymers exhibit a high degree of order that may be indicative of crown ether channel formation, which may facilitate Li(+) transport for use in battery membranes.

  7. Novel Ordered Crown Ether-Containing Polyimides for Ion Conduction

    NASA Technical Reports Server (NTRS)

    Irvin, Jennifer A.; Stasko, Daniel; Fallis, Stephen; Guenthner, Andrew J.; Webber, Cynthia; Blackwell, John; Chvalun, Sergei N.

    2003-01-01

    We report the synthesis and characterization of thermally-stable polyimides for use as battery and fuel cell electrolyte membranes. Dianhydrides used were 1,4,5,8- naphthalenetetracarboxylic dianhydride and/or 4,4'-(hexafluoroisopropylidene)diphthalic anhydride. Diamines used were anti-4,4-diaminodibenzo-l8-crown-6, 4,4'- diaminodibenzo-24-crown-8, 2,2-bis(4-aminophenyl)hexafluoropropane, and/or 2,5- diaminobenzenesulfonic acid. The polymers were characterized using electrochemical impedance spectroscopy (EIS), thermal analysis and X-ray diffraction. Polymers containing the hexafluoroisopropylidene (HFIP) group were soluble in common organic solvents, while polymers without the HFIP group were very poorly soluble. Sulfonation yields polymers that are sparingly soluble in aqueous base and/or methanol. Degree of sulfonation, determined by titration, was between one and three sulfonate groups per repeat unit. Proton conductivity was determined as a function of water content, with a maximum conductivity of l x 10(exp -2) per centimeter when fully hydrated. Crown ether-containing polymers exhibit a high degree of order that may be indicative of crown ether channel formation, which may facilitate Li(+) transport for use in battery membranes.

  8. On the Formation of Maleic Anhydride on a Vanadyl Pyrophosphate Surface: A Theoretical Study of the Mechanism

    DTIC Science & Technology

    1990-05-25

    synthesis of maleic anhydride from n - butane over a vanadium phosphorous oxide surface in the presence of molecular oxygen [equation ( 1 )]. 7 / • 3.5 0 2 (g...active vanadium phosphorous oxide phase in the oxidation of n - butane has been disputed in the literature. 7 0, 0 Generally, it is agreed that the presence...mechanism for the selective oxidation of n - butane to maleic anhydride. Satsuma et al. have described the surface structure in terms of the number of

  9. Imide/Arylene Ether Copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J.; Hergenrother, Paul M.; Bass, Robert G.

    1991-01-01

    New imide/arylene ether copolymers prepared by reacting anhydride-terminated poly(amic acids) with amine-terminated poly(arylene ethers) in polar aprotic solvents. Each resulting copolymer may have one glass-transition temperature or two, depending on chemical structure and/or compatibility of block units. Most of copolymers form tough, solvent-resistant films with high tensile properties. Films cast from solution tough and flexible, and exhibit useful thermal and mechanical properties. Potentially useful as moldings, adhesives, or composite matrices. Because of flexible arylene ether blocks, these copolymers easier to process than polyimides.

  10. Polyarylene Ethers with Improved Properties

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M. (Inventor); Jensen, B. J. (Inventor); Havens, S. J. (Inventor)

    1986-01-01

    This invention relates to novel polyarylene ethers which possess the combination of high strength, toughness, and high use temperature with ease of extrusion and formation into complex objects. These polyarylene ethers are suitable for use in adhesives, coatings, films, membranes, and composite matrices. The polyarylene ethers of this invention are the polycondensation products from the reaction of either 1,3-bis (4-chloro or fluorobenzoyl) benzene with any one of the following bisphenolic compounds: bis (3-hydroxyphenyl) methane; bis (4-hydroxyphenyl) methane; 1,1-dimethyl-bis (4-hydroxyphenyl)methane, or 9,9-bis (4-hydroxyphenyl) fluorene. Random and block copolymers are also comprehended.

  11. Preparation and Mechanical Properties of Chitosan-graft Maleic Anhydride Reinforced with Montmorillonite

    NASA Astrophysics Data System (ADS)

    Fajrin, A.; Sari, L. A.; Rahmawati, N.; Saputra, O. A.; Suryanti, V.

    2017-02-01

    The research aims to develop biodegradable composites as bio-based plastics from chitosan. The composites were prepared via solution casting method by introducing the maleic anhydride (MAH) as grafting agent and montmorillonite (MMt) as reinforcement. The grafting process of chitosan was conducted by varying concentrations of MAH which were 10, 20, and 30% w/w. It was observed that the chitosan-graft-maleic anhydride (Cs-g-MAH) containing 10% w/w of MAH increased its tensile strength by 70%. Reinforcement material was added to the Cs-g-MAH by varying MMt concentrations, e.g. 3, 6, 9 and 12% w/w. It was noted that the presence of 9% w/w of MMt in the Cs-g-MAH gave the best mechanical properties of the Cs-g-MAH/MMt composite.

  12. 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.

  13. Chemistry and properties of poly(arylene ether 1,3,4-oxadiazole)s and poly(arylene ether 1,2,4-triazole)s

    NASA Technical Reports Server (NTRS)

    Connell, J. W.; Hergenrother, P. M.; Wolf, P.

    1992-01-01

    Poly(arylene ether)s containing l,3,4-oxadiazole and 1,2,4-triazole units were prepared by the aromatic nucleophilic displacement reaction of bisphenol oxadiazole and bisphenol triazole compounds with activated aromatic dihalides. The polymers exhibited glass transition temperatures (Tg) ranging from 182 to 242 C, and several polymers exhibited melting transitions (Tm) ranging from 265 to 390 C. Inherent viscosities ranged from 1.02 to 3.40 dl/g, indicating relatively high molecular weights. Thin films exhibited tensile strengths, moduli, and elongations at 23 C of 90-110 MPa, 2.7-3.6 GPa, and 4-7 percent, respectively. Titanium-to-titanium tensile shear specimens of a poly(arylene ether 1,3,4-oxadiazole) exhibited tensile shear strengths at 23 and 150 C of 22.1 and 17.9 MPa, respectively.

  14. High resolution SEM evaluation of dentin etched with maleic and citric acid.

    PubMed

    Breschi, Lorenzo; Gobbi, Pietro; Mazzotti, Giovanni; Falconi, Mirella; Ellis, Tom H; Stangel, Ivan

    2002-01-01

    This study evaluated the ultra-morphological effects of maleic and citric acid on human dentin by means of a field emission in-lens scanning electron microscope (FEISEM). Both acids were tested on human dentin at pH 0.7 and 1.4 in aqueous solutions. Each of 12 dentin disks were divided into four groups and exposed to either maleic acid at pH 0.7, maleic acid at pH 1.4, citric acid at pH 0.7 and citric acid at pH 1.4. All samples were then fixed and dehydrated in a critical point drying apparatus. Observations were carried out by means of a FEISEM (JEOL 890) after coating with a carbon-platinum film. Both acids removed smear layer and partially removed smear plugs. Details of fine structures measuring from 5 to 15 nm were shown on the intertubular demineralized dentin. Maleic acid at pH 0.7 showed the highest depth of demineralization of all the tested samples; citric acid, showed a higher depth of demineralization values when tested at pH 1.4 than at pH 0.7. The FEISEM reveals ultra-structural aspects of the demineralization process of the dentin tissue of the both acids tested. Differences related to the pH of the acids were found. Images obtained at high magnification clarify the dentin collagen structure of both peritubular and intertubular dentin. Small periodic structures associated with collagen fibrils were also imagined.

  15. Protein adsorption from flowing solutions on pure and maleic acid copolymer modified glass particles.

    PubMed

    Klose, Theresia; Welzel, Petra B; Werner, Carsten

    2006-08-01

    The adsorption of human serum albumin (HSA) and lysozyme (LSZ) on pure as well as maleic acid (MA) copolymer coated spherical soda lime glass particles was investigated under flowing conditions. Coating the glass particles with two different maleic acid copolymers alters the properties of the particle surface concerning its charge and hydrophobicity in a well-defined gradation. Frontal chromatography was used to determine the surface concentration of the adsorbed proteins and to establish adsorption isotherms. The introduced methodology was demonstrated to provide a powerful means to study protein adsorption at solid/liquid interfaces. Investigations with virginal and protein-preadsorbed glass particles revealed that even under streaming conditions HSA is irreversibly adsorbed, whereas LSZ partially desorbs. For LSZ and HSA the adsorbed amounts and the isotherms strongly depend on the surface "history", i.e. the presence or absence of preadsorbed protein layers, and the kind of surface modification of the glass. Compared to the soda lime glass surface the adsorption of HSA was strongly increased on surfaces modified with a hydrophobic maleic acid copolymer indicating a strong hydrophobic protein-surface interaction. By coating the surface with a hydrophilic and more negatively charged maleic acid copolymer the adsorption of HSA to that surface was lower and comparable to the adsorption onto plain glass due to the electrostatic repulsion between HSA and the modified surface. In contrast the affinity to any of the investigated particle surfaces was generally higher for LSZ than for HSA which can be mainly attributed to the electrostatic attraction between LZS and the surface. The adsorbed amount of LSZ on the copolymer coated particle surfaces was much higher than on the pure soda lime glass particles indicating superposed hydrophobic interactions in the case of the hydrophobic MA copolymer layer and an increased density of anionic sites as well as interactions of

  16. Tailored and integrated production of carboxylated cellulose nanocrystals (CNC) with nanofibrils (CNF) through maleic acid hydrolysis

    Treesearch

    Ruibin Wang; Liheng Chen; J.Y. Zhu; Rendang Yang

    2017-01-01

    This study demonstrates the feasibility of tailored and integrated production of carboxylated cellulose nanocrystals (CNC) with nanofibrils (CNF) from bleached pulp fibers through hydrolysis using a recyclable dicarboxylic acid. Hydrolysis experiments were conducted using ranges of 15–75 wt% maleic acid concentrations, 60–120°C temperatures, and 5–300 min reaction...

  17. Whole slurry saccharification and fermentation of maleic acid-pretreated rice straw for ethanol production.

    PubMed

    Jung, Young Hoon; Park, Hyun Min; Kim, Kyoung Heon

    2015-09-01

    We evaluated the feasibility of whole slurry (pretreated lignocellulose) saccharification and fermentation for producing ethanol from maleic acid-pretreated rice straw. The optimized conditions for pretreatment were to treat rice straw at a high temperature (190 °C) with 1 % (w/v) maleic acid for a short duration (3 min ramping to 190 °C and 3 min holding at 190 °C). Enzymatic digestibility (based on theoretical glucose yield) of cellulose in the pretreated rice straw was 91.5 %. Whole slurry saccharification and fermentation of pretreated rice straw resulted in 83.2 % final yield of ethanol based on the initial quantity of glucan in untreated rice straw. These findings indicate that maleic acid pretreatment results in a high yield of ethanol from fermentation of whole slurry even without conditioning or detoxification of the slurry. Additionally, the separation of solids and liquid is not required; therefore, the economics of cellulosic ethanol fuel production are significantly improved. We also demonstrated whole slurry saccharification and fermentation of pretreated lignocellulose, which has rarely been reported.

  18. Synthesis and characterization of maleic anhydride esterified corn starch by the dry method.

    PubMed

    Zuo, Yingfeng; Gu, Jiyou; Yang, Long; Qiao, Zhibang; Tan, Haiyan; Zhang, Yanhua

    2013-11-01

    Maleic anhydride esterified starch was synthesized by a dry method using corn starch as the material and maleic anhydride as the esterifying agent. The esterified starch (ES) was analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), which confirmed that there was a successful esterification reaction between the maleic anhydride and corn starch. The effects of reaction temperature and time on the degree of substitution of esterified starch were studied, where the results showed that 80 °C of reaction temperature and 3h of reaction time were optimal conditions. The result of XPS testing demonstrated that the esterification reaction led to increase of ester bonds in starch. The scanning electron microscopy (SEM) and laser particle size analyzer results showed that esterification led to roughness on the surface of the starch particle, and the particle size and distribution rate of esterification starch became larger. X-ray diffraction (XRD) analysis demonstrated that esterification reaction did not change the crystalline type of native starch. The differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) confirmed that destruction of the crystal structure resulted in improved thermoplasticity of the starch, decreased the gelatinization temperature and increased the thermogravimetric rate of esterification starch. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Imide/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor); Bass, Robert G. (Inventor)

    1992-01-01

    Imide/arylene ether block copolymers are prepared by reacting anhydride terminated poly(amic acids) with amine terminated poly(arylene ethers) in polar aprotic solvents and by chemically or thermally cyclodehydrating the resulting intermediate poly(amic acids). The resulting block copolymers have one glass transition temperature or two, depending upon the particular structure and/or the compatibility of the block units. Most of these block copolymers form tough, solvent resistant films with high tensile properties.

  20. Photothermal and morphological characterization of PLA/PCL polymer blends

    NASA Astrophysics Data System (ADS)

    Correa-Pacheco, Z. N.; Jiménez-Pérez, J. L.; Sabino, M. A.; Cruz-Orea, A.; Loaiza, M.

    2015-09-01

    Nowadays, some synthetic polymers have been replaced by biodegradable polymers in order to avoid environmental contamination. Among these biodegradables polymers, aliphatic polyesters such as polylactic acid (PLA) and polycaprolactone (PCL) have been widely used. In the present study, solvent-casting films of PLA, PCL and polymer blends with and without compatibilizer (PLA grafted with maleic anhydride) were prepared. The thermal diffusivity ( α) of each sample was obtained by using the open photoacoustic cell technique. Morphology and thermal properties were determined by using scanning electron microscopy, transmission electron microscopy and differential scanning calorimetry (DSC), respectively. The blends showed lower thermal diffusivity compared to pure polymers. However, when the compatibilizer was used, the highest value of thermal diffusivity was obtained. Also, cold crystallization with the highest value of enthalpy of fusion was observed for the compatibilized sample, which was revealed by DSC. To our knowledge, this is the first time that the thermal diffusivity of these biodegradable polymer blends is reported.

  1. Process for crosslinking and extending conjugated diene-containing polymers

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L. (Inventor); Havens, Stephen J. (Inventor)

    1977-01-01

    A process using a Diels-Alder reaction which increases the molecular weight and/or crosslinks polymers by reacting the polymers with bisunsaturated dienophiles is developed. The polymer comprises at least 75% by weight based on the reaction product, has a molecular weight of at least 5000 and a plurality of conjugated 1,3-diene systems incorporated into the molecular structure. A dienophile reaction with the conjugated 1,3-diene of the polymer is at least 1% by weight based on the reaction product. Examples of the polymer include polyesters, polyamides, polyethers, polysulfones and copolymers. The bisunsaturated dienophiles may include bis-maleimides, bis maleic and bis tumaric esters and amides. This method for expanding the molecular weight chains of the polymers, preferable thermoplastics, is advantageous for processing or fabricating thermoplastics. A low molecular weight thermoplastic is converted to a high molecular weight plastic having improved strength and toughness for use in the completed end use article.

  2. Evaluating the Swelling, Erosion and Compaction Properties of Cellulose Ethers.

    PubMed

    Ghori, Muhammad U; Grover, Liam M; Asare-Addo, Kofi; Smith, Alan M; Conway, Barbara R

    2017-10-06

    Swelling, erosion, deformation and consolidation properties can affect the performance of cellulose ethers, the most commonly used matrix former in hydrophilic sustained tablet formulations. The present study was designed to comparatively evaluate the swelling, erosion, compression, compaction and relaxation properties of the cellulose ethers in a comprehensive study using standardised conditions. The interrelationship between various compressional models and the inherent deformation and consolidation properties of the polymers on the derived swelling and erosion parameters are consolidated. The impact of swelling (Kw) on erosion rates (KE) and the inter-relationship between Heckel and Kawakita plasticity constants was also investigated. It is evident from the findings that the increases in both substitution and polymer chain length led to higher Kw, but a lower KE; this was also true for all particle size fractions regardless of polymer grade. Smaller particle size and high substitution levels tend to increase the relative density of the matrix but reduce porosity, yield pressure (Py), Kawakita plasticity parameter (b(-1)) and elastic relaxation. Both KW vs KE (R(2) = 0.949-0.980) and Py vs b(-1) correlations (R(2) = 0.820-0.934) were reasonably linear with regards to increasing hydroxypropyl substitution and molecular size. Hence, it can be concluded that the combined knowledge of swelling and erosion kinetics in tandem with the in and out-of-die compression findings can be used to select a specific polymer grade and further to develop and optimise formulations for oral controlled drug delivery applications.

  3. Poly(hydroxy amide ethers): New high-barrier thermoplastics

    SciTech Connect

    Brennan, D.J.; White, J.E.; Haag, A.P.; Kram, S.L.; Brown, C.N.; Pikulin, S.

    1993-12-31

    Over the last several years the authors have been involved in a program to prepare thermoplastic resins having high-barrier to oxygen, good processing characteristics, and excellent mechanical properties. One result of these efforts has been the synthesis of poly(hydroxy amide ethers), a new class of high-barrier thermoplastics. These high-molecular-weight polymers are formed by reactions of aromatic diglycidyl ethers with amide-containing bisphenols in high-boiling alcohol solvent. The polymers have good to outstanding barrier to oxygen, with oxygen transmission rates (O{sub 2}TR) of 0.1 - 5.0 cc-mil/100 in{sup 2}-atm-day (barrier units or BU) at high relative humidity (60-80%). Glass transition temperatures (Tg) of the polymers range from 80 to 200{degrees}C. The example shown combines the Tg of an engineering thermoplastic (152{degrees}C) with good barrier (1.5 BU) and mechanical performance. The effect that structure has on O{sub 2}TR and Tg of the polymers will be discussed. Physical properties of selected examples will also be presented.

  4. Trifluoromethyl-substituted polymers

    NASA Technical Reports Server (NTRS)

    Cassidy, Patrick E.

    1990-01-01

    The synthesis of polymers is discussed. It includes: (1) the synthesis of fluorine-containing crosslinked poly(ether ketones); (2) the synthesis and characterization of poly(imide amides) and their N-methylated analogues; (3) the synthesis of fluorine-containing aromatic polyethers; (4) the synthesis of novel fluorine-containing aromatic polysiloxanes; and (5) the conversion of 6F-containing polythioethers to polysulfones. It is hoped that these polymers will find use as low dielectric materials in electronic applications, function as thermal control coatings, or be suitable elastomeric sealants for extreme service conditions.

  5. Space, Time, Ether, and Kant

    NASA Astrophysics Data System (ADS)

    Wong, Wing-Chun Godwin

    This dissertation focused on Kant's conception of physical matter in the Opus postumum. In this work, Kant postulates the existence of an ether which fills the whole of space and time with its moving forces. Kant's arguments for the existence of an ether in the so-called Ubergang have been acutely criticized by commentators. Guyer, for instance, thinks that Kant pushes the technique of transcendental deduction too far in trying to deduce the empirical ether. In defense of Kant, I held that it is not the actual existence of the empirical ether, but the concept of the ether as a space-time filler that is subject to a transcendental deduction. I suggested that Kant is doing three things in the Ubergang: First, he deduces the pure concept of a space-time filler as a conceptual hybrid of the transcendental object and permanent substance to replace the category of substance in the Critique. Then he tries to prove the existence of such a space-time filler as a reworking of the First Analogy. Finally, he takes into consideration the empirical determinations of the ether by adding the concept of moving forces to the space -time filler. In reconstructing Kant's proofs, I pointed out that Kant is absolutely committed to the impossibility of action-at-a-distance. If we add this new principle of no-action-at-a-distance to the Third Analogy, the existence of a space-time filler follows. I argued with textual evidence that Kant's conception of ether satisfies the basic structure of a field: (1) the ether is a material continuum; (2) a physical quantity is definable on each point in the continuum; and (3) the ether provides a medium to support the continuous transmission of action. The thrust of Kant's conception of ether is to provide a holistic ontology for the transition to physics, which can best be understood from a field-theoretical point of view. This is the main thesis I attempted to establish in this dissertation.

  6. Sub-micronic capsules based on gelatin and poly(maleic anhydride-alt-vinyl acetate) obtained by interfacial condensation with potential biomedical applications.

    PubMed

    Iurea, Delia Mihaela; Peptu, Cătălina Anişoara; Chailan, Jean-François; Carriere, Pascal; Popa, Marcel

    2013-06-01

    New sub-micronic capsules based on a copolymer of maleic anhydride-alt-vinyl acetate and a natural polymer (gelatin) using an interfacial condensation method were obtained. Sub-micronic capsules were characterized by Fourier Transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) method, zeta-potential, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The thermal properties were investigated by thermogravimetric analysis (TGA). According to some parameters of the synthesis reaction (polymer weight ratio, acetone/water ratio, surfactant concentration), the mean diameter of the sub-micronic capsules can be tuned from 200 to 760 nm. The sub-micronic capsules show a higher agglomeration tendency as the amount of gelatin in their composition increases. The swelling capacity in aqueous solutions is dependent on the composition and size of the sub-micronic capsules, decreasing with their diameter and gelatin composition. The drug loading and release capacity was studied using Penicillin G (sodium salt) (PG), and it has been proved that it is influenced by the sub-micronic capsules morphology induced by preparation parameters. Encapsulation and controlled release of small molecule were successfully carried out, demonstrating the potential biomedical applications of these new easily obtained sub-micronic capsules.

  7. Poly(arylene)-based anion exchange polymer electrolytes

    DOEpatents

    Kim, Yu Seung; Bae, Chulsung

    2015-06-09

    Poly(arylene) electrolytes including copolymers lacking ether groups in the polymer may be used as membranes and binders for electrocatalysts in preparation of anodes for electrochemical cells such as solid alkaline fuel cells.

  8. Preparation of Soy Polymers by a Green Processing Method

    USDA-ARS?s Scientific Manuscript database

    Ring opening polymerization of epoxidized soybean oil (ESO) initiated by boron trifluoride diethyl etherate was conducted in liquid carbon dioxide. The resulting polymers (RPESO) were characterized using Infrared (IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), 1H NM...

  9. Carbon nanoscrolls by pyrolysis of a polymer

    NASA Astrophysics Data System (ADS)

    Yadav, Prasad; Warule, Sambhaji; Jog, Jyoti; Ogale, Satishchandra

    2012-12-01

    3D network of carbon nanoscrolls was synthesized starting from pyrolysis of poly(acrylic acid-co-maleic acid) sodium salt. It is a catalyst-free process where pyrolysis of polymer leads to formation of carbon form and sodium carbonate. Upon water soaking of pyrolysis product, the carbon form undergoes self-assembly to form carbon nanoscrolls. The interlayer distance between the walls of carbon nanoscroll was found to be 0.34 nm and the carbon nanoscrolls exhibited a surface area of 188 m2/g as measured by the BET method.

