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

Injectible bodily prosthetics employing methacrylic copolymer gels

DOEpatents

Mallapragada, Surya K.; Anderson, Brian C.

2007-02-27

The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

Effect of end segment on physicochemical properties and platelet compatibility of poly(propylene glycol)-initiated poly(methyl methacrylate).

PubMed

Fukuda, Chihiro; Yahata, Chie; Kinoshita, Takuya; Watanabe, Takafumi; Tsukamoto, Hideo; Mochizuki, Akira

2017-10-01

It is well known that polyether-based copolymers have good blood compatibility, although many mechanisms have been proposed to explain their favorable performance. Our objective in carrying out the present study was to obtain a better understanding of the effect of the (poly)ether segment on blood compatibility. Therefore, we synthesized poly(propylene glycol) (PPG)-based initiators for atom transfer polymerization, where the number of propylene glycol (PG) units in the PPG (Pn(PG) was varied from 1 to 94. Methyl methacrylate (MMA) was polymerized using the initiators, resulting in the formation of polyMMAs with a PG-based ether part at the polymer terminal. We mainly investigated the effects of Pn(PG) on the surface properties and platelet compatibility of the PPG-polyMMA. X-ray photoelectron spectroscopy and surface contact angle (CA) analysis revealed the exposure of the PG units at the surface of the polymer. The platelet compatibility of the polymers was improved compared with a commercial polyMMA, even when Pn(PG) = 1. These results suggest that PG units have an important influence on favorable blood compatibility, regardless of the Pn(PG) value. We also investigated protein adsorption behavior in terms of the amount and deformation of fibrinogen adsorbed on the polymer surface.

Surface-initiated polymerization within mesoporous silica spheres for the modular design of charge-neutral polymer particles.

PubMed

Müllner, Markus; Cui, Jiwei; Noi, Ka Fung; Gunawan, Sylvia T; Caruso, Frank

2014-06-03

We report a templating approach for the preparation of functional polymer replica particles via surface-initiated polymerization in mesoporous silica templates. Subsequent removal of the template resulted in discrete polymer particles. Furthermore, redox-responsive replica particles could be engineered to disassemble in a reducing environment. Particles, made of poly(methacryloyloxyethyl phosphorylcholine) (PMPC) or poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA), exhibited very low association to human cancer cells (below 5%), which renders the reported charge-neutral polymer particles a modular and versatile class of highly functional carriers with potential applications in drug delivery.

Anionic polymer, poly(methyl vinyl ether-maleic anhydride)-coated beads-based capture of human influenza A and B virus.

PubMed

Sakudo, Akikazu; Baba, Koichi; Tsukamoto, Megumi; Sugimoto, Atsuko; Okada, Takashi; Kobayashi, Takanori; Kawashita, Norihito; Takagi, Tatsuya; Ikuta, Kazuyoshi

2009-01-15

An anionic magnetic beads-based method was developed for the capture of human influenza A and B viruses from nasal aspirates, allantoic fluid and culture medium. A polymer, poly(methyl vinyl ether-maleic anhydride) [poly(MVE-MA)], was used to endow magnetic beads with a negative charge and bioadhesive properties. After incubation with samples containing human influenza virus, the beads were separated from supernatants by applying a magnetic field. The adsorption [corrected] of the virus by the beads was confirmed by hemagglutinin assay, immunochromatography, Western blotting, egg infection, and cell infection. Successful capture was proved using 5 H1N1 influenza A viruses, 10 H3N2 influenza A viruses, and 6 influenza B viruses. Furthermore, the infectivity in chicken embryonated eggs and Madin-Darby canine kidney (MDCK) cells of the captured human influenza virus was similar to that of the total viral quantity of starting materials. Therefore, this method of capture using magnetic beads coated with poly(MVE-MA) can be broadly used for the recovery of infectious human influenza viruses.

Anion exchange membranes based on terminally crosslinked methyl morpholinium-functionalized poly(arylene ether sulfone)s

NASA Astrophysics Data System (ADS)

Kwon, Sohyun; Rao, Anil H. N.; Kim, Tae-Hyun

2018-01-01

Azide-assisted terminal crosslinking of methyl morpholinium-functionalized poly(arylene ether sulfone) block copolymers yields products (xMM-PESs) suitable for use as anion exchange membranes. By combining the advantages of bulky morpholinium conductors and our unique polymer network crosslinked only at the termini of the polymer chains, we can produce AEMs that after the crosslinking show minimal loss in conductivity, yet with dramatically reduced water uptake. Terminal crosslinking also significantly increases the thermal, mechanical and chemical stability levels of the membranes. A high ion conductivity of 73.4 mS cm-1 and low water uptake of 26.1% at 80 °C are obtained for the crosslinked membrane with higher amount of hydrophilic composition, denoted as xMM-PES-1.5-1. In addition, the conductivity of the crosslinked xMM-PES-1.5-1 membrane exceeds that of its non-crosslinked counterpart (denoted as MM-PES-1.5-1) above 60 °C at 95% relative humidity because of its enhanced water retention capacity caused by the terminally-crosslinked structure.

Thermoswitchable Janus Gold Nanoparticles with Stimuli-Responsive Hydrophilic Polymer Brushes.

PubMed

Niu, Xiaoqin; Ran, Fen; Chen, Limei; Lu, Gabriella Jia-En; Hu, Peiguang; Deming, Christopher P; Peng, Yi; Rojas-Andrade, Mauricio D; Chen, Shaowei

2016-05-03

Well-defined thermoswitchable Janus gold nanoparticles with stimuli-responsive hydrophilic polymer brushes were fabricated by combining ligand exchange reactions and the Langmuir technique. Stimuli-responsive polydi(ethylene glycol) methyl ether methacrylate was prepared by addition-fragmentation chain-transfer polymerization. The polymer brushes were then anchored onto the nanoparticle surface by interfacial ligand exchange reactions with hexanethiolate-protected gold nanoparticles, leading to the formation of a hydrophilic (polymer) hemisphere and a hydrophobic (hexanethiolate) one. The resulting Janus nanoparticles showed temperature-switchable wettability, hydrophobicity at high temperatures, and hydrophilicity at low temperatures, due to thermally induced conformational transition of the polymer ligands. The results further highlight the importance of interfacial engineering in the deliberate functionalization of nanoparticle materials.

Dual-Responsive pH and Temperature Sensitive Nanoparticles Based on Methacrylic Acid and Di(ethylene glycol) Methyl Ether Methacrylate for the Triggered Release of Drugs.

PubMed

Khine, Yee Yee; Jiang, Yanyan; Dag, Aydan; Lu, Hongxu; Stenzel, Martina H

2015-08-01

A series of thermo-and pH-responsive poly(methyl methacrylate)-block-poly[methacrylic acid-co-di(ethylene glycol) methyl ether methacrylate] PMMA-b-P[MAA-co-DEGMA] block copolymers were synthesized by RAFT polymerization and self-assembled into micelles. The molar ratio of MAA was altered from 0-12% in order to modulate the lower critical solution temperature (LCST) of PDEGMA. The release of the drug albendazole from the micelle was strongly dependent on the temperature and the LCST value of the polymer. Systems below the LCST released the drug slowly while increasing the temperature above the LCST or decreasing the pH value to 5 resulted in the burst-like release of the drug. ABZ delivered in this pH-responsive drug carrier had a higher toxicity than the free drug or the drug delivered in a non-responsive drug carrier. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... in residential settings. If EPA is able to determine that a finite tolerance is not necessary to... elements carbon, hydrogen, and oxygen. 3. The polymer does not contain as an integral part of its composition, except as impurities, any element other than those listed in 40 CFR 723.250(d)(2)(ii). 4. The...

Thermodynamic properties (enthalpy, bond energy, entropy, and heat capacity) and internal rotor potentials of vinyl alcohol, methyl vinyl ether, and their corresponding radicals.

PubMed

da Silva, Gabriel; Kim, Chol-Han; Bozzelli, Joseph W

2006-06-29

Vinyl alcohols (enols) have been discovered as important intermediates and products in the oxidation and combustion of hydrocarbons, while methyl vinyl ethers are also thought to occur as important combustion intermediates. Vinyl alcohol has been detected in interstellar media, while poly(vinyl alcohol) and poly(methyl vinyl ether) are common polymers. The thermochemical property data on these vinyl alcohols and methyl vinyl ethers is important for understanding their stability, reaction paths, and kinetics in atmospheric and thermal hydrocarbon-oxygen systems. Enthalpies , entropies , and heat capacities (C(p)()(T)) are determined for CH(2)=CHOH, C(*)H=CHOH, CH(2)=C(*)OH, CH(2)=CHOCH(3), C(*)H=CHOCH(3), CH(2)=C(*)OCH(3), and CH(2)=CHOC(*)H(2). Molecular structures, vibrational frequencies, , and C(p)(T) are calculated at the B3LYP/6-31G(d,p) density functional calculation level. Enthalpies are also determined using the composite CBS-Q, CBS-APNO, and G3 methods using isodesmic work reactions to minimize calculation errors. Potential barriers for internal rotors are calculated at the B3LYP/6-31G(d,p) level and used to determine the hindered internal rotational contributions to entropy and heat capacity. The recommended ideal gas phase values calculated in this study are the following (in kcal mol(-1)): -30.0, -28.9 (syn, anti) for CH(2)=CHOH; -25.6, -23.9 for CH(2)=CHOCH(3); 31.3, 33.5 for C(*)H=CHOH; 27.1 for anti-CH(2)=C(*)OH; 35.6, 39.3 for C(*)H=CHOCH(3); 33.5, 32.2 for CH(2)=C(*)OCH(3); 21.3, 22.0 for CH(2)=CHOC(*)H(2). Bond dissociation energies (BDEs) and group additivity contributions are also determined. The BDEs reveal that the O-H, O-CH(3), C-OH, and C-OCH(3) bonds in vinyl alcohol and methyl vinyl ether are similar in energy to those in the aromatic molecules phenol and methyl phenyl ether, being on average around 3 kcal mol(-1) weaker in the vinyl systems. The keto-enol tautomerization enthalpy for the interconversion of vinyl alcohol to acetaldehyde is determined to be -9.7 kcal mol(-1), while the activation energy for this reaction is calculated as 55.9 kcal mol(-1); this is the simplest keto-enol tautomerization and is thought to be important in the reactions of vinyl alcohol. Formation of the formyl methyl radical (vinoxy radical/vinyloxy radical) from both vinyl alcohol and methyl vinyl ether is also shown to be important, and its reactions are discussed briefly.

Three-Dimensional Photochemical Machining with Lasers

DTIC Science & Technology

1983-11-30

559.91 (1.00) 4-Hydroxybenzophenone 27.78 79.42 359.97 (1.00) 0 19.42 55.52 514.93 (0.78) Benzoin 27.03 77.28 369.96 (1.00) 21.01 60.07 475.96 (0.95...Xanthone I x 104 3 x 103 2 x 10 2 -3 Photosensitizer x = 318-320 nm x 2 340-345 nm Benzoin 310 -- x-Methyl benzoin 200 -- X-Hydroxymethyl benzoin -- 150... Benzoin isopropyl ether -- 230 Benzoin phenyl ether -- 250 (a) From: V. 0. McGinniss, in "Oevelopments in Polymer Photochemistry - 3", N. S. Allen, Ed

New Poly(amide-imide)/Nanocomposites Reinforced Silicate Nanoparticles Based on N-pyromellitimido-L-phenyl Alanine Containing Ether Moieties

NASA Astrophysics Data System (ADS)

Faghihi, Khalil; Shabanian, Meisam; Dadfar, Ehsan

2012-02-01

A series of Poly(amide-imide)/montmorillonite nanocomposites containing N-pyromellitimido-L-phenyl alanine moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 5 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N-pyromellitimido-L-phenyl alanine 3 with 4,4'-diamino diphenyl ether 4 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). The resulting nanocomposite films were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results showed that organo-modified clay was dispersed homogeneously in PAI matrix. TGA indicated an enhancement of thermal stability of new nanocomposites compared with the pure polymer.

A ring to rule them all: a cyclic ketene acetal comonomer controls the nitroxide-mediated polymerization of methacrylates and confers tunable degradability.

PubMed

Delplace, Vianney; Guégain, Elise; Harrisson, Simon; Gigmes, Didier; Guillaneuf, Yohann; Nicolas, Julien

2015-08-18

2-Methylene-4-phenyl-1,3-dioxolane (MPDL) was successfully used as a controlling comonomer in NMP with oligo(ethylene glycol) methyl ether methacrylate (MeOEGMA) to prepare well-defined and degradable PEG-based P(MeOEGMA-co-MPDL) copolymers. The level of ester group incorporation is controlled, leading to reductions in molecular weight of up to 95% on hydrolysis. Neither the polymer nor its degradation products displayed cytoxicity. The method was also successfully applied to methyl methacrylate.

Thermodynamic properties of hyperbranched polymer, Boltorn U3000, using inverse gas chromatography.

PubMed

Domańska, Urszula; Zołek-Tryznowska, Zuzanna

2009-11-19

Mass-fraction activity coefficients at infinite dilution (Omega13(infinity)) of alkanes (C5-C10), cycloalkanes (C5-C8), alkenes (C5-C8), alkynes (C5-C8), aromatic hydrocarbons (benzene, toluene, ethylbenzene, o-, m-, p-xylene, thiophene), alcohols (C1-C5), water, ethers (tetrahydrofuran (THF), methyl-tert-butylether (MTBE), diethyl-, di-n-propyl-, di-n-butyl ether), and ketones (propanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, cyclopentanone) in the hyperbranched polymer, Boltorn U3000 (B-U3000), have been determined by inverse gas chromatography (IGC) using the polymer as the stationary phase. The measurements were carried out at different temperatures between 308.15 and 348.15 K. The density and thermophysical properties of polymer were described. The specific retention volume (V(g)), the Flory-Huggins interaction parameter (chi13(infinity)), the molar enthalpy of sorption (the partial molar enthalpies of solute dissolution) (Delta(s)H), the partial molar excess enthalpy at infinite dilution of the solute and polymer (DeltaH1(E,infinity)), the partial molar Gibbs excess energy at infinite dilution (DeltaG1(E,infinity)), and the solubility parameter (delta3) were calculated.

A new route to synthesize aryl acetates from carbonylation of aryl methyl ethers

PubMed Central

Yang, Youdi; Li, Shaopeng; Han, Buxing

2018-01-01

Ether bond activation is very interesting because the synthesis of many valuable compounds involves conversion of ethers. Moreover, C–O bond cleavage is also very important for the transformation of biomass, especially lignin, which abundantly contains ether bonds. Developing efficient methods to activate aromatic ether bonds has attracted much attention. However, this is a challenge because of the inertness of aryl ether bonds. We proposed a new route to activate aryl methyl ether bonds and synthesize aryl acetates by carbonylation of aryl methyl ethers. The reaction could proceed over RhCl3 in the presence of LiI and LiBF4, and moderate to high yields of aryl acetates could be obtained from transformation of various aryl methyl ethers with different substituents. It was found that LiBF4 could assist LiI to cleave aryl methyl ether bonds effectively. The reaction mechanism was proposed by a combination of experimental and theoretical studies. PMID:29795781

NIOSH Manual of Analytical Methods (third edition). Fourth supplement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-08-15

The NIOSH Manual of Analytical Methods, 3rd edition, was updated for the following chemicals: allyl-glycidyl-ether, 2-aminopyridine, aspartame, bromine, chlorine, n-butylamine, n-butyl-glycidyl-ether, carbon-dioxide, carbon-monoxide, chlorinated-camphene, chloroacetaldehyde, p-chlorophenol, crotonaldehyde, 1,1-dimethylhydrazine, dinitro-o-cresol, ethyl-acetate, ethyl-formate, ethylenimine, sodium-fluoride, hydrogen-fluoride, cryolite, sodium-hexafluoroaluminate, formic-acid, hexachlorobutadiene, hydrogen-cyanide, hydrogen-sulfide, isopropyl-acetate, isopropyl-ether, isopropyl-glycidyl-ether, lead, lead-oxide, maleic-anhydride, methyl-acetate, methyl-acrylate, methyl-tert-butyl ether, methyl-cellosolve-acetate, methylcyclohexanol, 4,4'-methylenedianiline, monomethylaniline, monomethylhydrazine, nitric-oxide, p-nitroaniline, phenyl-ether, phenyl-ether-biphenyl mixture, phenyl-glycidyl-ether, phenylhydrazine, phosphine, ronnel, sulfuryl-fluoride, talc, tributyl-phosphate, 1,1,2-trichloro-1,2,2-trifluoroethane, trimellitic-anhydride, triorthocresyl-phosphate, triphenyl-phosphate, and vinyl-acetate.

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 P...

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 phenol...

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 P...

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...

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...

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...

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...

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 phenol...

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...

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...

40 CFR 721.10556 - Poly(oxy-1,2-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-15-alkyl ethers.

Code of Federal Regulations, 2013 CFR

2013-07-01

....- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers (PMN P-06-452; CAS No. 675869-05-3...-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-15-alkyl ethers. 721.10556 Section 721.10556 Protection of...-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-15-alkyl ethers. (a) Chemical substance...

40 CFR 721.10556 - Poly(oxy-1,2-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-15-alkyl ethers.

Code of Federal Regulations, 2014 CFR

2014-07-01

....- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers (PMN P-06-452; CAS No. 675869-05-3...-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-15-alkyl ethers. 721.10556 Section 721.10556 Protection of...-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-15-alkyl ethers. (a) Chemical substance...

40 CFR 721.10558 - Poly(oxy-1,2-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers.

Code of Federal Regulations, 2013 CFR

2013-07-01

....- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers (PMN P-06-452; CAS No. 675869-05-3...-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers. 721.10558 Section 721.10558 Protection of...-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers. (a) Chemical substance...

40 CFR 721.10557 - Poly(oxy-1,2-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C10-16-alkyl ethers.

Code of Federal Regulations, 2014 CFR

2014-07-01

....- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers (PMN P-06-452; CAS No. 675869-05-3...-methyl-2-propen-1-yl) -.omega.-hydroxy-,C10-16-alkyl ethers. 721.10557 Section 721.10557 Protection of...-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C10-16-alkyl ethers. (a) Chemical substance...

40 CFR 721.10558 - Poly(oxy-1,2-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers.

Code of Federal Regulations, 2014 CFR

2014-07-01

....- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers (PMN P-06-452; CAS No. 675869-05-3...-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers. 721.10558 Section 721.10558 Protection of...-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers. (a) Chemical substance...

40 CFR 721.10557 - Poly(oxy-1,2-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C10-16-alkyl ethers.

Code of Federal Regulations, 2013 CFR

2013-07-01

....- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C12-16-alkyl ethers (PMN P-06-452; CAS No. 675869-05-3...-methyl-2-propen-1-yl) -.omega.-hydroxy-,C10-16-alkyl ethers. 721.10557 Section 721.10557 Protection of...-ethanediyl), .alpha.- (2-methyl-2-propen-1-yl) -.omega.-hydroxy-,C10-16-alkyl ethers. (a) Chemical substance...

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.

Monodisperse microbeads of hypercrosslinked polystyrene for liquid and supercritical fluid chromatography

NASA Astrophysics Data System (ADS)

Tsyurupa, M. P.; Blinnikova, Z. K.; Il'in, M. M.; Davankov, V. A.; Parenago, O. O.; Pokrovskii, O. I.; Usovich, O. I.

2015-11-01

Monodisperse styrene-divinylbenzene (1 wt %) copolymer microbeads are obtained via the elaborate method of high-productivity precipitation polymerization. The crosslinking of this copolymer with chloromethyl methyl ether in the presence of Friedel-Crafts catalyst yields porous hypercrosslinked polymers with degrees of crosslinking that range from 200 to 500%. Microbead sorbents are shown to be suited for selective stationary phases for high-performance liquid chromatography and supercritical fluid chromatography.

Poly(glycidyl ether)-Based Monolayers on Gold Surfaces: Control of Grafting Density and Chain Conformation by Grafting Procedure, Surface Anchor, and Molecular Weight.

PubMed

Heinen, Silke; Weinhart, Marie

2017-03-07

For a meaningful correlation of surface coatings with their respective biological response reproducible coating procedures, well-defined surface coatings, and thorough surface characterization with respect to layer thickness and grafting density are indispensable. The same applies to polymeric monolayer coatings which are intended to be used for, e.g., fundamental studies on the volume phase transition of surface end-tethered thermoresponsive polymer chains. Planar gold surfaces are frequently used as model substrates, since they allow a variety of straightforward surface characterization methods. Herein we present reproducible grafting-to procedures performed with thermoresponsive poly(glycidyl ether) copolymers composed of glycidyl methyl ether (GME) and ethyl glycidyl ether (EGE). The copolymers feature different molecular weights (2 kDa, 9 kDa, 24 kDa) and are equipped with varying sulfur-containing anchor groups in order to achieve adjustable grafting densities on gold surfaces and hence control the tethered polymers' chain conformation. We determined "wet" and "dry" thicknesses of these coatings by QCM-D and ellipsometry measurements and deduced anchor distances and degrees of chain overlap of the polymer chains assembled on gold. Grafting under cloud point conditions allowed for higher degrees of chain overlap compared to grafting from a good solvent like ethanol, independent of the used sulfur-containing anchor group for polymers with low (2 kDa) and medium (9 kDa) molecular weights. By contrast, the achieved grafting densities and thus chain overlaps of surface-tethered polymers with high (24 kDa) molecular weights were identical for both grafting methods. Monolayers prepared from an ethanolic solution of poly(glycidyl ether)s equipped with sterically demanding disulfide-containing anchors revealed the lowest degrees of chain overlap. The ratio of the radius of gyration to the anchor distance (2 R g /l) of the latter coating was found to be lower than 1.4, indicating that the assembly was rather in the mushroom-like than in the brush regime. Polymer chains with thiol-containing anchors of different alkyl chain lengths (C 11 SH vs C 4 SH) formed assemblies with comparable degrees of chain overlap with 2 R g /l values above 1.4 and are thus in the brush regime. Molecular weights influenced the achievable degree of chain overlap on the surface. Coatings prepared with the medium molecular weight polymer (9 kDa) resulted in the highest chain packing density. Control of grafting density and thus chain overlap in different regimes (brush vs mushroom) on planar gold substrates are attainable for monolayer coatings with poly(GME-ran-EGE) by adjusting the polymer's molecular weight and anchor group as well as the conditions for the grafting-to procedure.

Distribution of methyl tert-butyl ether (MTBE) and selected water-quality constituents in the surficial aquifer at the Dover National Test Site, Dover Air Force Base, Delaware, 2001

USGS Publications Warehouse

Stewart, Marie; Guertal, William R.; Barbaro, Jeffrey R.; McHale, Timothy J.

2004-01-01

A joint study by the Dover National Test Site, Dover Air Force Base, Delaware, and the U.S. Geological Survey was conducted from June 27 through July 18, 2001, to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site. This report provides a summary assessment of the distribution of methyl tert-butyl ether and a preliminary screening of selected constituents that may affect natural attenuation and remediation demonstrations at the Dover National Test Site. The information gathered during this study is designed to assist potential remedial investigators who are considering conducting a methyl tert-butyl ether remedial demonstration at the test site. In addition, the study supported a planned enhanced bioremediation demonstration and assisted the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. A direct-push drill rig was used to collect a total of 147 ground-water samples (115 VOC samples and 32 quality-assurance samples) at varying depths. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloro-ethene, 1.14 micrograms per liter of trichloro-ethene, 2.65 micrograms per liter of tetrachloro-ethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest concentrations of methyl tert-butyl ether were detected in the surficial aquifer from ?4.6 to 6.4 feet mean sea level; however, methyl tert-butyl ether was detected as deep as ?9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations that were found in association with the ground-water samples that contained methyl tert-butyl ether are preliminary indicators that will assist in determining if natural attenuation of methyl tert-butyl ether is occurring in the surficial aquifer. A full assessment of natural attenuation of methyl tert-butyl ether at the site is beyond the scope of this study, but the data collected during the study will be useful in selecting appropriate remedial methyl tert-butyl ether demonstrations.

Synthesis and Characterization of New Phosphazene Polymers.

DTIC Science & Technology

1988-01-21

reaction of a poly( alkyl /arylphosphazene). In this study, one-half of the methyl groups in [Ph(Me)PN]n (chosen for its solubility in THF as opposed to...polymerization reaction ; and (5) the derivative chemistry of the preformed poly( alkyl /arylphosphazenes)., Synthesis of Poly( alkyl /arylphosphazenes) SC A... vessels , these phosphoranimines quantitatively eliminate the silyl ether byproduct, Me3SiOCH2CF 3 , to form the poly( alkyl /arylphosphazenes). The synthesis

Carboranylcyclotriphosphazenes and their polymers. [thermal insulation

NASA Technical Reports Server (NTRS)

Allcock, H. R.; Obrien, J. P.; Scopelianos, A. G.; Fewell, L. L. (Inventor)

1981-01-01

Carboranyl-substituted polyphosphazenes are prepared by heat polymerizing a carboranyl halocyclophosphazene at 250 C for about 120 hours in the absence of oxygen and moisture. The cyclophosphazene is obtained by allowing a lithium carborane, e.g., the reaction product of methyl-o-carborane with n-butyllithium in ethyl ether, to react with e.g., hexachlorocyclotriphosphazene at ambient temperatures and in anhydrous conditions. For greater stability in the presence of moisture, the chlorine substituents of the polymer are then replaced by aryloxy or alkoxy groups, such as CF3CH2O. The new substantially inorganic polymers are thermally stable materials which produce a high char yield when exposed to extreme temperatures, and can thus serve to insulate less heat and fire resistant substances.

Molecular modeling of interactions in electronic nose sensors for environmental monitoring

NASA Technical Reports Server (NTRS)

Shevade, A. V.; Ryan, M. A.; Homer, M. L.; Manfreda, A. M.; Yen, S. -P. S.; Zhou, H.; Manatt, K.

2002-01-01

We report a study aimed at understanding analyte interactions with sensors made from polymer-carbon black composite films. The sensors are used in an Electronic Nose (ENose) which is used for monitoring the breathing air quality in human habitats. The model mimics the experimental conditions of the composite film deposition and formation and was developed using molecular modeling and simulation tools. The Dreiding 2.21 Force Field was used for the polymer and analyte molecules while graphite parameters were assigned to the carbon black atoms. The polymer considered for this work is methyl vinyl ether / maleic acid copolymer. The target analytes include both inorganic (NH3) and organic (methanol) types of compound. Results indicate different composite-analyte interaction behavior.

Unimolecular Micelles of Amphiphilic Cyclodextrin-Core Star-Like Copolymers with Covalent pH-Responsive Linkage of Anticancer Prodrugs.

PubMed

Jia, Tao; Huang, Shuo; Yang, Cangjie; Wang, Mingfeng

2017-08-07

Multifunctional stable and stimuli-responsive drug delivery systems are important for efficient cancer treatment due to their advantages such as enhanced cancer-targeting efficiency, improved pharmacokinetics, minimized drug leaching, and reduced undesirable side effects. Here we report a robust and pH-responsive anticancer drug delivery system based on unimolecular micelles of star-like amphiphilic copolymers. The polymers (denoted as CPOFs) were facilely synthesized via one-step atom transfer radical polymerization of functionalizable benzoaldehyde and hydrophilic poly[(oligo ethylene glycol) methyl ether methacrylate] as comonomers from the core of heptakis [2,3,6-tri-o-(2-bromo-2-methyl propionyl]-β-cyclodextrin as the initiator. Doxorubicin (DOX) as an anticancer drug was covalently linked to the benzoaldehyde groups of CPOFs through pH-sensitive Schiff-base bonds. The DOX-conjugated polymers, denoted as CPOF-DOX, formed robust unimolecular micelles with an average diameter of 18 nm in aqueous media. More importantly, these unimolecular micelles showed higher drug loading capacity and more controllable drug release characteristics, compared to our previous unimolecular micelles of β-cyclodextrin-poly(lactic acid)-b-poly[(oligo ethylene glycol) methyl ether methacrylates] that physically encapsulated DOX via hydrophobic interaction. Moreover, the CPOF-DOX unimolecular micelles could be internalized by human cervical cancer HeLa cells in a stepwise way and showed less cytotoxicity compared to carrier-free DOX. We foresee that CPOF-DOX would provide a promising robust and controllable anticancer drug delivery system for future animal study and clinical trials for cancer treatment.

Phenolic sodium sulphates of Frankenia laevis L.

PubMed

Hussein, S A M

2004-04-01

Four new phenolic anionic conjugates have been isolated from the whole plant aqueous alcohol extract of Frankenia laevis L. Their structures were established, mainly on the basis of ESI-MS, 1D and 2D NMR spectroscopic evidence, as gallic acid-3-methyl ether-5-sodium sulphate, acetophenone-4-methyl ether-2-sodium sulphate, ellagic acid-3,3'-dimethyl ether-4,4'-di-sodium sulphate and ellagic acid-3-methyl ether-4-sodium sulphate.

Wetting-Dewetting and Dispersion-Aggregation Transitions Are Distinct for Polymer Grafted Nanoparticles in Chemically Dissimilar Polymer Matrix.

PubMed

Martin, Tyler B; Mongcopa, Katrina Irene S; Ashkar, Rana; Butler, Paul; Krishnamoorti, Ramanan; Jayaraman, Arthi

2015-08-26

Simulations and experiments are conducted on mixtures containing polymer grafted nanoparticles in a chemically distinct polymer matrix, where the graft and matrix polymers exhibit attractive enthalpic interactions at low temperatures that become progressively repulsive as temperature is increased. Both coarse-grained molecular dynamics simulations, and X-ray scattering and neutron scattering experiments with deuterated polystyrene (dPS) grafted silica and poly(vinyl methyl ether) PVME matrix show that the sharp phase transition from (mixed) dispersed to (demixed) aggregated morphologies due to the increasingly repulsive effective interactions between the blend components is distinct from the continuous wetting-dewetting transition. Strikingly, this is unlike the extensively studied chemically identical graft-matrix composites, where the two transitions have been considered to be synonymous, and is also unlike the free (ungrafted) blends of the same graft and matrix homopolymers, where the wetting-dewetting is a sharp transition coinciding with the macrophase separation.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashim, Nordiana; Ali, Ab Malik Marwan; Lepit, Ajis

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,more » 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.« less

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...

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...

UV-screening chitosan nanocontainers: increasing the photostability of encapsulated materials and controlled release

NASA Astrophysics Data System (ADS)

Anumansirikul, Nattaporm; Wittayasuporn, Mayura; Klinubol, Patcharawalai; Tachaprutinun, A.; Wanichwecharungruang, Supason P.