  10. Comparison of surface modification of poly(ether urethanes) on physical properties and blood compatibility

    SciTech Connect

    Wrobleski, D.A.; Cash, D.L.; Hermes, R.E.

    1988-01-01

    Because of their good elastomeric properties including the ability to undergo repeated flexing without failure, polyurethanes are used in a number of biomedical applications including flexing diaphragms or coatings on surfaces in artificial hearts and heart assist devices. In particular, the poly(ether urethanes), are preferred for use in biomedical applications because of their greater hydrolytic stability as compared to poly(ester urethanes). However, poly(ether urethanes), as other polymeric materials in contact with blood, cause formation of thrombus and bacterial infections. These problems might be overcome by incorporation of antithrombogenic substances and/or antibacterial agents in the surface of the polymer. We have explored both of these methods by examining the infusion of polyvinylpyrrolidone (PVP) and poly(ethylene glycol) (PEG) into commercially available poly(ether urethanes) and the graft polymerization of N-vinyl pyrrolidone onto poly(ether urethanes). Preliminary results are presented here. 7 refs., 1 fig.

  11. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    DOEpatents

    Smith, Jr., Lawrence A.

    1983-01-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C.sub.4 hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether.

  12. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    DOEpatents

    Smith, L.A. Jr.

    1983-03-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C[sub 4] hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether. 1 fig.

  13. Cross-linked sulfonated poly(ether ether ketone) by using diamino-organosilicon for proton exchange fuel cells.

    PubMed

    Kayser, Marie J; Reinholdt, Marc X; Kaliaguine, Serge

    2011-03-31

    Fuel cells are at the battlefront to find alternate sources of energy to the highly polluting, economically and environmentally constraining fossil fuels. This work uses an organosilicon molecule presenting two amine functions, bis(3-aminopropyl)-tetramethyldisiloxane (APTMDS) with the aim of preparing cross-linked sulfonated poly(ether ether ketone) (SPEEK) based membranes. The hybrid membranes obtained at varying APTMDS loadings are characterized for their acid, proton conductivity, water uptake, and swelling properties. APTMDS may be considered as an extreme case of silica nanoparticle and is therefore most advantageously distributed within the polymeric matrix. The two amine groups can interact, via electrostatic interactions, with the sulfonic acid groups of SPEEK, resulting in a double anchoring of the molecule. The addition of a small amount of APTMDS is enhancing the mechanical and hydrolytic properties of the membranes and allows some unfolding of the polymer chains, rendering some acid sites accessible to water molecules and thus available for proton transport.

  14. Factors influencing catalytic wet peroxide oxidation of maleic acid in aqueous phase over copper/micelle templated silica-3-aminopropyltrimethoxysilane catalyst.

    PubMed

    Daniel, Lilian; Katima, Jamidu H Y

    2009-01-01

    Catalytic wet peroxide oxidation (CWPO) of initial maleic acid feed concentration (0.005 to 0.03 M) was carried out in a temperature range of 20-50 degrees Celsius, on micelle templated silica-3-aminopropyltrimethoxysilane (MTS-AMP) supported copper catalyst. The influence of various operating parameters such as initial feed concentration of maleic acid, temperature, catalyst loading and the stability of the catalyst were investigated. CWPO reactions were performed in a stirred batch reactor at an atmospheric pressure in the presence of H(2)O(2) as an oxidant. Total conversion of maleic acid into acetic acid was obtained under mild conditions (i.e. atmospheric pressure and 40 degrees Celsius). Blank experiments showed no measurable maleic acid conversion (i.e. only approximately 0.5% conversion of initial maleic acid), indicating that a significant oxidation reaction of maleic acid is enhanced by the presence of a catalyst. Copper on micelle templated silica-3-aminopropyltrimethoxysilane catalyst therefore was found to be suitable for aqueous phase oxidation of maleic acid with 100% of maleic acid conversion.

  15. The modification and characterization of maleic anhydride-styrene-methyl metacrylate terpolymer by poly(ethylene adipate)

    NASA Astrophysics Data System (ADS)

    Boztuğ, Ali; Basan, Satilmiş

    2007-03-01

    In this study, the functionality of maleic anhydride was utilized in the maleic anhydride-styrene-methyl metacrylate (MAStMMA) terpolymer. First, the polyester of poly(ethylene adipate), PEA, polycondensation copolymer was synthesized from ethylene glycol and adipic acid monomers. PEA was then modified on its maleic anhydride units in the MAStMMA terpolymer which has been synthesized previously. This modified copolymer was characterized by FTIR (Fourier Transform Infrared spectroscopy). The viscosimetric and thermomechanical characterization of MAStMMA terpolymer and its modified copolymer were also performed and the results were compared. The modified copolymer obtained was found to be more elastic and more soluble, and had lower viscosity and density.

  16. Electrospun mats from styrene/maleic anhydride copolymers: modification with amines and assessment of antimicrobial activity.

    PubMed

    Ignatova, Milena; Stoilova, Olya; Manolova, Nevena; Markova, Nadya; Rashkov, Iliya

    2010-08-11

    New antimicrobial microfibrous electrospun mats from styrene/maleic anhydride copolymers were prepared. Two approaches were applied: (i) grafting of poly(propylene glycol) monoamine (Jeffamine® M-600) on the mats followed by formation of complex with iodine; (ii) modification of the mats with amines of 8-hydroxyquinoline or biguanide type with antimicrobial activity. Microbiological screening against S. aureus, E. coli and C. albicans revealed that both the formation of complex with iodine and the covalent attachment of 5-amino-8-hydroxyquinoline or of chlorhexidine impart high antimicrobial activity to the mats. In addition, S. aureus bacteria did not adhere to modified mats.

  17. Coal-water slurry viscosity reduction using olefin/maleic acid salt copolymers

    SciTech Connect

    Matt, J.; Ferrara, J.M.

    1984-04-10

    An improved coal-water slurry of the type comprising at least 45% by weight of finely divided coal particles and a dispersing agent, said slurry being characterized as having a Brookfield viscosity at 60 rpm of less than 4,000 centipoise, the improvement which comprises adjusting the pH of said slurry to at least 6 and using as the dispersing agent, a water-soluble salt of an olefin/maleic acid copolymer having a molecular weight within the range of about between 3,000-50,000.

  18. Space charge behaviour in maleic anhydride grafted polyethylene/ethylene - vinyl - acetate copolymer laminates

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyung; Park, Jung Ki; Han, Jae Hong; Suh, Kwang S.

    1997-01-01

    Charge distributions in maleic anhydride (MAH) grafted polyethylene (g-PE)/ethylene - vinyl - acetate (EVA) copolymer laminates have been measured with materials of different composition. All laminates showed interfacial charge, the polarity and the magnitude of which are explained by interfacial polarization. It was found that the interfacial charge increased with the increase of MAH content in the g-PE, whereas it decreased with the increase of vinyl - acetate content in the EVA. This feature was attributed to the differences in electrical conductivity of the materials. Details of the experimental results are described.

  19. Stress shielding and fatigue limits of poly-ether-ether-ketone dental implants.

    PubMed

    Lee, Woo-Taek; Koak, Jai-Young; Lim, Young-Jun; Kim, Seong-Kyun; Kwon, Ho-Beom; Kim, Myung-Joo

    2012-05-01

    The poly-ether-ether-ketone (PEEK) polymer is of great interest as an alternative to titanium in orthopedics because of its biocompatibility and low elastic modulus. This study evaluated the fatigue limits of PEEK and the effects of the low elastic modulus PEEK in relation to existing dental implants. Compressive loading tests were performed with glass fiber-reinforced PEEK (GFR-PEEK), carbon fiber-reinforced PEEK (CFR-PEEK), and titanium rods. Among these tests, GFR-PEEK fatigue tests were performed according to ISO 14801. For the finite element analysis, three-dimensional models of dental implants and bone were constructed. The implants in the test groups were coated with a 0.5-mm thick and 5-mm long PEEK layer on the upper intrabony area. The strain energy densities (SED) were calculated, and the bone resorption was predicted. The fatigue limits of GFR-PEEK were 310 N and were higher than the static compressive strength of GFR-PEEK. The bone around PEEK-coated implants showed higher levels of SED than the bone in direct contact with the implants, and the wider diameter and stiffer implants showed lower levels of SED. The compressive strength of the GFR-PEEK and CFR-PEEK implants ranged within the bite force of the anterior and posterior dentitions, respectively, and the PEEK implants showed adequate fatigue limits for replacing the anterior teeth. Dental implants with PEEK coatings and PEEK implants may reduce stress shielding effects. Dental implant application of PEEK polymer-fatigue limit and stress shielding. Copyright © 2012 Wiley Periodicals, Inc.

  20. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a...

  1. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a device...

  2. Characterization of the hyperline of D1/D0 conical intersections between the maleic acid and fumaric acid anion radicals

    NASA Astrophysics Data System (ADS)

    Takahashi, Ohgi; Sumita, Masato

    2004-10-01

    The cation and anion radicals of symmetrical 1,2-disubstituted ethylenes are expected to have a symmetry-allowed conical intersection (CI) between the ground doublet state (D0) and the lowest excited doublet state (D1) near a 90°-twisted geometry. By the complete active space self-consistent field method, we characterized the hyperline formed by D1/D0 CIs between the anion radicals of maleic acid (cis) and fumaric acid (trans). An implication of the results for the known one-way cis→trans photoisomerization of the maleic acid anion radical and other related ion radicals is presented.

  3. Contributions of polymers to bentonite and saponite fluids

    SciTech Connect

    Guven, N.; Carney, L.L.; Panfil, D.J. . Dept. of Geosciences)

    1991-02-01

    Polymers have been used in drilling fluids for many years. However, the confusion surrounding the use of polymers in the oil field has severely limited their effectiveness. Many oilfield workers simply put all polymers in the same category without regard to the many differences that exist among them. Homopolymers and copolymers of acrylic acid and a copolymer of styrene and maleic anhydride are found to have profound effects on the rheological and filtration properties of clay-based fluids up to 300{degrees}F. These contributions of the polymers are greatly diminished when the clay/polymer fluids were autoclaved at 400{degrees}F. Thus, the effects of these polymers are expected to be negligible at and above 400{degrees}F. Homo- and co-polymers of acrylic acid with molecular weights below 5000 almost eliminate the anomalous viscosity rise of the bentonite fluids at temperatures between 250--450{degrees}F. A homopolymer of acrylic acid with a molecular weight of 60,000 and a co-polymer of styrene and maleic anhydride with very high molecular weight further enhances the anomalous viscosity rise of the bentonite fluid. The original viscosity profile of the saponite fluid is characterized with a high initial viscosity up to 200{degrees}F which is followed by a steep thinning at higher temperatures. The addition of homo- and co-polymer of acrylic acid causes a complete reversal in the fluid viscosity. They become thin at lower temperatures (up to 250{degrees}F) and experience a sudden viscosity rise at higher temperatures. All the above polymers greatly improve the filtration losses of the fluids at room temperatures as indicated by the API test. The filtration tests at high pressure and high temperatures were inconclusive due to the frequent blow-outs that occur during the tests.

  4. Electron-donor dopant, method of improving conductivity of polymers by doping therewith, and a polymer so treated

    SciTech Connect

    Liepins, R.; Aldissi, M.

    1988-07-05

    The electrically conductive material is described comprising a polymer with a conjugated backbone selected from the group consisting of polyacetylene, polypyrrone, and polyphenylquinoxaline, the polymer being electron-donor doped to a controlled degree with an agent derived from an electride dopant or a dopant derived from an alkalide both of which contain a trapping agent being selected from the group consisting of: a crown ether, 1,4,7,10,13,16-hexaoxacyclooctadecane, cryptand, methyl ether cyclodextrin, spherand, methyl ether calixarene, podand, and an octopus molecule, the agent being made in the presence of lithium.

  5. Propylene glycol monomethyl ether (PGME)

    Integrated Risk Information System (IRIS)

    Propylene glycol monomethyl ether ( PGME ) ; CASRN 107 - 98 - 2 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 Assess

  6. Desoxyhemigossypol-6-methyl-ether

    USDA-ARS?s Scientific Manuscript database

    Desoxyhemigossypol-6-methyl ether is an antimicrobial compound produced by the cotton plant in response to attack by pathogens. For the first time, we now report the crystal structure of this compound. This may prove useful in studies on the interaction of the compound with pathogenic fungal cells...

  7. Lacinilene C 7-methyl ether

    USDA-ARS?s Scientific Manuscript database

    Lacinilene C 7-methyl ether is an antimicrobial compound produced by the cotton plant in response to attack by pathogens. For the first time, we now report the crystal structure of this compound. This may prove useful in studies on the interaction of the compound with pathogenic fungal cells....

  8. p,p\\'-Dibromodiphenyl ether

    Integrated Risk Information System (IRIS)

    p , p ' - Dibromodiphenyl ether ; CASRN 2050 - 47 - 7 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

  9. Bis(chloroethyl)ether (BCEE)

    Integrated Risk Information System (IRIS)

    Bis ( chloroethyl ) ether ( BCEE ) ; CASRN 111 - 44 - 4 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 fo

  10. Bis(chloromethyl)ether (BCME)

    Integrated Risk Information System (IRIS)

    Bis ( chloromethyl ) ether ( BCME ) ; CASRN 542 - 88 - 1 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 f

  11. Composites of vinyl polystyrylpyridine/bismaleimide-aliphatic ether copolymers

    NASA Technical Reports Server (NTRS)

    Heimbuch, Alvin H.; Rosser, Robert W.; Hsu, Ming-Ta S.

    1989-01-01

    An aliphatic ether bismaleimide was prepared and coreacted with a polyvinylstyrylpyridine (VPSP) oligomer. Studies showed that a controlled ratio of aliphatic to aromatic units in the polymer backbone improved both processibility and interlaminar shear properties for the carbon-fiber composite system. This modified resin was readily soluble in tetrahydrofuran, allowing for better fiber impregnation and thus enhancing adhesive properties and reproducibility. DSC studies have shown a lower cure temperature for the copolymer than for the neat aliphatic bismaleimide, and a glass transition temperature of 260 C, which is more than adequate for most applications. Limited measurements indicated an improvement in toughness (impact resistance).

  12. 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.

  13. Maleic acid and succinic acid in fermented alcoholic beverages are the stimulants of gastric acid secretion.

    PubMed

    Teyssen, S; González-Calero, G; Schimiczek, M; Singer, M V

    1999-03-01

    Alcoholic beverages produced by fermentation (e.g., beer and wine) are powerful stimulants of gastric acid output and gastrin release in humans. The aim of this study was to separate and specify the gastric acid stimulatory ingredients in alcoholic beverages produced by fermentation. Yeast-fermented glucose was used as a simple model of fermented alcoholic beverages; it was stepwise separated by different methods of liquid chromatography, and each separated solution was tested in human volunteers for its stimulatory action on gastric acid output and gastrin release. Five substances were detected by high-performance liquid chromatography and were analyzed by mass spectrometry and 1H-13C nuclear magnetic resonance spectroscopy. At the end of the separation process of the five identified substances, only the two dicarboxylic acids, maleic acid and succinic acid, had a significant (P < 0.05) stimulatory action on gastric acid output (76% and 70% of fermented glucose, respectively), but not on gastrin release. When given together, they increased gastric acid output by 100% of fermented glucose and by 95% of maximal acid output. We therefore conclude that maleic acid and succinic acid are the powerful stimulants of gastric acid output in fermented glucose and alcoholic beverages produced by fermentation, and that gastrin is not their mediator of action.

  14. Maleic acid and succinic acid in fermented alcoholic beverages are the stimulants of gastric acid secretion

    PubMed Central

    Teyssen, Stephan; González-Calero, Gloria; Schimiczek, Michael; Singer, Manfred V.

    1999-01-01

    Alcoholic beverages produced by fermentation (e.g., beer and wine) are powerful stimulants of gastric acid output and gastrin release in humans. The aim of this study was to separate and specify the gastric acid stimulatory ingredients in alcoholic beverages produced by fermentation. Yeast-fermented glucose was used as a simple model of fermented alcoholic beverages; it was stepwise separated by different methods of liquid chromatography, and each separated solution was tested in human volunteers for its stimulatory action on gastric acid output and gastrin release. Five substances were detected by high-performance liquid chromatography and were analyzed by mass spectrometry and 1H-13C nuclear magnetic resonance spectroscopy. At the end of the separation process of the five identified substances, only the two dicarboxylic acids, maleic acid and succinic acid, had a significant (P < 0.05) stimulatory action on gastric acid output (76% and 70% of fermented glucose, respectively), but not on gastrin release. When given together, they increased gastric acid output by 100% of fermented glucose and by 95% of maximal acid output. We therefore conclude that maleic acid and succinic acid are the powerful stimulants of gastric acid output in fermented glucose and alcoholic beverages produced by fermentation, and that gastrin is not their mediator of action. J. Clin. Invest. 103:707–713 (1999) PMID:10074488

  15. Adsorptions of some heavy metal ions in aqueous solutions by acrylamide/maleic acid hydrogels

    SciTech Connect

    Saraydin, D.; Karadag, E.; Gueven, O.

    1995-10-01

    In this study, acrylamide-maleic acid (AAm/MA) hydrogels in the form of rod have been prepared by {gamma}-radiation. They have been used for adsorption of some heavy metal ions such as uranium, iron, and copper. For the hydrogel containing 40 mg of maleic acid and irradiated at 3.73 kGy, maximum and minimum swellings in the aqueous solutions of the heavy metal ions have been observed with water (1480%) and the aqueous solution of iron(III) nitrate (410%), respectively. Diffusions of water and heavy metal ions onto hydrogels have been found to be of the non-Fickian type of diffusion. In experiments of uranyl ions adsorption, Type II adsorption has been found. One gram of AAa/MA hydrogels sorbed 14-86 mg uranyl ions from solutions of uranyl acetate, 14-90 mg uranyl ions from solutions of uranyl nitrate, 16-39 mg iron ions from solutions of iron(IV) nitrate, and 28-81 mg copper ions from solutions of copper acetate, while acrylamide hydrogel did not sorb any heavy metals ions.

  16. 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).

  17. Thermal stability of sulfonated polymers

    SciTech Connect

    Audibert, A.; Argillier, J.F.

    1995-11-01

    Polyacrylamides which are used in oil applications i.e. polymer flooding and water based muds, are hydrolyzed versus time and temperature. This leads to a lack of tolerance towards electrolyte contamination and to a rapid degradation inducing a loss of their properties. Modifications of polyacrylamide structure have been proposed to postpone their thermal stability to higher temperatures. Monomers such as acrylamido methylpropane sulfonate (AMPS) or sulfonated styrene/maleic anhydride can be used to prevent acrylamide comonomer from hydrolysis. The aim of this work is to study under controlled conditions, i.e. anaerobic atmosphere, neutral pH, the stability of sulfonated polymers in order to distinguish between hydrolysis and radical degradation reactions. It has been observed that up to 100 C, the AMPS group is stable and protects the acrylamide function from hydrolysis up to 80%. At higher temperature, even the hydrolysis of the AMPS group occurs, giving acrylate and {beta},{beta} dimethyl taurine, with a kinetics that depends on temperature and time. Degradation in terms of molecular weight then occurs indicating that it follows a radical decarboxylation reaction. It can be limited either by the use of free radical scavenger or when the polymer is in the presence of a mineral phase such as bentonite. These results provide valuable data for the determination of the limits of use of sulfonated copolymers and guidelines for optimizing chemical structure of sulfonated polymers used in water based formulation, in particular to enhance their thermal stability.

  18. Multifunctional electroactive electrospun nanofiber structures from water solution blends of PVA/ODA-MMT and poly(maleic acid-alt-acrylic acid): effects of Ag, organoclay, structural rearrangement and NaOH doping factors

    NASA Astrophysics Data System (ADS)

    Şimşek, Murat; Rzayev, Zakir M. O.; Bunyatova, Ulviya

    2016-06-01

    Novel multifunctional colloidal polymer nanofiber electrolytes were fabricated by green reactive electrospinning nanotechnology from various water solution/dispersed blends of poly (vinyl alcohol-co-vinyl acetate) (PVA)/octadecyl amine-montmorillonite (ODA-MMT) as matrix polymer nanocomposite and poly(maleic acid-alt-acrylic acid) (poly(MAc-alt-AA) and/or its Ag-carrying complex as partner copolymers. Polymer nanofiber electrolytes were characterized using FTIR, XRD, thermal (DSC, TGA-DTG), SEM, and electrical analysis methods. Effects of partner copolymers, organoclay, in situ generated silver nanoparticles (AgNPs), and annealing procedure on physical and chemical properties of polymer composite nanofibers were investigated. The electrical properties (resistance, conductivity, activation energy) of nanofibers with/without NaOH doping agent were also evaluated. This work presented a structural rearrangement of nanofiber mats by annealing via decarboxylation of anhydride units with the formation of new conjugated double bond sites onto partner copolymer main chains. It was also found that the semiconductor behaviors of nanofiber structures were essentially improved with increasing temperature and fraction of partner copolymers as well as presence of organoclay and AgNPs in nanofiber composite.

  19. Surface modification of poly(ether sulfone) membrane with a synthesized negatively charged copolymer.

    PubMed

    Zou, Wen; Qin, Hui; Shi, Wenbin; Sun, Shudong; Zhao, Changsheng

    2014-11-18

    In this study, we provide a new method to modify poly(ether sulfone) (PES) membrane with good biocompatibility, for which diazotized PES (PES-N2(+)) membrane is covalently coated by a negatively charged copolymer of sodium sulfonated poly(styrene-alt-maleic anhydride) (NaSPS-MA). First, aminated PES (PES-NH2) is synthesized by nitro reduction reaction of nitro-PES (PES-NO2), and then blends with pristine PES to prepare PES/PES-NH2 membrane; then the membrane is treated with NaNO2 aqueous solution at acid condition; after surface diazo reaction, surface positively charged PES/PES-N2(+) membrane is prepared. Second, poly(styrene-alt-maleic anhydride) (PS-alt-MA) is synthesized, then sulfonated and treated by sodium hydroxide solution to obtain sodium sulfonated (PS-alt-MA) (NaSPS-MA). Finally, the negatively charged NaSPS-MA copolymer is coated onto the surface positively charged PES/PES-N2(+) membrane via electrostatic interaction; after UV-cross-linking, the linkage between the PES-N2(+) and NaSPS-MA changes to a covalent bond. The surface-modified PES membrane is characterized by FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS) analyses, and surface zeta potential analyses. The modified membrane exhibits good hemocompatibility and cytocompatibility, and the improved biocompatibility might have resulted from the existence of the hydrophilic groups (sodium carboxylate (-COONa) and sodium sulfonate (-SO3Na)). Moreover, the stability of the modified membrane is also investigated. The results indicated that the modified PES membrane using negatively charged copolymers had a lot of potential in blood purification fields and bioartificial liver supports for a long time.