2008-05-01

Methyl ether terminated poly(ethylene glycol)-4-methoxycinnamoylphthaloylchitosan (PCPLC), a UV absorptive polymer, and methyl ether terminated poly(ethylene glycol)-phthaloylchitosan (PPLC) were synthesized, characterized and self-assembled into stable water-dispersible spherical nanoparticles. The encapsulation of a model compound, 2-ethylhexyl-4-methoxycinnamate (EHMC), was carried out to give particles with 67% (w/w) EHMC loading. The E to Z photoisomerization of EHMC encapsulated inside both particles was monitored and compared to non-encapsulated EHMC. Minimal E to Z photoisomerization was observed when EHMC was encapsulated in PCPLC particles prepared from a polymer with a maximum degree of 4-methoxycinnamoyl substitution. The results indicated that the grafted UVB absorptive chromophore, 4-methoxycinnamoyl moieties, situated at the shell of PCPLC nanoparticles acted as a UV-filtering barrier, protecting the encapsulated EHMC from the UVB radiation, thus minimizing its photoisomerization. In vitro experiments revealed the pH-dependent controlled release of EHMC from PCPLC and PPLC particles. Ex vivo experiments, using a Franz diffusion cell with baby mouse skin, indicated that neither PPLC nor PCPLC particles could penetrate the skin into the receptor medium after a 24 h topical application. When applied on the baby mouse skin, both EHMC-encapsulated PPLC and EHMC-encapsulated PCPLC showed comparable controlled releases of the EHMC. The released EHMC could transdermally penetrate the baby mouse skin.

Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

PubMed

Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

2017-06-15

Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m 3 ). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary. Copyright © 2017 Elsevier B.V. All rights reserved.

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 (P-91...

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 (P-91...

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...

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...

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...

Effect of substrate interaction on the degradation of methyl tert-butyl ether, benzene, toluene, ethylbenzene, and xylene by Rhodococcus sp.

PubMed

Lee, Eun-Hee; Cho, Kyung-Suk

2009-08-15

It was examined the substrate interactions of benzene (B), tolulene (T), ethylbenzene (E), xylene (X), and methyl tert-butyl ether (M) in binary, ternary, quaternary, and quinary mixtures by Rhodococcus sp. EH831 that could aerobically degrade all of five single components. The specific degradation rates (SDRs) of B, T, E, X, and M were 234, 913, 131, 184 and 139 micromol g-dry cell weight (DCW)(-1)h(-1), respectively. In binary, ternary, quaternary, and quinary mixtures of them, ethylbenzene was the strongest inhibitor for the other substrates, and methyl tert-butyl ether was the weakest inhibitor. Interestingly, no degradation of benzene and methyl tert-butyl ether was found in the coexistence of ethylbenzene. The degradation of benzene followed only after toluene became exhausted when both was present. Ethylbenzene was least inhibited by methyl tert-butyl ether and most inhibited by toluene.

46 CFR 30.25-1 - Cargoes carried in vessels certificated under the rules of this subchapter.

Code of Federal Regulations, 2013 CFR

2013-10-01

...-Amyl methyl ether (Methyl tert-pentyl ether) C Amyl methyl ketone, see Methyl amyl ketone D Animal and... heptyl ketone [C] Butyl methyl ketone, see Methyl butyl ketone n-Butyl propionate C Butyl stearate III... alcohol (all isomers) C Diisobutylene B Diisobutyl ketone D Diisobutyl phthalate B Diisodecyl phthalate...

Methylation patterns of aquatic humic substances determined by 13C NMR spectroscopy

USGS Publications Warehouse

Thorn, K.A.; Steelink, C.; Wershaw, R. L.

1987-01-01

13C NMR spectroscopy is used to examine the hydroxyl group functionality of a series of humic and fulvic acids from different aquatic environments. Samples first are methylated with 13C-labeled diazomethane. The NMR spectra of the diazomethylated samples allow one to distinguish between methyl esters of carboxylic acids, methyl ethers of phenolic hydroxyls, and methyl ethers of phenolic hydroxyls adjacent to two substituents. Samples are then permethylated with 13C-labeled methyl iodide/NaH. 13C NMR spectra of permethylated samples show that a significant fraction of the hydroxyl groups is not methylated with diazomethane alone. In these spectra methyl ethers of carbohydrate and aliphatic hydroxyls overlap with methyl ethers of phenolic hydroxyls. Side reactions of the methyltion procedure including carbon methylation in the CH3I/NaH procedure, are also examined. Humic and fulvic acids from bog, swamp, groundwater, and lake waters showssome differences in their distribution of hydroxyl groups, mainly in the concentrations of phenolic hydroxyls, which may be attributed to their different biogeochemical origins. ?? 1987.

Quercetin-3-methyl ether inhibits lapatinib-sensitive and -resistant breast cancer cell growth by inducing G2/M arrest and apoptosis

PubMed Central

Li, Jixia; Zhu, Feng; Lubet, Ronald A.; De Luca, Antonella; Grubbs, Clinton; Ericson, Marna E.; D’Alessio, Amelia; Normano, Nicola; Dong, Zigang; Bode, Ann M.

2012-01-01

Lapatinib, an oral, small-molecule, reversible inhibitor of both EGFR and HER2, is highly active in HER2 positive breast cancer as a single agent and in combination with other therapeutics. However, resistance against lapatinib is an unresolved problem in clinical oncology. Recently, interest in the use of natural compounds to prevent or treat cancers has gained increasing interest because of presumed low toxicity. Quercetin-3-methyl ether, a naturally occurring compound present in various plants, has potent anticancer activity. Here, we found that quercetin-3-methyl ether caused in a significant growth inhibition of lapatinib-sensitive and -resistant breast cancer cells. Western blot data showed that quercetin-3-methyl ether had no effect on Akt or ERKs signaling in resistant cells. However, quercetin-3-methyl ether caused a pronounced G2/M block mainly through the Chk1-Cdc25c-cyclin B1/Cdk1 pathway in lapatinib-sensitive and -resistant cells. In contrast, lapatinib produced an accumulation of cells in the G1 phase mediated through cyclin D1, but only in lapatinib-sensitive cells. Moreover, quercetin-3-methyl ether induced significant apoptosis, accompanied with increased levels of cleaved caspase 3, caspase 7 and poly (ADP-ribose) polymerase (PARP) in both cell lines. Overall, these results suggested that quercetin-3-methyl ether might be a novel and promising therapeutic agent in lapatinib-sensitive or -resistant breast cancer patients. PMID:22086611

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Phillips Petroleum Co. is poised to license its high conversion process to produce fuel ethers for blending in reformulated gasolines. The technology has been proven in a Phillips semiworks at Bartlesville, Okla. The process can produce methyl tertiary butyl ether, ethyl tertiary butyl ether, tertiary amyl methyl ether, or tertiary amyl ethyl ether with typical refinery process equipment and techniques. Phillips said it can achieve conversion levels of 92-99%, depending on the ether. The ether produced is determined by which hydrocarbon fraction is used for feedstock and which alcohol is chosen for reaction. The process is described.

Phytochemical Characterization of an Adaptogenic Preparation from Rhodiola heterodonta

PubMed Central

Grace, Mary H.; Yousef, Gad G.; Kurmukov, Anvar G.; Raskin, Ilya; Lila, Mary Ann

2013-01-01

The phytochemical constituents of a biologically active, standardized, 80% ethanol extract of Rhodiola heterodonta were characterized. The extract was fractionated over a Sephadex LH-20 column to afford two main fractions representing two classes of secondary metabolites: phenylethanoids and proanthocyanidins. This fractionation facilitated the identification and quantification of individual compounds in the fractions and sub-fractions using HPLC, and LC-MS. The major compounds in the phenylethanoid fraction were heterodontoside, tyrosol methyl ether, salidroside, viridoside, mongrhoside, tyrosol, and the cyanogenic glucoside rhodiocyanoside A. These seven compounds comprised 17.4% of the EtOH extract. Proanthocyanidins ranged from oligomers to polymers based on epigallocatechin and gallate units. The main identified oligomeric compounds in the proanthocyanidin fraction were epigallocatechin gallate, epigallocatechin-epigallocatechin-3-O-gallate and 3-O-galloylepigallocatechin-epigallocatechin-3-O-gallate, which constituted 1.75% of the ethanol extract. Tyrosol methyl ether, mongrhoside, and the two proanthocyanidin dimers were reported for the first time from this species in this study. Intraperitoneal injection of the 80% ethanol extract increased survival time of mice under hypoxia by 192%, as an indication of adaptogenic activity. PMID:19768982

40 CFR 799.5000 - Testing consent orders for substances and mixtures with Chemical Abstract Service Registry Numbers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Environmental Releases Report November 18, 1994. 112-35-6 Triethylene glycol monomethyl ether Health effects... Health effects November 23, 1993. 994-05-8 Tertiary-amyl methyl ether Health effects March 21, 1995. 1634-04-4 Methyl tert-butyl ether Health effects March 31, 1988. 2461-18-9 Lauryl glycidyl ether 1 Health...

Interface-engineering additives of poly(oxyethylene tridecyl ether) for low-band gap polymer solar cells consisting of PCDTBT:PCBM₇₀ bulk-heterojunction layers.

PubMed

Huh, Yoon Ho; Park, Byoungchoo

2013-01-14

We herein report on the improved photovoltaic (PV) effects of using a polymer bulk-heterojunction (BHJ) layer that consists of a low-band gap electron donor polymer of poly(N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)) (PCDTBT) and an acceptor of [6,6]-phenyl C₇₁ butyric acid methyl ester (PCBM₇₀), doped with an interface-engineering surfactant additive of poly(oxyethylene tridecyl ether) (PTE). The presence of an interface-engineering additive in the PV layer results in excellent performance; the addition of PTE to a PCDTBT:PCBM₇₀ system produces a power conversion efficiency (PCE) of 6.0%, which is much higher than that of a reference device without the additive (4.9%). We attribute this improvement to an increased charge carrier lifetime, which is likely to be the result of the presence of PTE molecules oriented at the interfaces between the BHJ PV layer and the anode and cathode, as well as at the interfaces between the phase-separated BHJ domains. Our results suggest that the incorporation of the PTE interface-engineering additive in the PCDTBT:PCBM₇₀ PV layer results in a functional composite system that shows considerable promise for use in efficient polymer BHJ PV cells.

Methyl substituted polyimides containing carbonyl and ether connecting groups

NASA Technical Reports Server (NTRS)

Hergenrother, Paul M. (Inventor); Havens, Stephen J. (Inventor)

1992-01-01

Polyimides were prepared from the reaction of aromatic dianhydrides with novel aromatic diamines having carbonyl and ether groups connecting aromatic rings containing pendant methyl groups. The methyl substituent polyimides exhibit good solubility and form tough, strong films. Upon exposure to ultraviolet irradiation and/or heat, the methyl substituted polyimides crosslink to become insoluble.

Star-shaped poly(oligoethylene glycol) copolymer-based gels: Thermo-responsive behaviour and bioapplicability for risedronate intranasal delivery.

PubMed

Soliman, Mahmoud E; Elmowafy, Enas; Casettari, Luca; Alexander, Cameron

2018-05-30

The aim of this work was to obtain an intranasal delivery system with improved mechanical and mucoadhesive properties that could provide prolonged retention time for the delivery of risedronate (RS). For this, novel in situ forming gels comprising thermo-responsive star-shaped polymers, utilizing either polyethylene glycol methyl ether (PEGMA-ME 188, Mn 188) or polyethylene glycol ethyl ether (PEGMA-EE 246, Mn 246), with polyethylene glycol methyl ether (PEGMA-ME 475, Mn 475), were synthesized and characterized. RS was trapped in the selected gel-forming solutions at a concentration of 0.2% w/v. The pH, rheological properties, in vitro drug release, ex vivo permeation as well as mucoadhesion were also examined. MTT assays were conducted to verify nasal tolerability of the developed formulations. Initial in vivo studies were carried out to evaluate anti-osteoporotic activity in a glucocorticoid induced osteoporosis model in rats. The results showed successful development of thermo-sensitive formulations with favorable mechanical properties at 37 °C, which formed non-irritant, mucoadhesive porous networks, facilitating nasal RS delivery. Moreover, sustained release of RS, augmented permeability and marked anti-osteoporotic efficacy as compared to intranasal (IN) and intravenous (IV) RS solutions were realized. The combined results show that the in situ gels should have promising application as nasal drug delivery systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Nano-imprint lithography using poly (methyl methacrylate) (PMMA) and polystyrene (PS) polymers

NASA Astrophysics Data System (ADS)

Ting, Yung-Chiang; Shy, Shyi-Long

2016-04-01

Nano-imprinting lithography (NIL) technology, as one of the most promising fabrication technologies, has been demonstrated to be a powerful tool for large-area replication up to wafer-level, with features down to nanometer scale. The cost of resists used for NIL is important for wafer-level large-area replication. This study aims to develop capabilities in patterning larger area structure using thermal NIL. The commercial available Poly (Methyl Methacrylate) (PMMA) and Polystyrene (PS) polymers possess a variety of characteristics desirable for NIL, such as low material cost, low bulkvolumetric shrinkage, high spin coating thickness uniformity, high process stability, and acceptable dry-etch resistance. PMMA materials have been utilized for positive electron beam lithography for many years, offering high resolution capability and wide process latitude. In addition, it is preferable to have a negative resist like PMMA, which is a simple polymer with low cost and practically unlimited shelf life, and can be dissolved easily using commercial available Propylene glycol methyl ether acetate (PGMEA) safer solvent to give the preferred film thickness. PS is such a resist, as it undergoes crosslinking when exposed to deep UV light or an electron beam and can be used for NIL. The result is a cost effective patterning larger area structure using thermal nano-imprint lithography (NIL) by using commercial available PMMA and PS ploymers as NIL resists.

Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

DOEpatents

Ramprasad, D.; Waller, F.J.

1999-04-06

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

Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

DOEpatents

Ramprasad, Dorai; Waller, Francis Joseph

1999-01-01

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

Environmental Assessment: Proposed Construction of Air Force Non-Appropriated Funds Bowling Center at Maxwell Air Force Base, Gunter Annex

DTIC Science & Technology

2004-04-01

indicates that the total residual gasoline constituents (Benzene, Toluene, Ethylbenzene, and Xylene [BTEX] and methyl tertiary butyl ether [MTBE]) are...mean sea level MTBE methyl tertiary butyl ether MW monitoring well N/A Not Applicable NAAQS National Ambient Air Quality Standards NAF Non...Toluene, Ethylbenzene, and Xylene [BTEX] and methyl tertiary butyl ether [MTBE]) are below concentrations which pose a threat to human health and

New HPLC methods to quantitate terpenoid aldehydes in foliage of cotton (Gossypium)

USDA-ARS?s Scientific Manuscript database

The cotton plant (Gossypium) produces protective terpenoid aldehydes in lysigenous pigment glands. These terpenoids include hemigossypolone, hemigossypolone-6-methyl ether, gossypol, gossypol-6-methyl ether, gossypol-6,6'-dimethyl ether, heliocides H1, H2, H3 and H4, and heliocides B1, B2, B3 and B4...

Removal of some organic pollutants in water employing ceramic membranes impregnated with cross-linked silylated dendritic and cyclodextrin polymers.

PubMed

Allabashi, Roza; Arkas, Michael; Hörmann, Gerold; Tsiourvas, Dimitris

2007-01-01

Triethoxysilylated derivatives of poly(propylene imine) dendrimer, polyethylene imine and polyglycerol hyperbranched polymers and beta-cyclodextrin have been synthesized and characterized. These compounds impregnated ceramic membranes made from Al(2)O(3), SiC and TiO(2) and subsequently sol-gel reaction led to their polymerization and chemical bond formation with the ceramic substrates. The resulting organic-inorganic filters were tested for the removal of a variety of organic pollutants from water. They were found to remove of polycyclic aromatic hydrocarbons (up to 99%), of monocyclic aromatic hydrocarbons (up to 93%), trihalogen methanes (up to 81%), pesticides (up to 43%) and methyl-tert-butyl ether (up to 46%).

Photo and Thermal Behavior of New Reinforced Polyamide-nanocomposite Montmorillonite on 2,3-Pyrazin Dicarboxylic Acid

NASA Astrophysics Data System (ADS)

Faghihi, Khalil; Samiei, Mojtaba; Hajibeygi, Mohsen

2012-06-01

Two new samples of reinforce polyamidemontmorillonite nanocomposites were synthesized by a convenient solution intercalation technique. Polyamide (PA) 3 as a source of polymer matrix was synthesized by the direct polycondensation reaction of pyrazine 2,3-dicarboxylic acid 1 with 4,4'-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). The resulting nanocomposite films were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results showed that organo-modified clay was dispersed homogeneously in PA matrix. TGA indicated an enhancement of thermal stability of new nanocomposites compared with the pure polymer.

40 CFR 413.02 - General definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-bromophenyl phenyl ether Bis (2-chloroisopropyl) ether Bis (2-chloroethoxy) methane Methylene chloride (dichloromethane) Methyl chloride (chloromethane) Methyl bromide (bromomethane) Bromoform (tribromomethane...-phenylene pyrene) Pyrene Tetrachloroethylene Toluene Trichloroethylene Vinyl chloride (chloroethylene...

Reducible, Dibromomaleimide-linked Polymers for Gene Delivery

PubMed Central

Tan, James-Kevin Y.; Choi, Jennifer L.; Wei, Hua; Schellinger, Joan G.; Pun, Suzie H.

2014-01-01

Polycations have been successfully used as gene transfer vehicles both in vitro and in vivo; however, their cytotoxicity has been associated with increasing molecular weight. Polymers that can be rapidly degraded after internalization are typically better tolerated by mammalian cells compared to their non-degradable counterparts. Here, we report the use of a dibromomaleimide-alkyne (DBM-alkyne) linking agent to reversibly bridge cationic polymer segments for gene delivery and to provide site-specific functionalization by azidealkyne cycloaddition chemistry. A panel of reducible and non-reducible, statistical copolymers of (2-dimethylamino) ethyl methacrylate (DMAEMA) and oligo(ethylene glycol) methyl ether methacrylate (OEGMA) were synthesized and evaluated. When complexed with plasmid DNA, the reducible and non-reducible polymers had comparable DNA condensation properties, sizes, and transfection efficiencies. When comparing cytotoxicity, the DBM-linked, reducible polymers were significantly less toxic than the non-reducible polymers. To demonstrate polymer functionalization by click chemistry, the DBM-linked polymers were tagged with an azidefluorophore and were used to monitor cellular uptake. Overall, this polymer system introduces the use of a reversible linker, DBM-alkyne, to the area of gene delivery and allows for facile, orthogonal, and site-specific functionalization of gene delivery vehicles. PMID:26214195

Thermoset epoxy polymers from renewable resources

DOEpatents

East, Anthony [Madison, NJ; Jaffe, Michael [Maplewood, NJ; Zhang, Yi [Harrison, NJ; Catalani, Luiz H [Carapicuiba, BR

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.

40 CFR Appendix A to Part 439 - Tables

Code of Federal Regulations, 2014 CFR

2014-07-01

... Isobutyraldehyde 1 Aldehydes. n-Heptane 1 Alkanes. n-Hexane 1 Diethylamine 1 Amines. Triethylamine Benzene... Methyl formate Tetrahydrofuran 1 Ethers. Isopropyl ether Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK...

40 CFR Appendix A to Part 439 - Tables

Code of Federal Regulations, 2012 CFR

2012-07-01

... Isobutyraldehyde 1 Aldehydes. n-Heptane 1 Alkanes. n-Hexane 1 Diethylamine 1 Amines. Triethylamine Benzene... Methyl formate Tetrahydrofuran 1 Ethers. Isopropyl ether Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK...

40 CFR Appendix A to Part 439 - Tables

Code of Federal Regulations, 2013 CFR

2013-07-01

... Isobutyraldehyde 1 Aldehydes. n-Heptane 1 Alkanes. n-Hexane 1 Diethylamine 1 Amines. Triethylamine Benzene... Methyl formate Tetrahydrofuran 1 Ethers. Isopropyl ether Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK...

Analytical results from ground-water sampling using a direct-push technique at the Dover National Test Site, Dover Air Force Base, Delaware, June-July 2001

USGS Publications Warehouse

Guertal, William R.; Stewart, Marie; Barbaro, Jeffrey R.; McHale, Timthoy J.

2004-01-01

A joint study by the Dover National Test Site and the U.S. Geological Survey was conducted from June 27 through July 18, 2001 to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site at Dover Air Force Base, Delaware. The study was conducted to support a planned enhanced bio-remediation demonstration and to assist the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. This report presents the analytical results from ground-water samples collected during the direct-push ground-water sampling study. A direct-push drill rig was used to quickly collect 115 ground-water samples over a large area at varying depths. The ground-water samples and associated quality-control samples were analyzed for volatile organic compounds and methyl tert-butyl ether by the Dover National Test Site analytical laboratory. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloroethene, 1.14 micrograms per liter of trichloroethene, 2.65 micrograms per liter of tetrachloroethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest methyl tert-butyl ether concentrations were found in the surficial aquifer from -4.6 to 6.4 feet mean sea level, however, methyl tert-butyl ether was detected as deep as -9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations were found in samples that contained methyl tert-butyl ether.

27 CFR 21.32 - Formula No. 1.

Code of Federal Regulations, 2012 CFR

2012-04-01

... methyl isobutyl ketone; 1 gallon of mixed isomers of nitropropane; or 1 gallon of methyl n- butyl ketone.... 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572...

27 CFR 21.32 - Formula No. 1.

Code of Federal Regulations, 2010 CFR

2010-04-01

... methyl isobutyl ketone; 1 gallon of mixed isomers of nitropropane; or 1 gallon of methyl n- butyl ketone.... 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572...

27 CFR 21.32 - Formula No. 1.

Code of Federal Regulations, 2011 CFR

2011-04-01

... methyl isobutyl ketone; 1 gallon of mixed isomers of nitropropane; or 1 gallon of methyl n- butyl ketone.... 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572...

27 CFR 21.32 - Formula No. 1.

Code of Federal Regulations, 2013 CFR

2013-04-01

... methyl isobutyl ketone; 1 gallon of mixed isomers of nitropropane; or 1 gallon of methyl n- butyl ketone.... 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572...

27 CFR 21.32 - Formula No. 1.

Code of Federal Regulations, 2014 CFR

2014-04-01

... methyl isobutyl ketone; 1 gallon of mixed isomers of nitropropane; or 1 gallon of methyl n- butyl ketone.... 551.Acetaldehyde. 552.Other aldehydes. 561.Ethyl ether. 562.Other ethers. 571.Ethylene dibromide. 572...

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) is...

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) is...

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) is...

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) is...

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) is...

Peter J Derrick and the Grand Scale 'Magnificent Mass Machine' mass spectrometer at Warwick.

PubMed

Colburn, A W; Derrick, Peter J; Bowen, Richard D

2017-12-01

The value of the Grand Scale 'Magnificent Mass Machine' mass spectrometer in investigating the reactivity of ions in the gas phase is illustrated by a brief analysis of previously unpublished work on metastable ionised n-pentyl methyl ether, which loses predominantly methanol and an ethyl radical, with very minor contributions for elimination of ethane and water. Expulsion of an ethyl radical is interpreted in terms of isomerisation to ionised 3-pentyl methyl ether, via distonic ions and, possibly, an ion-neutral complex comprising ionised ethylcyclopropane and methanol. This explanation is consistent with the closely similar behaviour of the labelled analogues, C 3 H 7 CH 2 CD 2 OCH 3 +. and C 3 H 7 CD 2 CH 2 OCH 3 +. , and is supported by the greater kinetic energy release associated with loss of ethane from ionised n-propyl methyl ether compared to that starting from directly generated ionised 3-pentyl methyl ether.

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.

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.

Hydrolyzable Poly[Poly(Ethylene Glycol) Methyl Ether Acrylate]-Colistin Prodrugs through Copper-Mediated Photoinduced Living Radical Polymerization.

PubMed

Zhu, Chongyu; Schneider, Elena K; Nikolaou, Vasiliki; Klein, Tobias; Li, Jian; Davis, Thomas P; Whittaker, Michael R; Wilson, Paul; Kempe, Kristian; Velkov, Tony; Haddleton, David M

2017-07-19

Through the recently developed copper-mediated photoinduced living radical polymerization (CP-LRP), a novel and well-defined polymeric prodrug of the antimicrobial lipopeptide colistin has been developed. A colistin initiator (Boc 5 -col-Br 2 ) was synthesized through the modification of colistin on both of its threonine residues using a cleavable initiator linker, 2-(2-bromo-2-methylpropanoyloxy) acetic acid (BMPAA), and used for the polymerization of acrylates via CP-LRP. Polymerization proceeds from both sites of the colistin initiator, and through the polymerization of poly(ethylene glycol) methyl ether acrylate (PEGA 480 ), three water-soluble polymer-colistin conjugates (col-PPEGA, having degrees of polymerization of 5, 10, and 20) were achieved with high yield (conversion of ≥93%) and narrow dispersities (Đ < 1.3) in 2-4 h. Little or no effect on the structure and activity of the colistin was observed during the synthesis, and most of the active colistin can be recovered from the conjugates in vitro within 2 days. Furthermore, in vitro biological analyses including disk diffusion, broth microdilution, and time-kill studies suggested that all of the conjugates have the ability to inhibit the growth of multidrug-resistant (MDR) Gram-negative bacteria, of which col-PPEGA DP5 and DP10 showed similar or better antibacterial performance compared to the clinically relevant colistin prodrug CMS, indicating their potential as an alternative antimicrobial therapy. Moreover, considering the control over the polymerization, the CP-LRP technique has the potential to provide an alternative platform for the development of polymer bioconjugates.

Anti-Helicobacter pylori activity of derivatives of the phthalide-containing antibacterial agents spirolaxine methyl ether, CJ-12,954, CJ-13,013, CJ-13,102, CJ-13,104, CJ-13,108 and CJ-13,015.

PubMed

Radcliff, Fiona J; Fraser, John D; Wilson, Zoe E; Heapy, Amanda M; Robinson, James E; Bryant, Christina J; Flowers, Christopher L; Brimble, Margaret A

2008-06-01

The naturally occurring phthalide-containing antibiotics spirolaxine methyl ether, CJ-12,954, CJ-13,013, CJ-13,015, CJ-13,102, CJ-13,103, CJ-13,104 and CJ-13,108, have been reported to exhibit anti-H. pylori activity. However, the exact stereochemistry of spirolaxine methyl ether, CJ-12,954 or CJ-13,013, contributing to this observed activity has not been confirmed. The anti-H. pylori activity of several analogues of spirolaxine methyl ether, CJ-12,954 and CJ-13,013 of defined stereochemistry together with the anti-H. pylori activity of several indole analogues of the simpler phthalide-containing antibiotics CJ-13,102, CJ-13,104, CJ-13,108 and CJ-13,015 is reported herein. A 1:1 mixture of spiroacetals 5b and 6b in which the phthalide substituent exhibited (3R)-stereochemistry was sixty times more active than the corresponding 1:1 mixture of spiroacetals with (3S)-stereochemistry. Notably, the unnatural (2''S)-diastereomer of spirolaxine methyl ether exhibited more potent anti-H. pylori activity than the natural product spirolaxine methyl ether. The 4,6-dimethoxyindoles 9, 10, 11 and 13 were all found to be less active than their parent compounds 1, 2, 3 and 4, respectively. Chain-shortened 4,6-dimethoxyindole analogue 12 of CJ-13,108 3 and 4,6-dimethoxyindole-spiroacetal 13 exhibited weak anti-H. pylori activity thus providing future opportunity for drug discovery programs.

Gel polymer electrolyte for lithium-ion batteries comprising cyclic carbonate moieties

NASA Astrophysics Data System (ADS)

Tillmann, S. D.; Isken, P.; Lex-Balducci, A.

2014-12-01

A polymer system based on oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and cyclic carbonate methacrylate (CCMA) was chosen as matrix to realize high-performance gel polymer electrolytes due to the fact that both monomers are able to interact with the liquid electrolyte, thus, retaining it inside the matrix. Additionally, OEGMA enables high flexibility, while CCMA provides mechanical stability. The polymer displays a high thermal stability up to 200 °C and a glass transition temperature below room temperature (5 °C) allowing an easy handling of the obtained films. By immobilizing the liquid electrolyte 1 M LiPF6 in EC:DMC 1:1 w:w in the polymer host a gel polymer electrolyte with a high conductivity of 2.3 mS cm-1 at 25 °C and a stable cycling behavior with high capacities and efficiencies in Li(Ni1/3Co1/3Mn1/3)O2 (NCM)/graphite full cells is obtained. The investigated gel polymer electrolyte is identified as promising electrolyte for lithium-ion batteries, because it combines good electrochemical properties comparable to that of liquid electrolytes with the safety advantage that no leakage of the flammable electrolyte solvents can occur.

Pyrocarbons prepared by carbonisation of polymers adsorbed or synthesised on a surface of silica and mixed oxides

NASA Astrophysics Data System (ADS)

Gun'ko, V. M.; Skubiszewska-Zi ęba, J.; Leboda, R.; Voronin, E. F.; Zarko, V. I.; Levitskaya, S. I.; Brei, V. V.; Guzenko, N. V.; Kazakova, O. A.; Seledets, O.; Janusz, W.; Chibowski, S.

2004-04-01

Initial oxides fumed silica, alumina/silica and titania/silica and silica gel and hybrid adsorbents with pyrocarbon formed on these oxide substrates by carbonisation of immobilised (adsorbed or synthesised) polymers such as starch, methyl cellulose, polyvinylpyrrolidone, polystyrene, and polybutylvinyl ether were studied by adsorption, AFM, TEM, and FTIR methods. Polymer/oxide materials were investigated by nitrogen and Pb(II) adsorption, FTIR, and potentiometric titration methods. Analysis of nitrogen adsorption-desorption isotherms by different methods, FTIR spectra, AFM and TEM images of the initial and hybrid adsorbents reveals that the morphology of the substrates significantly changes on carbonisation of oxygen-containing polymers because of hydrothermal treatment of them by water eliminated as a product of pyrolysis. Contribution of own microporosity of pyrocarbon deposits formed on carbonisation of immobilised polymers is greater (dependent on reaction conditions) than that on pyrolysis of low-molecular compounds at the same oxide substrates. Pyrocarbon particles formed on silica gel are larger than those formed on fumed oxides and larger than those formed on silica gel on pyrolysis of low-molecular compounds.

Aquatic Life Criteria - Methyl Tertiary-Butyl Ether (MTBE)

EPA Pesticide Factsheets

Information pertaining to the 1999 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Methyl Tertiary-Butyl Ether (MTBE) for freshwater and salt water. Information includes the safe levels of MTBE that should protect the majority of species.

29 CFR 1926.1106 - Methyl chloromethyl ether.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1106 Methyl chloromethyl ether. Note: The requirements applicable to construction work under this...

Novel alkyd-type coating resins produced using cationic polymerization

DOE PAGES

Chisholm, Bret J.; Kalita, Harjyoti; Alam, Samim; ...

2015-05-06

Novel, partially bio-based poly(vinyl ether) copolymers derived from soybean oil and cyclohexyl vinyl ether (CHVE) were produced by cationic polymerization and investigated for application as alkyd-type surface coatings. Compared to conventional alkyd resins, which are produced by high temperature melt condensation polymerization, the poly(v9nyl ether)s provide several advantages. These advantages include milder, more energy efficient polymer synthesis, elimination of issues associated with gelation during polymer synthesis, production of polymers with well-defined composition and relatively narrow molecular weight distribution, and elimination of film formation and physical property issues associated with entrained monomers, dimers, trimers, etc. The results of the studied showedmore » that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerably as a function of polymer composition and cure temperature. Overall, the results suggest a good potential for these novel copolymers to be used for coatings cured by autoxidation.« less

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

29 CFR 1910.1006 - Methyl chloromethyl ether.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 6 2011-07-01 2011-07-01 false Methyl chloromethyl ether. 1910.1006 Section 1910.1006 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous...

[Chalcones from Bauhinia glauca subsp. pernervosa].

PubMed

Wu, Zengbao; Wang, Bin; Zhao, Yuying; Yang, Xiuwei; Liang, Hong

2009-07-01

To study the chemical constituents of Bauhinia glauca subsp. pernervosa. The coulis of B. glauca subsp. pernervosa were extracted with 95% EtOH at room temperature. The compounds were isolated and separated by chromatographic techniques, and structures were identified by spectroscopic methods. Seven chalcones were isolated and identified: butein-4-methyl ether (1), isoliquiritigenin (2), butein (3), isoliquiritigenin-2'-methyl ether (4), 2',4'-dihydroxychalcone (5), isoliquiritigenin-4-methyl ether (6), 4-hydroxy-2',4'-dimethoxychalcone (7). Compounds 1, 3, and 7 were isolated from the genus Bauhinia for the first time, the other compounds were obtained from this plant for the first time.

Platinum(0)-mediated C-O bond activation of ethers via an SN2 mechanism.

PubMed

Ortuño, Manuel A; Jasim, Nasarella A; Whitwood, Adrian C; Lledós, Agustí; Perutz, Robin N

2016-11-29

A computational study of the C(methyl)-O bond activation of fluorinated aryl methyl ethers by a platinum(0) complex Pt(PCyp 3 ) 2 (Cyp = cyclopentyl) (N. A. Jasim, R. N. Perutz, B. Procacci and A. C. Whitwood, Chem. Commun., 2014, 50, 3914) demonstrates that the reaction proceeds via an S N 2 mechanism. Nucleophilic attack of Pt(0) generates an ion pair consisting of a T-shaped platinum cation with an agostic interaction with a cyclopentyl group and a fluoroaryloxy anion. This ion-pair is converted to a 4-coordinate Pt(ii) product trans-[PtMe(OAr F )(PCyp 3 ) 2 ]. Structure-reactivity correlations are fully consistent with this mechanism. The Gibbs energy of activation is calculated to be substantially higher for aryl methyl ethers without fluorine substituents and higher still for alkyl methyl ethers. These conclusions are in accord with the experimental results. Further support was obtained in an experimental study of the reaction of Pt(PCy 3 ) 2 with 2,3,5,6-tetrafluoro-4-allyloxypyridine yielding the salt of the Pt(η 3 -allyl) cation and the tetrafluoropyridinolate anion [Pt(PCy 3 ) 2 (η 3 -allyl)][OC 5 NF 4 ]. The calculated activation energy for this reaction is significantly lower than that for fluorinated aryl methyl ethers.

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 A-diglycidyl...

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 A-diglycidyl...

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

DTIC Science & Technology

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

Unexpected behavior of ultra-thin films of blends of polystyrene/poly(vinyl methyl ether) studied by specific heat spectroscopy

NASA Astrophysics Data System (ADS)

Madkour, Sherif; Szymoniak, Paulina; Schick, Christoph; Schönhals, Andreas

2017-05-01

Specific heat spectroscopy (SHS) employing AC nanochip calorimetry was used to investigate the glassy dynamics of ultra-thin films (thicknesses: 10 nm-340 nm) of a polymer blend, which is miscible in the bulk. In detail, a Poly(vinyl methyl ether) (PVME)/Polystyrene (PS) blend with the composition of 25/75 wt. % was studied. The film thickness was controlled by ellipsometry while the film topography was checked by atomic force microscopy. The results are discussed in the framework of the balance between an adsorbed and a free surface layer on the glassy dynamics. By a self-assembling process, a layer with a reduced mobility is irreversibly adsorbed at the polymer/substrate interface. This layer is discussed employing two different scenarios. In the first approach, it is assumed that a PS-rich layer is adsorbed at the substrate. Whereas in the second approach, a PVME-rich layer is suggested to be formed at the SiO2 substrate. Further, due to the lower surface tension of PVME, with respect to air, a nanometer thick PVME-rich surface layer, with higher molecular mobility, is formed at the polymer/air interface. By measuring the glassy dynamics of the thin films of PVME/PS in dependence on the film thickness, it was shown that down to 30 nm thicknesses, the dynamic Tg of the whole film was strongly influenced by the adsorbed layer yielding a systematic increase in the dynamic Tg with decreasing the film thickness. However, at a thickness of ca. 30 nm, the influence of the mobile surface layer becomes more pronounced. This results in a systematic decrease in Tg with the further decrease of the film thickness, below 30 nm. These results were discussed with respect to thin films of PVME/PS blend with a composition of 50/50 wt. % as well as literature results.

Methyl tert-butyl ether (MTBE)

Integrated Risk Information System (IRIS)

Methyl tert - butyl ether ( MTBE ) ; CASRN 1634 - 04 - 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 f

Hybrid sol-gel optical materials

DOEpatents

Zeigler, J.M.

1993-04-20

Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

Hybrid sol-gel optical materials

DOEpatents

Zeigler, John M.

1993-01-01

Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

Hybrid sol-gel optical materials

DOEpatents

Zeigler, John M.

1992-01-01

Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR HUMAN EXPOSURES TO METHYL TERTIARY-BUTYL ETHER

EPA Science Inventory

Humans can be exposed by inhalation, ingestion, or dermal absorption to methyl tertiary-butyl ether (MTBE), an oxygenated fuel additive, from contaminated water sources. The purpose of this research was to develop a physiologically based pharmacokinetic model describing in human...

PHOTOCATALYTIC OXIDATION OF METHYL-TERT-BUTYL ETHER FOR DRINKING WATER TREATMENT

EPA Science Inventory

The photo-oxidation of methyl tert-butyl ether (MTBE) in water was investigated to determine the feasibility of using photocatalysis for the treatment of MTBE-contaminated drinking water. The feasibility assessment was conducted using slurries of titanium dioxide in both a photo-...

29 CFR 1910.1006 - Methyl chloromethyl ether.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 6 2014-07-01 2013-07-01 true Methyl chloromethyl ether. 1910.1006 Section 1910.1006 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1006...

REFINED PBPK MODEL OF AGGREGATE EXPOSURE TO METHYL TERTIARY-BUTYL ETHER

EPA Science Inventory

Aggregate (multiple pathway) exposures to methyl tertiary-butyl ether (MTBE) in air and water occur via dermal, inhalation, and oral routes. Previously, physiologically-based pharmacokinetic (PBPK) models have been used to quantify the kinetic behavior of MTBE and its primary met...

Acid base chemistry of luteolin and its methyl-ether derivatives: A DFT and ab initio investigation

NASA Astrophysics Data System (ADS)

Amat, Anna; De Angelis, Filippo; Sgamellotti, Antonio; Fantacci, Simona

2008-09-01

The acid-base chemistry of luteolin, a flavonoid with important pharmacological and dyeing properties, and of the related methyl ether derivatives have been investigated by DFT and MP2 methods, testing different computational setups. We calculate the pK's of all the possible deprotonation sites, for which no experimental assignment could be achieved. The calculated pK's deliver a different acidity order for the two most acidic deprotonation sites between luteolin and its methyl ether derivatives, due to intramolecular hydrogen bonding in luteolin. A lowest p Ka of 6.19 is computed for luteolin, in good agreement with available experimental data.

Method for determination of methyl tert-butyl ether and its degradation products in water

USGS Publications Warehouse

Church, C.D.; Isabelle, L.M.; Pankow, J.F.; Rose, D.L.; Tratnyek, P.G.

1997-01-01

An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injection (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method can also give simultaneous identification of polar compounds that might occur as degradation products of gasoline oxygenates, such as TBA, TBF, TAA, methyl acetate, and acetone. When the method was applied to effluent from a column microcosm prepared with core material from an urban site in New Jersey, conversion of MTBE to TBA was observed after a lag period of 35 days. However, to date, analyses of water samples from six field sites using the DAI-GC/MS method have not produced evidence for the expected products of in situ degradation of MTBE.An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injection (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method can also give simultaneous identification of polar compounds that might occur as degradation products of gasoline oxygenates, such as TBA, TBF, TAA, methyl acetate, and acetone. When the method was applied to effluent from a column microcosm prepared with core material from an urban site in New Jersey, conversion of MTBE to TBA was observed after a lag period of 35 days. However, to date, analyses of water samples from six field sites using the DAI-GC/MS method have not produced evidence for the expected products of in situ degradation of MTBE.

EVALUATION OF METHYL TERT-BUTYL ETHER (MTBE) AS AN INTERFERENCE ON COMMERCIAL BREATH-ALCOHOL ANALYZERS

EPA Science Inventory

Anecdotal reports suggest that high environmental or occupational exposures to the fuel oxygenate methyl tert-butyl ether (MTBE) may result in breath concentrations that are sufficiently elevated to cause a false positive on commercial breath-alcohol analyzers. We evaluated th...

DERMAL, ORAL, AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

EPA Science Inventory

Methyl tertiary butyl ether (MTBE), a gasoline additive, used to increase octane and reduce carbon monoxide emissions and ozone precursors has contaminated drinking water leading to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhalation ki...

BIODEGRADATION OF METHYL TERT-BUTYL ETHER AND BTEX AT VARYING HYDRAULIC RETENTION TIMES

EPA Science Inventory

The feasibility of biologically degrading methyl tert-butyl ether (MTBE) contaminated groundwater is dependent on the ability to degrade MTBE and its byproducts in the presence of other gasoline contaminants. This study investigates a mixed culture degrading both MTBE and benzene...

REDUCTIVE ACTIVATION OF DIOXYGEN FOR DEGRADATION OF METHYL TERT-BUTYL ETHER BY BIFUNCTION

EPA Science Inventory

Bifunctional aluminum is prepared by sulfating aluminum metal with sulfuric acid. The use of bifunctional aluminum to degrade methyl tert-butyl ether (MTBE) in the presence of dioxygen has been examined using batch systems. Primary degradation products were tert-butyl alcohol, ...

Electrochemical systems and methods using metal halide to form products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albrecht, Thomas A.; Solas, Dennis; Leclerc, Margarete K.

There are provided electrochemical methods and systems to form one or more organic compounds or enantiomers thereof selected from the group consisting of substituted or unsubstituted dioxane, substituted or unsubstituted dioxolane, dichloroethylether, dichloromethyl methyl ether, dichloroethyl methyl ether, chloroform, carbon tetrachloride, phosgene, and combinations thereof.

Environmentally benign formation of polymeric microspheres by rapid expansion of supercritical carbon dioxide solution with a nonsolvent.

PubMed

Matsuyama, K; Mishima, K; Umemoto, H; Yamaguchi, S

2001-10-15

A novel method is reported for forming polymer microparticles, which reduce atmospheric emissions of environmentally harmful volatile organic compounds such as toluene and xylene used as paint solvent in paint industry. The polymer microparticles have formed through rapid expansion from supercritical solution with a nonsolvent (RESS-N). Solubilization of poly(styrene)-b-(poly(methyl methacrylate)-co-poly (glycidyl methacrylate)) copolymer(PS-b-(PMMA-co-PGMA), MW = 5000, PS/PMMA/PGMA = 2/5/3), poly(ethylene glycol) (PEG, M. W = 4000), bisphenol A type epoxy resin (EP, MW = 3000), poly(methyl methacrylate) (PMMA; MW = 15000, 75000, 120000), and poly(oxyalkylene) alkylphenyl ether (MW = 4000) in carbon dioxide (CO2) was achieved with the use of small alcohols as cosolvents. The solubility of the PS-b-(PMMA-co-PGMA) is extremely low in either CO2 or ethanol but becomes 20 wt % in a mixture of the two. Because ethanol is a nonsolvent for the polymer, it can be used as a cosolvent in rapid expansion from supercritical solution to produce 1-3 microm particles that do not agglomerate. Obtained polymer particles by RESS-N were applied as powder coatings. The resulting coatings have a smooth and coherent film. The particle size distribution of microspheres was controlled by changing the polymer concentration, preexpansion pressure, temperature, and injection distance. The feed compositions were more effective than the other factors in controlling the particle size. The polymeric microparticles formed by RESS-N method can be utilized to make the thin coating film without anytoxic organic solvents and/or surfactants.

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.

Reaction mechanism of dimethyl ether carbonylation to methyl acetate over mordenite – a combined DFT/experimental study

DOE PAGES

Rasmussen, D. B.; Christensen, J. M.; Temel, B.; ...

2017-01-23

The reaction mechanism of dimethyl ether carbonylation to methyl acetate over mordenite was studied theoretically with periodic density functional theory calculations including dispersion forces and experimentally in a fixed bed flow reactor at pressures between 10 and 100 bar, dimethyl ether concentrations in CO between 0.2 and 2.0%, and at a temperature of 438 K. The theoretical study showed that the reaction of CO with surface methyl groups, the rate-limiting step, is faster in the eight-membered side pockets than in the twelve-membered main channel of the zeolite; the subsequent reaction of dimethyl ether with surface acetyl to form methyl acetatemore » was demonstrated to occur with low energy barriers in both the side pockets and in the main channel. Here, the present analysis has thus identified a path, where the entire reaction occurs favourably on a single site within the side pocket, in good agreement with previous experimental studies. The experimental study of the reaction kinetics was consistent with the theoretically derived mechanism and in addition revealed that the methyl acetate product inhibits the reaction – possibly by sterically hindering the attack of CO on the methyl groups in the side pockets.« less

Pyrrolidone - a new solvent for the methylation of humic acid

USGS Publications Warehouse

Wershaw, R. L.; Pinckney, D.J.; Booker, S.E.

1975-01-01

In the past, humic acid has been methylated by suspending it in a solution of diazomethane in diethyl ether, and degrading the partly methylated humic acid to release those parts of the molecule that were methylated. Only small fragments of the molecule have been identified by this technique. In the procedure described here the humic acid is dissolved in 2-pyrrolidone and methylated by the addition of diazomethane in diethyl ether and ethanol to the solution. Because the humic acid is completely dissolved in the reaction medium, disaggregation of the humic acid particles takes place and much more complete methylation is obtained. The methylated products may be fractionated by countercurrent distribution and analyzed by mass spectrometry.

Understanding How the Presence of Uniform Electric Fields Can Shift the Miscibility of Polystyrene/Poly(vinyl methyl ether) Blends

NASA Astrophysics Data System (ADS)

Kriisa, Annika; Roth, Connie B.

2015-03-01

Techniques which can externally control and manipulate the phase behavior of polymeric systems, without altering chemistry on a molecular level, have great practical benefits. One such possible mechanism is the use of electric fields, shown to cause interfacial instabilities, orientation of morphologies, and phase transitions in polymer blends and block copolymers. We have recently demonstrated that the presence of uniform electric fields can also strongly enhance the miscibility of polystyrene (PS) / poly(vinyl methyl ether) (PVME) blends [J. Chem. Phys. 2014, 141, 134908]. Using fluorescence to measure the phase separation temperature Ts of PS/PVME blends with and without electric fields, we show that Ts can be reproducibly and reversibly increased by 13.5 +/- 1.4 K for electric fields of 17 kV/mm for this lower critical solution temperature (LCST) blend. This increase in blend miscibility with electric fields represents some of the largest absolute shifts in Ts ever recorded, well outside of experimental error. The best theoretical prediction for the expected shift in Ts with electric field for this system is still two orders of magnitude smaller than that observed experimentally. We discuss the limitations of this theoretical prediction and consider possible factors affecting miscibility that may need to be also included.

DERMAL, ORAL AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY-BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

EPA Science Inventory

Methyl tertiary butyl ether (MTBE), a gasoline additive used to increase octane and reduce carbon monoxide emissions and ozone precursors, has contaminated drinking water and can lead to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhal...

BIODEGRADATION OF METHYL TERT-BUTYL ETHER USING AN INNOVATIVE BIOMASS CONCENTRATOR REACTOR

EPA Science Inventory

The aerobic biodegradation of methyl tert-butyl ether (MTBE) was investigated using a pilot-scale Biomass Concentrator Reactor (BCR). The reactor was operated for a year at a flow rate of 2500 L/d of Cincinnati dechlorinated tap water and an influent MTBE concentration o...

TREATMENT OF METHYL TERT-BUTYL ETHER CONTAMINATED WATER USING PHOTOCATALYSIS

EPA Science Inventory

The feasibility of photo-oxidation treatment of methyl tert-butyl ether (MTBE) in water was investigated in three ways, 1) using a slurry falling film photo-reactor, 2) a batch solar reactor system, and 3) a combination of air-stripping and gas phase photooxidation system. MTBE-c...

REMOVAL OF METHYL T-BUTYL ETHER (MTBE) FROM WATER BY PERVAPORATION: BENCH-SCALE AND PILOT SCALE EVALUATIONS

EPA Science Inventory

The ability of pervaporation to remove methyl t-butyl ether (MTBE) from water was evaluated at bench- and pilot-scales. Process parameters studied included flow rate, temperature, MTBE concentration, membrane module type, and permeate pressure. Pervaporation performance was ass...

STRUCTURES AND BINDING ENERGIES OF METHYL TERT-BUTYL ETHER-WATER COMPLEXES

EPA Science Inventory

Methyl tert-butyl ether (MTBE) is a well-known environmental contaminant owing to its high solubility in water. Since the early 1990s, MTBE has been added to gasoline to improve air quality in some metropolitan areas of the United States. Improved air quality was, however, achiev...

Electron Microscopy of Intracellular Protozoa

DTIC Science & Technology

1988-12-20

LR Gold resin containing 0.75% (w/v) benzoin methyl ether as an ultraviolet initiator and left overnight in fresh resin. The samples were finally...ethanol at progressively lower temperatures between OC and -20°C, and infiltrated with LR Gold resin containing 0.5% w/w benzoin methyl ether as an

Application of Stable Carbon Isotope Ratios to Recognize Natural Biodegradation of MTBE

EPA Science Inventory

The organisms that degrade MTBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

A Cation-containing Polymer Anion Exchange Membrane based on Poly(norbornene)

NASA Astrophysics Data System (ADS)

Beyer, Frederick; Price, Samuel; Ren, Xiaoming; Savage, Alice

Cation-containing polymers are being studied widely for use as anion exchange membranes (AEMs) in alkaline fuel cells (AFCs) because AEMs offer a number of potential benefits including allowing a solid state device and elimination of the carbonate poisoning problem. The successful AEM will combine high performance from several orthogonal properties, having robust mechanical strength even when wet, high hydroxide conductivity, and the high chemical stability required for long device lifetimes. In this study, we have synthesized a model cationic polymer that combines three of the key advantages of Nafion. The polymer backbone based on semicrystalline atactic poly(norbornene) offers good mechanical properties. A flexible, ether-based tether between the backbone and fixed cation charged species (quaternary ammonium) should provide the low-Tg, hydrophilic environment required to facilitate OH- transport. Finally, methyl groups have been added at the beta position relative to the quaternary ammonium cation to prevent Hoffman elimination, one mechanism by which AEMs are neutralized in a high pH environment. In this poster, we will present our findings on mechanical properties, morphology, charge transport, and chemical stability of this material.

Side chain engineering of poly-thiophene and its impact on crystalline silicon based hybrid solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zellmeier, M.; Rappich, J.; Nickel, N. H.

The influence of ether groups in the side chain of spin coated regioregular polythiophene derivatives on the polymer layer formation and the hybrid solar cell properties was investigated using electrical, optical, and X-ray diffraction experiments. The polymer layers are of high crystallinity but the polymer with 3 ether groups in the side chain (P3TOT) did not show any vibrational fine structure in the UV-Vis spectrum. The presence of ether groups in the side chains leads to better adhesion resulting in thinner and more homogeneous polymer layers. This, in turn, enhances the electronic properties of the planar c-Si/poly-thiophene hybrid solar cell.more » We find that the power conversion efficiency increases with the number of ether groups in the side chains, and a maximum power conversion efficiency of η = 9.6% is achieved even in simple planar structures.« less

Phenylethynl-terminated poly(arylene ethers)

NASA Technical Reports Server (NTRS)

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

1993-01-01

Phenylethynyl-terminated poly(arylene ethers) are prepared in a wide range of molecular weights by adjusting monomer ratio and adding an appropriate amount of 4-fluoro- 4'-phenylethynyl benzophenone during polymer synthesis. The resulting phenylethynyl-terminated poly(arylene ethers) react and crosslink upon curing for one hour at 350 C to provide materials with improved solvent resistance, higher modulus, and better high temperature properties than the linear, uncrosslinked polymers.

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.

Poly(arylene ether)s containing pendent ethynyl groups

NASA Technical Reports Server (NTRS)

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

1994-01-01

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 C to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus.

The Knock-Limited Performance of Fuel Blends Containing Spiropentane, Methylenecyclobutane, Di-Tert-Butyl Ether, Methyl Tert-Butyl Ether, and Triptane

NASA Technical Reports Server (NTRS)

Meyer, Carl L.

1946-01-01

Tests show that at inlet-air temperatures of 250 deg F and 100 deg F the knock-limited performance of the base fuel of blends, leaded with 4 ml TEL per gallon and containing 20 percent spiropentane, was reduced at fuel/air ratios below 0.085. The 20 percent methylenecyclobutane reduced the knock-limited power of the base fuel at fuel/air ratios below 0.112. Di-tert-butyl ether, methyl-tert-butyl ether, and triptane increased the knock-limited power of the base fuel at all fuel/air ratios and at both temperatures.

Facile Fabrication of Hierarchically Thermoresponsive Binary Polymer Pattern for Controlled Cell Adhesion.

PubMed

Hou, Jianwen; Cui, Lele; Chen, Runhai; Xu, Xiaodong; Chen, Jiayue; Yin, Ligang; Liu, Jingchuan; Shi, Qiang; Yin, Jinghua

2018-03-01

A versatile platform allowing capture and detection of normal and dysfunctional cells on the same patterned surface is important for accessing the cellular mechanism, developing diagnostic assays, and implementing therapy. Here, an original and effective method for fabricating binary polymer brushes pattern is developed for controlled cell adhesion. The binary polymer brushes pattern, composed of poly(N-isopropylacrylamide) (PNIPAAm) and poly[poly(ethylene glycol) methyl ether methacrylate] (POEGMA) chains, is simply obtained via a combination of surface-initiated photopolymerization and surface-activated free radical polymerization. This method is unique in that it does not utilize any protecting groups or procedures of backfilling with immobilized initiator. It is demonstrated that the precise and well-defined binary polymer patterns with high resolution are fabricated using this facile method. PNIPAAm chains capture and release cells by thermoresponsiveness, while POEGMA chains possess high capability to capture dysfunctional cells specifically, inducing a switch of normal red blood cells (RBCs) arrays to hemolytic RBCs arrays on the pattern with temperature. This novel platform composed of binary polymer brush pattern is smart and versatile, which opens up pathways to potential applications as microsensors, biochips, and bioassays. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Blood clearance and biodistribution of polymer brush-afforded silica particles prepared by surface-initiated living radical polymerization.

PubMed

Ohno, Kohji; Akashi, Tatsuki; Tsujii, Yoshinobu; Yamamoto, Masaya; Tabata, Yasuhiko

2012-03-12

The physiological properties of polymer brush-afforded silica particles prepared by surface-initiated living radical polymerization were investigated in terms of the circulation lifetime in the blood and distribution in tissues. Hydrophilic polymers consisting mainly of poly(poly(ethylene glycol) methyl ether methacrylate) were grafted onto silica particles by surface-initiated atom transfer radical polymerization that was mediated by a copper complex to produce hairy hybrid particles. A series of hybrid particles was synthesized by varying the diameter of the silica core and the chain length of the polymer brush to examine the relationship between their physicochemical and physiological properties. The hybrid particles were injected intravenously into mice to investigate systematically their blood clearance and body distribution. It was revealed that the structural features of the hybrid particles significantly affected their in vivo pharmacokinetics. Some hybrid particles exhibited an excellently prolonged circulation lifetime in the blood with a half life of ∼20 h. When such hybrid particles were injected intravenously into a tumor-bearing mouse, they preferentially accumulated in tumor tissue. The tumor-targeted delivery was optically visualized using hybrid particles grafted with fluorescence-labeled polymer brushes.

Treatment Of Groundwater Contaminated With PAHs, Gasoline Hydrocarbons, And Methyl Tert-Butyl Ether In A Laboratory Biomass-Retaining Bioreactor

EPA Science Inventory

In this study, we investigated the treatability of co-mingled groundwater contaminated with polycyclic aromatic hydrocarbons (PAHs), gasoline hydrocarbons, and methyl tert-butyl ether (MtBE) using an ex-situ aerobic biotreatment system. The PAHs of interest were nap...

Anaerobic Biodegradation Of Methyl tert-Butyl Ether Under Iron-Reducing Conditions In Batch And Continuous-Flow Cultures

EPA Science Inventory

The feasibility of biodegradation of the fuel oxygenate methyl tert-butyl ether (MTBE) under iron-reducing conditions was explored in batch and continuous-flow systems. A porous pot completely-mixed reactor was seeded with diverse cultures and operated under iron-reducing...

INFLUENCE OF METHYL TERT-BUTYL ETHER (MTBE) ON LAKE WATER ALGAE

EPA Science Inventory

Methyl tert-butyl ether (MTBE) has been used as an octane booster in gasoline in the United States since the 1970s. MTBE use increased greatly in the 1990s with the implementation of the Clean Air Act Amendments of 1990. The MTBE enhanced a more complete combustion of fuel hydroc...

ATTENUATION OF METHYL TERT-BUTYL ETHER IN WATER USING SUNLIGHT AND A PHOTOCATALYST

EPA Science Inventory

The use of methyl tert-butyl ether (MTBE) as a gasoline additive has resulted in increasing pollution of ground water. Most of the conventional treatment technologies are inefficient or costly when the initial concentration of MTBE is low (<200 ug/L). In order to find an eco-frie...

DEVELOPMENT OF PHYSIOLOGICAL-BASED PHARMACOKINETIC MODEL FOR DERMAL ABSORPTION NAD PENETRATION OF METHYL TERTIARY BUTYL ETHER IN HUMANS

EPA Science Inventory

Background: Methyl tertiary butyl ether (MTBE) is a volatile organic chemical that is added to gasoline as an octane booster and to reduce vehicular emissions of carbon monoxide. MTBE is introduced into the environment through fuel spills, leakage of storage tanks, and evaporat...

CO-OCCURRENCE OF METHYL- TERT-BUTYL ETHER (MTBE) AND BTEX COMPOUNDS AT MARINAS IN A LARGE RESEVOIR

EPA Science Inventory

Methyl tert-butyl ether (MTBE) is released into the environment as one of some gasoline components, not as a pure compound. BTEX compounds (benzene, tolune, ethylbenzene, and xylenes) are major volatile constituents found in gasoline and are water soluble and mobile. This study...

INHALATION EXPOSURE TO METHYL TERT-BUTYL ETHER (MTBE) AND DIBROMOCHLOROMETHANE (DBCM) USING CONTINUOUS BREATH ANALYSIS

EPA Science Inventory

The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced haza...

DERMAL EXPOSURE TO METHYL TERT-BUTYL ETHER (MTBE) AND DIBROMOCHLOROMETHANE (DBCM) WHILE BATHING WITH CONTAMINATED WATER

EPA Science Inventory

The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced hazardous a...

WATER QUALITY AT FIVE MARINAS IN LAKE TEXOMA AS RELATED TO METHYL TERT-BUTYL ETHER (MTBE)

EPA Science Inventory

Occurrence of methyl tert-butyl ether (MTBE) in five marinas was monitored between June 1999 and November 2000 in Lake Texoma located on the border of Oklahoma and Texas. MTBE is a commonly used gasoline additive and a suspected carcinogen. Lake water was collected at locations i...

TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

EPA Science Inventory

Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

BIODEGRADATION - MONITORED NATURAL ATTENUATION (MNA) FOR OXYGENATES: HOW IT EVOLVED, WHY IT OCCURS AND STABLE ISOTOPES

EPA Science Inventory

The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

Short-wavelength ablation of polymers in the high-fluence regime

NASA Astrophysics Data System (ADS)

Liberatore, Chiara; Mann, Klaus; Müller, Matthias; Pina, Ladislav; Juha, Libor; Vyšín, Ludek; Rocca, Jorge J.; Endo, Akira; Mocek, Tomas

2014-05-01

Short-wavelength ablation of poly(1,4-phenylene ether-ether-sulfone) (PPEES) and poly(methyl methacrylate) (PMMA) was investigated using extreme ultraviolet (XUV) and soft x-ray (SXR) radiation from plasma-based sources. The initial experiment was performed with a 10 Hz desktop capillary-discharge XUV laser lasing at 46.9 nm. The XUV laser beam was focused onto the sample by a spherical mirror coated with a Si/Sc multilayer. The same materials were irradiated with 13.5 nm radiation emitted by plasmas produced by focusing an optical laser beam onto a xenon gas-puff target. A Schwarzschild focusing optics coated with a Mo/Si multilayer was installed at the source to achieve energy densities exceeding 0.1 J cm-2 in the tight focus. The existing experimental system at the Laser Laboratorium Göttingen was upgraded by implementing a 1.2 J driving laser. An increase of the SXR fluence was secured by improving the alignment technique.

HIGH LEVELS OF MONOAROMATIC COMPOUNDS LIMIT THE USE OF SOLID-PHASE MICROEXTRACTION OF METHYL TERTIARY BUTYL ETHER AND TERTIARY BUTYL ALCOHOL

EPA Science Inventory

Recently, two papers reported the use of solid-phase microextraction (SPME) with polydimethylsiloxane(PDMS)/Carboxen fibers to determine trace levels of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (tBA) in water. Attempts were made to apply this technique to th...

CONCENTRATIONS, SOURCES, AND FATE OF THE GASOLINE OXYGENATE METHYL TERT-BUTYL ETHER (MTBE) IN A MULTIPLE-USE LAKE. (R826282)

EPA Science Inventory

Discovery of the fuel additive methyl tert-butyl ether (MTBE) in
drinking water supplies is of concern to public health officials, water
suppliers, and the public. Despite recent policy decisions, few published
studies exist on the concentrations, sources, a...

INTERACTION OF METHYL-TERT BUTYL ETHER AND WATER STRESS ON SEED GERMINATION AND SEEDLING GROWTH IN SOIL MICROCOSMS

EPA Science Inventory

Methyl tert-butyl ether (MTBE) is a widespread contaminant in surface and ground water in the United States. Frequently irrigation is used to water fields to germinate planted seeds and sustain plant growth. A likely possibility exists that water used may have some MTBE. Our s...

MNA of Chlorinated Solvents and Fuel Oxygenates: Why it occurs, how it evolved, and using stable carbon isotopes to predict plume behavior

EPA Science Inventory

The organisms that degrade MTBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

Geissoschizine methyl ether, a corynanthean-type indole alkaloid from Uncaria rhynchophylla as a potential acetylcholinesterase inhibitor.