  20. 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.

  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

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl polycarboxylic acids, esters... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction...

  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

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl polycarboxylic acids, esters... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction...

  3. Synthesis of Caffeine/Maleic Acid Co-crystal by Ultrasound-assisted Slurry Co-crystallization.

    PubMed

    Apshingekar, Prafulla P; Aher, Suyog; Kelly, Adrian L; Brown, Elaine C; Paradkar, Anant

    2017-01-01

    A green approach has been used for co-crystallization of noncongruent co-crystal pair of caffeine/maleic acid using water. Ultrasound is known to affect crystallization; hence, the effect of high power ultrasound on the ternary phase diagram has been investigated in detail using a slurry co-crystallization approach. A systematic investigation was performed to understand how the accelerated conditions during ultrasound-assisted co-crystallization will affect different regions of the ternary phase diagram. Application of ultrasound showed considerable effect on the ternary phase diagram, principally on caffeine/maleic acid 2:1 (disappeared) and 1:1 co-crystal (narrowed) regions. Also, the stability regions for pure caffeine and maleic acid in water were narrowed in the presence of ultrasound, expanding the solution region. The observed effect of ultrasound on the phase diagram was correlated with solubility of caffeine and maleic acid and stability of co-crystal forms in water. Copyright © 2016. Published by Elsevier Inc.

  4. 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

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polycarboxylic acids, esters... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction...

  5. A new alternative to expandable pedicle screws: Expandable poly-ether-ether-ketone shell.

    PubMed

    Demir, Teyfik

    2015-05-01

    Screw pullout is a very common problem in the fixation of sacrum with pedicle screws. The principal cause of this problem is that the cyclic micro motions in the fixation of sacrum are higher than the other regions of the vertebrae that limit the osteo-integration between bone and screw. In addition to that, the bone quality is very poor at sacrum region. This study investigated a possible solution to the pullout problem without the expandable screws' handicaps. Newly designed poly-ether-ether-ketone expandable shell and classical pedicle screws were biomechanically compared. Torsion test, pullout tests, fatigue tests, flexion/extension moment test, axial gripping capacity tests and torsional gripping capacity tests were conducted in accordance with ASTM F543, F1798 and F1717. Standard polyurethane foam and calf vertebrae were used as embedding medium for pullout tests. Classical pedicle screw pullout load on polyurethane foam was 564.8 N compared to the failure load for calf vertebrae's 1264 N. Under the same test conditions, expandable poly-ether-ether-ketone shell system's pullout loads from polyurethane foam and calf vertebrae were 1196.3 and 1890 N, respectively. The pullout values for expandable poly-ether-ether-ketone shell were 33% and 53% higher than classical pedicle screw on polyurethane foam and calf vertebrae, respectively. The expandable poly-ether-ether-ketone shell exhibited endurance on its 90% of yield load. Contrary to poly-ether-ether-ketone shell, classical pedicle screw exhibited endurance on 70% of its yield load. Expandable poly-ether-ether-ketone shell exhibited much higher pullout performance than classical pedicle screw. Fatigue performance of expandable poly-ether-ether-ketone shell is also higher than classical pedicle screw due to damping the micro motion capacity of the poly-ether-ether-ketone. Expandable poly-ether-ether-ketone shell is a safe alternative to all other expandable pedicle screw systems on mechanical perspective.

  6. Preparation, characterization, and modeling of α-zirconium phosphonates with ether-functional surfaces

    PubMed Central

    Furman, Benjamin R.; Wellinghoff, Stephen T.; Thompson, Paul M.; Beall, Gary W.; Laine, Richard M.; Rawls, H. Ralph

    2009-01-01

    Layered α-zirconium(IV) phosphonates were prepared from novel ether-terminal alkyl phosphonic acids, providing nanoplatelets with brush-like polar surfaces. The precursor materials were characterized by NMR, mass spectrometry, and elemental analysis. The derived nanoparticles were examined by XRD, TEM, TGA, and elemental analysis. The experimental compositions were slightly rich in organophosphorus content. In general, the layered materials had good crystallinity, with layer reflections appearing up to (005) and d-spacings consistent with the anticipated α-phase structure. Computer simulations suggest that tailored surface chemistries, including ether functionalities, will offer favorable thermodynamic interactions with polyester polymer matrices. PMID:20090854

  7. Preparation of ordered and crosslinked films from liquid crystalline vinyl ether monomers

    SciTech Connect

    Andersson, H.; Sahlen, F.; Gedde, U.W.; Hult, A.

    1993-12-31

    Highly ordered densely crosslinked liquid crystalline poly(vinyl ether) films have been prepared by in-situ photopolymerization of oriented bifunctional mesogenic vinyl ether monomers. Orientation was achieved either by a simple surface treatment, using an unidirectionally rubbed polyimide film or by a magnetic field. Polymerization from various monomer phases resulted in LC polymer network films with different molecular organizations. The films were analyzed with small-angle X-ray scattering, polarized light microscopy and infrared-dichroism measurements. It was shown that films with nematic, smectic A and smectic B structures were obtained, the latter having a very high degree of orientation.

  8. Shifting from hydrogen bond network to π-π stacking: a key mechanism for reversible thermochromic sulfonated poly(ether ether ketone).

    PubMed

    Jarumaneeroj, Chatchai; Tashiro, Kohji; Chirachanchai, Suwabun

    2014-08-01

    Sulfonated poly(ether ether ketone) (SPEEK) thin film performs reversible thermochromic property by developing the color to be yellowish at the temperature above 190 °C. The detailed analyses based on temperature-dependent techniques suggest the thermal treatment inducing the shifting of the hydrogen bond network between the sulfonated group and the hydrated water molecules to the π-π stacking among aromatic rings in SPEEK chains. Although it is general that the polymer chain packing is unfavorable at high temperature, the present work shows a good example that when the polymer chains can form specific molecular interaction, such as π-π stacking, even in harsh thermal treatment, a rearrangement will effectively occur, which leads to an external stimuli-responsive property.

  9. Determination of fumaric and maleic acids with stacking analytes by transient moving chemical reaction boundary method in capillary electrophoresis.

    PubMed

    He, Jian-Feng; Yang, Wei-Ying; Yao, Fu-Jun; Zhao, Hong; Li, Xiang-Jun; Yuan, Zhuo-Bin

    2011-06-17

    The paper presents an on-line transient moving chemical reaction boundary (MCRB) method for simply but efficiently stacking analytes in capillary electrophoresis (CE). The CE technique was developed for a rapid determination of fumaric and maleic acid. Based on the theory of MCRB, Effects of several important factors such as the pH and concentration of running buffer and the conditions of stacking analytes were investigated to acquire the optimum conditions. The optimized separations were carried out in a 20 mmol/L sulphate neutralized with ethylenediamine to pH 6.0 electrolytes using a capillary coated with poly (diallyldimethylammonium chloride) and direct UV detection at 214 nm. The optimized preconcentrations were carried out in 50 mmol/L borax (pH 9.0). The calibration curves were linear in the concentration range of 1.0×10⁻⁷-1.0×10⁻⁴ mol/L and 5.0×10⁻⁷-1.0×10⁻⁴ mol/L for fumaric and maleic acid with correlation coefficients higher than 0.9991. The detection limits were 5.34×10⁻⁸ mol/L for fumaric acid and 1.92×10⁻⁷ mol/L for maleic acid. This method was applied for determination of fumaric acid in apple juice and of fumaric and maleic acid in dl-malic, the recovery tests established for real samples were within the range 95-105%. This work provided a valid and simple approach to detect fumaric and maleic acid. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Measuring exposures to glycol ethers.

    PubMed

    Clapp, D E; Zaebst, D D; Herrick, R F

    1984-08-01

    In 1981, NIOSH began investigating the potential reproductive health effects resulting from exposures to a class of organic solvents known generically as glycol ethers (GE). This research was begun as a result of the NIOSH criteria document development program which revealed little data available on the health effects of glycol ether exposure. Toxicologic research was begun by NIOSH and other researchers which suggested substantial reproductive effects in animals. These animal data motivated a study of human exposures in the occupational setting. In 1981 and 1982 NIOSH conducted several walk-through surveys which included preliminary measurements of exposures in a variety of industries including painting trades, coal mining, production blending and distribution facilities, aircraft fueling, and communications equipment repair facilities. The human exposure data from these surveys is summarized in this paper with most results well below 1 parts per million (ppm) and only a few values approaching 10 ppm. Blood samples were collected at one site resulting in GE concentrations below the limit of detection. Exposures to airborne glycol ethers, in the industries investigated during the collection of this data, revealed several problems in reliably sampling GE at low concentrations. It became apparent, from the data and observations of work practices, that air monitoring alone provided an inadequate index of GE exposure. Further field studies of exposure to GE are anticipated, pending location of additional groups of exposed workers and development of more reliable methods for characterizing exposure, especially biological monitoring.

  11. A New Approach to Prepare Vegetable Oil-Based Polymers

    USDA-ARS?s Scientific Manuscript database

    Polymers from vegetable oils, such as soybean oil, were prepared by cationic polymerization in supercritical carbon dioxide (scCO2) medium. Boron trifluoride diethyl etherate (BF3.OEt2) was selected as catalyst. The resulting polymers have molecular weight ranging from 21,842 to 118,300 g/mol. Nu...

  12. Simulated space environmental effects on some experimental high performance polymers

    NASA Technical Reports Server (NTRS)

    Connell, John W.

    1993-01-01

    High performance polymers for potential space applications were evaluated under simulated space environmental conditions. Experimental resins from blends of acetylene terminated materials, poly(arylene ether)s and low color polyimides were exposed to high energy electron and ultraviolet radiation in an attempt to simulate space environmental effects. Thin films, neat resin moldings, and carbon fiber reinforced composites were exposed, and the effect on certain polymer properties were determined. Recent research involving the effects of various radiation exposures on the physical, optical, and mechanical properties of several experimental polymer systems is reviewed.

  13. Physico-mechanical properties of silanized-montmorillonite reinforced chitosan-co-poly(maleic anhydride) composites

    NASA Astrophysics Data System (ADS)

    Saputra, O. A.; Fajrin, A.; Nauqinida, M.; Suryanti, V.; Pramono, E.

    2017-07-01

    To solve the problems of dependence on petroleum as starting material in the manufacturing of plastics in Indonesia, green plastic from biopolymer like chitosan to be one of promising options and alternative to replace the conventional plastics. However, to overcome the mechanical and physical properties of chitosan, the addition of reinforcement agent was introduced. In this study, silanized-montmorillonite (sMMt) has been prepared as a reinforcement agent in the chitosan-co-poly(maleic anhydride) (referred as Cs-MAH) matrix. Silanizing of montmorillonite is one of strategy to improve the interaction between montmorillonite and chitosan, consequently, the mechanical properties, tensile strength of composites contained 6 phr of sMMt improved 56.5% to chitosan. Moreover, the presence both MAH and sMMt on the comosites also reduced swelling degree and swelling area by 20.6% and 26.7%.

  14. 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.

  15. 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.

  16. The guanidine and maleic acid (1:1) complex. The additional theoretical and experimental studies

    NASA Astrophysics Data System (ADS)

    Drozd, Marek; Dudzic, Damian

    2012-04-01

    On the basis of experimental literature data the theoretical studies for guanidinium and maleic acid complex with using DFT method are performed. In these studies the experimental X-ray data for two different forms of investigated crystal were used. During the geometry optimization process one equilibrium structure was found, only. According to this result the infrared spectrum for one theoretical molecule was calculated. On the basis of potential energy distribution (PED) analysis the clear-cut assignments of observed bands were performed. For the calculated molecule with energy minimum the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were obtained and graphically illustrated. The energy difference (GAP) between HOMO and LUMO was analyzed. Additionally, the nonlinear properties of this molecule were calculated. The α and β (first and second order) hyperpolarizability values are obtained. On the basis of these results the title crystal was classified as new second order NLO generator.

  17. Ozonolysis of maleic acid aerosols: effect upon aerosol hygroscopicity, phase and mass.

    PubMed

    Pope, F D; Gallimore, P J; Fuller, S J; Cox, R A; Kalberer, M

    2010-09-01

    The hygroscopicity and mass loss of aerosols initially composed of maleic acid have been investigated before and after reaction with ozone. The phase of the aerosol, solid or aqueous, during the reaction with ozone strongly affects the composition of the processed aerosol. Furthermore the loss of aerosol mass, via the production of volatile ozonolysis products, does not occur until the processed aerosol has existed as an aqueous phase aerosol. The loss rate of the aerosol mass appears to follow unimolecular first order kinetics which is consistent with the rate determining step being the cleavage of a weak hydroperoxide, or peroxide, bond (approximately 104 kJ mol(-1)). This speculative rate determining step, which is not based on chemical analysis, is possibly a universal feature in the ozonolysis of organic aerosol containing the alkene functionality.

  18. Hydrogen bond cross-linked sulfonated poly(imino ether ether ketone) (PIEEK) for fuel cell membranes

    NASA Astrophysics Data System (ADS)

    Chang, Guanjun; Shang, Zhenfang; Yang, Li

    2015-05-01

    A new diamine monomer, 3,3‧-dihydroxydiphenylamine, is prepared by the palladium catalyzed C-N coupling reaction and the following reduction reaction of 3-bromoanisole and m-anisidine. A series of novel hydrogen bond cross-linked sulfonated poly(imino ether ether ketone) (SPIEEK) are obtained by the copolymerization of sodium 5,5‧-carbonylbis(2-fluorobenzene sulfonate), 4,4‧-difluorobenzophenone with 3,3‧-dihydroxydiphenylamine. The structures of resulting polymers are characterized by means of FT-IR, 1H NMR spectroscopy, and elemental analysis; the results show an agreement with the proposed structure. The resulting SPIEEK membranes display much better resistance to swelling than these without imino groups due to the strong interchain interaction through imino and sulfonic acid groups. The SPIEEK-60 and SPIEEK-80 membrane show the proton conductivity of 0.118 and 0.154 S cm-1 at 80 °C which is higher than Nafion 117 (0.082 S cm-1 at 80 °C). Moreover, the SPIEEK membranes exhibit good mechanical properties and lower methanol permeability due to the hydrogen bondings between the polymer chains.

  19. Polydopamine-functionalized poly(ether ether ketone) tube for capillary electrophoresis-mass spectrometry.

    PubMed

    Zhou, Wei; Zhang, Wenpeng; Liu, Yikun; Yu, Xinhong; Chen, Zilin

    2017-09-22

    Capillary electrophoresis-mass spectrometry (CE-MS) is a hyphenated technique that combines the advantages like low sample consumption, high separation efficiency, short analytical time in CE and high sensitivity, powerful molecular structure elucidation in MS. Polyimide-coated fused silica capillary has become the most dominant capillary for CE, but it suffers from swelling and aminolysis of polyimide coating when treated with organic solvents and alkaline buffer in the CE-MS interface in which the polyimide coating at the end of the capillary is exposed to the solution, and this phenomenon can result in current instability, irregular electrospray and clogging at outlet after prolonged use. In this work, poly(ether ether ketone) (PEEK) capillary was explored as separation capillary for CE-MS. The problems like swelling and aminolysis of polyimide coating were solved due to the high thermal and chemical stability of PEEK material. After modification with polydopamine, PEEK capillary (PD-PEEK) can generate adjustable electroosmotic flow and provide good separation selectivity. The zwitterion polymer of polydopamine can provide cathodic electroosmotic flow (EOF) at high pH value (pH ≥ 5) and anodic EOF at low pH value (pH ≤ 4), and the EOF mobility can also be adjusted by controlling the modification time of polydopamine. Good separation performance was obtained in the analysis for several classes of compounds including amino acids, phenols and plant hormones at rational EOF direction. Repeatability of the PD-PEEK capillary was studied, with relative standard deviations for intra-day, inter-day runs and between tubes less than 4.94%. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Aza crown ether compounds as anion receptors

    DOEpatents

    Lee, H.S.; Yang, X.O.; McBreen, J.

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI{sup +} ion in alkali metal batteries. 3 figs.

  1. Aza crown ether compounds as anion receptors

    DOEpatents

    Lee, Hung Sui; Yang, Xiao-Oing; McBreen, James

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI.sup.+ ion in alkali metal batteries.

  2. Crystalline Imide/Arylene Ether Copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J.; Hergenrother, Paul M.; Bass, Robert G.

    1991-01-01

    Series of imide/arylene ether block copolymers prepared by using arylene ether blocks to impart low melt viscosity, and imide blocks to provide high strength and other desirable mechanical properties. Work represents extension of LAR-14159 on imide/arylene ether copolymers in form of films, moldings, adhesives, and composite matrices. Copolymers potentially useful in variety of high-temperature aerospace and microelectronic applications.

  3. Is the ether group hydrophilic or hydrophobic?

    PubMed

    Menger, Fredric M; Chlebowski, Mary E

    2005-03-29

    A series of six surfactants, each with two ether oxygens within otherwise all-hydrocarbon chains, were synthesized and examined for their colloidal properties. Since an ether oxygen is sterically and conformationally similar to the methylene group it has replaced, the ether effect on micellization should stem mainly from solvation of the oxygen and, possibly, disrupted hydrophobicity of its adjacent carbons. It was found that critical aggregation values among the surfactants differ only modestly despite the total length of the ether-separated carbon segments ranging from 12 to 18. Shorter ether surfactants with only 12 or 14 total carbons appear to form small, loose aggregates owing, presumably, to a mild hydrophilicity of the ether groups. A surfactant with 18 chain carbons has a greater tendency to associate hydrophobically, but this is counterbalanced by a relatively water-free environment encountered by the ether groups within a more conventional micelle interior. The result is a leveling effect in which the critical aggregation concentration (cac) loses it sensitivity to chain length. Above their cac's, none of the ether surfactants is a good solubilizer of tetramethysilane or mesitylene. This is not necessarily a predictable finding since it was conceivable that the presence of interior ether groups might actually enhance solubilization (much as ether is a better solvent than hexane). Foamability and solid adsorption studies also indicate that the ethers impair surface activity. In response to the question posed in the paper's title, two ether groups are not sufficiently hydrophilic to prevent aggregation, but they do manage to alter the micelles' morphology and properties considerably.

  4. Electrochemical properties of composite polymer electrolyte applied to rechargeable lithium polymer battery

    NASA Astrophysics Data System (ADS)

    Matoba, Yasuo; Matsui, Shohei; Tabuchi, Masato; Sakai, Takaaki

    High-molecular-weight comb-shaped polyethers, poly(ethylene oxide-co-2-(2-methoxyethoxy) ethyl glycidyl ether-co-allyl glycidyl ether) (P(EO/EM/AGE)) and poly(ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether) (P(EO/EM)), were synthesized and used for the preparation of the all solid polymer electrolyte and the composite polymer electrolyte combined with a plasticizer Star-EO-OMe, pentaerythritol tetrakis(2-methoxyethyl ether), which shows low vapor pressure, respectively. Some electrochemical properties of the polymer electrolytes and performances of the cell consisting of lithium/polymer electrolyte/LiCoO 2 were studied. The addition of Star-EO-OMe to polymer electrolyte brought about a large increase in ionic conductivity. The composite electrolyte containing 50 wt.% of Star-EO-OMe complexed with LiTFSI, lithium bis(trifluoromethylsulfonyl)imide, exhibited high ionic conductivity in the order of 10 -4 S cm -1 at 10 °C and approximately 10 -5 S cm -1 at -20 °C. The cell performance was also improved by the addition of Star-EO-OMe.

  5. Ketimine modifications as a route to novel amorphous and derived semicrystalline poly(arylene ether ketone) homo- and copolymers

    NASA Technical Reports Server (NTRS)

    Mohanty, D. K.; Lowery, R. C.; Lyle, G. D.; Mcgrath, J. E.

    1987-01-01

    A series of amine terminal amorphous poly(arylene ether ketone) oligomers of controlled molecular weights (2-15 K) were synthesized. These oligomers have been found to undergo 'self-crosslinking' reactions upon heating above 220 C, via the reaction of the terminal amine groups with the in-chain keto carbonyl functionalities. The resulting networks are ductile, chemically resistant, and nonporous. The networks obtained via generated ketimine functionality were characterized by solid state NMR. They have also been found to be remarkably stable toward hydrolysis. Ketimine functional bishalide monomers have also been synthesized. Such monomers have been utilized to synthesize a wide variety of amorphous poly(arylene ether) ketimine polymers. A high molecular weight hydroquinone functional poly(arylene ether) ketimine has been acid treated to regenerate a poly(arylene ether ketone) backbone in solution. This novel procedure thus allows for the synthesis of important matrix resins under relatively mild conditions.

  6. Stable, hydroxyl functional polycarbonates with glycerol side chains synthesized from CO(2) and isopropylidene(glyceryl glycidyl ether).

    PubMed

    Geschwind, Jeannette; Frey, Holger

    2013-01-25

    A series of functional polycarbonates, poly((isopropylidene glyceryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((IGG-co-GME) C)) random copolymers with different fractions of 1,2-isopropylidene glyceryl glycidyl ether (IGG) units, is synthesized. After acidic hydrolysis of the acetal protecting groups, a new type of functional polycarbonate prepared directly from CO(2) and glycerol is obtained, namely poly((glyceryl glycerol)-co-(glycidyl methyl ether) carbonate) (P((GG-co-GME) C)). All hydroxyl functional samples exhibit monomodal molecular weight distributions with PDIs between 2.5 and 3.3 and M(n) between 12 000 and 25 000 g mol(-1) . Thermal properties reflect the amorphous structure of the polymers. The materials are stable in bulk and solution. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2008-12-30

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  8. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2004-05-25

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  9. Kinetics and Mechanism for Formation of Olefin Complexes in the Reaction between Palladium(II) and Maleic Acid.

    PubMed

    Shi, Tiesheng; Elding, Lars I.

    1998-10-19

    Complex formation between Pd(H(2)O)(4)(2+) and maleic acid (H(2)A) has been studied at 25 degrees C and 2.00 M ionic strength in acidic aqueous solution. Reaction takes place with 1:1 stoichiometry. The kinetics has been followed by use of stopped-flow spectrophotometry under pseudo-first-order conditions with maleic acid in excess. In the concentration ranges 0.01 maleic acid concentration are rationalized in terms of a complex reaction mechanism of the type A right arrow over left arrow B --> C where, in addition, both steps contain contributions from parallel reactions. The amplitude of the first phase increases with increasing [H(2)A](tot) and with decreasing [H(+)]. Multiwavelength global analysis of the kinetic traces and the UV-vis spectral changes suggest that a monodentate oxygen-bonded hydrogen maleate complex, [Pd(H(2)O)(3)OOCCH=CHCOOH](+), B, with stability constant K(2) = 205 +/- 40 M(-)(1) is formed as an intermediate in this first step via two parallel reversible reactions in which Pd(H(2)O)(4)(2+) reacts with maleic acid and hydrogen maleate, respectively. In the following step, B --> C, slow intramolecular ring closure with a rate constant of 0.8 +/- 0.1 s(-)(1) at 25 degrees C gives the reaction product C, which is concluded to be a 4.5-membered olefin-carboxylato chelate complex on the basis of stoichiometry and UV-vis/NMR spectra. Parallel and irreversible attack by maleic acid and hydrogen maleate acting as olefins on the intermediate B also leads to formation of C. C is stable for at least 20 h for concentrations of maleic acid. Neither a steady-state approximation nor a rapid preequilibrium assumption can be used for the

  10. PVDF-HFP/ether-modified polysiloxane membranes obtained via airbrush spraying as active separators for application in lithium ion batteries.

    PubMed

    Seidel, S M; Jeschke, S; Vettikuzha, P; Wiemhöfer, H-D

    2015-08-04

    Improved hybrid polymer electrolyte membranes are introduced based on ether-modified polysiloxanes and poly(vinylidene fluoride-co-hexafluoropropylene) yielding a safe separator membrane, which is able to be sprayed directly onto lithium ion battery active materials, with an active role for enhanced ion transport.

  11. Preparation and characterization of poly (arylene ether isoxazole)s by fluoride ion-mediated aromatic nucleophilic displacement reactions

    NASA Technical Reports Server (NTRS)

    Herbert, C. G.; Bass, R. G.

    1994-01-01

    As part of a continuing effort to prepare novel thermally stable high-performance polymers, poly(arylene ether isoxazole)s have been prepared by fluoride ion-catalyzed aromatic nucleophilic substitution reactions with bis(trimethylsiloxyphenyl) isoxazoles and activated bisarylhalides in diphenyl sulfone. Initial investigation involving the preparation of these materials with isoxazole bisphenols and activated bisarylhalides in the presence of potassium carbonate indicated that, under reaction conditions necessary to prepare high-molecular-weight materials, the isoxazole monomer was converted to an enamino ketone. This side reaction was avoided by using fluoride as a base. However, trimethylsilyl ether derivatives of the isoxazole bisphenols were required in these polymerizations for the preparation of high-molecular-weight materials. Moderate to high inherent viscosity eta(sub inh): 0.43-0.87 dl/g) materials with good thermal stability (air: 409-477 C, helium: 435-512 C) can be prepared by the silyl ether method. Glass transition temperatures ranged from 182 to 225 C for polymers with phenyl pendants and from 170 to 214 C for those without. Molecular weight control by 2% endcapping and the incorporation of a phenyl pendant at the 4 position of the isoxazole is necessary to yield polymers soluble in polar aprotic solvents at room temperature. There is evidence, however, indicating the existence of crosslinks between the polymer chains when the silyl ether approach is utilized.

  12. Preparation and characterization of poly (arylene ether isoxazole)s by fluoride ion-mediated aromatic nucleophilic displacement reactions

    NASA Technical Reports Server (NTRS)

    Herbert, C. G.; Bass, R. G.

    1994-01-01

    As part of a continuing effort to prepare novel thermally stable high-performance polymers, poly(arylene ether isoxazole)s have been prepared by fluoride ion-catalyzed aromatic nucleophilic substitution reactions with bis(trimethylsiloxyphenyl) isoxazoles and activated bisarylhalides in diphenyl sulfone. Initial investigation involving the preparation of these materials with isoxazole bisphenols and activated bisarylhalides in the presence of potassium carbonate indicated that, under reaction conditions necessary to prepare high-molecular-weight materials, the isoxazole monomer was converted to an enamino ketone. This side reaction was avoided by using fluoride as a base. However, trimethylsilyl ether derivatives of the isoxazole bisphenols were required in these polymerizations for the preparation of high-molecular-weight materials. Moderate to high inherent viscosity eta(sub inh): 0.43-0.87 dl/g) materials with good thermal stability (air: 409-477 C, helium: 435-512 C) can be prepared by the silyl ether method. Glass transition temperatures ranged from 182 to 225 C for polymers with phenyl pendants and from 170 to 214 C for those without. Molecular weight control by 2% endcapping and the incorporation of a phenyl pendant at the 4 position of the isoxazole is necessary to yield polymers soluble in polar aprotic solvents at room temperature. There is evidence, however, indicating the existence of crosslinks between the polymer chains when the silyl ether approach is utilized.

  13. Degradation of imidazolium- and quaternary ammonium-functionalized poly(fluorenyl ether ketone sulfone) anion exchange membranes.

    PubMed

    Chen, Dongyang; Hickner, Michael A

    2012-11-01

    Imidazolium and quaternary ammonium-functionalized poly(fluorenyl ether ketone sulfone)s were synthesized successfully with the same degree of cationic functionalization and identical polymer backbones for a comparative study of anion exchange membranes (AEMs) for solid-state alkaline membrane fuel cells (AMFCs). Both anion exchange membranes were synthesized using a new methyl-containing monomer that avoided the use of toxic chloromethylation reagents. The polymer chemical structures were confirmed by ¹H NMR and FTIR. The derived AEMs were fully characterized by water uptake, anion conductivity, stability under aqueous basic conditions, and thermal stability. Interestingly, both the cationic groups and the polymer backbone were found to be degraded in 1 M NaOH solution at 60 °C over 48 h as measured by changes of ion exchange capacity and intrinsic viscosity. Imidazolium-functionalized poly(fluorenyl ether ketone sulfone)s had similar aqueous alkaline stability to quaternary ammonium-functionalized materials at 60 °C but much lower stability at 80 °C. This work demonstrates that quaternary ammonium and imidazolium cationic groups are not stable on poly(arylene ether sulfone) backbones under relatively mild conditions. Additionally, the poly(arylene ether sulfone) backbone, which is one of the most common polymers used in ion exchange membrane applications, is not stable in the types of molecular configurations analyzed.

  14. Degradation of Imidazolium- and Quaternary Ammonium-Functionalized Poly(fluorenyl ether ketone sulfone) Anion Exchange Membranes

    SciTech Connect

    Chen, DY; Hickner, MA

    2012-11-01

    Imidazolium and quaternary ammonium-functionalized poly(fluorenyl ether ketone sulfone)s were synthesized successfully with the same degree of cationic functionalization and identical polymer backbones for a comparative study of anion exchange membranes (AEMs) for solid-state alkaline membrane fuel cells (AMFCs). Both anion exchange membranes were synthesized using a new methyl-containing monomer that avoided the use of toxic chloromethylation reagents. The polymer chemical structures were confirmed by H-1 NMR and FTIR. The derived AEMs were fully characterized by water uptake, anion conductivity, stability under aqueous basic conditions, and thermal stability. Interestingly, both the cationic groups and the polymer backbone were found to be degraded in 1 M NaOH solution at 60 degrees C over 48 h as measured by changes of ion exchange capacity and intrinsic viscosity. Imidazolium-functionalized poly(fluorenyl ether ketone sulfone)s had similar aqueous alkaline stability to quaternary ammonium-functionalized materials at 60 degrees C but much lower stability at 80 degrees C. This work demonstrates that quaternary ammonium and imidazolium cationic groups are not stable on poly(arylene ether sulfone) backbones under relatively mild conditions. Additionally, the poly(arylene ether sulfone) backbone, which is one of the most common polymers used in ion exchange membrane applications, is not stable in the types of molecular configurations analyzed.

  15. Low dielectric fluorinated poly(phenylene ether ketone) film and coating

    NASA Technical Reports Server (NTRS)

    Cassidy, Patrick E. (Inventor); Tullos, Gordon L. (Inventor); St.clair, Anne K. (Inventor)

    1990-01-01

    The present invention relates to film and coating materials prepared from novel fluorinated poly(phenylene ether ketones). A fluorinated poly(phenylene ether ketone) is prepared by reacting a bisphenol with 1,1,1,3,3,3 hexafluoro-2,2-bis 4-(4-halobenzoyl) phenyl propane (wherein halo is fluoro or chloro), which is a novel monomer formed as the reaction product of halobenzene (wherein halo is fluoro or chloro) and 1,1,1,3,3,3 hexafluoro-2,2-bis (p-chloro formyl phenyl) propane. Especially beneficial results of this invention are that films and coating materials prepared from the novel fluorinated poly(phenylene ether ketone) are essentially optically transparent/colorless and have a lower dielectric constant than otherwise comparable, commercially available poly(phenylene ether ketones). Moreover, unlike the otherwise comparable commercially available materials, the novel fluorinated poly(phenylene ether ketones) of the present invention can be solution cast or sprayed to produce the films and coatings. Furthermore, the long term thermal stability of the polymers of the present invention is superior to that of the commercially available materials.

  16. Conductivity enhancement of sulfonated poly(ether ketone ketone) blends using electric field structuring techniques

    NASA Astrophysics Data System (ADS)

    Gasa, Jeffrey V.; Shaw, Montgomery T.

    2004-03-01

    Binary blends composed of an ion-containing polymer and a secondary component were cast under an applied elec. field to produce membranes with anisotropic morphologies. The ion-containing polymer was sulfonated poly(ether ketone ketone) (SPEKK) and the secondary component was either poly(ether imide) (PEI) or styrene-acrylonitrile (SAN) copolymer. A range of compositions and sulfonation levels were studied using this blend system. Optical and SEM micrographs of the resulting membranes showed columnar structures that were oriented along the direction of the field. It was found that electric field alignment only occurs when SPEKK is the dispersed phase but not when it is the matrix. The results show that the conductivities of the membranes that were cast under an electric field were significantly higher than those of the membranes cast without electric field. The conductivity measurements were interpreted in terms of a composite equation with structure-dependent parameters.

  17. Conformational Study of Dibenzyl Ether

    NASA Astrophysics Data System (ADS)

    Hernandez-Castillo, Alicia O.; Abeysekera, Chamara; Hewett, Daniel M.; Zwier, Timothy S.

    2017-06-01

    Understanding the initial stages of polycyclic aromatic hydrocarbon (PAH) aggregation, the onset of soot formation, is an important goal on the pathway to cleaner combustion processes. PAHs with short alkyl chains, present in fuel-rich combustion environments, can undergo reactions that will chemically link aromatic rings together. One such example of a linked diaryl compound is dibenzyl ether, C_{6}H_{5}-CH_{2}-O-CH_{2}-C_{6}H_{5}. The -CH_{2}-O-CH_{2}- linkage has a length and flexibility well-suited to forming a π-stacked conformation between the two phenyl rings. In this talk, we will explore the single-conformation spectroscopy of dibenzyl ether under jet-cooled conditions in the gas phase. Laser-induced fluorescence, chirped pulse Fourier transform microwave (8-18 GHz region), and single-conformation infrared spectroscopy in the alkyl CH stretch region were all carried out on the molecule, thereby interrogating its full array of electronic, vibrational and rotational degrees of freedom. This work is the first step in a broader study to determine the extent of π-stacking in linked aryl compounds as a function of linkage and PAH size.

  18. Bacterial Utilization of Ether Glycols

    PubMed Central

    Fincher, Edward L.; Payne, W. J.

    1962-01-01

    A soil bacterium capable of using oligo- and polyethylene glycols and ether alcohols as sole sources of carbon for aerobic growth was isolated. The effects of substituent groups added to the ether bonds on the acceptability of the compounds as substrates were studied. Mechanisms for the incorporation of two-carbon compounds were demonstrated by the observation that acetate, glyoxylate, ethylene glycol, and a number of the tricarboxylic acid cycle intermediates served as growth substrates in minimal media. The rate of oxidation of the short-chained ethylene glycols by adapted resting cells varied directly with increasing numbers of two-carbon units in the chains from one to four. The amount of oxygen consumed per carbon atom of oligo- and polyethylene glycols was 100% of theoretical, but only 67% of theoretical for ethylene glycol. Resting cells oxidized oligo- and polyethylene glycols with 2 to 600 two-carbon units in the chains. Longer chained polyethylene glycols (up to 6,000) were oxidized at a very slow rate by these cells. Dehydrogenation of triethylene glycol by adapted cells was observed, coupling the reaction with methylene blue reduction. PMID:13945208

  19. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  20. Polymeric Electrolyte Containing 12-Crown-4 Ether

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesa; Distefano, Salvador

    1992-01-01

    Experiments show incorporation of 12-crown-4 ether into solid electrolytes based on polyethylene oxide enhances their electrochemical properties. More specifically, 12-crown-4 ether increases Faradaic efficiency for Li+ ions in low-power secondary Li cells and enables operation of these cells at lower temperatures with higher efficiencies.

  1. An expedient synthesis of linden ether.

    PubMed

    Serra, Stefano; Cominetti, Alessandra A

    2014-03-01

    We here describe a comprehensive study on the preparation of the intensive flavor 3,9-epoxy-p-mentha-1,4(8)-diene (1). Key steps of the presented synthesis are the selective addition of MeLi to the keto-ester 7, the regioselective cyclization of the obtained triol to give the ethers 4 and 8 and the selective dehydration of ether 4 through the use of POCI3 and pyridine. It is worth noting that the presented synthesis represents the first expedient and reliable entry to ether 1. Being present in linden honey, 1 is also known as linden ether and it has been regarded as a potential marker for the authentication of the linden honey origin. Therefore, ether 1 can be used as a useful reference standard for the analysis of the natural flavors, as we demonstrated by means of its identification in a sample ofunifloral linden honey.

  2. Silver-containing polymer composition used in spacecraft and semiconductor optoelectronics control systems

    NASA Astrophysics Data System (ADS)

    Ivanov, A. A.; Tuev, V. I.

    2015-10-01

    The copolymer of the vinyl chloride-maleic anhydride and silver nano- and microparticle (70 wt %) composition is offered as a conductive adhesive for fixing various chips on the dielectric substrate. The wiring volume resistivity is up to 3.1×10-8 Ohm×m. The adhesive strength of the silver-containing polymer composition (70% of Ag) applied under a shear on the dielectric substrate is 106 N/mm2. Adhesive layers obtained from these substances have a high thermal conductivity up to λ = 199.93 W/m×K that depends on the amount of Ag in the polymer composition.

  3. Silver-containing polymer composition used in spacecraft and semiconductor optoelectronics control systems

    SciTech Connect

    Ivanov, A. A. Tuev, V. I.

    2015-10-27

    The copolymer of the vinyl chloride-maleic anhydride and silver nano- and microparticle (70 wt %) composition is offered as a conductive adhesive for fixing various chips on the dielectric substrate. The wiring volume resistivity is up to 3.1×10{sup −8} Ohm×m. The adhesive strength of the silver-containing polymer composition (70% of Ag) applied under a shear on the dielectric substrate is 106 N/mm{sup 2}. Adhesive layers obtained from these substances have a high thermal conductivity up to λ = 199.93 W/m×K that depends on the amount of Ag in the polymer composition.

  4. 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.

  5. Octahedral d[sup 6] Bis(maleimide) and Bis(maleic anhydride) complexes of molybdenum

    SciTech Connect

    Lai, Chen-Hsing; Cheng, Chien-Hong; Liao, Fen-Ling; Wang, Sue-Lein )

    1993-12-08

    Mo(CO)[sub 3](CH[sub 3]CN)[sub 3] reacts with 2 equiv of alkene, where the alkene is maleimide (MI), N-phenylmaleimide (PhMI), or N-methylmaleimide, to give the corresponding Mo(CO)[sub 2](alkene)[sub 2](CH[sub 3]CN)[sub 2] complex (1a-c, respectively) in excellent yield. Dissolution of 1 in DMSO led to the substitution of acetonitrile ligands by DMSO to form the corresponding cis bis(DMSO) complexes 2a-c. Addition of 1 equiv of NN to 1 yields MO(CO)[sub 2](alkene)[sub 2](alkene)[sub 2](NN) (NN = en, alkene = PhMI (3b), MeMI (3c); NN = o-phenylenediamine, alkene = PhMI (4)). Treatment of Mo-(CO)[sub 4](NN) (NN = phen or bpy), with 2 equiv of alkene in refluxed acetonitrile for 2 h gave Mo(CO)[sub 2]-(alkene)[sub 2](NN) (NN = phen, alkene = MI (5a), PhMI (5b); NN = bpy, alkene = MI (6a), PhMI (6b)). Treatment of Mo(CO)[sub 3](CH[sub 3]CN)[sub 3] with 2 equiv of maleic anhydride (MA) gave Mo(CO)[sub 2](MA)[sub 2](CH[sub 3]CN)[sub 2] (7). The acetonitrile ligands in 7 were replaced by DMSO molecules to give complex 8 as 7 was dissolved in DMSO. Similarly, the reaction of 7 with a bidentate ligand NN (phen or bpy) gave the substituted product Mo(CO)[sub 2](MA)[sub 2](NN) (9 or 10). The structures and conformations of 1b and 7 were determined by X-ray diffraction. Both molecules adopt an octahedral geometry with mutually perpendicular trans alkene ligands and each alkene ligand eclipses a N-Mo-CO vector. Each PhMI or MA is oriented so that the central nitrogen or oxygen atom points to a carbonyl group. 1b crystallizes in triclinic space group P1. There are three possible conformations for a trans bis(maleimide) or bis(maleic anhydride) complex (I-III). The results of X-ray and NMR studies indicated that the main conformation of complexes 1-10 is I both in the solid state and in solution.

  6. Effects of hydrophobicity of diffusion layer on the electroreduction of biomass derivatives in polymer electrolyte membrane reactors.

    PubMed

    Chen, Wei; He, Gaohong; Ge, Feilong; Xiao, Wu; Benziger, Jay; Wu, Xuemei

    2015-01-01

    For the first time, the hydrophobicity design of a diffusion layer based on the volatility of hydrogenation reactants in aqueous solutions is reported. The hydrophobicity of the diffusion layer greatly influences the hydrogenation performance of two model biomass derivatives, namely, butanone and maleic acid, in polymer electrolyte membrane reactors operated at atmospheric pressure. Hydrophobic carbon paper repels aqueous solutions, but highly volatile butanone can permeate in vapor form and achieve a high hydrogenation rate, whereas, for nonvolatile maleic acid, great mass transfer resistance prevents hydrogenation. With a hydrophilic stainless-steel welded mesh diffusion layer, aqueous solutions of both butanone and maleic acid permeate in liquid form. Hydrogenation of maleic acid reaches a similar level as that of butanone. The maximum reaction rate is 340 nmol cm(-2)  s(-1) for both hydrogenation systems and the current efficiency reaches 70 %. These results are better than those reported in the literature. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Preparing alkaline anion exchange membrane with enhanced hydroxide conductivity via blending imidazolium-functionalized and sulfonated poly(ether ether ketone)

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Jiang, Zhongyi; Tian, Huimin; Wang, Siwen; Zhang, Bei; Cao, Ying; He, Guangwei; Li, Zongyu; Wu, Hong

    2015-08-01

    The development of alkaline anion exchange membrane (AEM) with both high ion conductivity and stabilities is of great significance for fuel cell applications. In this study, a facile acid-base blending method is designed to improve AEM performances. Basic imidazolium-functionalized poly (ether ether ketone) with a high functionalization degree is employed as polymer matrix to pursue high ion-exchange capacity (IEC) as well as high hydroxide conductivity, meanwhile acidic sulfonated poly (ether ether ketone) (SPEEK) is employed as the cross-linking agent to enhance the stabilities of the blend membranes. Particularly, an in-situ Menshutkin/crosslinking method is exploited to prevent the flocculation in the preparation process of blend membranes. As a result, dense and defect-free blend membranes are obtained. The blend membranes exhibit high level of IEC up to 3.15 mmol g-1, and consequently possess elevated hydroxide conductivity up to 31.59 mS cm-1 at 30 °C. In addition, benefiting from the strong electrostatic interaction introduced by the acid-base blending, the stabilities and methanol resistance of blend membranes are enhanced.

  8. Redox polymer electrodes for advanced batteries

    DOEpatents

    Gregg, Brian A.; Taylor, A. Michael

    1998-01-01

    Advanced batteries having a long cycle lifetime are provided. More specifically, the present invention relates to electrodes made from redox polymer films and batteries in which either the positive electrode, the negative electrode, or both, comprise redox polymers. Suitable redox polymers for this purpose include pyridyl or polypyridyl complexes of transition metals like iron, ruthenium, osmium, chromium, tungsten and nickel; porphyrins (either free base or metallo derivatives); phthalocyanines (either free base or metallo derivatives); metal complexes of cyclams, such as tetraazacyclotetradecane; metal complexes of crown ethers and metallocenes such as ferrocene, cobaltocene and ruthenocene.

  9. Radiation effects on high performance polymers

    NASA Technical Reports Server (NTRS)

    Orwoll, R. A.

    1986-01-01

    Polymer matrix materials are candidates for use in large space antennas and space platforms that may be deployed in geosynchronous orbit 22,500 miles above the Earth. A principal concern is the long term effects of an environment that is hostile to organic polymers, including high energy electromagnetic radiation, bombardment by charged particles, and large abrupt changes in temperature. Two polyarylene ethers which might be utilized as models for polymers in space applications were subjected to dosages of 70 keV electrons up to 3.4 x 10 to the 10th power rad. The irradiated films were then examined to determine the effects of the high-energy electrons.

  10. Redox polymer electrodes for advanced batteries

    DOEpatents

    Gregg, B.A.; Taylor, A.M.

    1998-11-24

    Advanced batteries having a long cycle lifetime are provided. More specifically, the present invention relates to electrodes made from redox polymer films and batteries in which either the positive electrode, the negative electrode, or both, comprise redox polymers. Suitable redox polymers for this purpose include pyridyl or polypyridyl complexes of transition metals like iron, ruthenium, osmium, chromium, tungsten and nickel; porphyrins (either free base or metallo derivatives); phthalocyanines (either free base or metallo derivatives); metal complexes of cyclams, such as tetraazacyclotetradecane; metal complexes of crown ethers and metallocenes such as ferrocene, cobaltocene and ruthenocene. 2 figs.

  11. Tailoring chemical and physical properties of fibrous scaffolds from block copolyesters containing ether and thio-ether linkages for skeletal differentiation of human mesenchymal stromal cells.