PubMed

Yang, Zhong-Duo; Duan, Dong-Zhu; Du, Juan; Yang, Ming-Jun; Li, Shuo; Yao, Xiao-Jun

2012-01-01

Geissoschizine methyl ether (1), a newly discovered strong acetylcholinesterase (AChE) inhibitor, along with six weakly active alkaloids, vallesiachotamine (2), hisuteine (3), hirsutine (4), isorhynchophylline (5), cisocorynoxeine (6) and corynoxeine (7) have been isolated from Uncaria rhynchophylla. Geissoschizine methyl ether (1) inhibited 50% of AChE activity at concentrations of 3.7 ± 0.3 µg mL(-1) while the IC(50) value of physostigmine as a standard was 0.013 ± 0.002 µg mL(-1). The mode of AChE inhibition by 1 was reversible and non-competitive. In addition, molecular modelling was performed to explore the binding mode of inhibitor 1 at the active site of AChE.

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.

Thermodynamic and Kinetic Behavior of the Polystyrene/Poly(vinyl methyl ether) Blend as Studied by Excimer Fluorescence.

DTIC Science & Technology

1986-01-02

AD-A±63 895 THERMODYNAMIC AND KINETIC BEHAVIOR OF THE / POLYSTYRENE/POLY(YINYL METHYL E..(U) STANFORD UNIY CALIFDEPT OF CHEMICAL ENGINEERING C N...Polystyrene/Poly(vinyl methyl ether) Blend 7. DEcFRMN 81 toOR 30USptE8 00~ as Studied by Excimer Fluorescence 6 EFRIGOG EOTNME *AUTHOR() a. CONTRACT OR GRANT...werea fondoare ihemoriisof * ~ Ex e sp fluodecositionsdu to deud Gen e and hoog Pinus Florsneis shownhase migrationprocSECURITY CLASIFICTIO OFd

Replacement solvents for use in chemical synthesis

DOEpatents

Molnar, Linda K.; Hatton, T. Alan; Buchwald, Stephen L.

2001-05-15

Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.

Ultraviolet-induced surface grafting of octafluoropentyl methacrylate on polyether ether ketone for inducing antibiofilm properties.

PubMed

Amdjadi, Parisa; Nojehdehian, Hanieh; Najafi, Farhood; Ghasemi, Amir; Seifi, Massoud; Dashtimoghadam, Erfan; Fahimipour, Farahnaz; Tayebi, Lobat

2017-07-01

Since octafluoropentyl methacrylate is an antifouling polymer, surface modification of polyether ether ketone with octafluoropentyl methacrylate is a practical approach to obtaining anti-biofilm biocompatible devices. In the current study, the surface treatment of polyether ether ketone by the use of ultraviolet irradiation, so as to graft (octafluoropentyl methacrylate) polymer chains, was initially implemented and then investigated. The Fourier-transform infrared and nuclear magnetic resonance spectra corroborated the appearance of new signals associated with the fluoroacrylate group. Thermogravimetric curves indicated enhanced asymmetry in the polymer structure due to the introduction of the said new groups. Measuring the peak area in differential scanning calorimetry experiments also showed additional bond formation. Static water contact angle measurements indicated a change in wettability to the more hydrophobic surface. The polyether ether ketone-octafluoropentyl methacrylate surface greatly reduced the protein adsorption. This efficient method can modulate and tune the surface properties of polyether ether ketone according to specific applications.

Photosynthesis Involvement in the Mechanism of Action of Diphenyl Ether Herbicides 1

PubMed Central

Ensminger, Michael P.; Hess, F. Dan

1985-01-01

Photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. Isolated spinach (Spinacia oleracea L.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with the methyl ester of acifluorfen (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid), oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], or MC15608 (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate). In most cases the toxicity of acifluorfen-methyl, oxyfluorfen, or MC15608 to the unicellular green alga Chlamydomonas eugametos (Moewus) did not decrease after simultaneous treatment with diuron. However, diuron significantly reduced cell death after paraquat treatment at all but the highest paraquat concentration tested (0.1 millimolar). These data indicate electron transport of photosynthesis is not serving the same function for diphenyl ether herbicides as for paraquat. Additional evidence for differential action of paraquat was obtained from the superoxide scavenger copper penicillamine (copper complex of 2-amino-3-mercapto-3-methylbutanoic acid). Copper penicillamine eliminated paraquat toxicity in cucumber (Cucumis sativus L.) cotyledons but did not reduce diphenyl ether herbicide toxicity. PMID:16664206

Photosynthesis involvement in the mechanism of action of diphenyl ether herbicides.

PubMed

Ensminger, M P; Hess, F D

1985-05-01

Photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. Isolated spinach (Spinacia oleracea L.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1'-dimethyl-4,4'-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with the methyl ester of acifluorfen (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid), oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], or MC15608 (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate). In most cases the toxicity of acifluorfen-methyl, oxyfluorfen, or MC15608 to the unicellular green alga Chlamydomonas eugametos (Moewus) did not decrease after simultaneous treatment with diuron. However, diuron significantly reduced cell death after paraquat treatment at all but the highest paraquat concentration tested (0.1 millimolar). These data indicate electron transport of photosynthesis is not serving the same function for diphenyl ether herbicides as for paraquat. Additional evidence for differential action of paraquat was obtained from the superoxide scavenger copper penicillamine (copper complex of 2-amino-3-mercapto-3-methylbutanoic acid). Copper penicillamine eliminated paraquat toxicity in cucumber (Cucumis sativus L.) cotyledons but did not reduce diphenyl ether herbicide toxicity.

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 into a solid or alternatively applied as a coating through several different methods with dissolving into an organic solvent and dried on by evaporation as a common means. PMID:27280150

Acid-catalyzed rearrangements of flavans to novelbenzofuran derivatives

Treesearch

Richard W. Hemingway; Weiling Peng; Anthony H. Conner; Petrus J. Steynberg; Jan P. Steynberg

1998-01-01

The objective of this work was to define reactions that occur when proanthocyanidins and their derivatives are reacted in the presence of acid catalysts. Pure compounds (either as the free phenols, the methyl ether, or the methyl ether-acetate derivatives) were isolated by a variety of chromatographic methods. Proof of their structure was based mainly on 2D-NMR, as...

Biodegradation – Monitored Natural Attenuation (MNA) for Oxygenates: How it Evolved, why it Occurs and Using Stable Carbon Isotopes to Predict Plume Behavior

EPA Science Inventory

The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

MNA for Chlorinated Solvents and Fuel Oxygenates: Why It Occurs, How It Evolved, and Using Stable Carbon Isotopes to Predict Plume Behavior

EPA Science Inventory

The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

In vitro study comparing the ability of mono-octanoin and mono-octanoin plus methyl tert-butyl ether to dissolve biliary stones.

PubMed

Tritapepe, R; Cesana, B

1996-01-01

This in vitro study compared the gallstone dissolution rates of mono-octanoin, mono-octanoin plus 10% distilled water, and mono-octanoin plus methyl tert-butyl ether 2:1. Sixteen stones were treated with each solvent at a slow perfusion rate of 3-4 ml/h and a rapid perfusion rate of 2.5 ml/30 min with 20-sec instillation/aspiration cycles, both with and without bile. The stones were weighed before, and 3, 6, 12 and 24 hrs after the start of treatment: the solvent was changed every 30 min. After 24 hrs of instillation/aspiration without bile, the mono-octanoin/methyl tert-butyl ether mixture reduced the weight of the stones by 93%, mono-octanoin plus water by 63%, and mono-octanoin alone by 52%; with bile, the figures were, respectively, 86%, 42% and 40%. The mono-octanoin/methyl tert-butyl ether mixture thus took approximately half the time needed by the other two preparations to dissolve the stones to the same extent, a finding which may be relevant for the clinical dissolution of bile duct stones.

QSPR models of n-octanol/water partition coefficients and aqueous solubility of halogenated methyl-phenyl ethers by DFT method.

PubMed

Zeng, Xiao-Lan; Wang, Hong-Jun; Wang, Yan

2012-02-01

The possible molecular geometries of 134 halogenated methyl-phenyl ethers were optimized at B3LYP/6-31G(*) level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for predicting aqueous solubility (-lgS(w,l)) and n-octanol/water partition coefficient (lgK(ow)) of halogenated methyl-phenyl ethers. The two models achieved in this work both contain three variables: energy of the lowest unoccupied molecular orbital (E(LUMO)), most positive atomic partial charge in molecule (q(+)), and quadrupole moment (Q(yy) or Q(zz)), of which R values are 0.992 and 0.970 respectively, their standard errors of estimate in modeling (SD) are 0.132 and 0.178, respectively. The results of leave-one-out (LOO) cross-validation for training set and validation with external test sets both show that the models obtained exhibited optimum stability and good predictive power. We suggests that two QSPR models derived here can be used to predict S(w,l) and K(ow) accurately for non-tested halogenated methyl-phenyl ethers congeners. Copyright © 2011 Elsevier Ltd. All rights reserved.

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(PEG 8k -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.

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Code of Federal Regulations, 2014 CFR

2014-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic.../methyl methacrylate polymers. The vinylidene chloride/methyl acrylate/methyl methacrylate polymers (CAS...

Preparation and Characterization of Various Poly(ether ether ketone) Containing Imidazolium Moiety for Anion Exchange Membrane Fuel Cell Application.

PubMed

Lee, Byeol-Nim; Son, Tae Yang; Park, Chi Hoon; Kim, Tae Hyun; Nam, Sang Yong

2018-09-01

In this study, various poly(ether ether ketone) were synthesized using three different monomers and the imidazolium group was introduced into synthesized poly(ether ether ketone)s by using substitution reaction. Synthesized polymers were used to prepare anion exchange membranes and to evaluate its properties. Thermal, chemical and structural properties were carried out using thermogravimetric analysis, nuclear magnetic resonance. The anion exchange membranes with different imidazolium moieties were characterized by several different analytical techniques such as water up take, ion exchange capacity, hydroxide conductivity for checking the possibility to apply the anion exchange membrane fuel cell. Consequently, results of characterization were studied to understand the correlation between stabilities of the membrane and functional group and polymer backbone structures. And we confirm membrane performance was improved by increasing imidazolium cation groups.

Facile synthesis of polymeric fluorescent organic nanoparticles based on the self-polymerization of dopamine for biological imaging.

PubMed

Shi, Yingge; Jiang, Ruming; Liu, Meiying; Fu, Lihua; Zeng, Guangjian; Wan, Qing; Mao, Liucheng; Deng, Fengjie; Zhang, Xiaoyong; Wei, Yen

2017-08-01

Polymeric fluorescent organic nanoparticles (polymer-FONs) have raised considerable research attention for biomedical applications owing to their advantages as compared with fluorescent inorganic nanoparticles and small organic molecules. In this study, we presented an efficient, facile and environment-friendly strategy to produce polymer-FONs, which relied on the self-polymerization of dopamine and polyethyleneimine (PEI) in rather mild conditions. To obtain the final polymer-FONs, aldehyde group-containing copolymers (named as poly(UA-co-PEGMA)) were synthesized by reversible addition-fragmentation chain-transfer polymerization using polyethylene glycol methyl ether methacrylate (PEGMA) and 1-undecen-10-al (UA) as monomers. The dopamine was conjugated onto poly(UA-co-PEGMA) through a multicomponent reaction between UA and dopamine to obtain poly(UA-co-PEGMA)-DA, which was further utilized for preparation of polymer-FONs through self-polymerization of dopamine and PEI. 1 H nuclear magnetic resonance, Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy were employed to characterize the structure, morphology, compositions and optical properties of these polymer-FONs. Cell viability and cell uptake behavior results suggested that these polymer-FONs possess good biocompatibility and can be potentially utilized for biomedical applications. More importantly, the method can be also applied to fabricate many other multifunctional polymer-FONs with great potential for biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

IRON(III) NITRATE-CATALYZED FACILE SYNTHESIS OF DIPHENYLMETHYL (DPM) ETHERS FROM ALCOHOLS

EPA Science Inventory

Diphenyl methyl (DPM) ethers constitute important structural portion of some pharmaceutical entities and also as protective group for hydroxyl groups in synthetic chemistry. DPM ethers are normally prepared using concentrated acids or base as catalysts, which may result in the fo...

40 CFR Table 36 to Subpart G of... - Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes...

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Ethylene Glycol MonobutylEther Acetate Chloroprene. Ethylene Glycol MonomethylEther Acetate Cumene (isopropylbenzene). Ethylene Glycol Dimethyl Ether Dibromoethane 1,2. Hexachlorobenzene Dichlorobenzene 1,4.... Ethylbenzene. Ethylene Oxide. Ethylene Dibromide. Hexachlorobutadiene. Hexachloroethane. Hexane-n. Methyl...

Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.

PubMed

Hanzawa, Yohko; Hashimoto, Kahoko; Kasashima, Yoshio; Takahashi, Yoshiko; Mino, Takashi; Sakamoto, Masami; Fujita, Tsutomu

2012-01-01

3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.

Toxicokinetics of ethers used as fuel oxygenates.

PubMed

Dekant, W; Bernauer, U; Rosner, E; Amberg, A

2001-10-15

The toxicokinetics and biotransformation of methyl-tert.butyl ether (MTBE), ethyl-tert.butyl ether (ETBE) and tert.amyl-methyl ether (TAME) in rats and humans are summarized. These ethers are used as gasoline additives in large amounts, and thus, a considerable potential for human exposure exists. After inhalation exposure MTBE, ETBE and TAME are rapidly taken up by both rats and humans; after termination of exposure, clearance by exhalation and biotransformation to urinary metabolites is rapid in rats. In humans, clearance by exhalation is slower in comparison to rats. Biotransformation of MTBE and ETBE is both qualitatively and quantitatively similar in humans and rats after inhalation exposure under identical conditions. The extent of biotransformation of TAME is also quantitatively similar in rats and humans; the metabolic pathways, however, are different. The results suggest that reactive and potentially toxic metabolites are not formed during biotransformation of these ethers and that toxic effects of these compounds initiated by covalent binding to cellular macromolecules are unlikely.

Development of sample clean up methods for the analysis of Mycobacterium tuberculosis methyl mycocerosate biomarkers in sputum extracts by gas chromatography–mass spectrometry

PubMed Central

Nicoara, Simona C.; Turner, Nicholas W.; Minnikin, David E.; Lee, Oona Y.-C.; O'Sullivan, Denise M.; McNerney, Ruth; Mutetwa, Reggie; Corbett, Liz E.; Morgan, Geraint H.

2015-01-01

A proof of principle gas chromatography–mass spectrometry method is presented, in combination with clean up assays, aiming to improve the analysis of methyl mycocerosate tuberculosis biomarkers from sputum. Methyl mycocerosates are generated from the transesterification of phthiocerol dimycocerosates (PDIMs), extracted in petroleum ether from sputum of tuberculosis suspect patients. When a high matrix background is present in the sputum extracts, the identification of the chromatographic peaks corresponding to the methyl derivatives of PDIMs analytes may be hindered by the closely eluting methyl ether of cholesterol, usually an abundant matrix constituent frequently present in sputum samples. The purification procedures involving solid phase extraction (SPE) based methods with both commercial Isolute-Florisil cartridges, and purpose designed molecularly imprinted polymeric materials (MIPs), resulted in cleaner chromatograms, while the mycocerosates are still present. The clean-up performed on solutions of PDIMs and cholesterol standards in petroleum ether show that, depending on the solvent mix and on the type of SPE used, the recovery of PDIMs is between 64 and 70%, whilst most of the cholesterol is removed from the system. When applied to petroleum ether extracts from representative sputum samples, the clean-up procedures resulted in recoveries of 36–68% for PDIMs, allowing some superior detection of the target analytes. PMID:25728371

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

Thioether-Bearing Hyperbranched Polyether Polyols with Methionine-Like Side-Chains: A Versatile Platform for Orthogonal Functionalization.

PubMed

Seiwert, Jan; Herzberger, Jana; Leibig, Daniel; Frey, Holger

2017-01-01

The synthesis of thioether-bearing hyperbranched polyether polyols based on an AB/AB 2 type copolymerization (cyclic latent monomers) is introduced. The polymers are prepared by anionic ring-opening multibranching copolymerization of glycidol and 2-(methylthio)ethyl glycidyl ether (MTEGE), which is conveniently accessible in a single etherification step. Slow monomer addition provides control over molecular weights. Moderate dispersities (Đ = 1.48-1.85) are obtained, given the hyperbranched structure. In situ 1 H NMR copolymerization kinetics reveal reactivity ratios of r G = 3.7 and r MTEGE = 0.27. Using slow monomer addition, copolymer composition can be systematically varied, allowing for the adjustment of the hydroxyl/thioether ratio, the degree of branching (DB = 0.36-0.48), thermal properties, and cloud point temperatures in aqueous solution in the range of 29-75 °C. Thioether oxidation to sulfoxides enables to tailor the copolymers' solubility profile. Use of these copolymers as a versatile, multifunctional platform for orthogonal modification is highlighted. The methyl sulfide groups can be selectively alkoxylated, using propylene oxide, allyl glycidyl ether, or furfuryl glycidyl ether, resulting in functional hyperbranched polyelectrolytes. Reaction of the alcohol groups with benzyl isocyanate demonstrates successful orthogonal functionalization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MEASUREMENT OF EXHALED BREATH AND VENOUS BLOOD TO DEVELOP A PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR HUMAN EXPOSURE TO METHYL TERTIARY-BUTYL ETHER AND THE PRODUCTION OF THE BIOMARKER TERTIARY-BUTYL ALCOHOL

EPA Science Inventory

Methyl tertiary-butyl ether (MTBE) is a common fuel additive used to increase the availability of oxygen in gasoline to reduce winter-time carbon monoxide emissions from automobiles. Also, MTBE boosts gasoline "octane" rating and, as such, allows reduction of benzene...

Review of Recent Developments on Using an Off-Lattice Monte Carlo Approach to Predict the Effective Thermal Conductivity of Composite Systems with Complex Structures

PubMed Central

Gong, Feng; Duong, Hai M.; Papavassiliou, Dimitrios V.

2016-01-01

Here, we present a review of recent developments for an off-lattice Monte Carlo approach used to investigate the thermal transport properties of multiphase composites with complex structure. The thermal energy was quantified by a large number of randomly moving thermal walkers. Different modes of heat conduction were modeled in appropriate ways. The diffusive heat conduction in the polymer matrix was modeled with random Brownian motion of thermal walkers within the polymer, and the ballistic heat transfer within the carbon nanotubes (CNTs) was modeled by assigning infinite speed of thermal walkers in the CNTs. Three case studies were conducted to validate the developed approach, including three-phase single-walled CNTs/tungsten disulfide (WS2)/(poly(ether ether ketone) (PEEK) composites, single-walled CNT/WS2/PEEK composites with the CNTs clustered in bundles, and complex graphene/poly(methyl methacrylate) (PMMA) composites. In all cases, resistance to heat transfer due to nanoscale phenomena was also modeled. By quantitatively studying the influencing factors on the thermal transport properties of the multiphase composites, it was found that the orientation, aggregation and morphology of fillers, as well as the interfacial thermal resistance at filler-matrix interfaces would limit the transfer of heat in the composites. These quantitative findings may be applied in the design and synthesis of multiphase composites with specific thermal transport properties. PMID:28335270

Interfacial Chemistry Regulation via a Skin-Grafting Strategy Enables High-Performance Lithium-Metal Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Yue; Zhao, Yuming; Li, Yuguang C.

The lithium (Li) metal anode suffers severe interfacial instability from its high reactivity toward liquid electrolytes, especially carbonate-based electrolytes, resulting in poor electrochemical performance of batteries that use 4 V high-capacity cathodes. In this paper, we report a new skin-grafting strategy that stabilizes the Li metal–liquid electrolyte interface by coating the Li metal surface with poly((N-2,2-dimethyl-1,3-dioxolane-4-methyl)-5-norbornene-exo-2,3-dicarboximide), a chemically and electrochemically active polymer layer. This layer, composed of cyclic ether groups with a stiff polycyclic main chain, serves as a grafted polymer skin on the Li metal anode not only to incorporate ether-based polymeric components into the solid-electrolyte interphase (SEI) butmore » also to accommodate Li deposition/dissolution under the skin in a dendrite/moss-free manner. Consequently, a Li-metal battery employing a Li metal anode with the grafted skin paired with LiNi 0.5Co 0.2Mn 0.3O 2 cathode has a 90.0% capacity retention after 400 charge/discharge cycles and a capacity of 1.2 mAh/cm 2 in a carbonate-based electrolyte. Finally, this proof-of-concept study provides a new direction for regulating the interfacial chemistry of Li metal anodes and for enabling high-performance Li-metal batteries.« less

Interfacial Chemistry Regulation via a Skin-Grafting Strategy Enables High-Performance Lithium-Metal Batteries

DOE PAGES

Gao, Yue; Zhao, Yuming; Li, Yuguang C.; ...

2017-10-06

The lithium (Li) metal anode suffers severe interfacial instability from its high reactivity toward liquid electrolytes, especially carbonate-based electrolytes, resulting in poor electrochemical performance of batteries that use 4 V high-capacity cathodes. In this paper, we report a new skin-grafting strategy that stabilizes the Li metal–liquid electrolyte interface by coating the Li metal surface with poly((N-2,2-dimethyl-1,3-dioxolane-4-methyl)-5-norbornene-exo-2,3-dicarboximide), a chemically and electrochemically active polymer layer. This layer, composed of cyclic ether groups with a stiff polycyclic main chain, serves as a grafted polymer skin on the Li metal anode not only to incorporate ether-based polymeric components into the solid-electrolyte interphase (SEI) butmore » also to accommodate Li deposition/dissolution under the skin in a dendrite/moss-free manner. Consequently, a Li-metal battery employing a Li metal anode with the grafted skin paired with LiNi 0.5Co 0.2Mn 0.3O 2 cathode has a 90.0% capacity retention after 400 charge/discharge cycles and a capacity of 1.2 mAh/cm 2 in a carbonate-based electrolyte. Finally, this proof-of-concept study provides a new direction for regulating the interfacial chemistry of Li metal anodes and for enabling high-performance Li-metal batteries.« less

Evaluation of PEG and mPEG-co-(PGA-co-PDL) microparticles loaded with sodium diclofenac

PubMed Central

Tawfeek, Hesham M.

2013-01-01

The aim of this study was to synthesize and evaluate novel biodegradable polyesters namely; poly(ethylene glycol)-Poly(glycerol adipate-co-ω-pentadecalactone), PEG-PGA-co-PDL-PEG, and poly(ethylene glycol methyl ether)-Poly(glycerol adipate-co-ω-pentadecalactone), PGA-co-PDL-PEGme as an alternative sustained release carrier for lung delivery compared with non-PEG containing polymer PGA-co-PDL. The co-polymers were synthesized through lipase catalysis ring opening polymerization reaction and characterized using GPC, FT-IR, 1H-NMR and surface contact angle. Furthermore, microparticles containing a model hydrophilic drug, sodium diclofenac, were prepared via spray drying from a modified single emulsion and characterized for their encapsulation efficiency, geometrical particle size, zeta potential, tapped density, primary aerodynamic diameter, amorphous nature, morphology, in vitro release and the aerosolization performance. Microparticles fabricated from mPEG-co-polymer can be targeted to the lung periphery with an optimum in vitro deposition. Furthermore, a significantly higher in vitro release (p > 0.05, ANOVA/Dunnett’s) was observed with the PEG and mPEG-co-polymers compared to PGA-co-PDL. In addition, these co-polymers have a good safety profile upon testing on human bronchial epithelial, 16HBE14o- cell lines. PMID:24227959

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

... 40 Protection of Environment 30 2010-07-01 2010-07-01 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...

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...

Protonation switching to the least-basic heteroatom of carbamate through cationic hydrogen bonding promotes the formation of isocyanate cations.

PubMed

Kurouchi, Hiroaki; Sumita, Akinari; Otani, Yuko; Ohwada, Tomohiko

2014-07-07

We found that phenethylcarbamates that bear ortho-salicylate as an ether group (carbamoyl salicylates) dramatically accelerate OC bond dissociation in strong acid to facilitate generation of isocyanate cation (N-protonated isocyanates), which undergo subsequent intramolecular aromatic electrophilic cyclization to give dihydroisoquinolones. To generate isocyanate cations from carbamates in acidic media as electrophiles for aromatic substitution, protonation at the ether oxygen, the least basic heteroatom, is essential to promote CO bond cleavage. However, the carbonyl oxygen of carbamates, the most basic site, is protonated exclusively in strong acids. We found that the protonation site can be shifted to an alternative basic atom by linking methyl salicylate to the ether oxygen of carbamate. The methyl ester oxygen ortho to the phenolic (ether) oxygen of salicylate is as basic as the carbamate carbonyl oxygen, and we found that monoprotonation at the methyl ester oxygen in strong acid resulted in the formation of an intramolecular cationic hydrogen bond (>CO(+) H⋅⋅⋅O<) with the phenolic ether oxygen. This facilitates OC bond dissociation of phenethylcarbamates, thereby promoting isocyanate cation formation. In contrast, superacid-mediated diprotonation at the methyl ester oxygen of the salicylate and the carbonyl oxygen of the carbamate afforded a rather stable dication, which did not readily undergo CO bond dissociation. This is an unprecedented and unknown case in which the monocation has greater reactivity than the dication. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and characterization of poly(L-alanine)-block-poly(ethylene glycol) monomethyl ether as amphiphilic biodegradable co-polymers.

PubMed

Zhang, Guolin; Ma, Jianbiao; Li, Yanhong; Wang, Yinong

2003-01-01

Di-block co-polymers of poly(L-alanine) with poly(ethylene glycol) monomethyl ether (MPEG) were synthesized as amphiphilic biodegradable co-polymers. The ring-opening polymerization of N-carboxy-L-alanine anhydride (NCA) in dichloromethane was initiated by amino-terminated poly(ethylene glycol) monomethyl ether (MPEG-NH2, M(n) = 2000) to afford poly(L-alanine)-block-MPEG. The weight ratio of two blocks in the co-polymers could be altered by adjusting the feeding ratio of NCA to MPEG-NH2. Their chemical structures were characterized on the basis of infrared spectrometry and nuclear magnetic resonance. According to circular dichroism measurement, the poly(L-alanine) chain on the co-polymers in an aqueous medium had a alpha-helix conformation. Two melting points from MPEG block and poly(L-alanine), respectively, could be observed in differential scanning calorimetry curves of the co-polymers, suggesting that a micro-domain phase separation appeared in their bulky states. The co-polymers could take up some water and the capacity was dependent on the ratio of poly(L-alanine) block to MPEG. Such co-polymers might be useful in drug-delivery systems and other biomedical applications.

Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

USGS Publications Warehouse

Leiker, T.J.; Abney, S.R.; Goodbred, S.L.; Rosen, Michael R.

2009-01-01

Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596????g kg- 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (< 51????g kg- 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

Methyl t-Butyl Ether Mineralization in Surface-Water Sediment Microcosms under Denitrifying Conditions

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

2001-01-01

Mineralization of [U-14C] methyl t-butyl ether (MTBE) to 14CO2 without accumulation of t-butyl alcohol (TBA) was observed in surface-water sediment microcosms under denitrifying conditions. Methanogenic activity and limited transformation of MTBE to TBA were observed in the absence of denitrification. Results indicate that bed sediment microorganisms can effectively degrade MTBE to nontoxic products under denitrifying conditions.

PRODUCTS OF THE GAS-PHASE REACTIONS OF THE OH RADICAL WITH N-BUTYL METHYL ETHER AND 2-ISOPROPOXYETHANOL: REACTIONS OF ROC(O)< RADICALS. (R825252)

EPA Science Inventory

The products of the gas-phase reactions of the OH radical with n-butyl methyl ether and 2-isopropoxyethanol in the presence of NO have been investigated at 298 ? 2 K and 740 Torr total pressure of air by gas chromatography and in situ atmospheric pressure ionization...

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.

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

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.

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.

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.

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.

DFT study on the adsorption of diethyl, ethyl methyl, and dimethyl ethers on the surface of gallium doped graphene

NASA Astrophysics Data System (ADS)

Shokuhi Rad, Ali; Sani, Emad; Binaeian, Ehsan; Peyravi, Majid; Jahanshahi, Mohsen

2017-04-01

In this study, we used density functional theory (DFT) to search on the adsorption properties of three important compounds of ether family; diethyl ether (DEE), ethyl methyl ether (EME), and dimethyl ether (DME) on the surface of Gallium doped graphene (GaG). We used three functionals (B3LYP, wb97xd, and MPW1PW91) for optimization and calculation of adsorption energy. After fully optimization, we scrutinized on the charge allocations on the adsorbed ethers as well as GaG (at the area of interaction) based on natural bond orbitals (NBO). Besides, we have calculated the amount of charge transfer upon adsorption of each analyte. We revel that GaG is an ideal adsorbent for chemisorption of all above-mentioned ethers. There is a little difference between the values of adsorption; -123.5, -120, and -118.3 kJ/mol (based on wb97xd) for DEE, EME, and DME, respectively. We found significant changes in the electronic structure of both adsorbent and adsorbate upon adsorption. Moreover, results of charge analyses confirm GaG is a p-type semiconductor.

75 FR 58315 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Direct Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

... benzene, ethyl ether, methyl isobutyl ketone, n-butyl alcohol, cyclohexane, methanol. F005 Toluene, methyl... alcohol. U147 Maleic anhydride. U154 Methanol. U159 Methyl ethyl ketone. U161 Methyl isobutyl ketone. U213..., methyl isobutyl ketone, n-butyl alcohol, cyclohexane, methanol. F005 Toluene, methyl ethyl ketone, carbon...

40 CFR Appendix A to Part 439 - Tables

Code of Federal Regulations, 2010 CFR

2010-07-01

... Aldehydes. n-Heptane 1 Alkanes. n-Hexane 1 Diethylamine 1 Amines. Triethylamine Benzene Aromatics. Toluene 1... Tetrahydrofuran 1 Ethers. Isopropyl ether Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK) Ammonia (aqueous...

40 CFR Appendix A to Part 439 - Tables

Code of Federal Regulations, 2011 CFR

2011-07-01

... Aldehydes. n-Heptane 1 Alkanes. n-Hexane 1 Diethylamine 1 Amines. Triethylamine Benzene Aromatics. Toluene 1... Tetrahydrofuran 1 Ethers. Isopropyl ether Acetone 1 Ketones. 4-Methyl-2-pentanone (MIBK) Ammonia (aqueous...

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.

Synthesis and Characterization of a Poly(ethylene glycol)-Poly(simvastatin) Diblock Copolymer

PubMed Central

Asafo-Adjei, Theodora A.; Dziubla, Thomas D.; Puleo, David A.

2014-01-01

Biodegradable polyesters are commonly used as drug delivery vehicles, but their role is typically passive, and encapsulation approaches have limited drug payload. An alternative drug delivery method is to polymerize the active agent or its precursor into a degradable polymer. The prodrug simvastatin contains a lactone ring that lends itself to ring-opening polymerization (ROP). Consequently, simvastatin polymerization was initiated with 5 kDa monomethyl ether poly(ethylene glycol) (mPEG) and catalyzed via stannous octoate. Melt condensation reactions produced a 9.5 kDa copolymer with a polydispersity index of 1.1 at 150 °C up to a 75 kDa copolymer with an index of 6.9 at 250 °C. Kinetic analysis revealed first-order propagation rates. Infrared spectroscopy of the copolymer showed carboxylic and methyl ether stretches unique to simvastatin and mPEG, respectively. Slow degradation was demonstrated in neutral and alkaline conditions. Lastly, simvastatin, simvastatin-incorporated molecules, and mPEG were identified as the degradation products released. The present results show the potential of using ROP to polymerize lactone-containing drugs such as simvastatin. PMID:25431653

Asbestos-Induced Epithelial Changes in Organ Cultures of Hamster Trachea: Inhibition by Retinyl Methyl Ether

NASA Astrophysics Data System (ADS)

Mossman, B. T.; Craighead, J. E.; MacPherson, B. V.