    PubMed

    Chen, Honglin; Gigli, Matteo; Gualandi, Chiara; Truckenmüller, Roman; van Blitterswijk, Clemens; Lotti, Nadia; Munari, Andrea; Focarete, Maria Letizia; Moroni, Lorenzo

    2016-01-01

    Bioactive scaffolds for tissue engineering call for demands on new materials which can enhance traditional biocompatibility requirements previously considered for clinical implantation. The current commercially available thermoplastic materials, such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly(ε-caprolactone) (PCL) and their copolymers, have been used to fabricate scaffolds for regenerative medicine. However, these polymers have limitations including lacking of broadly tuning mechanical and degradable properties, and activation of specific cell-scaffold interactions, which limit their further application in tissue engineering. In the present study, electrospun scaffolds were successfully fabricated from a new class of block poly(butylene succinate)-based (PBS-based) copolyesters containing either butylene thiodiglycolate (BTDG) or butylene diglycolate (BDG) sequences. The polyesters displayed tunable mechanical properties and hydrolysis rate depending on the molecular architecture and on the kind of heteroatom introduced along the polymer backbone. To investigate their potential for skeletal regeneration, human mesenchymal stromal cells (hMSCs) were cultured on the scaffolds in basic, osteogenic and chondrogenic media. Our results demonstrated that PBS-based copolyesters containing thio-ether linkages (i.e. BTDG segments) were more favorable for chondrogenesis of hMSCs than those containing ether linkages (i.e. BDG sequences). In contrast, PBS-based copolyesters containing ether linkages showed enhanced mineralization. Therefore, these new functional scaffolds might hold potential for osteochondral tissue engineering applications.

  12. Design of amine modified polymer dispersants for liquid-phase exfoliation of transition metal dichalcogenide nanosheets and their photodetective nanocomposites

    NASA Astrophysics Data System (ADS)

    Lee, Jinseong; Hahnkee Kim, Richard; Yu, Seunggun; Babu Velusamy, Dhinesh; Lee, Hyeokjung; Park, Chanho; Cho, Suk Man; Jeong, Beomjin; Sol Kang, Han; Park, Cheolmin

    2017-12-01

    Liquid-phase exfoliation (LPE) of transition metal dichalcogenide (TMD) nanosheets is a facile, cost-effective approach to large-area photoelectric devices including photodetectors and non-volatile memories. Non-destructive exfoliation of nanosheets using macromolecular dispersing agents is beneficial in rendering the TMD nanocomposite films suitable for mechanically flexible devices. Here, an efficient LPE of molybdenum disulfide (MoS2) with an amine modified poly(styrene-co-maleic anhydride) co-polymer (AM-PSMA) is demonstrated, wherein the maleic anhydrides were converted into maleic imides with primary amines using N-Boc-(CH2) n -NH2. The exfoliation of nanosheets was facilitated through Lewis acid-base interaction between the primary amine and transition metal. The results demonstrate that the exfoliation depends upon both the fraction of primary amines in the polymer chain and their distance from the polymer backbone. Under optimized conditions of primary amine content and its distance from the backbone, AM-PSMA gave rise to a highly concentrated MoS2 nanosheet suspension that was stable for over 10 d. Exfoliation of several other TMDs was also achieved using the optimized AM-PSMA, indicating the scope of AM-PSMA applications. Furthermore, a flexible composite film of AM-PSMA and MoS2 nanosheets fabricated by vacuum-assisted filtration showed excellent photoconductive performances including a high I on/I off ratio of 102 and a fast photocurrent switching of 300 ms.

  13. Two crown-ether-coordinated caesium halogen salts.

    PubMed

    Well, Natalija van; Klein, Christian; Ritter, Franz; Assmus, Wolf; Krellner, Cornelius; Bolte, Michael

    2014-05-01

    The crystal structures of two crown-ether-coordinated caesium halogen salt hydrates, namely di-μ-bromido-bis[aqua(1,4,7,10,13,16-hexaoxacyclooctadecane)caesium(I)] dihydrate, [Cs2Br2(C12H24O6)2(H2O)2]·2H2O, (I), and poly[[diaquadi-μ-chlorido-μ-(1,4,7,10,13,16-hexaoxacyclooctadecane)dicaesium(I)] dihydrate], {[Cs2Cl2(C12H24O6)(H2O)2]·2H2O}n, (II), are reported. In (I), all atoms are located on general positions. In (II), the Cs(+) cation is located on a mirror plane perpendicular to the a axis, the chloride anion is located on a mirror plane perpendicular to the c axis and the crown-ether ring is located around a special position with site symmetry 2/m, with two opposite O atoms exactly on the mirror plane perpendicular to the a axis; of one water molecule, only the O atom is located on a mirror plane perpendicular on the a axis, while the other water molecule is completely located on a mirror plane perpendicular to the c axis. Whereas in (I), hydrogen bonds between bromide ligands and water molecules lead to one-dimensional chains running along the b axis, in (II) two-dimensional sheets of water molecules and chloride ligands are formed which combine with the polymeric caesium-crown polymer to give a three-dimensional network. Although both compounds have a similar composition, i.e. a Cs(+) cation with a halogen, an 18-crown-6 ether and a water ligand, the crystal structures are rather different. On the other hand, it is remarkable that (I) is isomorphous with the already published iodide compound.

  14. The effect of oxygen concentration on the boundary lubricating characteristics of an unformulated C-ether to 300 C

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.

    1973-01-01

    The effect of oxygen concentration on the boundary lubricating characteristics of an unformulated C-ether was studied with the use of a ball-on disk sliding-friction apparatus. Results were compared with those obtained with a polyphenyl ether. Experimental conditions included oxygen concentrations ranging from 20 percent (air) to 0.001 percent (nitrogen), a load of 1 kilogram, a sliding speed of 17 meters per minute, and disk temperatures ranging from 20 to 300 C (77 to 572 F). The C-ether yielded better boundary lubricating characteristics than did the polyphenyl ether in air and nitrogen over most of the temperature range. The C-ether exhibited lower wear at high oxygen levels (10 to 20 percent O2) from 25 to 200 C (77 to 392 F) and at low oxygen levels (0.001 to 1.0 percent O2) from 200 to 300 C (392 to 572 F). Friction polymer was observed around the wear scars of most test specimens. Friction polymer generation and its effect on wear are discussed in light of current theories.

  15. Effect of surface modified kaolin on properties of polypropylene grafted maleic anhydride

    NASA Astrophysics Data System (ADS)

    Yang, Ni; Zhang, Zuo-Cai; Ma, Ning; Liu, Huan-Li; Zhan, Xue-Qing; Li, Bing; Gao, Wei; Tsai, Fang-Chang; Jiang, Tao; Chang, Chang-Jung; Chiang, Tai-Chin; Shi, Dean

    To achieve reinforcement of mechanical and thermal performances of polypropylene (PP) product, this work aimed at fabrication of surface modified kaolin (M-kaolin) filled polypropylene grafted maleic anhydride (PP-g-MAH) composites with varying contents of fillers and investigation of their mechanical and thermal properties. And the prepared PP-g-MAH/M-kaolin composites were characterized by means of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Fracture analysis by SEM showed M-kaolin particles were well dispersed in the PP-g-MAH matrix. Mechanical behaviors were determined by tensile strength, tensile strain at break and impact strength analysis. Impact strength of PP-g-MAH/2 wt% M-kaolin composites was improved up to 30% comparing with unfilled composites. Thermostability had been found enhanced when M-kaolin added. The results revealed PP-g-MAH/M-kaolin composites showed the optimal thermal and mechanical properties when 2 wt% of M-kaolin was added.

  16. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis

    PubMed Central

    Rizal, Govinda; Karki, Shanta; Garcia, Richard; Larazo, Nikki; Alcasid, Michael; Quick, William Paul

    2015-01-01

    An efficient method for crossing green foxtail (Setaria viridis) is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME) type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C) and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH), and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria. PMID:25910193

  17. Adsorption of α-amylase onto poly(acrylamide/maleic acid) hydrogels

    NASA Astrophysics Data System (ADS)

    Tümtürk, H.; Çaykara, T.; Şen, M.; Güven, O.

    1999-08-01

    Poly(acrylamide/maleic acid) [P(AAm/MA)] hydrogels were prepared by irradiating the ternary mixtures of AAm/MA and water by γ rays at ambient temperature. The influence of the MA on the adsorption of α-amylase, optimum working conditions and storage stability of enzyme were investigated. The adsorption capacity of hydrogels were found to increase from 0.40 to 0.71 mg α-amylase/g dry gel with increasing amount of MA in the gel system. Maximum enzyme activities were observed at lower pH values and higher temperatures for adsorbed enzyme compared with free enzyme. Kinetic parameters were calculated as 2.51 g/dm 3 for Km and 1.67×10 -3 g/dm 3 min for Vmax for free enzyme and in the range of 12.3-12.9 g/dm 3 for Km and 1.63×10 -3-1.96×10 -3 g/dm 3 min for Vmax depending on the amount of MA in the hydrogel. While, the enzymatic activity of free enzyme was completely lost after 20 days, adsorbed enzyme retained 47-59% of its original activity after 20 days, depending on the amount of MA in the hydrogels.

  18. Kaolinite Nanocomposite Platelets Synthesized by Intercalation and Imidization of Poly(styrene-co-maleic anhydride)

    PubMed Central

    Samyn, Pieter; Schoukens, Gustaaf; Stanssens, Dirk

    2015-01-01

    A synthesis route is presented for the subsequent intercalation, exfoliation and surface modification of kaolinite (Kln) by an imidization reaction of high-molecular weight poly(styrene-co-maleic anhydride) or SMA in the presence of ammonium hydroxide. In a first step, the intercalation of ammonolyzed SMA by guest displacement of intercalated dimethylsulfoxide has been proven. In a second step, the imidization of ammonolyzed SMA at 160 °C results in exfoliation of the kaolinite layers and deposition of poly(styrene-co-maleimide) or SMI nanoparticles onto the kaolinite surfaces. Compared with a physical mixture of Kln/SMI, the chemically reacted Kln/SMI provides more efficient exfoliation and hydrogen bonding between the nanoparticles and the kaolinite. The kaolinite nanocomposite particles are synthesized in aqueous dispersion with solid content of 65 wt %. The intercalation and exfoliation are optimized for a concentration ratio of Kln/SMI = 70:30, resulting in maximum intercalation and interlayer distance in combination with highest imide content. After thermal curing at 135 °C, the imidization proceeds towards a maximum conversion of the intermediate amic acid moieties. The changes in O–H stretching and kaolinite lattice vibrations have been illustrated by infrared and FT-Raman spectroscopy, which allow for a good quantification of concentration and imidization effects. PMID:28793445

  19. 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.

  20. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis.

    PubMed

    Rizal, Govinda; Karki, Shanta; Garcia, Richard; Larazo, Nikki; Alcasid, Michael; Quick, William Paul

    2015-01-01

    An efficient method for crossing green foxtail (Setaria viridis) is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME) type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C) and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH), and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria.

  1. Polymorphs of acyclovir-maleic acid salt and their reversible phase transition

    NASA Astrophysics Data System (ADS)

    Wang, Lianyan; Zhao, Yumei; Zhang, Zhengfeng; Wang, Jianming; Wang, Qiang; Zheng, Zhibing; Deng, Zongwu; Zhang, Hailu

    2017-01-01

    Acyclovir is a commonly used antiviral drug while its solubility is far from satisfied. It was reported that 1:1 acyclovir-maleic acid salt (ACV-MAL) possesses much higher maximum apparent solubility. In this contribution, a new crystal structure of ACV-MAL was solved at room temperature. This new crystal structure and previously reported structure at low temperature can transform to each other via a reversible solid phase transformation, which has been confirmed by single-crystal X-ray diffraction, solid state NMR and cycling differential scanning calorimetry tests. The phase change temperature is ca. 283-293 K (10-20 °C), which is slightly lower than room temperature (298 ± 2 K/25 ± 2 °C), but is in the range of ambient temperature. This kind of near room temperature phase transformation is less concerned and tends to be neglected. This case report reminds that more attention should be paid to the polymorphism of pharmaceuticals at such temperature range due to its fundamental and practical significance.

  2. 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

    2016-04-08

    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Solubilization of lipids and lipid phases by the styrene-maleic acid copolymer.

    PubMed

    Dominguez Pardo, Juan J; Dörr, Jonas M; Iyer, Aditya; Cox, Ruud C; Scheidelaar, Stefan; Koorengevel, Martijn C; Subramaniam, Vinod; Killian, J Antoinette

    2017-01-01

    A promising tool in membrane research is the use of the styrene-maleic acid (SMA) copolymer to solubilize membranes in the form of nanodiscs. Since membranes are heterogeneous in composition, it is important to know whether SMA thereby has a preference for solubilization of either specific types of lipids or specific bilayer phases. Here, we investigated this by performing partial solubilization of model membranes and analyzing the lipid composition of the solubilized fraction. We found that SMA displays no significant lipid preference in homogeneous binary lipid mixtures in the fluid phase, even when using lipids that by themselves show very different solubilization kinetics. By contrast, in heterogeneous phase-separated bilayers, SMA was found to have a strong preference for solubilization of lipids in the fluid phase as compared to those in either a gel phase or a liquid-ordered phase. Together the results suggest that (1) SMA is a reliable tool to characterize native interactions between membrane constituents, (2) any solubilization preference of SMA is not due to properties of individual lipids but rather due to properties of the membrane or membrane domains in which these lipids reside and (3) exploiting SMA resistance rather than detergent resistance may be an attractive approach for the isolation of ordered domains from biological membranes.

  4. Effect of maleic anhydride on the damping property of magnetorheological elastomers

    NASA Astrophysics Data System (ADS)

    Fan, Y. C.; Gong, X. L.; Jiang, W. Q.; Zhang, W.; Wei, B.; Li, W. H.

    2010-05-01

    In this study, maleic anhydride (MA) was selected as the compatibilizer to modify the interfaces of magnetorheological elastomers (MREs) for improving the damping property. Several samples of MREs with different contents of MA were prepared. The content of bound-rubber was measured by the extraction method. The microstructures were observed by using an environmental scanning electron microscope (SEM). The dynamic performances of these samples, including shear storage modulus, loss factor and MR effect were measured with a modified dynamic mechanical analyzer (DMA). The tensile strength was tested by using an electronic tensile machine. The experimental results indicate that both the content of bound-rubber and the compatibility between the magnetic particles and rubber matrix were enhanced with the increase of MA. The enhancement of the bond between the two phases resulted in different mechanical properties: the increase of shear storage modulus; the reduction of the loss factor; the stability improvement of the loss factor; the enhancement of the tensile strength; and the reduction of the MR effect.

  5. Determination of hydrazine in maleic hydrazide technical and pesticide formulations by gas chromatography: collaborative study.

    PubMed

    Riggs, Anthony S; Borth, David M; Tutty, David G; Yu, Wan S

    2008-01-01

    Twelve collaborating laboratories assayed hydrazine in technical maleic hydrazide (MH), 6-hydroxy-2H-pyridazin-3-one, and 2 formulated products, a liquid concentrate and a soluble granule, using gas chromatography (GC) with electron capture detection. The hydrazine content in the samples ranged from 0.03 ppm, in the liquid concentrate, to 0.26 ppm, in MH technical. Hydrazine and MH are dissolved in an aqueous solution. The MH is then precipitated out of solution by acidification. The solution containing hydrazine is treated with excess pentafluorobenzaldehyde (PFB) to form pentafluorobenzaldehyde azine (PFBA). The PFBA is extracted with hexane for analysis by GC using an electron capture detector. Peak area responses of PFBA are measured and quantified by external standardization. Hydrazine concentration is calculated from the PFBA determination. The laboratories weighed each test sample in duplicate with duplicate analysis for each weighing. Data from these laboratories were statistically analyzed. The average relative repeatability was determined to be 5.34% and the average relative reproducibility was 27.99%.

  6. Structure of associates of vinyl molecules and maleic anhydride in CCl4 solution

    NASA Astrophysics Data System (ADS)

    Zaitseva, V. V.; Tyurina, T. G.; Shtonda, A. V.; Zaitsev, S. Yu.

    2012-04-01

    The self-association of styrene, acrylonitrile, methylmethacrylate, N-vinylpyrrolidone, and maleic anhydride molecules is considered in dependence on the nature of the monomer, i.e., on the conjugation between functional groups. The AM1, Hartree-Fock (RHF), and density functional theory (DFT) methods of calculation are used in our investigations. Charge distributions on the atoms of interacting groups and contributions from overlapping molecular orbitals to the energy of formation of self-associates are found. The calculated parameters are compared with experimental data on absorption band shifts in IR spectra and on chemical shifts ΔH and ΔC for the hydrogen and carbon atoms of =CH, =CH2, C=O groups of bound molecules in 1H and 13C NMR spectra. The formation of π-H, CH…O, and CH…N bonds is proved. Analysis of CCl4/monomer dependences shows that dimers are present in dilute solutions, while the presence of trimers in concentrated solutions cannot be excluded. Self-association constants are determined along with the degree of self-association, which lies within the range of 40-60% for 50 mol% of a monomer in solution.

  7. Isolation and biochemical characterization of maleic-acid hydratase, an iron-requiring hydro-lyase.

    PubMed

    Dreyer, J L

    1985-07-01

    A procedure for the isolation of maleic acid hydratase (D-malate hydro-lyase, EC 4.2.1.31) of about 95% purity from rabbit kidneys is described. The enzyme consists of a single polypeptide chain of 582 amino-acid residues with an approximate molecular mass of 68 kDa. The enzyme is very unstable and has an absolute requirement for chloride ions. Addition of sodium sulphide during the purification process was essential to maintain the enzyme in an activatable state. The pure preparation has low activity but responds to activation with Fe2+ ions, Na2S and a thiol. The sequence of adding the activating reagents is critical to achieve optimal activity. Ni2+ and to a lesser extent Co2+ can replace iron in the activation process. The enzyme incorporates 4-5 mol iron/mol and 4.5-6 mol sulphide/mol during activation. In this process an [Fe-S] cluster appears to be built up, as indicated by optical and electron paramagnetic resonance (EPR) spectroscopy. In activated samples exposed to air the [Fe-S] cluster is EPR-detectable through an axial signal with g = 2.01 and g = 2.029 whose temperature and power saturation characteristics were similar to those of other [3Fe-xS] clusters. The activated enzyme, however, is readily inactivated even upon minor manipulation with destruction of the iron-sulfur core.

  8. Thermotropic behavior of poly(oxyethylene) cholesterol ethers.

    PubMed

    López-Quintela, M Arturo; Akahane, Akira; Rodríguez, Carlos; Kunieda, Hironobu

    2002-03-01

    The thermotropic behavior of poly(oxyethylene) cholesterol ether surfactants was studied by differential scanning calorimetry and small-angle X-ray scattering. Contrary to what is usually observed in conventional poly(oxyethylene)-type surfactant systems, poly(oxyethylene) cholesterol ether surfactants show a change of the fusion mechanism as the chain length is varied. For long chain lengths (n > or = 15) the usual solid-liquid transition is found, but for short chain lengths (n < or = 10) the transition goes through a birefringent lamellar phase. The appearance of this liquid crystal (LC) phase seems to be related with the predominance of the cholesterol part in the short chain polyoxyethylene surfactants. On the contrary, for long polyexyethylene chains the polymer gains in importance and only a solid crystalline structure is observed at low temperatures. An antiparallel packing structure with totally overlapped chains is found for both, the solid and the LC phase. The chains seem to be in a zigzag configuration, and only for the longest surfactant here studied (n = 30) a change of the chain configuration to a much shorter meander configuration is observed.

  9. Size-exclusion chromatography of ultrahigh molecular weight methylcellulose ethers and hydroxypropyl methylcellulose ethers for reliable molecular weight distribution characterization.

    PubMed

    Li, Yongfu; Shen, Hongwei; Lyons, John W; Sammler, Robert L; Brackhagen, Meinolf; Meunier, David M

    2016-03-15

    Size-exclusion chromatography (SEC) coupled with multi-angle laser light scattering (MALLS) and differential refractive index (DRI) detectors was employed for determination of the molecular weight distributions (MWD) of methylcellulose ethers (MC) and hydroxypropyl methylcellulose ethers (HPMC) having weight-average molecular weights (Mw) ranging from 20 to more than 1,000kg/mol. In comparison to previous work involving right-angle light scattering (RALS) and a viscometer for MWD characterization of MC and HPMC, MALLS yields more reliable molecular weight for materials having weight-average molecular weights (Mw) exceeding about 300kg/mol. A non-ideal SEC separation was observed for cellulose ethers with Mw>800kg/mol, and was manifested by upward divergence of logM vs. elution volume (EV) at larger elution volume at typical SEC flow rate such as 1.0mL/min. As such, the number-average molecular weight (Mn) determined for the sample was erroneously large and polydispersity (Mw/Mn) was erroneously small. This non-ideality resulting in the late elution of high molecular weight chains could be due to the elongation of polymer chains when experimental conditions yield Deborah numbers (De) exceeding 0.5. Non-idealities were eliminated when sufficiently low flow rates were used. Thus, using carefully selected experimental conditions, SEC coupled with MALLS and DRI can provide reliable MWD characterization of MC and HPMC covering the entire ranges of compositions and molecular weights of commercial interest. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Thin film composite nanofiltration membranes fabricated from quaternized poly(ether ether ketone) with crosslinkable moiety using a benign solvent.

    PubMed

    Dong, Xue; Zhang, Qifeng; Zhang, Suobo; Li, Shenghai

    2016-02-01

    Thin film composite nanofiltration membranes were fabricated through dip-coating and in situ cross-linking of quaternized poly(ether ether ketone) containing a certain amount of tertiary amine groups (QAPEEKs) on polyacrylonitrile (PAN) support. The effects of the variables in membrane formation such as the coating polymer concentration, the curing temperature, and the cross-linking agent types on resultant membrane were studied and the membrane properties such as the barrier layer chemical structure, the surface element composition and morphology were investigated. The obtained performance of uncross-linked and cross-linked QAPEEK-70 thin film composites in nanofiltration test was compared. The results indicated that the cross-linking improved the composite membranes' performance. For instance, the membrane cross-linked by bisphenol A diglycidyl ether (BPADGE) named M-C-BPADGE exhibited a MgCl2 rejection of 97.8%, a water flux of 11.8Lm(-2)h(-1), a MWCO of 800Da and corresponding pore size of 0.69nm, while for its uncross-linked membrane named M-U, a MgCl2 rejection of 91.2%, a water flux of 13.5Lm(-2)h(-1), a MWCO with 960Da and a pore size of 0.77nm were found. Furthermore, the M-C-BPADGE membrane exhibited selectivities of 16.0 for separation of mixed Mg(2+) and Na(+) cations, much larger than selectivity of 5.2 obtained for M-U, suggesting that the cross-linked membranes are promising in cation separation.

  11. Chain-extended poly(aryl ether ketones)

    SciTech Connect

    Robeson, L.M.; Winslow, P.A.; Matzner, M.; Harris, J.E.; Maresca, L.M.

    1992-06-09

    This patent describes a process for preparing a poly(aryl ether ketone) polymer. It comprises reacting (n) moles of HAr H with (n + 1) moles of YCOAr{sub 1}COY under Friedel-Crafts polymerization conditions; reacting the product obtained with 2XAR{sub 2}H under Friedel-Crafts polymerization conditions; reacting the product obtained with HOAr{sub 3}OH in the presence of a base and an aprotic solvent; wherein Ar and Ar{sub 1} are divalent aromatic groups, Ar{sub 2} is a divalent aromatic group wherein the substituents X and CO are in para or ortho position relative to each other, Ar{sub 3} is a residue of a dihydric phenol, X and Y are halogen, n is an integer of 1 to 50 and X is one or greater.

  12. A Rational Entry to Cyclic Polymers via Selective Cyclization by Self-Assembly and Topology Transformation of Linear Polymers.

    PubMed

    Aoki, Daisuke; Aibara, Gouta; Uchida, Satoshi; Takata, Toshikazu

    2017-05-24

    A simple and effective synthetic route to cyclic polymers has been developed based on the following sequence: (i) selective cyclization of two self-complementary sec-ammonium-containing crown ether monomers to afford [c2] daisy-chain bifunctional initiators, (ii) living polymerization to afford the corresponding linear polymers, and (iii) a topology transformation of these linear polymers to furnish cyclic polymers. The key step in this sequence is the quantitative cyclization via self-assembly of two crown ether molecules with hydroxyl and sec-ammonium moieties. After the living polymerization, the linear polymers release the daisy-chain assembly to generate a cyclic topology. The specific advantages of the present synthetic protocol, i.e., procedural simplicity and concentration independence, are demonstrated by a gram-scale synthesis.

  13. Relaxation behavior and nonlinear properties of thermally stable polymers based on glycidyl derivatives of quercetin

    NASA Astrophysics Data System (ADS)

    Mishurov, Dmytro; Voronkin, Andrii; Roshal, Alexander; Brovko, Oleksandr

    2016-07-01

    Cross-linked polymers on the basis of di-, tri and tetraglycidyl ethers of quercetin (3,3‧,4‧,5,7-pentahydroxyflavone) were synthesized, and then, poled in electrical field of corona discharge. Investigations of structural, thermal and optical parameters of the polymer films were carried out. It was found that the polymers obtained from di- and triglycidyl quercetin ethers had high values of macroscopic quadratic susceptibilities and substantial stability of nonlinear optical (NLO) properties after the poling. Tetraglycidyl ether of quercetin forms the polymer of lower quadratic susceptibility, which demonstrates noticeable relaxation process resulting in decrease of the NLO effect. It is supposed that the difference of the NLO properties is due to peculiarities of physical network of the polymers, namely to the ratio between numbers of hydrogen bonds formed by hydroxyl groups of chromophore fragments and by the ones of interfragmental parts of the polymeric chains.

  14. Microbial degradation of 4-monobrominated diphenyl ether in an aerobic sludge and the DGGE analysis of diversity.

    PubMed

    Chen, Chun-Yao; Wang, Chun-Kang; Shih, Yang-Hsin

    2010-07-01

    Polybrominated diphenyl ethers (PBDEs) were applied as flame retardant additives in polymers for many plastic and electronic products. Due to their ubiquitous distribution in the environment, potential toxicity to human and tendency for bioaccumulation, PBDEs have raised public safety concern. In this study we examined the degradation of 4-monobrominated diphenyl ether (4-BDE) in aerobic sludge, as a model for PBDE biodegradation. Degradation of 4-BDE was observed in aerobic sludge. Co-metabolism with toluene or diphenyl ether facilitated 4-BDE biodegradation in terms of kinetics and efficiency. Diphenyl ether seems to perform slightly better as an auxiliary carbon source than toluene in facilitating 4-BDE degradation. During the experiment we identified diphenyl ether by gas chromatography/mass spectrometry(GC/MS), which indicates that an anaerobic debromination has occurred. Bacterial community composition was monitored with denaturing gradient gel electrophoresis. The fragments enriched in 4-BDE-degrading aerobic sludge samples belong to presumably a novel anaerobic Clostridiales species distantly related to all known debrominating microbes. This suggests that 4-BDE biodegradation can occur in anaerobic micro-niche in an apparently aerobic environment, by a previously unknown bacterial species. These findings can provide better understandings of biodegradation of brominated diphenyl ethers and can facilitate the prediction of the fate of PBDEs in the environment.

  15. A new interpretation of SAXS peaks in sulfonated poly(ether ether ketone) (sPEEK) membranes for fuel cells.

    PubMed

    Mendil-Jakani, H; Zamanillo Lopez, I; Legrand, P M; Mareau, V H; Gonon, L

    2014-06-21

    The structure of a commercial sulfonated poly(ether ether ketone) (sPEEK) membrane was analyzed by Small-Angle X-Ray Scattering (SAXS) for different water uptakes obtained after immersion in liquid water at various temperatures. For low membrane swelling, the SAXS profile displays only a wide-angle peak in the 0.2-0.3 Å(-1) region. As the membrane swells, two supplementary correlation peaks arise and shift towards small angles, which are the signature of a structural evolution of the membrane, whereas the wide angle peak remains stable. The SAXS spectra of sPEEK membranes can thus display three correlation peaks simultaneously. Therefore we propose a new interpretation of these SAXS spectra which conclude that the two small angle peaks are attributed to the so-called matrix and ionomer peaks and the wide-angle peak is ascribed to the mean separation distance between sulfonic acid groups grafted onto the polymer backbone. This peak attribution implies that the sPEEK nano-phase separation is triggered by an immersion in hot water (ionomer peak apparition). Our new peak attribution was confirmed by studying the impact of temperature, electron density contrast and ionic exchange capacity.

  16. A transferable force field to predict phase equilibria and surface tension of ethers and glycol ethers.

    PubMed

    Ferrando, Nicolas; Lachet, Véronique; Pérez-Pellitero, Javier; Mackie, Allan D; Malfreyt, Patrice; Boutin, Anne

    2011-09-15

    We propose a new transferable force field to simulate phase equilibrium and interfacial properties of systems involving ethers and glycol ethers. On the basis of the anisotropic united-atom force field, only one new group is introduced: the ether oxygen atom. The optimized Lennard-Jones (LJ) parameters of this atom are identical whatever the molecule simulated (linear ether, branched ether, cyclic ether, aromatic ether, diether, or glycol ether). Accurate predictions are achieved for pure compound saturated properties, critical properties, and surface tensions of the liquid-vapor interface, as well as for pressure-composition binary mixture diagrams. Multifunctional molecules (1,2-dimethoxyethane, 2-methoxyethanol, diethylene glycol) have also been studied using a recently proposed methodology for the calculation of the intramolecular electrostatic energy avoiding the use of additional empirical parameters. This new force field appears transferable for a wide variety of molecules and properties. It is furthermore worth noticing that binary mixtures have been simulated without introducing empirical binary parameters, highlighting also the transferability to mixtures. Hence, this new force field gives future opportunities to simulate complex systems of industrial interest involving molecules with ether functions.

  17. Releasable Conjugation of Polymers to Proteins.

    PubMed

    Gong, Yuhui; Leroux, Jean-Christophe; Gauthier, Marc A

    2015-07-15

    Many synthetic strategies are available for preparing well-defined conjugates of peptides/proteins and polymers. Most reports on this topic involve coupling methoxy poly(ethylene glycol) to therapeutic proteins, a process referred to as PEGylation, to increase their circulation lifetime and reduce their immunogenicity. Unfortunately, the major dissuading dogma of PEGylation is that, in many cases, polymer modification leads to significant (or total) loss of activity/function. One approach that is gaining momentum to address this challenge is to release the native protein from the polymer with time in the body (releasable PEGylation). This contribution will present the state-of-the-art of this rapidly evolving field, with emphasis on the chemistry behind the release of the peptide/protein and the means for altering the rate of release in biological fluids. Linkers discussed include those based on the following: substituted maleic anhydride and succinates, disulfides, 1,6-benzyl-elimination, host-guest interactions, bicin, β-elimination, biodegradable polymers, E1cb elimination, β-alanine, photoimmolation, coordination chemistry, zymogen activation, proteolysis, and thioesters.

  18. Polybrominated Diphenyl Ethers (PBDEs) Action Plan

    EPA Pesticide Factsheets

    Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants in a number of applications. EPA is concerned that some of the component congeners are persistent, bioaccumulative and toxic.

  19. Triethylene Glycol Monomethyl Ether; Final Test Rule

    EPA Pesticide Factsheets

    EPA is issuing a final test rule under section 4 of the Toxic Substances Control Act (TSCA) requiring manufacturers and processors of triethylene glycol monomethyl ether (TGME, CAS No. 112-35-6) to perform developmental neurotoxicity tasting.

  20. Enzyme immobilization on reactive polymer films.

    PubMed

    Cordeiro, Ana L; Pompe, Tilo; Salchert, Katrin; Werner, Carsten

    2011-01-01

    Immobilized enzymes are currently used in many bioanalytical and biomedical applications. This protocol describes the use of thin films of maleic anhydride copolymers to covalently attach enzymes directly to solid supports at defined concentrations. The concentration and activity of the surface-bound enzymes can be tuned over a wide range by adjusting the concentration of enzyme used for immobilization and the physicochemical properties of the polymer platform, as demonstrated here for the proteolytic enzyme Subtilisin A. The versatile method presented allows for the immobilization of biomolecules containing primary amino groups to a broad variety of solid carriers, ranging from silicon oxide surfaces to standard polystyrene well plates and metallic surfaces. The approach can be used to investigate the effects of immobilized enzymes on cell adhesion, and on the catalysis of specific reactions.

  1. 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

    2015-07-08

    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.

  2. Crosslinkage of collagen by polyglycidyl ethers.

    PubMed

    Tang, Z; Yue, Y

    1995-01-01

    Calcification is the principal cause of failure of glutaraldehyde treated bioprosthetic heart valves. This article reports the crosslinkage of several polyglycidyl ethers. Calcification of yak pericardium with polyglycidyl ethers was significantly decreased compared with that crosslinked with glutaraldehyde. The process of calcification of crosslinked yak pericardium was studied using 21 day subdermal implants in rats. The uptake of calcium with ethane diglycidyl ether was reduced (0.57 +/- 0.19 vs 4.28 +/- 1.62 micrograms/mg) over that with glutaraldehyde. Four polyglycidyl ethers were developed and compared. The best compound for raising the shrinkage temperature was the shortest chain compound without steric hindrance. In the polyglycidyl ether process, a suitable amount of alcohol was necessary to promote crosslinking; the catalyst, 2, 4, 6 -tris (dimethyl aminomethyl) phenol (TDAMP) and salicylic acid, were not favorable for long-term treatment of tissues because of the unnecessarily deep dyeing of the tissue, in addition to raising the shrinkage temperature. Unlike glutaraldehyde treatment, which reacts with lysine, polyglycidyl ether treated tissues maintained flexibility of the pericardial tissue, while binding amino acids such as lysine, methionine, tyrosine, aspartic acid and glutamic acid. The authors conclude that the ethane diglycidyl ether process combined with formaldehyde would further raise the shrinkage temperature from 78 degrees C to 87.5 degrees C and sustain it above 80 degrees C. Reverse treatment was not as effective. Compared with glutaraldehyde, polyglycidyl ether treatment renders tissue more flexible, increases the thermal stability of collagen, and decreases the incidence of calcification in vivo.

  3. Graft-crosslinked copolymers based on poly(arylene ether ketone)-gc-sulfonated poly(arylene ether sulfone) for PEMFC applications.

    PubMed

    Zhang, Xuan; Hu, Zhaoxia; Luo, Linqiang; Chen, Shanshan; Liu, Jianmei; Chen, Shouwen; Wang, Lianjun

    2011-07-15

    Novel poly(arylene ether ketone) polymers with fluorophenyl pendants and phenoxide-terminated wholly sulfonated poly(arylene ether sulfone) oligomers are prepared via Ni(0)-catalyzed and nucleophilic polymerization, respectively, and subsequently used as starting materials to obtain graft-crosslinked membranes as polymer electrolyte membranes. The phenoxide-terminated sulfonated moieties are introduced as hydrophilic parts as well as crosslinking units. The chemical structure and morphology of the obtained membranes are confirmed by (1) H NMR and tapping-mode AFM. The properties required for fuel cell applications, including water uptake and dimensional change, as well as proton conductivity, are investigated. AFM results show a clear nanoscale phase-separation microstructure of the obtained membranes. The membranes show good dimensional stability and reasonably high proton conductivities under 30-90% relative humidity. The anisotropic proton conductivity ratios (σ(formula see text) ) of the membranes in water are in the range 0.65-0.92, and increase with an increase in hydrophilic block length. The results indicate that the graft-crosslinked membranes are promising candidates for applications as polymer electrolyte membranes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Highly sensitive colorimetric detection of lead using maleic acid functionalized gold nanoparticles.

    PubMed

    Ratnarathorn, Nalin; Chailapakul, Orawon; Dungchai, Wijitar

    2015-01-01

    Highly sensitive colorimetric detection for Pb(2+) has been developed using maleic acid (MA) functionalized GNP. The -COOH on MA was used to modify GNP surface whereas the other -COOH functional group have strong affinity to coordination behavior of Pb(2+) allowing the selective formation more than other ions. MA-GNPs solution changed from red to blue color after the addition of Pb(2+) due to nanoparticle aggregation. The different optical absorption and discriminate of particle size between the MA-GNPs solution with and without Pb(2+) were characterized by UV-visible spectroscopy and transmission electron microscopy (TEM), respectively. The color intensity as a function of Pb(2+) concentration gave a linear response in the range of 0.0-10.0 µg L(-1) (R(2)=0.990). The detection limit was found at 0.5 µg L(-1) by naked eye and can be completed the analysis within 15 min. The MA-GNPs aggregated with Pb(2+) showed high selectivity when was compared to other metal ions (As(3+), Ca(2+), Cd(2+), Co(2+), Cu(2+), Fe(3+), Hg(2+), Mg(2+), Mn(2+), Ni(2+), Pb(2+) and Zn(2+)) and anions (Cl(-), NO3(-) and SO4(2-)). Our proposed method was also applied for the determination of Pb(2+) in real drinking water samples from 5 sources. The result of real water samples were not statistically significant different from the standard methods at the 95% confidence level (pair t-test method). Moreover, we evaluated our proposed method for the determination of trace Pb(2+) concentration in real breast milk samples. The recoveries were acceptable and ranged from 101 to 104% for spiked Pb(2+) in real breast milk samples. Thus, MA-GNP colorimetric sensing provides a simple, rapid, sensitive, easy-to-use, inexpensive and low detection limit for the monitoring of Pb(2+).

  5. Synthesis and therapeutic effect of styrene–maleic acid copolymer-conjugated pirarubicin

    PubMed Central

    Tsukigawa, Kenji; Liao, Long; Nakamura, Hideaki; Fang, Jun; Greish, Khaled; Otagiri, Masaki; Maeda, Hiroshi

    2015-01-01

    Previously, we prepared a pirarubicin (THP)-encapsulated micellar drug using styrene–maleic acid copolymer (SMA) as the drug carrier, in which active THP was non-covalently encapsulated. We have now developed covalently conjugated SMA-THP (SMA-THP conjugate) for further investigation toward clinical development, because covalently linked polymer–drug conjugates are known to be more stable in circulation than drug-encapsulated micelles. The SMA-THP conjugate also formed micelles and showed albumin binding capacity in aqueous solution, which suggested that this conjugate behaved as a macromolecule during blood circulation. Consequently, SMA-THP conjugate showed significantly prolonged circulation time compared to free THP and high tumor-targeting efficiency by the enhanced permeability and retention (EPR) effect. As a result, remarkable antitumor effect was achieved against two types of tumors in mice without apparent adverse effects. Significantly, metastatic lung tumor also showed the EPR effect, and this conjugate reduced metastatic tumor in the lung almost completely at 30 mg/kg once i.v. (less than one-fifth of the maximum tolerable dose). Although SMA-THP conjugate per se has little cytotoxicity in vitro (1/100 of free drug THP), tumor-targeted accumulation by the EPR effect ensures sufficient drug concentrations in tumor to produce an antitumor effect, whereas toxicity to normal tissues is much less. These findings suggest the potential of SMA-THP conjugate as a highly favorable candidate for anticancer nanomedicine with good stability and tumor-targeting properties in vivo. PMID:25529761

  6. Anticlastogenic effect of Spirulina maxima extract on the micronuclei induced by maleic hydrazide in Tradescantia.

    PubMed

    Ruiz Flores, L Elvia; Madrigal-Bujaidar, Eduardo; Salazar, María; Chamorro, Germán

    2003-02-07

    The aim of this investigation was to determine if extracts of Spirulina maxima reduce the genotoxic damage induced by maleic hydrazide (MH) using the Tradescantia biosssay. Two types of extracts from the alga were prepared: an aqueous extract with two different concentrations, 100 and 500 mg/ml, and a second one, the extract of a 1% solution of dimethyl sulfoxide (DMSO) which corresponded to 100 mg/ml of the alga. The capacity of MH to induce micronuclei (MN) was initially established by administering 0.005, 0.01, and 0.015 mg/ml of the chemical to the Tradescantia inflorescences, and observing its effect after 24 h.The results of this experiment showed a significant MN increase with the two high concentrations tested, although no dose-response effect was observed. For the anticlastogenic assay, the extracts of Spirulina were applied to the inflorescences alone or immediately before the application of MH (0.01 mg/ml) and the induced MN were observed 24 h later. We found that none of the extracts increased the MN level with respect to the untreated plants; also, that MH more or less doubled the basal micronuclei frequency, and finally, that all tested extracts reduced the genotoxic damage caused by MH. The inhibitory indices obtained for the aqueous extracts (100 and 500 mg/ml) and for the DMSO extract were respectively 59, 85, and 56.3%. These data indicate that Spirulina is an anticlastogenic agent and suggest that it is advisable to extend studies on this matter using other biological models.

  7. Biomass-derived monomers for performance-differentiated fiber reinforced polymer composites

    DOE PAGES

    Rorrer, Nicholas A.; Vardon, Derek R.; Dorgan, John R.; ...

    2017-03-14

    Nearly all polymer resins used to manufacture critically important fiber reinforced polymer (FRP) composites are petroleum sourced. In particular, unsaturated polyesters (UPEs) are widely used as matrix materials and are often based on maleic anhydride, a four-carbon, unsaturated diacid. Typically, maleic anhydride is added as a reactant in a conventional step-growth polymerization to incorporate unsaturation throughout the backbone of the UPE, which is then dissolved in a reactive diluent (styrene is widely used) infused into a fiber mat and cross-linked. Despite widespread historical use, styrene has come under scrutiny due to environmental and health concerns; in addition, many conceivable UPEsmore » are not soluble in styrene. In this study, we demonstrate that renewably-sourced monomers offer the ability to overcome these issues and improve overall composite performance. The properties of poly(butylene succinate)-based UPEs incorporating maleic anhydride are used as a baseline for comparison against UPEs derived from fumaric acid, cis,cis-muconate, and trans,trans-muconate, all of which can be obtained biologically. The resulting biobased UPEs are combined with styrene, methacrylic acid, or a mixture of methacrylic acid and cinnaminic acid, infused into woven fiberglass and cross-linked with the addition of a free-radical initiator and heat. This process produces a series of partially or fully bio-derived composites. Overall, the muconate-containing UPE systems exhibit a more favorable property suite than the maleic anhydride and fumaric acid counterparts. In all cases at the same olefinic monomer loading, the trans,trans-muconate polymers exhibit the highest shear modulus, storage modulus, and glass transition temperature indicating stronger and more thermally resistant materials. They also exhibit the lowest loss modulus indicating a greater adhesion to the glass fibers. The use of a mixture of methacrylic and cinnaminic acid as the reactive diluent

  8. Co-processing as a tool to improve aqueous dispersibility of cellulose ethers.

    PubMed

    Sharma, Payal; Modi, Sameer R; Bansal, Arvind K

    2015-01-01

    Cellulose ethers are important materials with numerous applications in pharmaceutical industry. They are widely employed as stabilizers and viscosity enhancers for dispersed systems, binders in granulation process and as film formers for tablets. These polymers, however, exhibit challenge during preparation of their aqueous dispersions. Rapid hydration of their surfaces causes formation of a gel that prevents water from reaching the inner core of the particle. Moreover, the surfaces of these particles become sticky, thus leading to agglomeration, eventually reducing their dispersion kinetics. Numerous procedures have been tested to improve dispersibility of cellulose ethers. These include the use of cross-linking agents, alteration in the synthesis process, adjustment of water content of cellulose ether, modification by attaching hydrophobic substituents and co-processing using various excipients. Among these, co-processing has provided the most encouraging results. This review focuses on the molecular mechanisms responsible for the poor dispersibility of cellulose ethers and the role of co-processing technologies in overcoming the challenge. An attempt has been made to highlight various co-processing techniques and specific role of excipients used for co-processing.

  9. Friction and wear performance of some thermoplastic polymers and polymer composites against unsaturated polyester

    NASA Astrophysics Data System (ADS)

    Unal, H.; Mimaroglu, A.; Arda, T.

    2006-09-01

    Wear experiments have been carried out with a range of unfilled and filled engineering thermoplastic polymers sliding against a 15% glass fibre reinforced unsaturated polyester polymer under 20, 40 and 60 N loads and 0.5 m/s sliding speed. Pin materials used in this experimental investigation are polyamide 66 (PA 66), poly-ether-ether-ketone (PEEK) and aliphatic polyketone (APK), glass fibre reinforced polyamide 46 (PA 46 + 30% GFR), glass fibre reinforced polytetrafluoroethylene (PTFE + 17% GFR), glass fibre reinforced poly-ether-ether-ketone (PEEK + 20% GFR), glass fibre reinforced poly-phylene-sulfide (PPS + 30% GFR), polytetrafluoroethylene filled polyamide 66 (PA 66 + 10% PTFE) and bronze filled pofytetrafluoroethylene (PTFE + 25% bronze) engineering polymers. The disc material is a 15% glass fibre reinforced unsaturated polyester thermoset polymer produced by Bulk Moulding Compound (BMC). Sliding wear tests were carried out on a pin-on-disc apparatus under 0.5 m/s sliding speed and load values of 20, 40 and 60 N. The results showed that the highest specific wear rate is for PPS + 30% GFR with a value of 1 × 10 -11 m 2/N and the lowest wear rate is for PTFE + 17% GFR with a value of 9.41 × 10 -15 m 2/N. For the materials and test conditions of this investigation, apart from polyamide 66 and PA 46 + 30% GFR polymers, the coefficient of friction and specific wear rates are not significantly affected by the change in load value. For polyamide 66 and PA 46 + 30% GFR polymers the coefficient of friction and specific wear rates vary linearly with the variation in load values.

  10. 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.

  11. Microgravity Polymers

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A one-day, interactive workshop considering the effects of gravity on polymer materials science was held in Cleveland, Ohio, on May 9, 1985. Selected programmatic and technical issues were reviewed to introduce the field to workshop participants. Parallel discussions were conducted in three disciplinary working groups: polymer chemistry, polymer physics, and polymer engineering. This proceedings presents summaries of the workshop discussions and conclusions.