1980-01-01

The epithelium of the hamster trachea in organ culture undergoes hyperplasia and squamous metaplasia after exposure to the amphibole types of asbestos, crocidolite and amosite. These changes are inhibited when the synthetic vitamin A analog, retinyl methyl ether, is incorporated into the culture medium. These findings suggest a possible use for retinoids in the prevention and treatment of respiratory tract disease associated with environmental exposure to asbestos.

Alkaloids from the hook-bearing branch of Uncaria rhynchophylla and their neuroprotective effects against glutamate-induced HT22 cell death

PubMed Central

Qi, Wen; Yue, Si-Jia; Sun, Jia-Hong; Simpkins, James W.; Zhang, Lin; Yuan, Dan

2015-01-01

One new alkaloid, 4-geissoschizine N-oxide methyl ether (1), was isolated from the EtOH extract of the hook-bearing branch of Uncaria rhynchophylla, together with 10 known alkaloids, 3-epi-geissoschizine methyl ether (2) isolated from U. rhynchophylla for the first time, geissoschizine methyl ether (3), 4-hirsuteine N-oxide (4), hirsuteine (5), hirsutine (6), 3α-dihydro-cadambine (7), 3β-isodihydro-cadambine (8), cadambine (9), strictosamide (10), and akuammigine (11). The structures were elucidated by spectroscopic methods including UV, ESI-QTOF MS, NMR, and circular dichroism experiments. Neuroprotective effects of 1–9 were investigated against 3 mM glutamate-induced HT22 cell death. The activity assay showed that 2, 3, 5, and 6 exhibited potent neuroprotective effects against glutamate-induced HT22 cell death. However, only weak neuroprotective activities were observed for 1, 4, 7, 8, and 9. PMID:24899363

Alkaloids from the hook-bearing branch of Uncariarhynchophylla and their neuroprotective effects against glutamate-induced HT22 cell death.

PubMed

Qi, Wen; Yue, Si-Jia; Sun, Jia-Hong; Simpkins, James W; Zhang, Lin; Yuan, Dan

2014-01-01

One new alkaloid, 4-geissoschizine N-oxide methyl ether (1), was isolated from the EtOH extract of the hook-bearing branch of Uncariarhynchophylla, together with 10 known alkaloids, 3-epi-geissoschizine methyl ether (2) isolated from U.rhynchophylla for the first time, geissoschizine methyl ether (3), 4-hirsuteine N-oxide (4), hirsuteine (5), hirsutine (6), 3α-dihydro-cadambine (7), 3β-isodihydro-cadambine (8), cadambine (9), strictosamide (10), and akuammigine (11). The structures were elucidated by spectroscopic methods including UV, ESI-QTOF MS, NMR, and circular dichroism experiments. Neuroprotective effects of 1-9 were investigated against 3 mM glutamate-induced HT22 cell death. The activity assay showed that 2, 3, 5, and 6 exhibited potent neuroprotective effects against glutamate-induced HT22 cell death. However, only weak neuroprotective activities were observed for 1, 4, 7, 8, and 9.

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.

Novel Side-Chain Liquid Cyrstalline Polymers

DTIC Science & Technology

1989-01-01

Synthesis and Characterization of Liquid Crystalline Polyacrylates and Poly- methacrylates Containing Benzyl Ether and Diphenyl Ethane Based Mesogens J...Crystalline Polymethacrylates and Polyacrylates of trans 2-[4-(11- hydroxyundecanyloxy)-3,5-dimethylphenylI-4-(4-methoxyphenyl)-l,3-dioxane Makromol. Chem., 189...and Characterization of Liquid Crystalline Polyacrylates and Poly- met acrylates Containing Benzyl Ether and Diphenyl Ethane Based Mesogens J. Polym

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.

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.

Preparation of Poly-(Methyl vinyl ether-co-maleic Anhydride) Nanoparticles by Solution-Enhanced Dispersion by Supercritical CO2

PubMed Central

Chen, Ai-Zheng; Wang, Guang-Ya; Wang, Shi-Bin; Feng, Jian-Gang; Liu, Yuan-Gang; Kang, Yong-Qiang

2012-01-01

The supercritical CO2-based technologies have been widely used in the formation of drug and/or polymer particles for biomedical applications. In this study, nanoparticles of poly-(methyl vinyl ether-co-maleic anhydride) (PVM/MA) were successfully fabricated by a process of solution-enhanced dispersion by supercritical CO2 (SEDS). A 23 factorial experiment was designed to investigate and identify the significance of the processing parameters (concentration, flow and solvent/nonsolvent) for the surface morphology, particle size, and particle size distribution of the products. The effect of the concentration of PVM/MA was found to be dominant in the results regarding particle size. Decreasing the initial solution concentration of PVM/MA decreased the particle size significantly. After optimization, the resulting PVM/MA nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution. Fourier transform infrared spectroscopy (FTIR) spectra demonstrated that the chemical composition of PVM/MA was not altered during the SEDS process and that the SEDS process was therefore a typical physical process. The absolute value of zeta potential of the obtained PVM/MA nanoparticles was larger than 40 mV, indicating the samples’ stability in aqueous suspension. Analysis of thermogravimetry-differential scanning calorimetry (TG-DSC) revealed that the effect of the SEDS process on the thermostability of PVM/MA was negligible. The results of gas chromatography (GC) analysis confirmed that the SEDS process could efficiently remove the organic residue.

Some actions of substituted choline phenyl ethers, particularly of choline 2:6-xylyl ether

PubMed Central

Edge, N. D.; Mason, D. F. J.; Wyllie, J. H.

1957-01-01

Marked nicotine-like stimulant properties are possessed by choline phenyl ether and choline o-tolyl ether, and to a decreasing extent by choline 2:6-xylyl ether and choline 2:4:6-mesityl ether. The compounds all show neuromuscular blocking properties, which are of short duration and pass from mainly decamethonium-like to mainly curare-like as more methyl groups are added to the phenyl nucleus. This series of compounds also possesses muscarinic, weak anti-adrenaline and vasodilator properties, as well as long-lasting local anaesthetic effects in the two compounds tested by intradermal injection. PMID:13460236

A new cytotoxic flavonoid from the fruit of Sinopodophyllum hexandrum.

PubMed

Kong, Yue; Xiao, Jun-Jun; Meng, Shu-Cong; Dong, Xiao-Min; Ge, Yue-Wei; Wang, Ru-Feng; Shang, Ming-Ying; Cai, Shao-Qing

2010-07-01

Constituents of the fruit of Sinopodophyllum hexandrum (Royle) Ying (Sinopodophylli Fructus) were investigated. A new flavonoid, 8,2'-diprenylquercetin 3-methyl ether along with 9 known compounds were isolated and identified. Among them, the new compound 8,2'-diprenylquercetin 3-methyl ether exhibited cytotoxic activities against MDA-231 and T47D breast cancer cell lines, quercetin, kaempferol and rutin were isolated from Sinopodophylli Fructus for the first time. Copyright 2009 Elsevier B.V. All rights reserved.

Proton-Ionizable Crown Ethers. A Short Review

DTIC Science & Technology

1989-05-30

acid methyl ester using sodium hydride as the base in tetrahydrofuran. The m3thyl ester group was hydrolyzed to the carboxylic acid as shown in Procedure...prepared via the appropriate hydroxydibenzo-crown ether and allyl bromide RýIý R2 or ethyl acrylate as shown in Procedure N. 5 2 . 5 6 Disulfonic acid ...similar to Procedure p. 7 4 Once the precursor binrephtho-crown was obtained, it was coupled with bromoacetic acid methyl ester and R, , - R

Conformation and Complexation of Tannins: NMR Spectra and Molecular Search Modeling of Flavan-3-ols

Treesearch

Richard W. Hemingway; Fred L. Tohiason; G. Wayne McGraw; Jan P. Steynberg

1996-01-01

Studies offlavan-3-01sin their biologically significant phenolic form show that both H-6 and C-6 resonances are downfield from H-8 and C-8. Therefore, assignments for the H atoms of the A-ring are inverse to those commonly reported. By contrast, in the methyl ether and methyl ether acetate derivatives, both H-8 and C-8 are downfield from H-6 and C-6 and assignments...

Geissoschizine methyl ether N-oxide, a new alkaloid with antiacetylcholinesterase activity from Uncaria rhynchophylla.

PubMed

Jiang, Wei-Wei; Su, Jia; Wu, Xing-De; He, Juan; Peng, Li-Yan; Cheng, Xiao; Zhao, Qin-Shi

2015-01-01

Geissoschizine methyl ether N-oxide, a new oxindole alkaloid, along with 14 known alkaloids, was isolated from the aerial part of Uncaria rhynchophylla. Their structures were identified by comprehensive spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that the new compound exhibited anti-AChE activity with IC₅₀ value of 23.4 μM.

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.

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.

Polymeric micellar pH-sensitive drug delivery system for doxorubicin.

PubMed

Hrubý, Martin; Konák, Cestmír; Ulbrich, Karel

2005-03-02

A novel polymeric micellar pH-sensitive system for delivery of doxorubicin (DOX) is described. Polymeric micelles were prepared by self-assembly of amphiphilic diblock copolymers in aqueous solutions. The copolymers consist of a biocompatible hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic block containing covalently bound anthracycline antibiotic DOX. The starting block copolymers poly(ethylene oxide)-block-poly(allyl glycidyl ether) (PEO-PAGE) with a very narrow molecular weight distribution (Mw/Mn ca. 1.05) were prepared by anionic ring opening polymerization using sodium salt of poly(ethylene oxide) monomethyl ether as macroinitiator and allyl glycidyl ether as functional monomer. The copolymers were covalently modified via reactive double bonds by the addition of methyl sulfanylacetate. The resulting ester subsequently reacted with hydrazine hydrate yielding polymer hydrazide. The hydrazide was coupled with DOX yielding pH-sensitive hydrazone bonds between the drug and carrier. The resulting conjugate containing ca. 3 wt.% DOX forms micelles with Rh(a)=104 nm in phosphate-buffered saline. After incubation in buffers at 37 degrees C DOX was released faster at pH 5.0 (close to pH in endosomes; 43% DOX released within 24 h) than at pH 7.4 (pH of blood plasma; 16% DOX released within 24 h). Cleavage of hydrazone bonds between DOX and carrier continues even after plateau in the DOX release from micelles incubated in aqueous solutions is reached.

Polymer Brush-Functionalized Chitosan Hydrogels as Antifouling Implant Coatings.

PubMed

Buzzacchera, Irene; Vorobii, Mariia; Kostina, Nina Yu; de Los Santos Pereira, Andres; Riedel, Tomáš; Bruns, Michael; Ogieglo, Wojciech; Möller, Martin; Wilson, Christopher J; Rodriguez-Emmenegger, Cesar

2017-06-12

Implantable sensor devices require coatings that efficiently interface with the tissue environment to mediate biochemical analysis. In this regard, bioinspired polymer hydrogels offer an attractive and abundant source of coating materials. However, upon implantation these materials generally elicit inflammation and the foreign body reaction as a consequence of protein fouling on their surface and concomitant poor hemocompatibility. In this report we investigate a strategy to endow chitosan hydrogel coatings with antifouling properties by the grafting of polymer brushes in a "grafting-from" approach. Chitosan coatings were functionalized with polymer brushes of oligo(ethylene glycol) methyl ether methacrylate and 2-hydroxyethyl methacrylate using photoinduced single electron transfer living radical polymerization and the surfaces were thoroughly characterized by XPS, AFM, water contact angle goniometry, and in situ ellipsometry. The antifouling properties of these new bioinspired hydrogel-brush coatings were investigated by surface plasmon resonance. The influence of the modifications to the chitosan on hemocompatibility was assessed by contacting the surfaces with platelets and leukocytes. The coatings were hydrophilic and reached a thickness of up to 180 nm within 30 min of polymerization. The functionalization of the surface with polymer brushes significantly reduced the protein fouling and eliminated platelet activation and leukocyte adhesion. This methodology offers a facile route to functionalizing implantable sensor systems with antifouling coatings that improve hemocompatibility and pave the way for enhanced device integration in tissue.

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.

Imide/arylene ether copolymers with pendent trifluoromethyl groups

NASA Technical Reports Server (NTRS)

Jensen, Brian J.; Havens, Stephen J.

1992-01-01

A series of imide/arylene ether block copolymers were prepared using an arylene ether block containing a hexafluoroisopropylidene group and an imide block containing a hexafluoroisopropylidene and a trifluoromethyl group in the polymer backbone. The copolymers were characterized and mechanical properties were determined and compared to the homopolymers.

Quasi-Solid-State Rechargeable Li-O2 Batteries with High Safety and Long Cycle Life at Room Temperature.

PubMed

Cho, Sung Man; Shim, Jimin; Cho, Sung Ho; Kim, Jiwoong; Son, Byung Dae; Lee, Jong-Chan; Yoon, Woo Young

2018-05-09

As interest in electric vehicles and mass energy storage systems continues to grow, Li-O 2 batteries are attracting much attention as a candidate for next-generation energy storage systems owing to their high energy density. However, safety problems related to the use of lithium metal anodes have hampered the commercialization of Li-O 2 batteries. Herein, we introduced a quasi-solid polymer electrolyte with excellent electrochemical, chemical, and thermal stabilities into Li-O 2 batteries. The ion-conducting QSPE was prepared by gelling a polymer network matrix consisting of poly(ethylene glycol) methyl ether methacrylate, methacrylated tannic acid, lithium trifluoromethanesulfonate, and nanofumed silica with a small amount of liquid electrolyte. The quasi-solid-state Li-O 2 cell consisted of a lithium powder anode, a quasi-solid polymer electrolyte, and a Pd 3 Co/multiwalled carbon nanotube cathode, which enhanced the electrochemical performance of the cell. This cell, which exhibited improved safety owing to the suppression of lithium dendrite growth, achieved a lifetime of 125 cycles at room temperature. These results show that the introduction of a quasi-solid electrolyte is a potentially new alternative for the commercialization of solid-state Li-O 2 batteries.

miktoarm polymer: controlled synthesis, characterization, and application as anticancer drug carrier

NASA Astrophysics Data System (ADS)

Lin, Wenjing; Nie, Shuyu; Xiong, Di; Guo, Xindong; Wang, Jufang; Zhang, Lijuan

2014-05-01

Amphiphilic A2(BC)2 miktoarm star polymers [poly(ɛ-caprolactone)]2-[poly(2-(diethylamino)ethyl methacrylate)- b- poly(poly(ethylene glycol) methyl ether methacrylate)]2 [(PCL)2(PDEA- b-PPEGMA)2] were developed by a combination of ring opening polymerization (ROP) and continuous activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The critical micelle concentration (CMC) values were extremely low (0.0024 to 0.0043 mg/mL), depending on the architecture of the polymers. The self-assembled empty and doxorubicin (DOX)-loaded micelles were spherical in morphologies, and the average sizes were about 63 and 110 nm. The release of DOX at pH 5.0 was much faster than that at pH 6.5 and pH 7.4. Moreover, DOX-loaded micelles could effectively inhibit the growth of cancer cells HepG2 with IC50 of 2.0 μg/mL. Intracellular uptake demonstrated that DOX was delivered into the cells effectively after the cells were incubated with DOX-loaded micelles. Therefore, the pH-sensitive (PCL)2(PDEA- b-PPEGMA)2 micelles could be a prospective candidate as anticancer drug carrier for hydrophobic drugs with sustained release behavior.

Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

NASA Astrophysics Data System (ADS)

Wang, Jingjing; Wei, Jun

2016-09-01

Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

Electrochemical and structural characterization of polymer gel electrolytes based on a PEO copolymer and an imidazolium-based ionic liquid for dye-sensitized solar cells.

PubMed

Freitas, Flavio S; de Freitas, Jilian N; Ito, Bruno I; De Paoli, Marco-A; Nogueira, Ana F

2009-12-01

Polymer electrolytes based on mixtures of poly(ethylene oxide-co-propylene oxide) and 1-methyl-3-propyl-imidazolium iodide (MPII) were investigated, aiming at their application in dye-sensitized solar cells (DSSC). The interactions between the copolymer and the ionic liquid were analyzed by infrared spectroscopy and (1)H NMR. The results show interactions between the ether oxygen in the polymer and the hydrogen in the imidazolium cations. The ionic conductivities, electrochemical behaviors, and thermal properties of the electrolytes containing different concentrations of MPII were investigated. The electrolyte containing 70 wt % MPII presented the highest ionic conductivity (2.4 x 10(-3) S cm(-1)) and a diffusion coefficient of 1.9 x 10(-7) cm(2) s(-1). The influence of LiI addition to the electrolytes containing different concentrations of MPII was also investigated. The DSSC assembled with the electrolyte containing 70 wt % MPII showed an efficiency of 3.84% at 100 mW cm(-2). The stability of the devices for a period of 30 days was also evaluated using sealed cells. The devices assembled with the electrolyte containing less ionic liquid showed to be more stable.

76 FR 72311 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Final Exclusion

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-23

... waste in any State with delisting authorization, Eastman Chemical must obtain delisting authorization... benzene, ethyl ether, methyl isobutyl ketone, n-butyl alcohol, cyclohexane, methanol. F005 Toluene, methyl... Isobutyl alcohol. U147 Maleic anhydride. U154 Methanol. U159 Methyl ethyl ketone. U161 Methyl isobutyl...

Thermo-responsive cell culture carrier: Effects on macrophage functionality and detachment efficiency.

PubMed

Rennert, Knut; Nitschke, Mirko; Wallert, Maria; Keune, Natalie; Raasch, Martin; Lorkowski, Stefan; Mosig, Alexander S

2017-01-01

Harvesting cultivated macrophages for tissue engineering purposes by enzymatic digestion of cell adhesion molecules can potentially result in unintended activation, altered function, or behavior of these cells. Thermo-responsive polymer is a promising tool that allows for gentle macrophage detachment without artificial activation prior to subculture within engineered tissue constructs. We therefore characterized different species of thermo-responsive polymers for their suitability as cell substrate and to mediate gentle macrophage detachment by temperature shift. Primary human monocyte- and THP-1-derived macrophages were cultured on thermo-responsive polymers and characterized for phagocytosis and cytokine secretion in response to lipopolysaccharide stimulation. We found that both cell types differentially respond in dependence of culture and stimulation on thermo-responsive polymers. In contrast to THP-1 macrophages, primary monocyte-derived macrophages showed no signs of impaired viability, artificial activation, or altered functionality due to culture on thermo-responsive polymers compared to conventional cell culture. Our study demonstrates that along with commercially available UpCell carriers, two other thermo-responsive polymers based on poly(vinyl methyl ether) blends are attractive candidates for differentiation and gentle detachment of primary monocyte-derived macrophages. In summary, we observed similar functionality and viability of primary monocyte-derived macrophages cultured on thermo-responsive polymers compared to standard cell culture surfaces. While this first generation of custom-made thermo-responsive polymers does not yet outperform standard culture approaches, our results are very promising and provide the basis for exploiting the unique advantages offered by custom-made thermo-responsive polymers to further improve macrophage culture and recovery in the future, including the covalent binding of signaling molecules and the reduction of centrifugation and washing steps. Optimizing these and other benefits of thermo-responsive polymers could greatly improve the culture of macrophages for tissue engineering applications.

Non-Leaching, Benign Antifouling Multilayer Polymer Coatings for Marine Applications

DTIC Science & Technology

2010-03-01

polymerization b block BF3•Et2O boron trifluoride diethyl etherate BNL Brookhaven National Labs BF3•Et2O boron trifluoride diethyl etherate BSA...surface characterization of the polymers. We also acknowledge Brookhaven National Laboratory ( BNL ) where the NEXAFS surface characterization was...National Synchrotron Light Source at Brookhaven National Laboratory ( BNL ). The X-ray beam was elliptically polarized (polarization factor = 0.85

40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...

40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...

40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...

40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...

Transesterification of propylene glycol methyl ether in chromatographic reactors using anion exchange resin as a catalyst.

PubMed

Oh, Jungmin; Sreedhar, Balamurali; Donaldson, Megan E; Frank, Timothy C; Schultz, Alfred K; Bommarius, Andreas S; Kawajiri, Yoshiaki

2016-09-30

Reactive chromatography using an anion exchange resin is proposed for a transesterification reaction of propylene glycol methyl ether (DOWANOL™ PM) with ethyl acetate to produce propylene glycol methyl ether acetate (DOWANOL™ PMA). This reaction is studied in batch and chromatographic reactors catalyzed by an anion exchange resin. Several anion exchange resins are tested and compared based on the performance of resin as an adsorbent and a catalyst. A chromatographic column is packed with a selected catalyst, AMBERLITE™ IRA904, and both reaction and chromatographic elution are studied at different temperatures and feed concentrations. The resulting chromatograms are fitted to a mathematical model to obtain adsorption equilibrium and reaction kinetic parameters by the inverse method. Compared to esterification investigated in a previous study, transesterification has advantages such as a higher conversion at lower temperature and easy removal of the byproduct which may lead to higher productivity. Deactivation of anion exchange resins is observed and potential solutions are suggested. Copyright © 2016 Elsevier B.V. All rights reserved.

New biphasic solvent system based on cyclopentyl methyl ether for the purification of a non-polar synthetic peptide by pH-zone refining centrifugal partition chromatography.

PubMed

Amarouche, Nassima; Boudesocque, Leslie; Borie, Nicolas; Giraud, Matthieu; Forni, Luciano; Butte, Alessandro; Edwards, Florence; Renault, Jean-Hugues

2014-06-01

A new type 1 ternary biphasic system composed of cyclopentyl methyl ether, dimethylformamide and water was developed, characterized and successfully used for the purification of a lipophilic, protected peptide by pH-zone refining centrifugal partition chromatography. The protected peptide is an 8-mer, key intermediate in bivalirudin (Angiomax®) synthesis and shows a very low solubility in the solvents usually used in liquid chromatography. All ionic groups, except the N-terminal end of the peptide, are protected by a benzyl group. The purification of this peptide was achieved with a purity of about 99.04% and a recovery of 94% using the new ternary biphasic system cyclopentyl methyl ether/dimethylformamide/water (49:40:11, v/v) in the descending pH-zone refining mode with triethylamine (28 mM) as the retainer and methanesulfonic acid (18 mM) as the eluter. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

The effect of polymer aging on the uptake of fuel aromatics and ethers by microplastics.

PubMed

Müller, Axel; Becker, Roland; Dorgerloh, Ute; Simon, Franz-Georg; Braun, Ulrike

2018-05-14

Microplastics are increasingly entering marine, limnic and terrestrial ecosystems worldwide, where they sorb hydrophobic organic contaminants. Here, the sorption behavior of the fuel-related water contaminants benzene, toluene, ethyl benzene and xylene (BTEX) and four tertiary butyl ethers to virgin and via UV radiation aged polypropylene (PP) and polystyrene (PS) pellets was investigated. Changes in material properties due to aging were recorded using appropriate polymer characterization methods, such as differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, X-ray photoelectron spectroscopy, and microscopy. Pellets were exposed to water containing BTEX and the ethers at 130-190 μg L -1 for up to two weeks. Aqueous sorbate concentrations were determined by headspace gas chromatography. Sorption to the polymers was correlated with the sorbate's K ow and was significant for BTEX and marginal for the ethers. Due to substantially lower glass transition temperatures, PP showed higher sorption than PS. Aging had no effect on the sorption behavior of PP. PS sorbed less BTEX after aging due to an oxidized surface layer. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

Separator for alkaline electric batteries and method of making

NASA Technical Reports Server (NTRS)

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

1970-01-01

Battery separator membranes of high electrolytic conductivity comprising a cellulose ether and a compatible metallic salt of water soluble aliphatic acids and their hydroxy derivatives are described. It was found that methyl cellulose can be modified by another class of materials, nonpolymeric in nature, to form battery separator membranes of low electrolytic resistance but which have the flexibility of membranes made of unmodified methyl cellulose, and which in many cases enhance flexibility over membranes made with unmodified methyl cellulose. Separator membranes for electrochemical cells comprising a cellulose ether and a modified selected from the group consisting of metallic salts of water soluble alphatic acids and their hydroxy derivatives and to electrochemical cells utilizing said membranes are described.

Simultaneous quantitative analyses of indole and oxindole alkaloids of Uncaria Hook in rat plasma and brain after oral administration of the traditional Japanese medicine Yokukansan using high-performance liquid chromatography with tandem mass spectrometry.

PubMed

Kushida, Hirotaka; Fukutake, Miwako; Tabuchi, Masahiro; Katsuhara, Takao; Nishimura, Hiroaki; Ikarashi, Yasushi; Kanitani, Masanao; Kase, Yoshio

2013-12-01

Uncaria Hook (UH) alkaloids are involved in the beneficial effects of Yokukansan. However, the pharmacokinetics of UH alkaloids after oral administration of Yokukansan has not yet been sufficiently investigated. Therefore, we developed and validated a sensitive and specific high-performance liquid chromatography with tandem mass spectrometry (LC/MS/MS) method for the simultaneous quantitation of seven UH alkaloids (corynoxeine, isocorynoxeine, rhynchophylline, isorhynchophylline, hirsutine, hirsuteine and geissoschizine methyl ether) in rat plasma and brain. After protein precipitation with acetonitrile, chromatographic separation was performed using an Ascentis Express RP-amide column, with gradient elution with 0.2% formic acid and acetonitrile at 0.3 mL/min. All analytes in the plasma and brain showed good linearity over a wide concentration range (r > 0.995). Intra-day and inter-day variations of each constituent were 8.6 and 8.0% or less in the plasma, and 14.9 and 15.0% or less in the brain, respectively. The validated LC/MS/MS method was applied in the pharmacokinetic studies of UH alkaloids after oral administration of Yokukansan to rats. In the plasma, rhynchophylline, hirsutine, hirsuteine and geissoschizine methyl ether were detected, but only geissoschizine methyl ether was detected in the brain. These results suggest that geissoschizine methyl ether is an important constituent of the pharmacological effects of Yokukansan. Copyright © 2013 John Wiley & Sons, Ltd.

40 CFR Table 7 to Subpart Vvvvvv... - Partially Soluble HAP

Code of Federal Regulations, 2011 CFR

2011-07-01

... 111444 31. Dinitrophenol 51285 32. Epichlorohydrin 106898 33. Ethyl acrylate 140885 34. Ethylbenzene.... Hexachlorobutadiene 87683 39. Hexachloroethane 67721 40. Methyl methacrylate 80626 41. Methyl-t-butyl ether 1634044 42...

40 CFR Table 7 to Subpart Vvvvvv... - Partially Soluble HAP

Code of Federal Regulations, 2010 CFR

2010-07-01

... 111444 31. Dinitrophenol 51285 32. Epichlorohydrin 106898 33. Ethyl acrylate 140885 34. Ethylbenzene.... Hexachlorobutadiene 87683 39. Hexachloroethane 67721 40. Methyl methacrylate 80626 41. Methyl-t-butyl ether 1634044 42...

Gas Phase Conformations and Methyl Internal Rotation for 2-PHENYLETHYL Methyl Ether and its Argon Van Der Waals Complex from Fourier Transform Microwave Spectroscopy

NASA Astrophysics Data System (ADS)

Gurusinghe, Ranil M.; Tubergen, Michael

2015-06-01

A mini-cavity microwave spectrometer was used to record the rotational spectra arising from 2-phenylethyl methyl ether and its weakly bonded argon complex in the frequency range of 10.5 - 22 GHz. Rotational spectra were found for two stable conformations of the monomer: anti-anti and gauche-anti, which are 1.4 kJ mol-1 apart in energy at wB97XD/6-311++G(d,p) level. Doubled rotational transitions, arising from internal motion of the methyl group, were observed for both conformers. The program XIAM was used to fit the rotational constants, centrifugal distortion constants, and barrier to internal rotation to the measured transition frequencies of the A and E internal rotation states. The best global fit values of the rotational constants for the anti-anti conformer are A= 3799.066(3) MHz, B= 577.95180(17) MHz, C= 544.7325(3) MHz and the A state rotational constants of the gauche-anti conformer are A= 2676.1202(7) MHz, B= 760.77250(2) MHz, C= 684.78901(2) MHz. The rotational spectrum of 2-phenylethyl methyl ether - argon complex is consistent with the geometry where argon atom lies above the plane of the benzene moiety of gauche-anti conformer. Tunneling splittings were too small to resolve within experimental accuracy, likely due to an increase in three fold potential barrier when the argon complex is formed. Fitted rotational constants are A= 1061.23373(16) MHz, B= 699.81754(7) MHz, C= 518.33553(7) MHz. The lowest energy solvated ether - water complex with strong intermolecular hydrogen bonding has been identified theoretically. Progress on the assignment of the water complex will also be presented.

Sensitive multiresidue method by HS-SPME/GC-MS for 10 volatile organic compounds in urine matrix: a new tool for biomonitoring studies on children.

PubMed

Antonucci, Arianna; Vitali, Matteo; Avino, Pasquale; Manigrasso, Maurizio; Protano, Carmela

2016-08-01

A HS-SPME method coupled with GC-MS analysis has been developed for simultaneously measuring the concentration of 10 volatile organic compounds (VOCs) (benzene, toluene, ethylbenzene, o-, m-, and p-xylene, methyl tert-butyl ether, ethyl tert-butyl ether, 2-methyl-2-butyl methyl ether, and diisopropyl ether) in urine matrix as a biomonitoring tool for populations at low levels of exposure to such VOCs. These compounds, potentially toxic for human health, are common contaminants of both outdoor and indoor air, as they are released by autovehicular traffic; some of them are also present in environmental tobacco smoke (ETS). Thus, the exposure to these pollutants cannot be neglected and should be assessed. The low limits of detection and quantification (LODs and LOQs <6.5 and 7.5 ng L(-1), respectively) and the high reproducibility (CVs <4 %) make the developed method suited for biomonitoring populations exposed at low levels such as children. Further, the method is cost-effective and low in time-consumption; therefore, it is useful for investigating large populations. It has been applied to children exposed to traffic pollution and/or ETS; the relevant results are reported, and the relevant implications are discussed.

Single step synthesis and organization of gold colloids assisted by copolymer templates

NASA Astrophysics Data System (ADS)

Sarrazin, Aurélien; Gontier, Arthur; Plaud, Alexandre; Béal, Jérémie; Yockell-Lelièvre, Hélène; Bijeon, Jean-Louis; Plain, Jérôme; Adam, Pierre-Michel; Maurer, Thomas

2014-06-01

We report here an original single-step process for the synthesis and self-organization of gold colloids by simply incorporating gold salts into a solution prepared using polystyrene (PS)-polymethylmethacrylate copolymer and thiolated PS with propylene glycol methyl ether acetate as a solvent. The spin-coating and annealing of this solution then allows the formation of PS domains. Depending on the polymer concentration of the as-prepared solution, there can be either one or several gold nanoparticles (Au NPs) per PS domain. For high concentrations of Au NPs in PS domains, the coupling between plasmonic NPs leads to the observation of a second peak in the optical extinction spectrum. Such a collective effect could be relevant for the development of optical strain sensors in the near future.

Effects of surfactants on the properties of mortar containing styrene/methacrylate superplasticizer.

PubMed

Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

2014-01-01

The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA.

Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

PubMed Central

Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

2014-01-01

The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA. PMID:24955426

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Butyl acrylate, polymer with... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.6920 Butyl... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

The conformation of the monomethyl ethers of methyl beta-lactoside in D2O and Me2SO-d6 solutions.

PubMed

Fernández, P; Jiménez-Barbero, J

1993-10-04

The solution conformations of all the possible monomethyl ethers of methyl beta-lactoside have been analysed using molecular mechanics and dynamics calculations and nuclear magnetic resonance data (variable temperature and NOE experiments). The overall shape of all the compounds studied is fairly similar and may be described by conformers included in a low-energy region with phi = -100 +/- 40 degrees and psi = -135 +/- 35 degrees, which is ca. 5% of the total potential energy surface for the glycosidic linkages of the disaccharides.

Polymer and Composite Membranes for Proton-Conducting, High-Temperature Fuel Cells: A Critical Review

PubMed Central

Quartarone, Eliana; Angioni, Simone; Mustarelli, Piercarlo

2017-01-01

Polymer fuel cells operating above 100 °C (High Temperature Polymer Electrolyte Membrane Fuel Cells, HT-PEMFCs) have gained large interest for their application to automobiles. The HT-PEMFC devices are typically made of membranes with poly(benzimidazoles), although other polymers, such as sulphonated poly(ether ether ketones) and pyridine-based materials have been reported. In this critical review, we address the state-of-the-art of membrane fabrication and their properties. A large number of papers of uneven quality has appeared in the literature during the last few years, so this review is limited to works that are judged as significant. Emphasis is put on proton transport and the physico-chemical mechanisms of proton conductivity. PMID:28773045

Polymer and Composite Membranes for Proton-Conducting, High-Temperature Fuel Cells: A Critical Review.

PubMed

Quartarone, Eliana; Angioni, Simone; Mustarelli, Piercarlo

2017-06-22

Polymer fuel cells operating above 100 °C (High Temperature Polymer Electrolyte Membrane Fuel Cells, HT-PEMFCs) have gained large interest for their application to automobiles. The HT-PEMFC devices are typically made of membranes with poly(benzimidazoles), although other polymers, such as sulphonated poly(ether ether ketones) and pyridine-based materials have been reported. In this critical review, we address the state-of-the-art of membrane fabrication and their properties. A large number of papers of uneven quality has appeared in the literature during the last few years, so this review is limited to works that are judged as significant. Emphasis is put on proton transport and the physico-chemical mechanisms of proton conductivity.

Materials for use as proton conducting membranes for fuel cells

DOEpatents

Einsla, Brian R [Blacksburg, VA; McGrath, James E [Blacksburg, VA

2009-01-06

A family of polymers having pendent sulfonate moieties connected to polymeric main chain phenyl groups are described. These polymers are prepared by the steps of polymerization (using a monomer with a phenyl with an alkoxy substitution), deportation by converting the alkoxy to a hydroxyl, and functionalization of the polymer with a pendant sulfonate group. As an example, sulfonated poly(arylene ether sulfone) copolymers with pendent sulfonic acid groups are synthesized by the direct copolymerization of methoxy-containing poly(arylene ether sulfone)s, then converting the methoxy groups to the reactive hydroxyl form, and finally functionalizing the hydroxyl form with proton-conducting sites through nucleophilic substitution. The family of polymers may have application in proton exchange membranes and in other applications.

AVOIDING HYDROLYSIS OF FUEL ETHER OXYGENATES DURING STATIC HEADSPACE ANALYSIS

EPA Science Inventory

A headspace autosampler, gas chromatograph and ion trap mass spectrometer (headspace GC/MS) were used for trace analysis of fuel oxygenates and related compounds and aromatics in water. A method has been developed for determination of methyl tert-butyl ether (MTBE), ethyl tert-b...

40 CFR Table 7 to Subpart Hhhhh of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Methyl methacrylate 80626 42. Methyl-t-butyl ether 1634044 43. Methylene chloride 75092 44. N-hexane 110543 45. N,N-dimethylaniline 121697 46. Naphthalene 91203 47. Phosgene 75445 48. Propionaldehyde 123386...

40 CFR Table 7 to Subpart Hhhhh of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Methyl methacrylate 80626 42. Methyl-t-butyl ether 1634044 43. Methylene chloride 75092 44. N-hexane 110543 45. N,N-dimethylaniline 121697 46. Naphthalene 91203 47. Phosgene 75445 48. Propionaldehyde 123386...

40 CFR Table 8 to Subpart Ffff of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Methyl methacrylate 80626 41. Methyl-t-butyl ether 1634044 42. Methylene chloride 75092 43. N-hexane 110543 44. N,N-dimethylaniline 121697 45. Naphthalene 91203 46. Phosgene 75445 47. Propionaldehyde 123386...

40 CFR Table 8 to Subpart Ffff of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Methyl methacrylate 80626 41. Methyl-t-butyl ether 1634044 42. Methylene chloride 75092 43. N-hexane 110543 44. N,N-dimethylaniline 121697 45. Naphthalene 91203 46. Phosgene 75445 47. Propionaldehyde 123386...

40 CFR Table 7 to Subpart Hhhhh of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Methyl methacrylate 80626 42. Methyl-t-butyl ether 1634044 43. Methylene chloride 75092 44. N-hexane 110543 45. N,N-dimethylaniline 121697 46. Naphthalene 91203 47. Phosgene 75445 48. Propionaldehyde 123386...

40 CFR Table 7 to Subpart Hhhhh of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Methyl methacrylate 80626 42. Methyl-t-butyl ether 1634044 43. Methylene chloride 75092 44. N-hexane 110543 45. N,N-dimethylaniline 121697 46. Naphthalene 91203 47. Phosgene 75445 48. Propionaldehyde 123386...

40 CFR Table 7 to Subpart Hhhhh of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Methyl methacrylate 80626 42. Methyl-t-butyl ether 1634044 43. Methylene chloride 75092 44. N-hexane 110543 45. N,N-dimethylaniline 121697 46. Naphthalene 91203 47. Phosgene 75445 48. Propionaldehyde 123386...

Photosensitizers derived from 132-oxo-methyl pyropheophorbide-a: enhanced effect of indium(III) as a central metal in in vitro and in vivo photosensitizing efficacy.

PubMed

Rosenfeld, Andrew; Morgan, Janet; Goswami, Lalit N; Ohulchanskyy, Tymish; Zheng, Xiang; Prasad, Paras N; Oseroff, Allan; Pandey, Ravindra K

2006-01-01

The effects of an additional keto group on absorption wavelength and the corresponding metal complexes Zn(II), Cu(II) In(III) on singlet oxygen production and photodynamic efficacy were examined among the alkyl ether analogs of pyropheophorbide-a. For the preparation of the desired photosensitizers, the methyl 13(2)-oxo-pyropheophorbide-a obtained by reacting methyl pyropheophorbide-a with aqueous LiOH-THF was converted into a series of alkyl ether analogs. These compounds were evaluated for photophysical properties and in vitro (by means of the MTT assay and intracellular localization in RIF cells) and in vivo (in C3H mice implanted with RIF tumors) photosensitizing efficacy. Among the alkyl ether derivatives, the methyl 3-decyloxyethyl-3-devinyl-13(2)-oxo-pyropheophorbide-a was found to be most effective and the insertion of In(III) into this analog further enhanced its in vitro and in vivo photosensitizing efficacy. Fluorescence microscopy showed that, in contrast to the hexyl and dodecyl ether derivatives of HPPH (which localize in mitochondria and lysosomes, respectively), the diketo-analogs and their In(III) complexes localized in Golgi bodies. The preliminary in vitro and in vivo results suggest that, in both free-base and metalated analogs, the introduction of an additional keto group at the five-member exocyclic ring in pyropheophorbide-a diminishes its photosensitizing efficacy. This may be due to a shift in subcellular localization from mitochondria to the Golgi bodies. The further introduction of In(III) enhances photoactivity, but not by shifting the localization of the photosensitizer.

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.

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.

Thermo-Responsive Complexes of c-Myc Antisense Oligonucleotide with Block Copolymer of Poly(OEGMA) and Quaternized Poly(4-Vinylpyridine).

PubMed

Topuzogullari, Murat; Elalmis, Yeliz Basaran; Isoglu, Sevil Dincer

2017-04-01

Solution behavior of thermo-responsive polymers and their complexes with biological macromolecules may be affected by environmental conditions, such as the concentration of macromolecular components, pH, ion concentration, etc. Therefore, a thermo-responsive polymer and its complexes should be characterized in detail to observe their responses against possible environments under physiological conditions before biological applications. To briefly indicate this important issue, thermo-responsive block copolymer of quaternized poly(4-vinylpyridine) and poly(oligoethyleneglycol methyl ether methacrylate) as a potential nonviral vector has been synthesized. Polyelectrolyte complexes of this copolymer with the antisense oligonucleotide of c-Myc oncogene are also thermo-responsive but, have lower LCST (lower critical solution temperature) values compared to individual copolymer. LCST values of complexes decrease with molar ratio of macromolecular components and presence of salt. Dilution of solutions also affects solution behavior of complexes and causes a significant decrease in size and an increase in LCST, which indicates possible effects of severe dilutions in the blood stream. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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 with...

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...

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...

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...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Diethylene glycol, polymer with... Substances § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl... subject to reporting. (1) The chemical substance identified generically as diethylene glycol, polymer with...

A new cytotoxic sterol methoxymethyl ether from a deep water marine sponge Scleritoderma sp. cf. paccardi.

PubMed

Gunasekera, S P; Kelly-Borges, M; Longley, R E

1996-02-01

24(R)-Methyl-5 alpha-cholest-7-enyl 3 beta-methoxymethyl ether (1), a new sterol ether, has been isolated from a deep-water marine sponge Scleritoderma sp. cf. paccardi. Compound 1 exhibited in vitro cytotoxicity against the cultured murine P-388 tumor cell line with an IC50 of 2.3 micrograms/mL. The isolation and structure elucidation of 1 by NMR spectroscopy is described.

a Comparison of the Molecular Structures of C_4H_9OCH_3, C_4H_9SCH_3, C_5H_{11}OCH_3, and C_5H_{11}SCH_3 Using Microwave Spectroscopy

NASA Astrophysics Data System (ADS)

Long, Brittany E.; Betancur, Juan; Choi, Yoon Jeong; Cooke, S. A.; Grubbs, G. S., II; Ogulnick, Jonathan; Holmes, Tara

2017-06-01

Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy. Under our experimental conditions only one conformer has been observed for each of the four compounds. These conformers have torsional angles of CXCC = 180^o, XCCC = 60^o, CCCC = 180^o, and, for the C_5H_{11}-X-CH_3 species, CCCC_{Methyl} = 180^o. These angles correspond to anti-gauche-anti conformations for the butyl methyl ether/thioether species, and anti-gauche-anti-anti conformations for the pentyl methyl ether/thioether species. Splittings due to the internal rotation of the X-CH_3 group are observed in both butyl species but are not observed in the pentyl species. The barrier to the X-CH_3 internal rotation has been investigated through spectral analyses and quantum chemical calculations. The differences in the internal rotation barrier between the ethers and thioethers will be discussed and will further be compared to the barriers obtained for similar molecules.

Role of Petal-Specific Orcinol O-Methyltransferases in the Evolution of Rose Scent1

PubMed Central

Scalliet, Gabriel; Lionnet, Claire; Le Bechec, Mickaël; Dutron, Laurence; Magnard, Jean-Louis; Baudino, Sylvie; Bergougnoux, Véronique; Jullien, Frédéric; Chambrier, Pierre; Vergne, Philippe; Dumas, Christian; Cock, J. Mark; Hugueney, Philippe

2006-01-01

Orcinol O-methyltransferase (OOMT) 1 and 2 catalyze the last two steps of the biosynthetic pathway leading to the phenolic methyl ether 3,5-dimethoxytoluene (DMT), the major scent compound of many rose (Rosa x hybrida) varieties. Modern roses are descended from both European and Chinese species, the latter being producers of phenolic methyl ethers but not the former. Here we investigated why phenolic methyl ether production occurs in some but not all rose varieties. In DMT-producing varieties, OOMTs were shown to be localized specifically in the petal, predominanty in the adaxial epidermal cells. In these cells, OOMTs become increasingly associated with membranes during petal development, suggesting that the scent biosynthesis pathway catalyzed by these enzymes may be directly linked to the cells' secretory machinery. OOMT gene sequences were detected in two non-DMT-producing rose species of European origin, but no mRNA transcripts were detected, and these varieties lacked both OOMT protein and enzyme activity. These data indicate that up-regulation of OOMT gene expression may have been a critical step in the evolution of scent production in roses. PMID:16361520

75 FR 37795 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-30

...-methyl-, polymer with alkyl 2- propenoates, ethenyl acetate and methyl-2- methyl-2-propenoate P-10-0389...), polymers with cycloaliphatic diamine, alkyldiisocyanate, alpha-hydro-omega- hydroxy(alkyldiyl) and... dicarboxylic acid, polymer with cycloaliphatic diamine, aliphatic diisocyanate, aliphatic dicarboxylic acid...

Special Issue on Powering the Future Force: New Power & Energy Technologies for the Warfighter (AMMTIAC Quarterly, Volume 4, Number 1 / WSTIAC Quarterly, Volume 9, Number 1)

DTIC Science & Technology

2009-04-27

an aromatic acidic polymer such as SPEEK or SPSf. Figure 5 shows four basic polymers in which benzimidazole (BIm), amino- benzimidazole (ABIm...Z., A. Manthiram, and M. D. Guiver, “Blend Membranes Based on Sulfonated Polyetheretherketone and Polysulfone Bearing Benzimidazole Side Groups for...Sulfonated Poly(ether ether ketone) and Polysulfone Bearing Benzimidazole Side Groups for Direct Methanol Fuel Cells,” Electrochemical and Solid State Letters

pH-responsive micelles based on (PCL)2(PDEA-b-PPEGMA)2 miktoarm polymer: controlled synthesis, characterization, and application as anticancer drug carrier.

PubMed

Lin, Wenjing; Nie, Shuyu; Xiong, Di; Guo, Xindong; Wang, Jufang; Zhang, Lijuan

2014-01-01

Amphiphilic A2(BC)2 miktoarm star polymers [poly(ϵ-caprolactone)]2-[poly(2-(diethylamino)ethyl methacrylate)-b- poly(poly(ethylene glycol) methyl ether methacrylate)]2 [(PCL)2(PDEA-b-PPEGMA)2] were developed by a combination of ring opening polymerization (ROP) and continuous activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The critical micelle concentration (CMC) values were extremely low (0.0024 to 0.0043 mg/mL), depending on the architecture of the polymers. The self-assembled empty and doxorubicin (DOX)-loaded micelles were spherical in morphologies, and the average sizes were about 63 and 110 nm. The release of DOX at pH 5.0 was much faster than that at pH 6.5 and pH 7.4. Moreover, DOX-loaded micelles could effectively inhibit the growth of cancer cells HepG2 with IC50 of 2.0 μg/mL. Intracellular uptake demonstrated that DOX was delivered into the cells effectively after the cells were incubated with DOX-loaded micelles. Therefore, the pH-sensitive (PCL)2(PDEA-b-PPEGMA)2 micelles could be a prospective candidate as anticancer drug carrier for hydrophobic drugs with sustained release behavior.

Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.

PubMed

Kim, Si-Eun; Zhang, Cong; Advincula, Abigail A; Baer, Eric; Pokorski, Jonathan K

2016-04-13

Antifouling surfaces are important for biomedical devices to prevent secondary infections and mitigate the effects of the foreign body response. Herein, we describe melt-coextruded poly(ε-caprolactone) (PCL) nanofiber mats grafted with antifouling polymers. Nonwoven PCL fiber mats are produced using a multilayered melt coextrusion process followed by high-pressure hydroentanglement to yield porous patches. The resulting fiber mats show submicrometer cross-sectional fiber dimensions and yield pore sizes that were nearly uniform, with a mean pore size of 1.6 ± 0.9 μm. Several antifouling polymers, including hydrophilic, zwitterionic, and amphipathic molecules, are grafted to the surface of the mats using a two-step procedure that includes photochemistry followed by the copper-catalyzed azide-alkyne cycloaddition reaction. Fiber mats are evaluated using separate adsorption tests for serum proteins and E. coli. The results indicate that poly(oligo(ethylene glycol) methyl ether methacrylate)-co-(trifluoroethyl methacrylate) (poly(OEGMEMA-co-TFEMA)) grafted mats exhibit approximately 85% less protein adhesion and 97% less E. coli adsorption when compared to unmodified PCL fibermats. In dynamic antifouling testing, the amphiphilic fluorous polymer surface shows the highest flux and highest rejection value of foulants. The work presented within has implications on the high-throughput production of antifouling microporous patches for medical applications.

Syntheses of all the possible monomethyl ethers and several deoxyhalo analogues of methyl beta-lactoside as ligands for the Ricinus communis lectins.

PubMed

Fernández, P; Jiménez-Barbero, J; Martín-Lomas, M

1994-02-17

The synthesis of all the possible monomethyl ethers of methyl beta-lactoside (1) has been performed from 1 in a straightforward way, making use of the different reactivity of the hydroxyl groups in alkylation and stannylation reactions. In addition, the deoxyfluoro derivatives of 1 at positions, 6,3',4',epi-4', and 6' have been prepared by reaction of the appropriate substrates with diethylaminosulfur trifluoride or tetrabutylammonium fluoride. Finally, the 6-deoxyiodo and 6'-bromodeoxy analogues of 1 have also been prepared.

Overview of technologies for removal of methyl tert-butyl ether (MTBE) from water.

PubMed

Levchuk, Irina; Bhatnagar, Amit; Sillanpää, Mika

2014-04-01

Wide use of methyl tert-butyl ether (MTBE) as fuel oxygenates leads to worldwide environment contamination with this compound basically due to fuel leaks from storage or pipelines. Presence of MTBE in drinking water is of high environmental and social concern. Existing methods for MTBE removal from water have a number of limitations which can be possibly overcome in the future with use of emerging technologies. This work aims to provide an updated overview of recent developments in technologies for MTBE removal from water. Copyright © 2014. Published by Elsevier B.V.

Incombustible resin composition

NASA Technical Reports Server (NTRS)

Akima, T.

1982-01-01

Incombustible resin compositions composed of aromatic compounds were obtained through (1) combustion polymer material and (2) bisphenol A or halogenated bisphenol A and bisphenol A diglycidl ether or halogenated bisphenol A diglycidyl ether. The aromatic compound is an adduct of bifunctional phenols and bifunctional epoxy resins.

High Performance Solid Polymer Electrolytes for Rechargeable Batteries: A Self-Catalyzed Strategy toward Facile Synthesis.

PubMed

Cui, Yanyan; Liang, Xinmiao; Chai, Jingchao; Cui, Zili; Wang, Qinglei; He, Weisheng; Liu, Xiaochen; Liu, Zhihong; Cui, Guanglei; Feng, Jiwen

2017-11-01

It is urgent to seek high performance solid polymer electrolytes (SPEs) via a facile chemistry and simple process. The lithium salts are composed of complex anions that are stabilized by a Lewis acid agent. This Lewis acid can initiate the ring opening polymerization. Herein, a self-catalyzed strategy toward facile synthesis of crosslinked poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte (C-PEGDE) is presented. It is manifested that the poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte possesses a superior electrochemical stability window up to 4.5 V versus Li/Li + and considerable ionic conductivity of 8.9 × 10 -5 S cm -1 at ambient temperature. Moreover, the LiFePO 4 /C-PEGDE/Li batteries deliver stable charge/discharge profiles and considerable rate capability. It is demonstrated that this self-catalyzed strategy can be a very effective approach for high performance solid polymer electrolytes.

Tunable thermoresponsive pyrrolidone-based polymers from pyroglutamic acid, a bio-derived resource.

PubMed

Bhat, Rajani; Pietrangelo, Agostino

2013-03-12

A series of pyrrolidone-based polymers is prepared from pyroglutamic acid, a bio-derived resource. Polymers bearing simple alkoxy substituents (e.g., methoxy, ethoxy, and butoxy) are soluble in common organic solvents and possess glass transition temperatures that are dependent on the length of the alkoxy residue. Replacing these substituents with an ether moiety (CH3 OCH2 CH2 O-) affords a highly sensitive and reversible thermoresponsive polymer with a lower critical solution temperature (LCST) of 42 °C in water. Copolymers composed of repeat units bearing both the ether and simple alkoxy residues are found to exhibit LCSTs that are highly dependent on the nature of the hydrophobic alkoxy residue suggesting that the LCSTs of these polymers can be successfully tuned by simply tailoring the copolymer structure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Coordination Chemistry Inside Polymeric Nanoreactors: Interparticle Metal Exchange and Ionic Compound Vectorization in Phosphine-Functionalized Amphiphilic Polymer Latexes.

PubMed

Chen, Si; Gayet, Florence; Manoury, Eric; Joumaa, Ahmad; Lansalot, Muriel; D'Agosto, Franck; Poli, Rinaldo

2016-04-25

Stable latexes of hierarchically organized core-cross-linked polymer micelles that are functionalized at the core with triphenylphosphine (TPP@CCM) have been investigated by NMR spectroscopic analysis at both natural (ca. pH 5) and strongly basic (pH 13.6) pH values after core swelling with toluene. The core-shell interface structuring forces part of the hydrophilic poly(ethylene oxide) (PEO) chains to reside inside the hydrophobic core at both pH values. Loading the particle cores with [Rh(acac)(CO)2 ] (acac=acetylacetonate) at various Rh/P ratios yielded polymer-supported [Rh(acac)(CO)(TPP)] (TPP=triphenylphosphine). The particle-to-particle rhodium migration is very fast at natural pH, but slows down dramatically at high pH, whereas the size distribution of the nanoreactors remains unchanged. The slow migration at pH 13.6 leads to the generation of polymer-anchored [Rh(OH)(CO)(TPP)2 ], which is also generated immediately upon the addition of NaOH to the particles with a [Rh(acac)(CO)] loading of 50 %. Similarly, treatment of the same particles with NaCl yielded polymer-anchored [RhCl(CO)(TPP)2 ]. Interparticle coupling occurs during these rapid processes. These experiments prove that the major contribution to metal migration is direct core-core contact. The slow migration at the high pH value, however, must result from a pathway that does not involve core-core contact. The facile penetration of the polymer cores by NaOH and NaCl results from the presence of shell-linked poly(ethylene oxide) methyl ether functions both outside and inside the polymer core-shell interface. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Variability in Lignin Composition and Structure in Cell Walls of Different Parts of Macaúba (Acrocomia aculeata) Palm Fruit.

PubMed

Rencoret, Jorge; Kim, Hoon; Evaristo, Anderson B; Gutiérrez, Ana; Ralph, John; Del Río, José C

2018-01-10

The lignins from different anatomical parts of macaúba (Acrocomia aculeata) palm fruit, namely stalks, epicarp, and endocarp, were studied. The lignin from stalks was enriched in S-lignin units (S/G 1.2) and β-ether linkages (84% of the total) and was partially acylated at the γ-OH of the lignin side-chains (26% lignin acylation), predominantly with p-hydroxybenzoates and acetates. The epicarp lignin was highly enriched in G-lignin units (S/G 0.2) and consequently depleted in β-ethers (65%) and enriched in condensed structures such as phenylcoumarans (24%) and dibenzodioxocins (3%). The endocarp lignin was strikingly different from the rest and presented large amounts of piceatannol units incorporated into the polymer. This resulted in a lignin polymer depleted in β-ethers but enriched in condensed structures and linked piceatannol moieties. The incorporation of piceatannol into the lignin polymer seems to have a role in seed protection.

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... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with... uses subject to reporting. (1) The chemical substance identified generically as a phenol, polymer with...

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 diglycidyl...

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 diglycidyl...

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... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with... uses subject to reporting. (1) The chemical substance identified generically as a phenol, polymer with...

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...

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...

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... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with... uses subject to reporting. (1) The chemical substance identified generically as a phenol, polymer with...

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... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with... uses subject to reporting. (1) The chemical substance identified generically as a phenol, polymer with...

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... 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...

Partially Fluorinated Solvent as a co-solvent for the Non-aqueous Electrolyte of Li/air Battery

DTIC Science & Technology

2010-11-11

ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP), respectively, as a co-solvent for the non-aqueous electrolyte of Li–air battery. Results...fluorinated solvents on the discharge performance of Li–air bat- tery. For this purpose, we here selectmethyl nonafluorobutyl ether ( MFE ) and tris...196, (2011) pgs. 2867-2870 14. ABSTRACT In this workwestudy methyl nonafluorobutyl ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP

40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

Code of Federal Regulations, 2012 CFR

2012-07-01

... glycol dimethyl ether 111966 Diethyl sulfate 64675 Dimethylaniline (N,N-) 121697 Dimethylhydrazine (1,1... 67721 Hexane 110543 Isophorone 78591 Methanol 67561 Methyl bromide (Bromomethane) 74839 Methyl chloride...

Bacterial adhesion to orthopedic implant polymers.

PubMed

Barton, A J; Sagers, R D; Pitt, W G

1996-03-01

The degradable polymers poly(orthoester) (POE), poly(L-lactic acid) (PLA), and the nondegradable polymers polysulfone (PSF), polyethylene (PE), and poly(ether ether ketone) (PEEK) were exposed to cultures of Staphylococcus epidermidis, Pseudomonas aeruginosa, or Escherichia coli. Bacteria washed and resuspended in phosphate buffered saline (PBS) adhered to polymers in amounts nearly twice those of bacteria that were left in their growth medium, tryptic soy broth (TSB). In TSB, there was variation in adhesion from species to species, but no significant variation from polymer to polymer within one species. In PBS there were significant differences in the amounts of bacteria adhering to the various polymers with the exception, of S. epidermidis, which had similar adhesion to all polymers. As a whole, P. aeruginosa was the most adherent while S. epidermidis was the least adherent. The estimated values of the free energy of adhesion (delta Fadh) correlated with the amount of adherent P. aeruginosa. When POE, PLA, and PSF were exposed to hyaluronic acid (HA) before exposure to the bacteria, there was 50% more adhesion of E. coli and P. aeruginosa on POE and PLA. With respect to bacterial adhesion, the biodegradable polymers (POE and PLA) in general were not significantly different from the nondegradable polymers.

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.

OCCURRENCE OF METYL TERT-BUTYL ETHER (MTBE) AT FIVE MARINAS IN LAKE TEXOMA

EPA Science Inventory

Occurrence of methyl tert-butyl ether (MTBE) in five marinas was monitored between June 1999 and November 2000 in Lake Texoma located on the border of Oklahoma and Texas. MTBE is a commonly used gasoline additive and a suspected carcinogen. Lake water was collected at loc...

Enrichment of Desulfitobacterium spp. from forest and grassland soil using the O-demethylation of phenyl methyl ethers as a growth-selective process.

PubMed

Mingo, Felix Sebastian; Diekert, Gabriele; Studenik, Sandra

2016-02-01

The O-demethylation of phenyl methyl ethers under anaerobic conditions is a metabolic feature of acetogens and Desulfitobacterium spp. Desulfitobacteria as well as most acetogens are Gram-positive bacteria with a low GC content and belong to the phylum Firmicutes. The consumption of the phenyl methyl ether syringate was studied in enrichment cultures originating from five different topsoils. Desulfitobacterium spp. were detected in all topsoils via quantitative PCR. Desulfitobacteria could be enriched using the O-demethylation of syringate as a growth-selective process. The enrichment was significantly favoured by an external electron acceptor such as 3-chloro-4-hydroxyphenylacetate or thiosulfate. Upon cultivation in the presence of syringate and thiosulfate, which naturally occur in soil, a maximum number of 16S rRNA gene copies of Desulfitobacterium spp. was reached within the first three subcultivation steps and accounted for 3-10% of the total microbial community depending on the soil type. Afterwards, a loss of Desulfitobacterium gene copies was observed. Community analyses revealed that Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the main phyla in the initial soil samples. Upon addition of syringate and thiosulfate as growth substrates, these phyla were rapidly outcompeted by Firmicutes, which were under-represented in soil. The main Firmicutes genera identified were Alkalibaculum, Clostridium, Sporobacterium, Sporomusa and Tissierella, which might be responsible for outcompeting the desulfitobacteria. Most of these organisms belong to the acetogens, which have previously been described to demethylate phenyl methyl ethers. The shift of the native community structure to almost exclusively Firmicutes supports the participation of members of this phylum in environmental demethylation processes.

Application of a source apportionment model in consideration of volatile organic compounds in an urban stream

USGS Publications Warehouse

Asher, W.E.; Luo, W.; Campo, K.W.; Bender, D.A.; Robinson, K.W.; Zogorski, J.S.; Pankow, J.F.

2007-01-01

Position-dependent concentrations of trichloroethylene and methyl-tert-butyl ether are considered for a 2.81-km section of the Aberjona River in Massachusetts, USA. This river flows through Woburn and Winchester (Massachusetts, USA), an area that is highly urbanized, has a long history of industrial activities dating to the early 1800s, and has gained national attention because of contamination from chlorinated solvent compounds in Woburn wells G and H. The river study section is in Winchester and begins approximately five stream kilometers downstream from the Woburn wells superfund site. Approximately 300 toxic release sites are documented in the watershed upstream from the terminus of the study section. The inflow to the river study section is considered one source of contamination. Other sources are the atmosphere, a tributary flow, and groundwater flows entering the river; the latter are categorized according to stream zone (1, 2, 3, etc.). Loss processes considered include outflows to groundwater and water-to-atmosphere transfer of volatile compounds. For both trichloroethylene and methyl-rerf-butyl ether, degradation is neglected over the timescale of interest. Source apportionment fractions with assigned values ??inflow, ??1, ??2, ??3, etc. are tracked by a source apportionment model. The strengths of the groundwater and tributary sources serve as fitting parameters when minimizing a reduced least squares statistic between water concentrations measured during a synoptic study in July 2001 versus predictions from the model. The model fits provide strong evidence of substantial unknown groundwater sources of trichloroethylene and methyl-tert-butyl ether amounting to tens of grams per day of trichloroethylene and methyl-tert-butyl ether in the river along the study section. Modeling in a source apportionment manner can be useful to water quality managers allocating limited resources for remediation and source control. ?? 2007 SETAC.

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetanisole; 4′-methoxyacetophenone. Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate... ethyl ether. Benzyl formate. 3-Benzyl-4-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl...

Liquid-chromatographic analysis for cyclosporine with use of a microbore column and small sample volume.

PubMed

Annesley, T; Matz, K; Balogh, L; Clayton, L; Giacherio, D

1986-07-01

This liquid-chromatographic assay requires 0.2 to 0.5 mL of whole blood, avoids the use of diethyl ether, and consumes only 10 to 20% of the solvents used in prior methods. Sample preparation involves an acidic extraction with methyl-t-butyl ether, performed in a 13 X 100 mm disposable glass tube, then a short second extraction of the organic phase with sodium hydroxide. After evaporation of the methyl-t-butyl ether, chromatography is performed on an "Astec" 2.0-mm (i.d.) octyl column. We compared results by this procedure with those by use of earlier larger-scale extractions and their respective 4.6-mm (i.d.) columns; analytical recoveries of cyclosporins A and D were comparable with previous findings and results for patients' specimens were equivalent, but the microbore columns provided greatly increased resolution and sensitivity.