  12. Biodegradable Polymers

    PubMed Central

    Vroman, Isabelle; Tighzert, Lan

    2009-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. The following review presents an overview of the different biodegradable polymers that are currently being used and their properties, as well as new developments in their synthesis and applications.

  13. Conformations and Barriers to Methyl Group Internal Rotation in Two Asymmetric Ethers: Propyl Methyl Ether and Butyl Methyl Ether

    NASA Astrophysics Data System (ADS)

    Long, B. E.; Dechirico, F.; Cooke, S. A.

    2012-06-01

    The conformational preferences of the O-C-C-C unit are important in many biological systems with the unit generally preferring a gauche configuration compared to an anti configuration. Butyl methyl ether and propyl methyl ether provide very simple systems for this phenomenom to manifest. Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy (CP-FTMW). In the case of butyl methyl ether, only one conformer has been observed. This conformer has torsional angles of COCC = 180°, OCCC = 62° and CCCC = 180° (anti-gauche-anti) and rotational constants of A = 10259.4591(33) MHz, B = 1445.6470(13) MHz, and C = 1356.2944(14) MHz. The rotational spectrum was doubled and has been analyzed to produce an effective barrier to methyl group internal rotation of 780(35) cm-1. A prior rotational spectroscopic study on propyl methyl ether had focused only on the high energy anti-anti conformer. We have analyzed spectra from the lowest energy anti-gauche conformer and the spectroscopic constants will be presented. A summary of the differences in conformational energies and methyl group internal rotation barriers for the class of aliphatic asymmetric ethers will be presented. K. N. Houk, J. E. Eksterowicz, Y.-D. Wu, C. D. Fuglesang, D. B. Mitchell. J. Am. Chem. Soc. 115 (4170), 1993. Hiroshi Kato, Jun Nakagawa, Michiro Hayashi. J. Mol. Spectrosc. 80 (272), 1980.

  14. Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

    PubMed Central

    Lu, Chunliang; Su, Xiaoge; Floreancig, Paul E.

    2013-01-01

    Vinyl ethers can be protonated to generate oxocarbenium ions that react with Me3SiCN to form cyanohydrin alkyl ethers. Reactions that form racemic products proceed efficiently upon converting the vinyl ether to an α-chloro ether prior to cyanide addition in a pathway that proceeds through Brønsted acid-mediated chloride ionization. Enantiomerically enriched products can be accessed by directly protonating the vinyl ether with a chiral Brønsted acid to form a chiral ion pair. Me3SiCN acts as the nucleophile and PhOH serves as a stoichiometric proton source in a rare example of an asymmetric bimolecular nucleophilic addition reaction into an oxocarbenium ion. Computational studies provide a model for the interaction between the catalyst and the oxocarbenium ion. PMID:23968162

  15. Molecular Engineering of Liquid Crystalline Polymers by Living Polymerization. 10. Influence of Molecular Weight on the Phase Transitions of Poly(Omega-((4-Cyano-4’-Biphenyl)oxy)alkyl Vinyl Ethers)s with Nonyl and Decanyl Alkyl Groups

    DTIC Science & Technology

    1990-10-16

    Report No. 41 NAMAE OF PERFOMN4iNG OIRGANLZAI0N 60 OF~iCE SYMBOL 76 NAME OF MONITORING ORGANIZATION ase Western Reserve Univ. 4Btak N L ADRESS (Oty...PL/NO’NG/SPONSOMRNG 8b OfFCE SYMBOL 9 PROCUJREMENT INSTRUJMENT IOENTIFiC-ATiON NJMBEgt ,ftGANLZATION 0f sp9J’catJe) L ADORE S(Cfry. Stire..ria ZIP...polymerization of 9.-[(4-cyano-4’-biphenyl)oxylnonyI vinyl ether ( L -9) and 10-[(4- cyano-4’-bipnenyl)oxy]decanyl vinyl ether (6-10) are described. The

  16. Polymer-coated fluorescent CdSe-based quantum dots for application in immunoassay.

    PubMed

    Speranskaya, Elena S; Beloglazova, Natalia V; Lenain, Pieterjan; De Saeger, Sarah; Wang, Zhanhui; Zhang, Suxia; Hens, Zeger; Knopp, Dietmar; Niessner, Reinhard; Potapkin, Dmitry V; Goryacheva, Irina Yu

    2014-03-15

    The paper describes all stages of synthesis and characterization of biocompatible CdSe-based core/shell quantum dots (QDs) and their application as fluorescent label for immunoassay. Special attention was focused on development of maleic anhydride-based amphiphilic polymers for QDs solubilization in aqueous media. In this work two PEG-amines were tried for polymer modification: monoamine Jeffamine M 1000 used previously in some researches and diamine Jeffamine ED-2003 applied for the first time for QDs solubilization. The use of different Jeffamines allows us to obtain QDs with carboxyl or amine functional groups available for conjugation. The influence of polymer composition on optical properties of the nanocrystals and their stability in aqueous solutions as well as on their conjugation with biomolecules was studied. QDs with different coatings were used as biolabels in quantitative fluorescence microtiter plate immunoassay and qualitative on-site column test. It was found that quantum dots covered with amphiphilic polymer prepared from poly(maleic anhydride-alt-1-octadecene) and Jeffamine ED-2003 retained up to 90% of their initial brightness, easily conjugated with protein and showed low non-specific adsorption. In optimized conditions the obtained QDs were successfully used for determination of mycotoxin deoxynivalenol in wheat and maize samples by fluorescence microtiter plate immunoassay with an IC50 of 220 μg kg(-1) and by on-site column test with cut-off of 500 μg kg(-1).

  17. Molecular Engineering of Liquid Crystal Polymers by Lining Polymerization. 16. Tailor-Made sC* Mesophase in Copolymers of 4-((S-(-)-2- Methyl-1-Butyl)Oxycarbonyl)-4’-omega-Oxyalkyl-1-Vinyl Ether)Biphenyl With Undecanyl and Octyl Alkyl Groups

    DTIC Science & Technology

    1991-10-30

    4-{ [S-(-)-2-Methyl- l -Butyl]Oxycarbonyl) -4’-(W-Oxyalkyl- 1 -Vinyl Ethcr)Biphenyl with Undecanyl and Octyl Alkyl Groups 12. PERSONAL AUTHOR(S...polymerization lower than 40 and polydispersities 1.15 were synthesized and characterized by differential scanning calorimetry (DSC) and thermal optical...an enantiotropic unidentified sx mesophase. Copolymers of 14-8 with 4-{[S(-)2-methyl- l -butyll oxycarbonyl)- 4 ’-( l - oxyuindecanyl-lI-vinyl ether

  18. 78 FR 4792 - Epoxy Polymer; Exemption From the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    ... AGENCY 40 CFR Part 180 Epoxy Polymer; Exemption From the Requirement of a Tolerance AGENCY: Environmental... requirement of a tolerance for residues of polymers of one or more diglycidyl ethers of bisphenol A...- cyclohexane-dicarboxylic anhydride and 1,2,3,6-tetrahydrophthalic anhydride; also referred to as epoxy...

  19. Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

    NASA Astrophysics Data System (ADS)

    Semelsberger, Troy A.; Borup, Rodney L.

    The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

  20. Exploration of CO2-Philicity of Poly(vinyl acetate-co-alkyl vinyl ether) through Molecular Modeling and Dissolution Behavior Measurement.

    PubMed

    Hu, Dongdong; Sun, Shaojun; Yuan, Pei-Qing; Zhao, Ling; Liu, Tao

    2015-09-24

    Hydrocarbon CO2-philes are of great interest for use in expanding CO2 applications as a green solvent. In this work, multiscale molecular modeling and dissolution behavior measurement were both applied to explore CO2-philicity of the poly(vinyl acetate) (PVAc)-based copolymer. Introduction of a favorable comonomer, i.e., vinyl ethyl ether (VEE), could significantly reduce the polymer-polymer interaction on the premise that the polymer-CO2 interaction was not weakened but enhanced. The ab initio calculated interaction of the model molecules with CO2 demonstrated that the ether group in VEE or VBE was the suitable CO2-philic segment. From the molecular dynamics (MD) simulations of polymer/CO2 systems, the interaction energy and Flory-Huggins parameter (χ12) of poly(VAc-alt-VEE)/CO2 supported that poly(VAc-alt-VEE) possessed better CO2-philicity than PVAc. The dissolution behaviors of the synthesized poly(VAc-co-alkyl vinyl ether) copolymers in CO2 showed the best CO2-phile had the VEE content of about 34 mol %. The MD simulations also indicated that the interaction of random poly(VAc-co-VEE) containing about 30 mol % VEE with CO2 was the strongest and the χ12 was the smallest in these polymer/CO2 systems. Not only could the VEE monomer reduce the polymer-polymer interaction, but it could also enhance the polymer-CO2 interaction with an optimized composition. Introducing a suitable comonomer with a certain composition might be a promising strategy to form the synergistic effect of polymer-polymer interaction and polymer-CO2 interaction for screening the hydrocarbon CO2-philes.

  1. Chemistry and properties of poly(arylene ether benzoxazole)s

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    Several new poly(arylene ether benzoxazole)s (PAEBs) were prepared by the nucleophilic displacement reaction of activated aromatic difluorides with two novel bis(hydroxyphenyl benzoxazole), using potassium carbonate. The 6F-containing PAEBs exhibited better solubility and higher Tgs than did the 6,6'-bis-(2-(4-hydroxyphenyl)benzoxazole)-derived polymers. Several of the 6,6'bis(2-(4-hydroxyphenyl)benzoxazole)-derived polymers exhibited crystallinity by DSC and wide-angle X-ray diffraction. Unorientated thin film properties of the 6F-containing PAEBs were comparable to those of other 6F-containing PAEBS that were previously reported. The chemistry and the physical and mechanical properties of the above polymers are discussed.

  2. Chemistry and properties of poly(arylene ether benzoxazole)s

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    Several new poly(arylene ether benzoxazole)s (PAEBs) were prepared by the nucleophilic displacement reaction of activated aromatic difluorides with two novel bis(hydroxyphenyl benzoxazole), using potassium carbonate. The 6F-containing PAEBs exhibited better solubility and higher Tgs than did the 6,6'-bis-(2-(4-hydroxyphenyl)benzoxazole)-derived polymers. Several of the 6,6'bis(2-(4-hydroxyphenyl)benzoxazole)-derived polymers exhibited crystallinity by DSC and wide-angle X-ray diffraction. Unorientated thin film properties of the 6F-containing PAEBs were comparable to those of other 6F-containing PAEBS that were previously reported. The chemistry and the physical and mechanical properties of the above polymers are discussed.

  3. Zero-birefringence photosensitive poly(arylene ether) for optical waveguides

    NASA Astrophysics Data System (ADS)

    Li, Xiang-Dan; Zhong, Zhen-Xin; Kim, Jang Joo; Lee, Myong-Hoon

    2005-01-01

    Novel photosensitive fluorinated poly(arylene ether) containing chalcone unit (F-PAECh) in the main chain was synthesized from decafluorinated chalcone and fluorinated bisphenol at low temperature for polymer optical waveguide application. Upon UV irradiation on the resulting polymer film, [2+2] cycloaddition of chalocone moiety induced the anisotropic decrease of the refractive indices (nTE and nTM) accompanied with crosslinking of polymer film. The decrease was more significant in in-plane direction than out-of-plane direction, and consequently, zero birefringence was obtained with 4.5 min of exposure. Zero-birefringence as well as its excellent optical properties of F-PAECh makes it a promising candidate material for use in high-performance wavelength division multiplexing components such as polarization-independent arrayed waveguide gratings and Bragg wavelength filters.

  4. A plasticized polymer-electrolyte-based photoelectrochemical solar cell

    SciTech Connect

    Mao, D.; Ibrahim, M.A.; Frank, A.J.

    1998-01-01

    A photoelectrochemical solar cell based on an n-GaAs/polymer-redox-electrolyte junction is reported. Di(ethylene glycol) ethyl ether acrylate containing ferrocene as a redox species and benzoin methyl ether as a photoinitiator is polymerized in situ. Propylene carbonate is used as a plasticizer to improve the conductivity of the polymer redox electrolyte. For thin (1 {micro}m) polymer electrolytes, the series resistance of the cell is negligible. However, the short-circuit photocurrent density of the cell at light intensities above 10 mW/cm{sup 2} is limited by mass transport of redox species within the polymer matrix. At a light intensity of 70 mW/cm{sup 2}, a moderate light-to-electrical energy conversion efficiency (3.1%) is obtained. The interfacial charge-transfer properties of the cell in the dark and under illumination are studied.

  5. Ether and the atmospheric chemistry data assimilation

    NASA Astrophysics Data System (ADS)

    Ricaud, P.; Phulpin, T.; Girod, F.; Boonne, C.

    The French atmospheric chemistry data base Ether has been developed and funded by the French Space Agency (CNES) and the Institut National des Sciences de l'Univers (INSU/CNRS) for about 6 years. The role of Ether is to assist French atmospheric researchers, European scientists, as long as they are involved in co-operation agreements with French scientists, to locate, access and interpret atmospheric data. This centre gathers data from satellite, balloon campaigns linked to satellite validation, aircraft and model results for stratospheric and tropospheric purposes and from different levels of production (raw data, physical data, interpolated or assimilated data). All Ether data are available on-line through a World Web interface (http://ether.ipsl.jussieu.fr). Software and added-value services are provided to assist in the manipulation of the data or to generate higher levels standard data products. Extensive information is also provided on the data collection procedures, formats, contact names and references to scientific papers. In addition to data support activities, a major goal of Ether is to promote the creation of different expertise networks on varying atmospheric chemistry topics. The first working group has been created on data assimilation. It consists in gathering expertises in different themes (satellites, assimilation techniques, modelling, real-time processing) in order to optimally develop a tool able to answer different scientific questions relative to the evolution of the Earth atmosphere in terms of chemistry and dynamics. Based on the PALM tool able to interconnect different codes, it will be able to process different satellite data using two atmospheric models and assimilation schemes within the French Ether data base. Ether will focus on the handling and on the development of added-value services of data for which the French community is directly or indirectly involved. For these projects Ether will provide all the data needed, and will

  6. Atmospheric degradation of 2-chloroethyl vinyl ether, allyl ether and allyl ethyl ether: Kinetics with OH radicals and UV photochemistry.

    PubMed

    Antiñolo, M; Ocaña, A J; Aranguren, J P; Lane, S I; Albaladejo, J; Jiménez, E

    2017-08-01

    Unsaturated ethers are oxygenated volatile organic compounds (OVOCs) emitted by anthropogenic sources. Potential removal processes in the troposphere are initiated by hydroxyl (OH) radicals and photochemistry. In this work, we report for the first time the rate coefficients of the gas-phase reaction with OH radicals (kOH) of 2-chloroethyl vinyl ether (2ClEVE), allyl ether (AE), and allyl ethyl ether (AEE) as a function of temperature in the 263-358 K range, measured by the pulsed laser photolysis-laser induced fluorescence technique. No pressure dependence of kOH was observed in the 50-500 Torr range in He as bath gas, while a slightly negative T-dependence was observed. The temperature dependent expressions for the rate coefficients determined in this work are: The estimated atmospheric lifetimes (τOH) assuming kOH at 288 K were 3, 2, and 4 h for 2ClEVE, AE and AEE, respectively. The kinetic results are discussed in terms of the chemical structure of the unsaturated ethers by comparison with similar compounds. We also report ultraviolet (UV) and infrared (IR) absorption cross sections (σλ and σ(ν˜), respectively). We estimate the photolysis rate coefficients in the solar UV actinic region to be less than 10(-7) s(-1), implying that these compounds are not removed from the atmosphere by this process. In addition, from σ(ν˜) and τOH, the global warming potential of each unsaturated ether was calculated to be almost zero. A discussion on the atmospheric implications of the titled compounds is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Polymer grafting onto starch nanocrystals.

    PubMed

    Labet, Marianne; Thielemans, Wim; Dufresne, Alain

    2007-09-01

    Monocrystalline starch nanoparticles were successfully grafted with poly(tetrahydrofuran), poly(caprolactone), and poly(ethylene glycol) monobutyl ether chains using toluene 2,4-diisocyanate as a linking agent. Surface grafting was confirmed using Fourier transform infrared and X-ray photoelectron spectroscopies, differential scanning calorimetry, elemental analysis, and contact angle measurements. Transmission electron microscopy observations of modified starch nanocrystals showed either the individualization of nanoparticles or the formation of a film, depending on the polymer used. It was shown that grafting efficiency decreased with the length of the polymeric chains, as expected. The resulting modified nanoparticles can find applications in the field of co-continuous nanocomposite materials.

  8. Evaluation of poly(styrene-alt-maleic anhydride)-ethanol as enteric coating material.

    PubMed

    Lai, Xiaolin; Sun, Chengdong; Tian, Hua; Zhao, Wenjun; Gao, Lin

    2008-03-20

    This study aims at evaluating the potential of SMA-ethanol as enteric coating polymer for erythromycin tablets. SMA-ethanol was synthesized and characterized for physicochemical properties, molecular weight and thermal analysis. Free films were prepared by adding different kinds and amounts of plasticizers, the film surface topography was determined by a SEM, the tensile strength, water vapor transmission rate and moisture absorption were also tested to choose the most promising film. DBP was proved to be the most suitable plasticizer with a best using amount of 20%, such polymer films had low vapor transmission rate and low moisture absorption which were very important to an enteric coating material. The polymer was further characterized for film coating by evaluating the release of erythromycin tablets in vitro, tablets coated with SMA-ethanol can satisfy the drug release requests of USP when the film weight gains were between 4 and 6%; tablets coated with both a subcoat and the polymer showed excellent gastro-resistance, less than 0.2% drug release occurred even with weight gains as less as 2% after 2h exposure to acid (pH 1), while over 90% drug release occurred in pH 6.8 sodium phosphate buffer within 45 min, regardless of weight gains of coating material, moreover, we confirmed that the application of a subcoat could decrease the amount of required coating polymer. In conclusion, the potential use of SMA-ethanol as enteric coating material was demonstrated.

  9. Synthesis of Fluorinated Polymers and Evaluation of Wettability.

    PubMed

    Kimura, Tamami; Kasuya, Maria Carmelita; Hatanaka, Kenichi; Matsuoka, Koji

    2016-03-17

    Two kinds of fluorinated polymers were synthesized: an acrylate polymer having a fluorinated triethylene glycol as a pendant group (2a) and a fluoroalkyl acrylate polymer (2b). The contact angle of these fluorinated polymers against water, non-fluorinated alcohols and fluorinated alcohols were evaluated. As compared with the fluoroalkyl polymer (2b), fluoroethylene glycol polymer (2a) showed smaller contact angle against water and non-fluorinated alcohols. This supports the proposition that changing the alkyl chain into the ethylene glycol-type chain gave some interaction between etheric oxygen and water or non-fluorinated alcohols. In addition, fluoroalkyl acrylate polymer (2b) showed remarkably low values of critical surface tension.

  10. Reduced clastogenic activity of maleic hydrazide in Vicia faba seedlings grown in a situation of overcrowding stress.

    PubMed

    De Marco, Antonio; Owczarek, Malgorzata; Raglione, Marcello; Lanza, Barbara

    2005-03-07

    A pre-treatment stress situation of overcrowding of Vicia faba seedlings in the phase of germination and growth influenced their subsequent sensibility to treatment with the mutagenic herbicide maleic hydrazide. The seedlings showed a significant reduction in the frequency of micronucleated cells when they grew in a strongly crowded manner compared with scattered and uniformly distributed seedlings (3.83% versus 11.46%). The findings do not provide evidence for the involvement of phytochelatins in response to stress conditions in this process: pre-treatment with buthionine sulfoximine, a specific inhibitor of phytochelatin synthesis, did not modify the response of the seedlings to maleic hydrazide under conditions of overcrowding or under normal conditions. Scanning electron microscopy (SEM) was used to observe the root tip of V. faba grown in conditions of normal growth or overcrowding. SEM micrographs revealed differences between the tips with regards to root hair density and root surface morphology. Finally, we found a positive correlation between the frequency of micronucleated cells and the length of the primary root, for every time of growth considered (1, 3, 4 and 5 days).

  11. Preparation and characterization of poly(maleic acid)-grafted cross-linked chitosan microspheres for Cd(II) adsorption.

    PubMed

    Yu, Zhenzhen; Dang, Qifeng; Liu, Chengsheng; Cha, Dongsu; Zhang, Haifeng; Zhu, Wenjing; Zhang, Qianqian; Fan, Bing

    2017-09-15

    A novel adsorbent, composed of poly(maleic acid)-grafted cross-linked chitosan microspheres (PMACCMs), was prepared via cross-linking with glutaraldehyde and modification by grafting maleic acid. FTIR, zeta potential, elemental analysis, (13)C NMR, DTG, laser particle size analysis, SEM, and BET methods were applied to characterize PMACCMs, exhibiting a successful fabrication, good thermostability, and well-defined surface microstructure beneficial to Cd(II) adsorption. The effects of pH, contact time, and initial concentration on Cd(II) adsorption were also investigated, and the maximum adsorption capacity was 39.2mgg(-1), indicating a great improvement as compared with that (14.5mgg(-1)) of cross-linked chitosan microspheres. The experimental data were well fitted with pseudo-second-order kinetic and Langmuir isotherm models. Five-cycle reusability tests demonstrated PMACCMs could be repeatedly used with a small adsorption capacity loss (<15%). Additionally, the adsorption mechanism was proposed. All the results confirmed that PMACCMs, which presented outstanding adsorption capability and reusability, could be a good candidate for wastewater purification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Adsorptive removal of copper (II) and lead (II) using chitosan-g-maleic anhydride-g-methacrylic acid copolymer.

    PubMed

    Lavanya, R; Gomathi, T; Vijayalakshmi, K; Saranya, M; Sudha, P N; Anil, Sukumaran

    2017-11-01

    In the present work, the maleic anhydride and methacrylic acid monomers were grafted one after another onto chitosan by using ceric ammonium nitrate as the initiator. The optimum conditions for grafting were studied by varying the initiator concentration, monomer concentration and reaction temperature. The synthesized grafted samples were subjected to various analytical techniques such as FTIR, XRD, TGA and DSC methods The proof of formation of graft copolymer was ascertained from the results of FTIR analysis and XRD studies. The TGA and DSC results conclude the highly thermally stable behavior of the prepared graft copolymer sample. The prepared graft copolymer was utilized for removing copper and lead from aqueous solutions and optimum adsorption parameters were evaluated under various pH, adsorbent dose, contact time and initial metal ion concentration. The adsorption and kinetic studies have been explained by Langmuir, Freundlich and pseudo - first order, second order and intra particle diffusion models. From the results, it was seen that Freundlich isotherm was best fit in the case of adsorption studies which followed pseudo second order kinetics. The obtained results showed that the chitosan-g-maleic anhydride-g-methacrylic acid copolymer was very efficient in removing the heavy metals copper and lead from aqueous solution. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Keto-Functionalized Polymer Scaffolds As Versatile Precursors to Polymer Side Chain Conjugates.