Potential Replacements for Solvents that are Ozone Depleting Substances

DTIC Science & Technology

1994-09-01

18.4 d-Lumonene 17.8 Glidsafe-LUI54B 18.2 Turpentine 16.5 isobutyl acetate 17.2 Diisobutyl phthalate 18.3 Dipropylene glycol monomethyl ether 19.0...Diethylene glycol monomethyl ether 22.3 N- Methyl pyrrolidone 23.0 Water 47.8 1. Barton (1983): 2. Gallagher (date unknown). 9 TI DSTO-TR-0046 For blends...parameters. For example, Glidsafe UTS-4B which is a mixture of terpenes and dipropylene glycol monomethyl ether has a Hildebrand solubility of 18.2 MPal/ 2

High-Temperature Shape Memory Polymers

NASA Technical Reports Server (NTRS)

Yoonessi, Mitra; Weiss, Robert A.

2012-01-01

physical conformation changes when exposed to an external stimulus, such as a change in temperature. Such materials have a permanent shape, but can be reshaped above a critical temperature and fixed into a temporary shape when cooled under stress to below the critical temperature. When reheated above the critical temperature (Tc, also sometimes called the triggering or switching temperature), the materials revert to the permanent shape. The current innovation involves a chemically treated (sulfonated, carboxylated, phosphonated, or other polar function group), high-temperature, semicrystalline thermoplastic poly(ether ether ketone) (Tg .140 C, Tm = 340 C) mix containing organometallic complexes (Zn++, Li+, or other metal, ammonium, or phosphonium salts), or high-temperature ionic liquids (e.g. hexafluorosilicate salt with 1-propyl-3- methyl imidazolium, Tm = 210 C) to form a network where dipolar or ionic interactions between the polymer and the low-molecular-weight or inorganic compound forms a complex that provides a physical crosslink. Hereafter, these compounds will be referred to as "additives". The polymer is semicrystalline, and the high-melt-point crystals provide a temporary crosslink that acts as a permanent crosslink just so long as the melting temperature is not exceeded. In this example case, the melting point is .340 C, and the shape memory critical temperature is between 150 and 250 C. PEEK is an engineering thermoplastic with a high Young fs modulus, nominally 3.6 GPa. An important aspect of the invention is the control of the PEEK functionalization (in this example, the sulfonation degree), and the thermal properties (i.e. melting point) of the additive, which determines the switching temperature. Because the compound is thermoplastic, it can be formed into the "permanent" shape by conventional plastics processing operations. In addition, the compound may be covalently cross - linked after forming the permanent shape by S-PEEK by applying ionizing radiation ( radiation, neutrons), or by chemical crosslinking to form a covalent permanent network. With respect to other shape memory polymers, this invention is novel in that it describes the use of a thermoplastic composition that can be thermally molded or solution-cast into complex "permanent" shapes, and then reheated or redissolved and recast from solution to prepare another shape. It is also unique in that the shape memory behavior is provided by a non-polymer additive.

Structure-property relationships in polymers for dielectric capacitors

NASA Astrophysics Data System (ADS)

Gupta, Sahil

Effective energy storage is a key challenge of the 21st century that has fueled research in the area of energy storage devices. In this dissertation, structure-property relationships have been evaluated for polymers that might be suitable for storing energy in high-energy density, high-temperature capacitors. Firstly, hydroxyl-modified polypropylenes (PPOH) were synthesized by copolymerization of the propylene and undecenyloxytrimethylsilane monomers. The presence of H-bonding in PPOH copolymers increased their glass-transition temperature. Steric hindrance by the comonomer reduced the PP crystal growth rate and crystal size, resulting in a melting point depression. The comonomer was restricted outside the crystalline domains leaving the alpha-monoclinic crystal structure of PP unaffected, but increasing the fold-surface free energy. Crystallization was slower for PPOH copolymers than PP, but exhibited a skewed bell curve as a function of hydroxyl concentration. H-bonding persisted even at melt temperatures up to 250°C resulting in a higher elasticity and viscosity for PPOH copolymers. Secondly, sulfonated poly(ether ether ketone) (HSPEEK) was synthesized by sulfonating PEEK with sulfuric acid, and further neutralized with Zn to obtain ZnSPEEK. The thermal and dielectric properties of SPEEK were compared with PEEK. The glass-transition increased and melting point were high enough to enable the use of polymer at 180°C. The incorporation of sulfonic groups in PEEK increased the dielectric constant. HSPEEK had a higher dielectric constant than ZnSPEEK due to higher dipolar mobility, but the dielectric loss was also higher for HSPEEK due to electrode polarization and DC conduction. These results were consistent with our observations from sulfonated polystyrene (HSPS), which was used as a >model&lang' polymer. Lastly, commercial poly(4-methyl-1-pentene) (P4MP) was characterized to check its viability as a high-temperature polymer dielectric. Thermal stability up to 200°C, high melting point (> 225°C) and melting onset at 160 - 190°C indicated that P4MP could be used at 180 - 200°C. Thin free-standing films (~10 mum) with controlled crystal structure and surface morphology were prepared using blade coating and their drying dynamics were measured using a custom-designed solvent-casting platform. These films were further stretched uniaxially or biaxially, and their effect on the dielectric properties of P4MP was studied.

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

NASA Astrophysics Data System (ADS)

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V.; Noll, Thomas; Funk, Richard H. W.; Engelmann, Katrin; Werner, Carsten

2015-08-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty.

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)-the effect of biomolecular ligands to balance cell adhesion and stimulated detachment.

PubMed

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V; Noll, Thomas; Funk, Richard H W; Engelmann, Katrin; Werner, Carsten

2015-08-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly( N -isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na + /K + -ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro . The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty.

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

PubMed Central

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V; Noll, Thomas; Funk, Richard H W; Engelmann, Katrin; Werner, Carsten

2015-01-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty. PMID:27877823

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.

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...

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...

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.

Preparation, Fabrication, and Evaluation of Advanced Polymeric and Composite Materials

NASA Technical Reports Server (NTRS)

Orwoll, Robert A.

1997-01-01

The thesis titles are given below: physical and mechanical behavior of amorphous poly(arylene ether-co-imidasole)s and poly(arylene ether-co-imidasole) modification epoxies; the requirements of patentability as applied to the chemical arts; fabrication of thermoplastic polymer composite ribbon; blend of reactive diluents with phenylethynyl-terminated arylene ether oligomers; the synthesis, characterization, and application of ether-containing polyimides; the synthesis of reflective and electrically conductive polyimide films via an in-situ self-metalization procedure using silver (I) complexes; the thermal cure of phenylethynyl terminated polyimides and selected model compounds; and the synthesis, characterization, and molecular modeling of cyclic arylene ether oligomers.

40 CFR 721.10283 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and linear...

Code of Federal Regulations, 2013 CFR

2013-07-01

...)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and linear alkyl ethers, sodium salts. 721.10283 Section... Substances § 721.10283 Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and.... (1) The chemical substance identified as poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega...

40 CFR 721.10284 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and linear...

Code of Federal Regulations, 2012 CFR

2012-07-01

...)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and linear alkyl ethers, sodium salts. 721.10284 Section... Substances § 721.10284 Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and.... (1) The chemical substance identified as poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega...

40 CFR 721.10284 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and linear...

Code of Federal Regulations, 2014 CFR

2014-07-01

...)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and linear alkyl ethers, sodium salts. 721.10284 Section... Substances § 721.10284 Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and.... (1) The chemical substance identified as poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega...

40 CFR 721.10283 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and linear...

Code of Federal Regulations, 2012 CFR

2012-07-01

...)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and linear alkyl ethers, sodium salts. 721.10283 Section... Substances § 721.10283 Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and.... (1) The chemical substance identified as poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega...

40 CFR 721.10284 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and linear...

Code of Federal Regulations, 2013 CFR

2013-07-01

...)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and linear alkyl ethers, sodium salts. 721.10284 Section... Substances § 721.10284 Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C14-15-branched and.... (1) The chemical substance identified as poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega...

40 CFR 721.10283 - Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and linear...

Code of Federal Regulations, 2014 CFR

2014-07-01

...)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and linear alkyl ethers, sodium salts. 721.10283 Section... Substances § 721.10283 Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega.-hydroxy-, C12-13-branched and.... (1) The chemical substance identified as poly[oxy(methyl-1,2-ethanediyl)], .alpha.-sulfo-.omega...

40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

Code of Federal Regulations, 2011 CFR

2011-07-01

... diamine and phenol, reaction products with 4-methyl-2-pentanone (generic). 721.10190 Section 721.10190... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4...

40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

Code of Federal Regulations, 2010 CFR

2010-07-01

... diamine and phenol, reaction products with 4-methyl-2-pentanone (generic). 721.10190 Section 721.10190... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4...

METHYL TERT-BUTYLETHER-WATER INTERACTION

EPA Science Inventory

Methyl tert-butyl ether (MTBE) is a well-known environmental contaminant owing to its high solubility in water. Since the early 1990s, MTBE has been added to gasoline to improve air quality in some metropolitan areas of the United States. Improved air quality was, however, achiev...

40 CFR Table 1 to Subpart Dd of... - List of Hazardous Air Pollutants (HAP) for Subpart DD

Code of Federal Regulations, 2011 CFR

2011-07-01

... Methanol 0.855 74-83-9 Methyl bromide (Bromomethane) 1.000 74-87-3 Methyl chloride (Choromethane) 1.000 71... more common glycol ethers can be obtained by contacting the Waste and Chemical Processes Group, Office...

40 CFR Table 1 to Subpart Dd of... - List of Hazardous Air Pollutants (HAP) for Subpart DD

Code of Federal Regulations, 2010 CFR

2010-07-01

... Methanol 0.855 74-83-9 Methyl bromide (Bromomethane) 1.000 74-87-3 Methyl chloride (Choromethane) 1.000 71... more common glycol ethers can be obtained by contacting the Waste and Chemical Processes Group, Office...

Neurotoxic effects of gasoline and gasoline constituents.

PubMed Central

Burbacher, T M

1993-01-01

This overview was developed as part of a symposium on noncancer end points of gasoline and key gasoline components. The specific components included are methyl tertiary butyl ether, ethyl tertiary butyl ether, tertiary amyl methyl ether, butadiene, benzene, xylene, toluene, methyl alcohol, and ethyl alcohol. The overview focuses on neurotoxic effects related to chronic low-level exposures. A few general conclusions and recommendations can be made based on the results of the studies to date. a) All the compounds reviewed are neuroactive and, as such, should be examined for their neurotoxicity. b) For most of the compounds, there is a substantial margin of safety between the current permissible exposure levels and levels that would be expected to cause overt signs of neurotoxicity in humans. This is not the case for xylene, toluene, and methanol, however, where neurologic effects are observed at or below the current Threshold Limit Value. c) For most of the compounds, the relationship between chronic low-level exposure and subtle neurotoxic effects has not been studied. Studies therefore should focus on examining the dose-response relationship between chronic low-level exposure and subtle changes in central nervous system function. PMID:8020437

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...

High temperature polymers for proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Einsla, Brian Russel

Novel proton exchange membranes (PEMs) were investigated that show potential for operating at higher temperatures in both direct methanol (DMFC) and H 2/air PEM fuel cells. The need for thermally stable polymers immediately suggests the possibility of heterocyclic polymers bearing appropriate ion conducting sites. Accordingly, monomers and random disulfonated poly(arylene ether) copolymers containing either naphthalimide, benzoxazole or benzimidazole moieties were synthesized via direct copolymerization. The ion exchange capacity (IEC) was varied by simply changing the ratio of disulfonated monomer to nonsulfonated monomer in the copolymerization step. Water uptake and proton conductivity of cast membranes increased with IEC. The water uptake of these heterocyclic copolymers was lower than that of comparable disulfonated poly(arylene ether) systems, which is a desirable improvement for PEMs. Membrane electrode assemblies were prepared and the initial fuel cell performance of the disulfonated polyimide and polybenzoxazole (PBO) copolymers was very promising at 80°C compared to the state-of-the-art PEM (NafionRTM); nevertheless these membranes became brittle under operating conditions. Several series of poly(arylene ether)s based on disodium-3,3'-disulfonate-4,4 '-dichlorodiphenylsulfone (S-DCDPS) and a benzimidazole-containing bisphenol were synthesized and afforded copolymers with enhanced stability. Selected properties of these membranes were compared to separately prepared miscible blends of disulfonated poly(arylene ether sulfone) copolymers and polybenzimidazole (PBI). Complexation of the sulfonic acid groups with the PBI structure reduced water swelling and proton conductivity. The enhanced proton conductivity of NafionRTM membranes has been proposed to be due to the aggregation of the highly acidic side-chain sulfonic acid sites to form ion channels. A series of side-chain sulfonated poly(arylene ether sulfone) copolymers based on methoxyhydroquinone was synthesized in order to investigate this possible advantage and to couple this with the excellent hydrolytic stability of poly(arylene ether)s. The methoxy groups were deprotected to afford reactive phenolic sites and nucleophilic substitution reactions with functional aryl sulfonates were used to prepare simple aryl or highly acidic fluorinated sulfonated copolymers. The proton conductivity and water sorption of the resulting copolymers increased with the ion exchange capacity, but changing the acidity of the sulfonic acid had no apparent effect.

Alternating Magnetic Field Controlled, Multifunctional Nano-Reservoirs: Intracellular Uptake and Improved Biocompatibility

NASA Astrophysics Data System (ADS)

Ghosh, Santaneel; Ghoshmitra, Somesree; Cai, Tong; Diercks, David R.; Mills, Nathaniel C.; Hynds, Dianna L.

2010-01-01

Biocompatible magnetic nanoparticles hold great therapeutic potential, but conventional particles can be toxic. Here, we report the synthesis and alternating magnetic field dependent actuation of a remotely controllable, multifunctional nano-scale system and its marked biocompatibility with mammalian cells. Monodisperse, magnetic nanospheres based on thermo-sensitive polymer network poly(ethylene glycol) ethyl ether methacrylate- co-poly(ethylene glycol) methyl ether methacrylate were synthesized using free radical polymerization. Synthesized nanospheres have oscillating magnetic field induced thermo-reversible behavior; exhibiting desirable characteristics comparable to the widely used poly- N-isopropylacrylamide-based systems in shrinkage plus a broader volumetric transition range. Remote heating and model drug release were characterized for different field strengths. Nanospheres containing nanoparticles up to an iron concentration of 6 mM were readily taken up by neuron-like PC12 pheochromocytoma cells and had reduced toxicity compared to other surface modified magnetic nanocarriers. Furthermore, nanosphere exposure did not inhibit the extension of cellular processes (neurite outgrowth) even at high iron concentrations (6 mM), indicating minimal negative effects in cellular systems. Excellent intracellular uptake and enhanced biocompatibility coupled with the lack of deleterious effects on neurite outgrowth and prior Food and Drug Administration (FDA) approval of PEG-based carriers suggest increased therapeutic potential of this system for manipulating axon regeneration following nervous system injury.

Thermodynamics of Interaction between Some Cellulose Ethers and SDS by Titration Microcalorimetry.

PubMed

Singh; Nilsson

1999-05-01

The interaction between certain nonionic cellulose ethers (ethyl hydroxyethyl cellulose and hydroxypropyl methyl cellulose) and sodium dodecyl sulphate (SDS) has been investigated using isothermal titration microcalorimetry at temperatures between 25-50 degrees C. The observed heat flow curves have been interpreted in terms of a plausible mechanism of the interaction of the substituent groups with SDS monomers and clusters. The data have been related to changes occuring in the system at the macro- and microscopic levels with the addition of surfactants and with temperature. The process consists predominantly of polymer-surfactant interactions initially and surfactant-surfactant interactions at the later stages. A phenomenological model of the cooperative interaction (adsorption) process has been derived, and earlier published equilibrium binding data have been used to recover binding constants and Gibbs energy changes for this process. The adsorption enthalpies and entropies have been recovered along with the heat capacity change. The enthalpic cost of confining the nonpolar regions of the polymers in surfactant clusters is high, but the entropy gain from release of hydration shell water molecules as well as increased freedom of movement of these nonpolar regions in the clusters gives the process a strong entropic driving force. The process is entropy-driven initially and converts to being both enthalpy and entropy-driven at high SDS concentrations. An enthalpy-entropy compensation behavior is seen. Strongly negative heat capacity changes have been obtained resulting from the transfer of nonpolar groups from aqueous into nonpolar environments, as well as a reduction of conformational domains that the chains can populate. Changes in these two components cause the heat capacity change to become less negative at the higher binding levels. The system can be classified as exhibiting nonclassical hydrophobic binding at the later stages of binding. Copyright 1999 Academic Press.

Characterization of an O-Demethylase of Desulfitobacterium hafniense DCB-2

PubMed Central

Studenik, Sandra; Vogel, Michaela

2012-01-01

Besides acetogenic bacteria, only Desulfitobacterium has been described to utilize and cleave phenyl methyl ethers under anoxic conditions; however, no ether-cleaving O-demethylases from the latter organisms have been identified and investigated so far. In this study, genes of an operon encoding O-demethylase components of Desulfitobacterium hafniense strain DCB-2 were cloned and heterologously expressed in Escherichia coli. Methyltransferases I and II were characterized. Methyltransferase I mediated the ether cleavage and the transfer of the methyl group to the superreduced corrinoid of a corrinoid protein. Desulfitobacterium methyltransferase I had 66% identity (80% similarity) to that of the vanillate-demethylating methyltransferase I (OdmB) of Acetobacterium dehalogenans. The substrate spectrum was also similar to that of the latter enzyme; however, Desulfitobacterium methyltransferase I showed a higher level of activity for guaiacol and used methyl chloride as a substrate. Methyltransferase II catalyzed the transfer of the methyl group from the methylated corrinoid protein to tetrahydrofolate. It also showed a high identity (∼70%) to methyltransferases II of A. dehalogenans. The corrinoid protein was produced in E. coli as cofactor-free apoprotein that could be reconstituted with hydroxocobalamin or methylcobalamin to function in the methyltransferase I and II assays. Six COG3894 proteins, which were assumed to function as activating enzymes mediating the reduction of the corrinoid protein after an inadvertent oxidation of the corrinoid cofactor, were studied with respect to their abilities to reduce the recombinant reconstituted corrinoid protein. Of these six proteins, only one was found to catalyze the reduction of the corrinoid protein. PMID:22522902

Water-soluble resist for environmentally friendly lithography

NASA Astrophysics Data System (ADS)

Lin, Qinghuang; Simpson, Logan L.; Steinhaeusler, Thomas; Wilder, Michelle; Willson, C. Grant; Havard, Jennifer M.; Frechet, Jean M. J.

1996-05-01

This paper describes an 'environmentally friendly,' water castable, water developable photoresist system. The chemically amplified negative-tone resist system consists of three water-soluble components: a polymer, poly(methyl acrylamidoglycolate methyl ether), [poly(MAGME)]; a photoacid generator, dimethyl dihydroxyphenylsulfonium triflate and a crosslinker, butanediol. Poly(MAGME) was synthesized by solution free radical polymerization. In the three-component resist system, the acid generated by photolysis of the photoacid generator catalyzes the crosslinking of poly(MAGME) in the exposed regions during post-exposure baking, thus rendering the exposed regions insoluble in water. Negative tone relief images are obtained by developing with pure water. The resist is able to resolve 1 micrometer line/space features (1:1 aspect ratio) with an exposure dose of 100 mJ/cm2 at 248 nm. The resist can be used to generate etched copper relief images on printed circuit boards using aqueous sodium persulfate as the etchant. The crosslinking mechanism has been investigated by model compound studies using 13C NMR. These studies have revealed that the acid catalyzed reaction of the poly(MAGME) with butanediol proceeds via both transesterification and transacetalization (transaminalization) reactions at low temperatures, and also via transamidation at high temperatures.

40 CFR 433.11 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-chloroisopropyl) ether Bis (2-chloroethoxy) methane Methylene chloride (dichloromethane) Methyl chloride...-phenlene pyrene) Pyrene Tetrachloroethylene Toluene Trichloroethylene Vinyl chloride (chloroethylene...

A long life 4 V class lithium-ion polymer battery with liquid-free polymer electrolyte

NASA Astrophysics Data System (ADS)

Kobayashi, Yo; Shono, Kumi; Kobayashi, Takeshi; Ohno, Yasutaka; Tabuchi, Masato; Oka, Yoshihiro; Nakamura, Tatsuya; Miyashiro, Hajime

2017-02-01

Ether-based solid polymer electrolyte (SPE) is one of the most well-known lithium ion conductors. Unlike the other inorganic electrolytes, SPE exhibits advantages of flexibility and large-area production, enabling low cost production of large size batteries. However, because the ether group is oxidized at 4 V versus Li/Li+ cathode, and due to its high irreversibility with the carbon anode, ether-based SPE was believed to be inapplicable to 4 V class lithium-ion batteries with carbon anode. Here we report a remarkably stable SPE in combination with a 4 V class cathode and carbon anode achieved by the proper design at the interface. The introduced boron-based lithium salt prohibits further oxidation of SPE at the cathode interface. The surface modification of graphite by the annealing of polyvinyl chloride mostly prohibits the continuous consumption of lithium at the graphite anode. Using above interface design, we achieved 60% capacity retention after 5400 cycles. The proposed battery provides a possible approach for realizing flammable electrolyte-free lithium-ion batteries, which achieve innovative safety improvements of large format battery systems for stationary use.

A study on optical properties of poly (ethylene oxide) based polymer electrolyte with different alkali metal iodides

NASA Astrophysics Data System (ADS)

Rao, B. Narasimha; Suvarna, R. Padma

2016-05-01

Polymer electrolytes were prepared by adding poly (ethylene glycol) dimethyl ether (PEGDME), TiO2 (nano filler), different alkali metal iodide salts RI (R+=Li+, Na+, K+, Rb+, Cs+) and I2 into Acetonitrile gelated with Poly (ethylene oxide) (PEO). Optical properties of poly (ethylene oxide) based polymer electrolytes were studied by FTIR, UV-Vis spectroscopic techniques. FTIR spectrum reveals that the alkali metal cations were coordinated to ether oxygen of PEO. The optical absorption studies were made in the wavelength range 200-800 nm. It is observed that the optical absorption increases with increase in the radius of alkali metal cation. The optical band gap for allowed direct transitions was evaluated using Urbach-edges method. The optical properties such as optical band gap, refractive index and extinction coefficient were determined. The studied polymer materials are useful for solar cells, super capacitors, fuel cells, gas sensors etc.

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

76 FR 32196 - Certain New Chemicals; Receipt and Status Information; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

... use (S) 2-propenoic Inc. of this polymer is acid, 2-methyl-, 2- for refinishing hydroxyethyl ester, vehicles. through polymer with rel- the hydroxyl groups (1r,2r,4r)-1,7,7- on the polymer, the...)-, (t-4)-, polymers; polymer with 3- surfactant, flow, methyl-3-[(2,2,2- leveling, and trifluoroethoxy...

Omega-functionalized fatty acids, alcohols, and ethers via olefin metathesis

USDA-ARS?s Scientific Manuscript database

Methyl 17-hydroxy stearate was converted to methyl octadec-16-enoate using copper sulfate adsorbed on silica gel. This compound, possessing unsaturation at the opposite end of the chain from the carboxylate, served as a useful substrate for the olefin metathesis reaction. As a result, several fatt...

Type A polymer concrete overlay field trials : final report.

DOT National Transportation Integrated Search

1984-12-01

This report describes placement and subsequent performance of two methyl methacrylate polymer concrete overlays. Performance is evaluated as to: 1) the mixing and placement characteristics of the methyl methacrylate polymer concretes as overlay mater...

Deuterohemin-Peptide Enzyme Mimic-Embedded Metal-Organic Frameworks through Biomimetic Mineralization with Efficient ATRP Catalytic Activity.

PubMed

Jiang, Wei; Wang, Xinghuo; Chen, Jiawen; Liu, Ying; Han, Haobo; Ding, Yi; Li, Quanshun; Tang, Jun

2017-08-16

An enzyme mimic harboring iron porphyrin (DhHP-6) embedded in zeolite imidazolate framework-8 (ZIF-8) was constructed through a biomimetic mineralization approach to obtain composite DhHP-6@ZIF-8. The composite was then used as a catalyst in the atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA 500 ) in which poly(PEGMA 500 ) could be synthesized with monomer conversion of 76.1% and M n of 45 900 g/mol, stronger than that obtained when using free DhHP-6 as a catalyst. More importantly, it could efficiently overcome the drawbacks of free DhHP-6 and achieve the easy separation of DhHP-6 from the catalytic system and the elimination of iron residues in the synthesized polymer. In addition, it exhibited an enhanced recyclability with monomer conversion of 75.7% after five cycles and favorable stability during the ATRP reaction with <3.0% of DhHP-6 release within 100 h. Thus, the enzyme mimic-ZIF-8 composite developed through biomimetic mineralization can be potentially used as an effective catalyst for preparing well-defined polymers with biomedical applications.

Acetylcholinesterase and Acetylcholine Receptor

DTIC Science & Technology

1989-01-30

trimethyl analogue, neopentyl alcohol, (CH 3 ) 3 CCH20H, Ki(comi - 29 mM, Ki(nonc)’ = 74 mM, and to the ether isomer of the latter, =-butyl methyl ether, (CH...Trietrylene glycol di-tert-butylether is being prepared from the glycol via the di-p-toluenesulfonate, mp 80-81"C from methanol, lit. 80-810C (60). 2-N,N

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 A...

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 A...

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...

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...

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...

Methyl tert-butyl ether biodegradation by microbial consortia obtained from soil samples of gasoline-polluted sites in Mexico.

PubMed

Morales, Marcia; Velázquez, Elia; Jan, Janet; Revah, Sergio; González, Uriel; Razo-Flores, Elías

2004-02-01

Microbial consortia obtained from soil samples of gasoline-polluted sites were individually enriched with pentane, hexane, isooctane and toluene. Cometabolism with methyl tert-butyl ether, (MTBE), gave maximum degradation rates of 49, 12, 32 and 0 mg g(-1)protein h(-1), respectively. MTBE was fully degraded even when pentane was completely depleted with a cometabolic coefficient of 1 mgMTBE mg(-1)pentane. The analysis of 16S rDNA from isolated microorganisms in the pentane-adapted consortia showed that microorganisms could be assigned to Pseudomonas. This is the first work reporting the cometabolic mineralization of MTBE by consortium of this genus.

Rotational Investigation of the Adducts of Formic Acid with Alcohols, Ethers and Esters

NASA Astrophysics Data System (ADS)

Evangelisti, Luca; Spada, Lorenzo; Li, Weixing; Caminati, Walther

2016-06-01

Mixtures of formic acid with methyl alcohol, with isopropyl alcohol, with tert-butyl alcohol, with dimethylether and with isopropylformiate have been supersonically expanded as pulsed jets. The obtained cool plumes have been analyzed by Fourier transform microwave spectroscopy. It has been possible to assign the rotational spectra of the 1:1 adducts of formic acid with tert-butyl alcohol, with dimethyl ether and with isopropylformiate. The conformational shapes and geometries of these adducts, as well as the topologies of their itermolecular hydrogen bonds will be presented. An explanation is given of the failure of the assignments of the rotational spectra of the adducts of formic acid with methyl alcohol and isopropyl alcohol.

Purification and Characterization of S-Adenosyl-l-Methionine: Desoxyhemigossypol-6-O-Methyltransferase from Cotton Plants. An Enzyme Capable of Methylating the Defense Terpenoids of Cotton1

PubMed Central

Liu, Jinggao; Benedict, Chauncey R.; Stipanovic, Robert D.; Bell, Alois A.

1999-01-01

Cotton contains a unique group of terpenoids including desoxyhemigossypol, hemigossypol, gossypol, hemigossypolone, and the heliocides that are part of the plant's defense system against pathogenic fungi and insects. Desoxyhemigossypol is a key intermediate in the biosynthesis of these compounds. We have isolated, purified, and characterized from cotton stele tissue infected with Verticillium dahliae a methyltransferase (S-adenosyl-l-Met: desoxyhemigossypol-6-O-methyltransferase) that specifically methylates the 6-position of desoxyhemigossypol to form desoxyhemigossypol-6-methyl ether with a Km value of 4.5 μm for desoxyhemigossypol and a Kcat/Km of 5.08 × 104 s−1 (mol/L)−1. The molecular mass of the native enzyme is 81.4 kD and is dissociated into two subunits of 41.2 kD on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels. The enzymatic reaction does not require Mg+2 and is inhibited 98% with 10 mm p-chloromercuribenzoate. Desoxyhemigossypol-6-methyl ether leads to the biosynthesis of methylated hemigossypol, gossypol, hemigossypolone, and the heliocides, which lowers their effectiveness as phytoalexins and insecticides. PMID:10557251

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.

40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymer with aliphatic... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4...

The Ether-Cleaving Methyltransferase System of the Strict Anaerobe Acetobacterium dehalogenans: Analysis and Expression of the Encoding Genes▿

PubMed Central

Schilhabel, Anke; Studenik, Sandra; Vödisch, Martin; Kreher, Sandra; Schlott, Bernhard; Pierik, Antonio Y.; Diekert, Gabriele

2009-01-01

Anaerobic O-demethylases are inducible multicomponent enzymes which mediate the cleavage of the ether bond of phenyl methyl ethers and the transfer of the methyl group to tetrahydrofolate. The genes of all components (methyltransferases I and II, CP, and activating enzyme [AE]) of the vanillate- and veratrol-O-demethylases of Acetobacterium dehalogenans were sequenced and analyzed. In A. dehalogenans, the genes for methyltransferase I, CP, and methyltransferase II of both O-demethylases are clustered. The single-copy gene for AE is not included in the O-demethylase gene clusters. It was found that AE grouped with COG3894 proteins, the function of which was unknown so far. Genes encoding COG3894 proteins with 20 to 41% amino acid sequence identity with AE are present in numerous genomes of anaerobic microorganisms. Inspection of the domain structure and genetic context of these orthologs predicts that these are also reductive activases for corrinoid enzymes (RACEs), such as carbon monoxide dehydrogenase/acetyl coenzyme A synthases or anaerobic methyltransferases. The genes encoding the O-demethylase components were heterologously expressed with a C-terminal Strep-tag in Escherichia coli, and the recombinant proteins methyltransferase I, CP, and AE were characterized. Gel shift experiments showed that the AE comigrated with the CP. The formation of other protein complexes with the O-demethylase components was not observed under the conditions used. The results point to a strong interaction of the AE with the CP. This is the first report on the functional heterologous expression of acetogenic phenyl methyl ether-cleaving O-demethylases. PMID:19011025

Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores

NASA Astrophysics Data System (ADS)

Chang, Qiang; Herbst, Eric

2016-03-01

The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules (COMs). The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which COMs and the methoxy radical can be formed on dust grains via a so-called chain reaction mechanism, in a similar manner to CO2. A unified gas-grain microscopic-macroscopic Monte Carlo approach with both normal and interstitial sites for icy grain mantles is used to perform the chemical simulations. Reactive desorption with varying degrees of efficiency is included to enhance the nonthermal desorption of species formed on cold dust grains. In addition, varying degrees of efficiency for the surface formation of methoxy are also included. The observed abundances of a variety of organic molecules in cold cores can be reproduced in our models. The strong correlation between the abundances of methyl formate and dimethyl ether in cold cores can also be explained. Nondiffusive chemical reactions on dust grain surfaces may play a key role in the formation of some COMs.