    PubMed

    Liu, Jingquan; Li, Ronald C; Sand, Gregory J; Bulmus, Volga; Davis, Thomas P; Maynard, Heather D

    2013-01-01

    A new methacrylate monomer with a reactive ketone side-chain, 2-(4-oxo-pentanoate) ethyl methacrylate (PAEMA), was synthesized and subsequently polymerized by reversible addition-fragmentation chain transfer (RAFT) polymerization to give a polymer with a narrow molecular weight distribution (PDI = 1.25). The polymer was chain extended with poly(ethylene glycol methyl ether acrylate) (PEGMA) to yield a block copolymer. Aminooxy containing small molecules and oligoethylene glycol were conjugated to the ketone functionality of the side chain in high yields. Cytotoxicity of the oxime-linked tetra(ethylene glycol) polymer to mouse fibroblast cells was investigated; the polymer was found to be non-cytotoxic up to 1 mg/mL. The ease with which this polymer is functionalized, suggests that it may be useful in forming tailored polymeric medicines.

  14. Inhalation anaesthesia: from diethyl ether to xenon.

    PubMed

    Bovill, J G

    2008-01-01

    Modern anaesthesia is said to have began with the successful demonstration of ether anaesthesia by William Morton in October 1846, even though anaesthesia with nitrous oxide had been used in dentistry 2 years before. Anaesthesia with ether, nitrous oxide and chloroform (introduced in 1847) rapidly became commonplace for surgery. Of these, only nitrous oxide remains in use today. All modern volatile anaesthetics, with the exception of halothane (a fluorinated alkane), are halogenated methyl ethyl ethers. Methyl ethyl ethers are more potent, stable and better anaesthetics than diethyl ethers. They all cause myocardial depression, most markedly halothane, while isoflurane and sevoflurane cause minimal cardiovascular depression. The halogenated ethers also depress the normal respiratory response to carbon dioxide and to hypoxia. Other adverse effects include hepatic and renal damage. Hepatitis occurs most frequently with halothane, although rare cases have been reported with the other agents. Liver damage is not caused by the anaesthetics themselves, but by reactive metabolites. Type I hepatitis occurs fairly commonly and takes the form of a minor disturbance of liver enzymes, which usually resolves without treatment. Type II, thought to be immune-mediated, is rare, unpredictable and results in a severe fulminant hepatitis with a high mortality. Renal damage is rare, and was most often associated with methoxyflurane because of excessive plasma fluoride concentrations resulting from its metabolism. Methoxyflurane was withdrawn from the market because of the high incidence of nephrotoxicity. Among the contemporary anaesthetics, the highest fluoride concentrations have been reported with sevoflurane, but there are no reports of renal dysfunction associated with its use. Recently there has been a renewed interest in xenon, one of the noble gases. Xenon has many of the properties of an ideal anaesthetic. The major factor limiting its more widespread is the high cost, about

  15. Preparation of soybean oil polymers with high molecular weight

    USDA-ARS?s Scientific Manuscript database

    The cationic polymerization of soybean oils was initiated by boron trifluoride diethyl etherate BF3.O(C2H5)2 in supercritical carbon dioxide (scCO2) medium. The resulting polymers had molecular weight ranging from 21,842 to 118,300 g/mol. Nuclear magnetic resonance spectroscopy (NMR) and gel perme...

  16. New Development of Polymer-Based Cotton for Breathable Material

    USDA-ARS?s Scientific Manuscript database

    Recently, we converted the poly (ethylene oxide) dibromide to poly (ethylene oxide) diazides and reacted to study cycloaddition polymerization with bisphenol-A dipropargyl ether to produce elastomers compatible with cotton (Polymer Preprints, 2005, 46(1), 737-738). The reactants were characterized w...

  17. Functional Aromatic Poly(1,3,4-Oxadiazole-Ether)s with Benzimidazole Pendants: Synthesis, Thermal and Dielectric Studies

    PubMed Central

    Ganesh, Shimoga D.; Pai, Vasantakumar K.; Kariduraganavar, Mahadevappa Y.; Jayanna, Madhu B.

    2014-01-01

    Poly(1,3,4-oxadiazole-ether) with reactive carboxylic acid pendants was synthesized from solution polymerization via nucleophilic displacement polycondensation among 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (BFPOx) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). Without altering the polymeric segments, benzimidazole modified poly(1,3,4-oxadiazole-ether)s were prepared by varying stoichiometric ratios of 1,2-phenylenediamine. The molecular structural characterization of these polymers was achieved by, FT-IR, NMR, TGA, elemental analysis, and analytical techniques. The weight-average molecular weight of virgin polymer with carboxylic acid functionality was determined by gel permeation chromatography (GPC) and was found to be 22400 (Mw/Mn = 2.07). All the synthesized polyethers were compressed into pellets and electrical contacts were established to perform dielectric properties. PMID:27437448

  18. Crystalline imide/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor); Bass, Robert G. (Inventor)

    1995-01-01

    Crystalline imide/arylene ether block copolymers are prepared by reacting anhydride terminated poly(amic acids) with amine terminated poly)arylene ethers) in polar aprotic solvents and chemically or thermally cyclodehydrating the resulting intermediate poly(amic acids). The block copolymers of the invention have one glass transition temperature or two, depending on the particular structure and/or the compatibility of the block units. Most of these crystalline block copolymers for tough, solvent resistant films with high tensile properties. While all of the copolymers produced by the present invention are crystalline, testing reveals that copolymers with longer imide blocks or higher imide content have increased crystallinity.

  19. 41. LOOKING WEST AT BUILDING NO. 519, ETHER AND ALCOHOL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. LOOKING WEST AT BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, (LEFT) AND BUILDING NO. 521, ETHER VAULT, (RIGHT) IN FOREGROUND - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  20. 37. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, NORTHWEST CORNER OF BUILDING. BUILDING NO. 521 (ETHER VAULT) IN BACKGROUND LEFT. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  1. Discovery of Antibiotics-derived Polymers for Gene Delivery using Combinatorial Synthesis and Cheminformatics Modeling

    PubMed Central

    Potta, Thrimoorthy; Zhen, Zhuo; Grandhi, Taraka Sai Pavan; Christensen, Matthew D.; Ramos, James; Breneman, Curt M.; Rege, Kaushal

    2014-01-01

    We describe the combinatorial synthesis and cheminformatics modeling of aminoglycoside antibiotics-derived polymers for transgene delivery and expression. Fifty-six polymers were synthesized by polymerizing aminoglycosides with diglycidyl ether cross-linkers. Parallel screening resulted in identification of several lead polymers that resulted in high transgene expression levels in cells. The role of polymer physicochemical properties in determining efficacy of transgene expression was investigated using Quantitative Structure-Activity Relationship (QSAR) cheminformatics models based on Support Vector Regression (SVR) and ‘building block’ polymer structures. The QSAR model exhibited high predictive ability, and investigation of descriptors in the model, using molecular visualization and correlation plots, indicated that physicochemical attributes related to both, aminoglycosides and diglycidyl ethers facilitated transgene expression. This work synergistically combines combinatorial synthesis and parallel screening with cheminformatics-based QSAR models for discovery and physicochemical elucidation of effective antibiotics-derived polymers for transgene delivery in medicine and biotechnology. PMID:24331709

  2. Discovery of antibiotics-derived polymers for gene delivery using combinatorial synthesis and cheminformatics modeling.

    PubMed

    Potta, Thrimoorthy; Zhen, Zhuo; Grandhi, Taraka Sai Pavan; Christensen, Matthew D; Ramos, James; Breneman, Curt M; Rege, Kaushal

    2014-02-01

    We describe the combinatorial synthesis and cheminformatics modeling of aminoglycoside antibiotics-derived polymers for transgene delivery and expression. Fifty-six polymers were synthesized by polymerizing aminoglycosides with diglycidyl ether cross-linkers. Parallel screening resulted in identification of several lead polymers that resulted in high transgene expression levels in cells. The role of polymer physicochemical properties in determining efficacy of transgene expression was investigated using Quantitative Structure-Activity Relationship (QSAR) cheminformatics models based on Support Vector Regression (SVR) and 'building block' polymer structures. The QSAR model exhibited high predictive ability, and investigation of descriptors in the model, using molecular visualization and correlation plots, indicated that physicochemical attributes related to both, aminoglycosides and diglycidyl ethers facilitated transgene expression. This work synergistically combines combinatorial synthesis and parallel screening with cheminformatics-based QSAR models for discovery and physicochemical elucidation of effective antibiotics-derived polymers for transgene delivery in medicine and biotechnology.

  3. High octane ethers from synthesis gas-derived alcohols

    SciTech Connect

    Klier, K.; Herman, R.G.; Johansson, M.; Feeley, O.C.

    1992-01-01

    The objective of the proposed research is to synthesize high octane ethers, primarily methyl isobutyl ether (MIBE) and methyl tertiary butyl ether (MTBE), directly from H{sub 2}/CO/CO{sub 2} coal-derived synthesis gas via alcohol mixtures that are rich in methanol and 2-methyl-1-propanol (isobutanol). The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers.

  4. High octane ethers from synthesis gas-derived alcohols

    SciTech Connect

    Klier, K.; Herman, R.G.; Johansson, M.A.; Feeley, O.C.

    1992-04-01

    The objective of the proposal research is to synthesize high octane ethers, primarily methyl isobutyl ether (MIBE) and methyl tertiary butyl ether (MTBE), directly from H{sub 2}/CO/CO{sub 2} coal-derived synthesis gas via alcohol mixtures that are rich in methanol and 2-methyl-1-propanol (isobutanol). The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers.

  5. Layer-by-layer assembly and characterization of multilayers of a manganese porphyrin linked poly(4-vinylpyridinium) derivative and poly(styrenesulfonic acid-o-maleic) acid.

    PubMed

    Wang, Hong-Lei; Sun, Qing; Chen, Meng; Miyake, Jun; Qian, Dong-Jin

    2011-08-16

    Multilayers of manganese(III) porphyrin-linked poly(vinylpyridinium) (MnTMPyP-PVPMe) polyelectrolyte and poly(styrenesulfonic acid-o-maleic) acid (PSS) have been assembled on gold, quartz, and indium tin oxide surfaces by a layer-by-layer (LBL) technique. The assembly process was monitored by measuring their absorption spectra and frequency change after each assembly, both of which confirmed the formation of three-dimensional MnTMPyP-PVPMe/PSS multilayers. The Soret absorption band of porphyrin red shifted about 8 nm in the multilayer compared with that in the dilute aqueous solution. The average mass changes for each assembly of MnTMPyP-PVPMe and PSS were estimated to be about 2.9 and 0.25 μg/cm(2), respectively. X-ray photoelectron spectra revealed that the as-prepared multilayers were composed of S 2p, C 1s, N 1s, O 1s, and Mn 2p, corresponding to polymers of MnTMPyP-PVPMe and PSS. A rough surface was observed after the assembly of MnTMPyP-PVPMe on the gold surface, but it became smoother when the PSS layer was adsorbed. The significant difference in the mass change and film morphology after the assembly of MnTMPyP-PVPMe compared to those after the assembly of PSS was ascribed to the reason that the MnTMPyP-PVPMe polyelectrolyte contained large metalloporphyrin macrocycles, which were axially coordinated to the pyridyl substituents of the PVP polymeric backbones. The cyclic voltammograms revealed two couples of redox waves in the phosphate electrolyte solution at pH 11, which corresponded to the electron-transfer processes of Mn(II)/Mn(III) and Mn(III)/Mn(IV) of polymeric manganese porphyrin MnTMPyP-PVPMe. The charge-transfer process was also investigated. Finally, the present MnTMPyP-PVPMe/PSS multilayers were used as a heterogeneous catalyst for the decoloration of an azo dye.

  6. Production of nabumetone nanoparticles: Effect of molecular weight, concentration and nature of cellulose ether stabiliser.

    PubMed

    Goodwin, D J; Martini, L G; Lawrence, M J

    2016-12-05

    The ability of a range of hydrophilic nonionic cellulose ethers (CEs) (namely methylhydroxethylcellulose, hydroxypropylmethylcellulose, ethylhydroxyethylcellulose, hydroxyethylcellulose and hydroxypropylcellulose) to prepare stable nabumetone nanoparticles (<1000nm, as measured by laser diffraction) using wet-bead milling has been investigated. Due to the limited range of CE molecular weights commercially available, the CEs were degraded using ultrasonication for varying lengths of time to yield CEs of lower molecular weight. Of the CEs tested, only hydroxyethylcellulose was found not to stabilise the production of nabumetone nanoparticles at any of the molecular weights tested, namely viscosity average molecular weights (Mv) in the range of 236-33kg/mol. All other CEs successfully stabilised nabumetone nanoparticles, with the lower molecular weight/viscosity polymers within a series being more likely to result in nanoparticle production than their higher molecular weight counterparts. Unfortunately due to the nature of the ultrasonication process, it was not possible to compare the size of nabumetone particles produced using polymers of identical Mv. There was, however, enough similarity in the Mv of the various polymers to draw the general conclusion that there was no strong correlation between the Mv of the various polymers and their ability to produce nanoparticles. For example hydroxypropylcellulose of 112.2kg/mol or less successfully produced nanoparticles while only ethylhydroxyethylcellulose and hydroxypropylmethyl polymers of 52 and 38.8kg/mol or less produced nanoparticles. These results suggest that polymer molecular weight is not the only determinant of nanoparticle production and that structure of the polymer is at least as important as its molecular weight. In particular the hydrophobic nature of the CE was thought to be an important factor in the production of nabumetone nanoparticles: the more hydrophobic the polymer, the stronger its interaction

  7. Maleic anhydride polypropylene modified cellulose nanofibril polypropylene nanocomposites with enhanced impact strength

    Treesearch

    Yucheng Peng; Sergio A. Gallegos; Douglas J. Gardner; Yousoo Han; Zhiyong Cai

    2014-01-01

    The unique aspect of polymer composites reinforced by various fillers or additives is that the mechanical properties of the material can be tailored to fit a variety of uses: construction, transportation, industrial, and consumer applications. By selecting a specific reinforcement or designing a particular manufacturing process a material with desired properties can be...

  8. 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...

  9. Characterization of maleic acid/anhydride copolymer films by low-rate dynamic liquid-fluid contact angle measurements using axisymmetric drop shape analysis.

    PubMed

    Uhlmann, Petra; Skorupa, Sebastian; Werner, Carsten; Grundke, Karina

    2005-07-05

    Thin films of alternating maleic acid/anhydride copolymers (poly(octadecene-alt-maleic acid/anhydride), POMA; poly(propene-alt-maleic acid/anhydride), PPMA; poly(styrene-alt-maleic acid/anhydride), PSMA) were studied to unravel the influence of the comonomer characteristics in the backbone on the surface-energetic properties of the copolymer films in the dry state and in contact with aqueous solutions. Water contact angle measurements revealed a graduation of the wettability of the dry hydrolyzed and annealed copolymer films that was dependent on the comonomer unit. It ranged from moderately hydrophilic (PPMA, annealed gamma(sv) = 39.9 mJ/m2) to very hydrophobic (POMA, annealed, gamma(sv) = 18.4 mJ/m2) surfaces. Liquid-fluid contact angle measurements using captive air bubbles were performed in different aqueous media (pure water, phosphate-buffered saline, and 10(-)(3) M KCl of two different pH values (pH = 3 and pH = 10) to study the copolymer films in their hydrated states relevant for biointerfacial phenomena. It was found that the graduation of the wettability of the copolymer films in the dry state is overall maintained upon immersion in aqueous solutions. The dependence of the wettability on the pH value of the aqueous medium could be related to the (de)protonation of the carboxylic groups.

  10. 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...

  11. The carry-through of residues of maleic hydrazide from treated potatoes, following manufacture into potato crisps and 'jacket' potato crisps.

    PubMed

    Lewis, D J; Thorpe, S A; Wilkinson, K; Reynolds, S L

    1998-07-01

    Potatoes, which had been treated 'in the field' with a commercial formulation of maleic hydrazide, were processed into potato crisps and jacket potato crisps on a factory production line using standard manufacturing conditions. Samples were taken at strategic points throughout the process and analysed to determine the degree of carry-through of residues. Results demonstrated that ca 56% of the maleic hydrazide residue in a potato could be carried through into the potato crisps, irrespective of which type of crisp was being manufactured. Results from a similarly constructed study investigating the fate of pesticides applied post-harvest showed that carry-through was less than 10%. This difference is explained in terms of the different modes of action of the two classes of pesticides being investigated. It is known that, as maleic hydrazide is a systemic pesticide, it will be located within the flesh of the potato tuber and is therefore likely to be protected from the various stages of the crisping process. However, the post-harvest non-systemic pesticides are applied to the exterior surface of the tuber and are therefore not likely to be protected in the same way. The results also showed that, due to the concentration effect caused by the loss of moisture during crisp manufacture, the levels of maleic hydrazide residues in crisps (on a mg/kg product basis) were approximately twice those measured in the original potatoes.

  12. Morphology and phase controlled cobalt nanostructures in magnetic polypropylene nanocomposites: the role of alkyl chain-length in maleic anhydride grafted polypropylene.

    PubMed

    He, Qingliang; Yuan, Tingting; Luo, Zhiping; Haldolaarachchige, Neel; Young, David P; Wei, Suying; Guo, Zhanhu

    2013-04-04

    A novel function of maleic anhydride grafted polypropylene (PP) with different backbone chain-lengths was demonstrated, i.e., in controlling the cobalt morphologies (dispersed polyhedral vs. assembled chain nanostructure), crystalline structures (ε- vs. β-phase), and magnetic property (242 vs. 808 Oe) in the synthesized magnetic PP nanocomposites.

  13. 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...

  14. 40 CFR 721.3435 - Butoxy-substituted ether alkane.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butoxy-substituted ether alkane. 721... Substances § 721.3435 Butoxy-substituted ether alkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as butoxy-substituted ether...

  15. 40 CFR 721.3465 - Stilbene diglycidyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Stilbene diglycidyl ether. 721.3465... Substances § 721.3465 Stilbene diglycidyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as stilbene diglycidyl ether (PMN P-96-1427) is subject...

  16. 39. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, LOOKING AT SOUTHWEST CORNER WITH BUILDING NO. 521, ETHER VAULT, AND BUILDING NO. 519-A, ETHER & ALOCOHL STORAGE TANKS, IN BACKGROUND RIGHT. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  17. Alkyl Aryl Ether Bond Formation with PhenoFluor**

    PubMed Central

    Shen, Xiao; Neumann, Constanze N.; Kleinlein, Claudia; Claudia, Nathaniel W.; Ritter, Tobias

    2015-01-01

    An alkyl aryl ether bond formation reaction between phenols and primary and secondary alcohols with PhenoFluor has been developed. The reaction features a broad substrate scope and tolerates many functional groups, and substrates that are challenging for more conventional ether bond forming processes may be coupled. A preliminary mechanistic study indicates reactivity distinct from conventional ether bond formation. PMID:25800679

  18. Hydrothermal Synthesis and Processing of Barium Titanate Nanoparticles Embedded in Polymer Films.

    PubMed

    Toomey, Michael D; Gao, Kai; Mendis, Gamini P; Slamovich, Elliott B; Howarter, John A

    2015-12-30

    Barium titanate nanoparticles embedded in flexible polymer films were synthesized using hydrothermal processing methods. The resulting films were characterized with respect to material composition, size distribution of nanoparticles, and spatial location of particles within the polymer film. Synthesis conditions were varied based on the mechanical properties of the polymer films, ratio of polymer to barium titanate precursors, and length of aging time between initial formulations of the solution to final processing of nanoparticles. Block copolymers of poly(styrene-co-maleic anhydride) (SMAh) were used to spatially separate titanium precursors based on specific chemical interactions with the maleic anhydride moiety. However, the glassy nature of this copolymer restricted mobility of the titanium precursors during hydrothermal processing. The addition of rubbery butadiene moieties, through mixing of the SMAh with poly(styrene-butadiene-styrene) (SBS) copolymer, increased the nanoparticle dispersion as a result of greater diffusivity of the titanium precursor via higher mobility of the polymer matrix. Additionally, an aminosilane was used as a means to retard cross-linking in polymer-metalorganic solutions, as the titanium precursor molecules were shown to react and form networks prior to hydrothermal processing. By adding small amounts of competing aminosilane, excessive cross-linking was prevented without significantly impacting the quality and composition of the final barium titanate nanoparticles. X-ray diffraction and X-ray photoelectron spectroscopy were used to verify nanoparticle compositions. Particle sizes within the polymer films were measured to be 108 ± 5 nm, 100 ± 6 nm, and 60 ± 5 nm under different synthetic conditions using electron microscopy. Flexibility of the films was assessed through measurement of the glass transition temperature using dynamic mechanical analysis. Dielectric permittivity was measured using an impedance analyzer.

  19. Piezoelectric Polymers

    NASA Technical Reports Server (NTRS)

    Harrison, J. S.; Ounaies, Z.; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    The purpose of this review is to detail the current theoretical understanding of the origin of piezoelectric and ferroelectric phenomena in polymers; to present the state-of-the-art in piezoelectric polymers and emerging material systems that exhibit promising properties; and to discuss key characterization methods, fundamental modeling approaches, and applications of piezoelectric polymers. Piezoelectric polymers have been known to exist for more than forty years, but in recent years they have gained notoriety as a valuable class of smart materials.

  20. Molecular Engineering of Liquid Crystal Polymers by Living Polymerization. 13. Synthesis and Living Cationic Polymerization of 4-((S(-)-2- Methyl-1-Butyl)Oxycarbonyl)-4’-(omega-Oxyalkyl-1-Vinyl Ether)Biphenyl with Undecanyl and Hexyl Alkyl Groups

    DTIC Science & Technology

    1991-04-10

    Ether (9& 9-6 was synthesized by the same prozedure as the one used for in the synthesis of 9-11. 6-Bromohexan- l -ol (12 g, 66.3 mmol) and 1,10...its distribution is unlimited. 91-00241 ______________ \\Il\\I\\\\ll\\\\ll\\1\\ l \\\\lll/!ll\\\\ l \\ll 5 21 0 9 3 "’REPORT DOCUMENTATION PAGE I& 49POAT S$ C.AiTf...apo.Cabie) & L . ADORESS (Cmry. State, ia ZIP Coot) 10 SOURCE of tUNOtNG F4UMIERS Offic o.C Naval Research PRGA POE. TASK VYORX UNIT 800 N. QuincY ELEMENT