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).

Phase equilibrium measurements on twelve binary mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giles, N.F.; Wilson, H.L.; Wilding, W.V.

1996-11-01

Phase equilibrium measurements have been performed on twelve binary mixtures. The PTx method was used to obtain vapor-liquid equilibrium data for the following binary systems at two temperatures each: ethanethiol + propylene; nitrobenzene + methanol; pyridine + ethyl acetate; octane + tert-amyl methyl ether; diisopropyl ether + butane; 1,3-dichloro-2-propanol + epichlorohydrin; 2,3-dichloro-1-propanol + epichlorohydrin; 2,3-epoxy-1-propanol + epichlorohydrin; 3-chloro-1,2-propanediol + epichlorohydrin; methanol + hydrogen cyanide. For these systems, equilibrium vapor and liquid phase compositions were derived from the PTx data using the Soave equation of state to represent the vapor phase and the Wilson, NRTL, or Redlich-Kister activity coefficient model tomore » represent the liquid phase. The infinite dilution activity coefficient of methylamine in N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone-rich half of the binary. Liquid-liquid equilibrium studies were made on the triethylene glycol + 1-pentene system at two temperatures by directly analyzing samples taken from each liquid phase.« less

Degradable Networks Containing Silyl Ether Bonds

NASA Astrophysics Data System (ADS)

Bassampour, Zahra S.

Degradable networks possess applications in many fields such as medical implants, electrical devices, industrial coatings, adhesives, and aerospace. Silyl ether bonds are reactive functionalities capable of degrading under physiological condition without significantly affecting the pH of the surrounding environment. This dissertation focuses on preparative methods of degradable networks utilizing silyl ether functionalities. Epoxy polymers are broadly utilized in many different applications. Despite the broad utilization of epoxy polymer thermosets in long-term applications, these thermosets are not very popular candidates in short-term applications. This unpopularity is mostly due to the fact that epoxy networks are non-degradable systems, which results in their recycling being very costly and environmentally unfriendly. In the first and second part of this dissertation, the synthesis of various amine and thiol curing agents containing hydrolyzable silyl ether bonds is described. Using these curing agents, thermosetting epoxy polymers with degradable properties were prepared. The degradation behavior and thermal properties of the cured networks were studied. Age-related macular degeneration (AMD) is a leading cause of vision loss in the industrialized world. The high prevalence of AMD and the complications and shortcomings of available treatment options give rise to a great need for the development of novel types of biodegradable implants to provide sustainable drug release. The third part of this dissertation describes the utilization of hydrolyzable silyl ether bonds in the synthesis of novel implants capable of reserving and releasing a drug in a controlled manner in order to treat AMD. Base- catalyzed thiol-Michael reactions were exploited to prepare a series of biodegradable cross- linked networks. The networks were characterized by FTIR, TGA, and DMA. The effect of monomer structure on degradation, release behavior, and thermal properties was investigated.

Solvent Effects of Model Polymeric Corrosion Control Coatings on Water Transport and Corrosion Rate

NASA Astrophysics Data System (ADS)

Konecki, Christina

Industrial coating formulations are often made for volatile organic content compliance and ease of application, with little regard for the solvent impact on resultant performance characteristics. Our research objective was to understand the effect of both solvent retention and chemical structure on water transport through polymer films and resultant corrosion area growth of coated steel substrates. A clear, unpigmented Phenoxy(TM) thermoplastic polymer (PKHH) was formulated into resin solutions with three separate solvent blends selected by Hansen solubility parameter (HSP), boiling point, and ability to solubilize PKHH. Polymer films cast from MEK/PGME (methyl ethyl ketone/ propylene glycol methyl ether), dried under ambient conditions (AMB, > 6wt.% residual solvent) produced a porous morphology, which resulted in a corrosion area greater than 50%. We attributed this to the water-soluble solvent used in film preparation, which enabled residual PGME to be extracted by water. The resin solution prepared with CYCOH/DXL (Cyclohexanol/ 1,3 dioxolane) was selected because CYCOH is a solid at room temperature which acts as a pigment in the final film. Therefore, increasing the tortuosity of water transport, as well as a high hydrogen bonding character, which caused more interactions with water, slowing diffusion, producing a nodular morphology, and 37% less corrosion area than MEK/PGME AMB. The HSP of PKHH and EEP (ethyl 3-ethoxypropionate) are within 5% of each other, which produced a homogeneous morphology and resulted in comparable corrosion rates regardless of residual solvent content. We utilized electrochemical techniques and attenuated total reflectance- Fourier transform infrared spectroscopy to elucidate dynamic water absorption and solvent extraction in the exposed model formulations. We found that water absorption resulted in a loss of barrier properties, and increased corrosion due to the voids formed by solvent extraction. The polymer films were rejuvenated (removal of water) as an attempt to decrease the number of water transport pathways during exposure. Results found that samples rejuvenated at temperatures above the glass transition temperature of the samples achieved lower moisture content and consequently, lower corrosion growth rates. In commercial systems, rejuvenation lowered the corrosion rate up to 60% indicating better coating formulations and maintenance cycles would control the corrosion rate.

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2'-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

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

methanol (15 ml). The mixture was refluxed for 12 hr. After cooling and filtration (to remove the catalyst ) the solvent was distilled in a rotavapor and...was controlled by the monomer/initiator ([M]/[I]0 ) ratio. After quenching the polymerization with ammoniacal methanol , the reaction mixture was...The Phase Behavior of Poly(co-[(4-cyano-4’- biphenyl)oxy] alkyl Vinyl Ether]s with Ethyl, Propyl and Butyl Alkyl Groups Acc,--.o ,; ., x .... V

Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

NASA Astrophysics Data System (ADS)

Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

2016-07-01

Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

Simulation study of the lithium ion transport mechanism in ternary polymer electrolytes: the critical role of the segmental mobility.

PubMed

Diddens, Diddo; Heuer, Andreas

2014-01-30

We present an extensive molecular dynamics (MD) simulation study of the lithium ion transport in ternary polymer electrolytes consisting of poly(ethylene oxide) (PEO), lithium-bis(trifluoromethane)sulfonimide (LiTFSI), and the ionic liquid N-methyl-N-propylpyrrolidinium bis(trifluoromethane)sulfonimide (PYR13TFSI). In particular, we focus on two different strategies by which the ternary electrolytes can be devised, namely by (a) adding the ionic liquid to PEO20LiTFSI and (b) substituting the PEO chains in PEO20LiTFSI by the ionic liquid. To grasp the changes of the overall lithium transport mechanism, we employ an analytical, Rouse-based cation transport model (Maitra et al. Phys. Rev. Lett. 2007, 98, 227802), which has originally been devised for binary PEO-based electrolytes. This model distinguishes three different microscopic transport mechanisms, each quantified by an individual time scale. In the course of our analysis, we extend this mathematical description to account for an entirely new transport mechanism, namely, the TFSI-supported diffusion of lithium ions decoupled from the PEO chains, which emerges for certain stoichiometries. We find that the segmental mobility plays a decisive role in PEO-based polymer electrolytes. That is, whereas the addition of the ionic liquid to PEO20LiTFSI plasticizes the polymer network and thus also increases the lithium diffusion, the amount of free, mobile ether oxygens reduces when substituting the PEO chains by the ionic liquid, which compensates the plasticizing effect. In total, our observations allow us to formulate some general principles about the lithium ion transport mechanism in ternary polymer electrolytes. Moreover, our insights also shed light on recent experimental observations (Joost et al. Electrochim. Acta 2012, 86, 330).

Preparation of Chitin Nanofibers-Gold Metallic Nanocomposite by Phase Transfer Method

NASA Astrophysics Data System (ADS)

Shervani, Zameer; Taisuke, Yukawa; Ifuku, Shinsuke; Saimoto, Hiroyuki; Morimoto, Minoru

2012-10-01

Chitin nanofibers (CNFs)-Au(0) nanoparticles (Au NPs) blends in dispersion, flakes and thin film or sheet forms were first prepared by mixing pre-organized Au NPs prepared in triblock copolymer with diluted CNFs suspension. Water soluble polymer triblock copolymer poly (methyl vinyl ether, PMVE) in the amount 0.6 wt.% was used to prepare NPs and 0.12 wt.% net chitin content was used as CNFs suspension to prepare the blended composite. Au NPs of size 4.4 nm (σ = 1.2) were obtained when Au salt (HAuCl4ṡ3H2O (hydrogen tetrachloroaurate (III) trihydrate) was reduced by 5 equivalents of NaBH4. PMVE polymer acted as a stabilizing or capping agent for pre-organized NPs. Completion of reaction was fast, all salt reduced to metallic form in just 15 min after the addition of NaBH4. CNFs (1 wt.% chitin) which was used to prepare CNFs-Au NPs blend composite were prepared from crab shell in never dried acidic condition by established combination of chemical and mechanical processes that gave 25-40 nm width and high aspect ratio CNFs. When polymer capped Au NPs mixed with CNF suspension, all Au NPs and 56% polymer were mass transferred from water phase to entangle with more polar moieties of CNFs-water suspension as no trace of Au NPs were noticed in water-polymer mother liquor after blending with CNFs suspension. Particles size of CNFs-Au NPs composite was measured by employing TEM, SAXS and SEM techniques. CNFs-Au NPs composite were characterized in solution and compressed dried sheet form by recording digital images, UV-vis and XRD spectroscopies. CNFs-Au NPs suspension had antibacterial activity against gram positive bacteria S. aureus.

Preparation of Soypolymers by Ring-opening Polymerization of Epoxdized Soybean Oil

USDA-ARS?s Scientific Manuscript database

Ring opening polymerization of epoxidized soybean oil (ESO) initiated by boron trifluoride diethyl etherate in methylene chloride was conducted in an effort to develop useful biodegradable polymers. The resulting polymers (PESO) were characterized using Infrared (IR), differential scanning calorime...

Ring-opening Polymerization of Epoxidized Soybean Oil

USDA-ARS?s Scientific Manuscript database

Ring opening polymerization of epoxidized soybean oil (ESO) initiated by boron trifluoride diethyl etherate, (BF3•OEt2), in methylene chloride was conducted in an effort to develop useful biodegradable polymers. The resulting polymers (PESO) were characterized using Infrared (IR), differential scan...

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...

DIPPR Project 871 For 1995 - Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Methyl Benzoate, Ethyl Benzoate, (R)-(+)-Limonene, Tert-Amyl Methyl Ether, Trans-Crotonaldehyde, and

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steele, W.V.

2002-07-01

Ideal-gas enthalpies of formation of methyl benzoate, ethyl benzoate, (R)-(+)-limonene, tert-amyl methyl ether, trans-crotonaldehyde, and diethylene glycol are reported. The standard energy of combustion and hence standard enthalpy of formation of each compound in the liquid phase has been measured using an oxygen rotating-bomb calorimeter without rotation. Vapor pressures were measured to a pressure limit of 270 kPa or the lower decomposition point for each of the six compounds using a twin ebulliometric apparatus. Liquid-phase densities along the saturation line were measured for each compound over a range of temperature (ambient to a maximum of 548 K). A differential scanningmore » calorimeter was used to measure two-phase (liquid + vapor) heat capacities for each compound in the temperature region ambient to the critical temperature or lower decomposition point. For methyl benzoate and tert-amyl methyl ether, critical temperatures and critical densities were determined from the DSC results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for each of the remaining compounds. The results of the measurements were combined to derive a series of thermophysical properties including critical temperature, critical density, critical pressure, acentric factor, enthalpies of vaporization (restricted to within {+-}50 K of the temperature region of the experimentally determined vapor pressures), and heat capacities along the saturation line. Wagner-type vapor-pressure equations were derived for each compound. All measured and derived values were compared with those obtained in a search of the literature. Recommended critical parameters are listed for each of the compounds studied. Group-additivity parameters, useful in the application of the Benson gas-phase group-contribution correlations, were derived.« less

40 CFR 721.6620 - Alkanaminium, polyalkyl-[(2-methyl-1-oxo-2-propenyl)oxy] salt, polymer with acrylamide and...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-oxo-2-propenyl)oxy] salt, polymer with acrylamide and substituted alkyl methacrylate. 721.6620 Section... Substances § 721.6620 Alkanaminium, polyalkyl-[(2-methyl-1-oxo-2-propenyl)oxy] salt, polymer with acrylamide...-propenyl)oxy] salt, polymer with acrylamide and substituted alkyl methacrylate (PMN P-87-252) is subject to...

40 CFR 721.3807 - Formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with phenol and... Significant New Uses for Specific Chemical Substances § 721.3807 Formaldehyde, polymer with phenol and 1,2,3... chemical substance identified as formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated (PMN...

40 CFR 721.6620 - Alkanaminium, polyalkyl-[(2-methyl-1-oxo-2-propenyl)oxy] salt, polymer with acrylamide and...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-oxo-2-propenyl)oxy] salt, polymer with acrylamide and substituted alkyl methacrylate. 721.6620 Section... Substances § 721.6620 Alkanaminium, polyalkyl-[(2-methyl-1-oxo-2-propenyl)oxy] salt, polymer with acrylamide...-propenyl)oxy] salt, polymer with acrylamide and substituted alkyl methacrylate (PMN P-87-252) is subject to...

40 CFR 721.3807 - Formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, polymer with phenol and... Significant New Uses for Specific Chemical Substances § 721.3807 Formaldehyde, polymer with phenol and 1,2,3... chemical substance identified as formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated (PMN...

40 CFR 721.3807 - Formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymer with phenol and... Significant New Uses for Specific Chemical Substances § 721.3807 Formaldehyde, polymer with phenol and 1,2,3... chemical substance identified as formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated (PMN...

40 CFR 721.3807 - Formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Formaldehyde, polymer with phenol and... Significant New Uses for Specific Chemical Substances § 721.3807 Formaldehyde, polymer with phenol and 1,2,3... chemical substance identified as formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated (PMN...

40 CFR 721.3807 - Formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Formaldehyde, polymer with phenol and... Significant New Uses for Specific Chemical Substances § 721.3807 Formaldehyde, polymer with phenol and 1,2,3... chemical substance identified as formaldehyde, polymer with phenol and 1,2,3-propanetriol, methylated (PMN...

U.S. Geological Survey laboratory method for methyl tert-Butyl ether and other fuel oxygenates

USGS Publications Warehouse

Raese, Jon W.; Rose, Donna L.; Sandstrom, Mark W.

1995-01-01

Methyl tert-butyl ether (MTBE) was found in shallow ground-water samples in a study of 8 urban and 20 agricultural areas throughout the United States in 1993 and 1994 (Squillace and others, 1995, p. 1). The compound is added to gasoline either seasonally or year round in many parts of the United States to increase the octane level and to reduce carbon monoxide and ozone levels in the air. The U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL), near Denver, uses state-of-the-art technology to analyze samples for MTBE as part of the USGS water-quality studies. In addition, the NWQL offers custom analyses to determine two other fuel oxygenates--ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME). The NWQL was not able to obtain a reference standard for tert-amyl ethyl ether (TAEE), another possible fuel oxygenate (Shelley and Fouhy, 1994, p. 63). The shallow ground-water samples were collected as part of the USGS National Water-Quality Assessment Program. These samples were collected from 211 urban wells or springs and 562 agricultural wells sampled by the USGS in 1993 and 1994. The wells were keyed to specific land-use areas to assess the effects of different uses on ground-water quality (Squillace and others, 1995, p. 2). Ground-water samples were preserved on site to pH less than or equal to 2 with a solution of 1:1 hydrochloric acid. All samples were analyzed at the NWQL within 2 weeks after collection. The purpose of this fact sheet is to explain briefly the analytical method implemented by the USGS for determining MTBE and other fuel oxygenates. The scope is necessarily limited to an overview of the analytical method (instrumentation, sample preparation, calibration and quantitation, identification, and preservation of samples) and method performance (reagent blanks, accuracy, and precision).

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

Optical monitoring of proteins at solid interfaces

NASA Astrophysics Data System (ADS)

Dunne, G.; McDonnell, L.; Miller, R.; McMillan, N. D.; O'Rourke, B.; Mitchell, C. I.

2005-06-01

The adsorption properties of polymers are of great importance for implant studies. A better understanding of these properties can lead to improved implant materials. In this study the surface energy of different polymers was derived from contact angle measurements taken using profile analysis tensiometry (PAT) of sessile drops of water. The contact angles were measured for advancing and receding water drops on polished polymer surfaces and also on polymer surfaces modified by adsorbing protein to the surface prior to analysis of the sessile drop. The protein used was bovine serum albumin (BSA) and the surfaces were poly-methylmethacrylate (PMMA), poly-ether-ether-ketone (PEEK) and stainless steel. The polymer surfaces were also studied using atomic force microscopy (AFM). Images of the surfaces were taken in different states: rough, smooth and with albumin adsorbed. As a method to identify the proteins on the surface easier, anti-albumin antibodies with 30nm nano gold particles attached were adsorbed to the albumin on the surfaces. Using nano gold particles made the imaging more straightforward and thus made identification of the protein on the surface easier. The results from this work show the differing hydrophobicities of polymer surfaces under different conditions and a new nanotechnological method of protein identification.

Room-Temperature Performance of Poly(Ethylene Ether Carbonate)-Based Solid Polymer Electrolytes for All-Solid-State Lithium Batteries.

PubMed

Jung, Yun-Chae; Park, Myung-Soo; Kim, Duck-Hyun; Ue, Makoto; Eftekhari, Ali; Kim, Dong-Won

2017-12-13

Amorphous poly(ethylene ether carbonate) (PEEC), which is a copolymer of ethylene oxide and ethylene carbonate, was synthesized by ring-opening polymerization of ethylene carbonate. This route overcame the common issue of low conductivity of poly(ethylene oxide)(PEO)-based solid polymer electrolytes at low temperatures, and thus the solid polymer electrolyte could be successfully employed at the room temperature. Introducing the ethylene carbonate units into PEEC improved the ionic conductivity, electrochemical stability and lithium transference number compared with PEO. A cross-linked solid polymer electrolyte was synthesized by photo cross-linking reaction using PEEC and tetraethyleneglycol diacrylate as a cross-linking agent, in the form of a flexible thin film. The solid-state Li/LiNi 0.6 Co 0.2 Mn 0.2 O 2 cell assembled with solid polymer electrolyte based on cross-linked PEEC delivered a high initial discharge capacity of 141.4 mAh g -1 and exhibited good capacity retention at room temperature. These results demonstrate the feasibility of using this solid polymer electrolyte in all-solid-state lithium batteries that can operate at ambient temperatures.

Photophysical properties and photoisomerization processes of Methyl Red embedded in rigid polymer

NASA Astrophysics Data System (ADS)

Lee, Geon Joon; Kim, Dongho; Lee, Minyung

1995-01-01

The photophysical properties of Methyl Red molecules embedded in a poly(methyl methacrylate) (PMMA) matrix were investigated with photoinduced absorption, absorption kinetics, steady-state, and time-resolved luminescence spectroscopy. The excited singlet (S1) state lifetimes for trans and cis isomers of Methyl Red in PMMA at room temperature have been measured as 35 and 420 ps, respectively. The excited triplet (T1) state energy level and its lifetime at 77 K were also obtained. A slow trans-cis isomerization process having a time constant of a few hundred seconds was observed for the illuminated Methyl Red in rigid polymer. Based on measured photophysical properties and dynamic processes, an energy-level diagram for Methyl Red molecules in rigid polymer is introduced to explain these observations.

Health assessment of gasoline and fuel oxygenate vapors: developmental toxicity in rats.

PubMed

Roberts, Linda G; Gray, Thomas M; Trimmer, Gary W; Parker, Robert M; Murray, F Jay; Schreiner, Ceinwen A; Clark, Charles R

2014-11-01

Gasoline-vapor condensate (BGVC) or condensed vapors from gasoline blended with methyl t-butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME) diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA) were evaluated for developmental toxicity in Sprague-Dawley rats exposed via inhalation on gestation days (GD) 5-20 for 6h/day at levels of 0 (control filtered air), 2000, 10,000, and 20,000mg/m(3). These exposure durations and levels substantially exceed typical consumer exposure during refueling (<1-7mg/m(3), 5min). Dose responsive maternal effects were reduced maternal body weight and/or weight change, and/or reduced food consumption. No significant malformations were seen in any study. Developmental effects occurred at 20,000mg/m(3) of G/TAME (reduced fetal body weight, increased incidence of stunted fetuses), G/TBA (reduced fetal body weight, increased skeletal variants) and G/DIPE (reduced fetal weight) resulting in developmental NOAEL of 10,000mg/m(3) for these materials. Developmental NOAELs for other materials were 20,000mg/m(3) as no developmental toxicity was induced in those studies. Developmental NOAELs were equal to or greater than the concurrent maternal NOAELs which ranged from 2000 to 20,000mg/m(3). There were no clear cut differences in developmental toxicity between vapors of gasoline and gasoline blended with the ether or alcohol oxygenates. Copyright © 2014 Elsevier Inc. All rights reserved.

Modified extraction procedure for gas-liquid chromatography applied to the identification of anaerobic bacteria.

PubMed Central

Thomann, W R; Hill, G B

1986-01-01

Chloroform and ether commonly are used as solvents to extract metabolic organic acids for analysis by gas-liquid chromatography in the identification of anaerobic bacteria. Because these solvents are potentially hazardous to personnel, modified extraction procedures involving the use of a safer solvent, methyl tert-butyl ether were developed which remained both simple to perform and effective for organism identification. PMID:3700623

Synthesis of Quaternary Ammonium Salts of Tricyclic Cationic Drugs: A One-Pot Synthesis for the Bioorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Brunauer, Linda S.; Mogannam, Abid C.; Hwee, Won B.; Chen, James Y.

2007-01-01

A one-pot conversion of tricyclic cationic drugs to their quaternary ammonium forms is described for a widely used bioactive drug: chlorpromazine, a phenothiazine-based antipsychotic. After conversion to its free base, the parent drug was methylated using substoichiometric amounts of methyl iodide dissolved in ether; the charged quaternary…

40 CFR 721.10286 - Formaldehyde, polymer with .alpha.- (2-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly...

Code of Federal Regulations, 2013 CFR

2013-07-01

...-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly[ oxy(methyl - 1,2 - ethanediyl)] and 4 - (1,1... Specific Chemical Substances § 721.10286 Formaldehyde, polymer with .alpha.- (2-aminomethylethyl)- .omega... formaldehyde, polymer with .alpha.-(2-aminomethylethyl)-.omega.-(2-aminomethylethoxy)poly[oxy(methyl-1,2...

Identification of potent odorants in different cultivars of snake fruit [Salacca zalacca (Gaert.) Voss] using gas chromatography-olfactometry.

PubMed

Wijaya, C H; Ulrich, D; Lestari, R; Schippel, K; Ebert, G

2005-03-09

Three cultivars of snake fruits, Pondoh Hitam, Pondoh Super, and Gading, were freshly extracted using liquid-liquid extraction. The aroma compounds of the three samples were analyzed by GC-MS and GC-olfactometry using the nasal impact frequency (NIF) method. A total of 24 odor-active compounds were associated with the aroma of snake fruit. Methyl 3-methylpentanoate was regarded as the character impact odorant of typical snake fruit aroma. 2-Methylbutanoic acid, 3-methylpentanoic acid, and an unknown odorant with very high intensity were found to be responsible for the snake fruit's sweaty odor. Other odorants including methyl 3-methyl-2-butenoate (overripe fruity, ethereal), methyl 3-methyl-2-pentenoate (ethereal, strong green, woody), and 2,5-dimethyl-4-hydroxy-3[2]-furanone (caramel, sweet, cotton candy-like) contribute to the overall aroma of snake fruit. Methyl dihydrojasmonate and isoeugenol, which also have odor impact, were identified for the first time as snake fruit volatiles. The main differences between the aroma of Pondoh and Gading cultivars could be attributed to the olfactory attributes (metallic, chemical, rubbery, strong green, and woody), which were perceived by most of the panelists in the Pondoh samples but were not detected in the Gading samples. This work is a prerequisite for effective selection of salak genotypes with optimal aroma profiles for high consumer acceptance.

40 CFR 721.10286 - Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega.-(2- aminomethylethoxy)poly[ oxy...

Code of Federal Regulations, 2014 CFR

2014-07-01

...-aminomethylethyl)- .omega.-(2- aminomethylethoxy)poly[ oxy(methyl- 1,2-ethanediyl)] and 4-(1,1-dimethylethyl)phenol... Specific Chemical Substances § 721.10286 Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega... formaldehyde, polymer with .alpha.-(2- aminomethylethyl)-.omega.-(2- aminomethylethoxy)poly[oxy(methyl- 1,2...

40 CFR 721.10286 - Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega.-(2-aminomethylethoxy) poly[oxy...

Code of Federal Regulations, 2012 CFR

2012-07-01

...-aminomethylethyl)- .omega.-(2-aminomethylethoxy) poly[oxy(methyl-1,2-ethanediyl)] and 4-(1,1-dimethylethyl)phenol... Specific Chemical Substances § 721.10286 Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega... formaldehyde, polymer with .alpha.-(2-aminomethylethyl)-.omega.-(2-aminomethylethoxy)poly[oxy(methyl-1,2...

CHLORINATED SOLVENT PLUME CONTROL

EPA Science Inventory

This lecture will cover recent success in controlling and assessing the treatment of shallow ground water plumes of chlorinated solvents, other halogenated organic compounds, and methyl tert-butyl ether (MTBE).

High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

DOEpatents

Janke, C.J.; Lopata, V.J.; Havens, S.J.; Dorsey, G.F.; Moulton, R.J.

1999-03-02

A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

DOEpatents

Janke, Christopher J.; Lopata, Vincent J.; Havens, Stephen J.; Dorsey, George F.; Moulton, Richard J.

1999-01-01

A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

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.

Synthesis of Perfluorinated Ethers by Solution Phase Direct Fluorination: An Adaptation of the La-Mar Technique

DTIC Science & Technology

1990-08-22

Six of the 3 perfluorinated ethers prepared have been previously synthesized by other methods: perfluoro -5,5-bis(ethoxy- f methyl) -3,7-dioxanonane...from partially fluorinated starting material [34]. Third, as with perfluoroalkanes and simple perfluoroethers , Clark’s experimental results indicated 3...a highly branched perfluoroether ) by direct fluorination 3 in solution. Second, since some of these perfluorinated compounds had been previously

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

Code of Federal Regulations, 2013 CFR

2013-07-01

..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (generic). 721.10189...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (PMN P-05-186, Chemical...

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

Code of Federal Regulations, 2014 CFR

2014-07-01

..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (generic). 721.10189...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (PMN P-05-186, Chemical...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (generic). 721.10189...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (PMN P-05-186, Chemical...

Polymerization of euphorbia oil with Lewis acid in carbon dioxide media

USDA-ARS?s Scientific Manuscript database

Boron trifluoride diethyl etherate (BF3-OEt2) Lewis acid catalyzed ring-opening polymerization of euphorbia oil (EO), a natural epoxy oil, in liquid carbon dioxide was conducted in an effort to develop useful vegetable oil based polymers. The resulting polymers (RPEO) were characterized by FTIR, 1H-...

Design and preparation of novel polyarylene ether materials based on Diels-Alder reaction as the crosslinker for electrooptical modulators

NASA Astrophysics Data System (ADS)

Gao, Wu; Hou, Wenjun; Zhen, Zhen; Liu, Xinhou; Liu, Jialei; Fedorchuk, A. A.; Czaja, P.

2016-07-01

Novel crosslinkable organic linear electro-optical (EO) material based on polyarylene ether as the main chain host polymer was designed and prepared. The host polymer with rigid aromatic has demonstrated a good compatibility with the guest chromophore. Long side chain with anthracene ensured the crosslinkable reaction and appropriate glass transition temperature of the host polymer (55 °C). The EO r33 tensor coefficient for this novel EO material has been magnitude of 66 pm/V at 1310 nm and the excellent long term stability at 85 °C. These parameters permit to consider their application in fabrication of organic electro optical devices. The semi-empirical and DFT quantum chemical simulations were performed for 4 principal chromophores to clarify a role of cross-linker in the enhancement of the ground state dipole moments and effective hyperpolarizabilities.

Isolation of infectious chikungunya virus and dengue virus using anionic polymer-coated magnetic beads.

PubMed

Patramool, Sirilaksana; Bernard, Eric; Hamel, Rodolphe; Natthanej, Luplertlop; Chazal, Nathalie; Surasombatpattana, Pornapat; Ekchariyawat, Peeraya; Daoust, Simon; Thongrungkiat, Supatra; Thomas, Frédéric; Briant, Laurence; Missé, Dorothée

2013-10-01

Mosquitoes-borne viruses are a major threat for human populations. Among them, chikungunya virus (CHIKV) and dengue virus (DENV) cause thousands of cases worldwide. The recent propagation of mosquito vectors competent to transmit these viruses to temperate areas increases their potential impact on susceptible human populations. The development of sensitive methods allowing the detection and isolation of infectious viruses is of crucial interest for determination of virus contamination in humans and in competent mosquito vectors. However, simple and rapid method allowing the capture of infectious CHIKV and DENV from samples with low viral titers useful for further genetic and functional characterization of circulating strains is lacking. The present study reports a fast and sensitive isolation technique based on viral particles adsorption on magnetic beads coated with anionic polymer, poly(methyl vinyl ether-maleic anhydrate) and suitable for isolation of infectious CHIKV and DENV from the four serotypes. Starting from quite reduced biological material, this method was accurate to combine with conventional detection techniques, including qRT-PCR and immunoblotting and allowed isolation of infectious particles without resorting to a step of cultivation. The use of polymer-coated magnetic beads is therefore of high interest for rapid detection and isolation of CHIKV and DENV from samples with reduced viral loads and represents an accurate approach for the surveillance of mosquito vector in area at risk for arbovirus outbreaks. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Mobil cuts the alcohol out of oxygenate production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, A.

1992-04-15

Mobil Corp. has unveiled a new etherification technology that can produce fuel oxygenated based only on olefinic refinery streams and water. The process has the potential to allow refiners to produce oxygenates without having to rely on an external supply of alcohols such as methanol or ethanol. Mobil has developed the technology around a new oxygenate, disopropyl ether (DIPE), based on propylene. However, the process has also been tested using mixed propylene/C{sub 4} and straight C{sub 4} streams, says Michael J. McNally, manager of Mobil`s Motor Gasoline Group (Paulsboro, NJ), producing ethers analogous to methyl tert-butyl ether (MTBE).

Discovery and characterizaton of a novel lipase with transesterification activity from hot spring metagenomic library.

PubMed

Yan, Wei; Li, Furong; Wang, Li; Zhu, Yaxin; Dong, Zhiyang; Bai, Linhan

2017-03-01

A new gene encoding a lipase (designated as Lip-1 ) was identified from a metagenomic bacterial artificial chromosome(BAC) library prepared from a concentrated water sample collected from a hot spring field in Niujie, Eryuan of Yunnan province in China. The open reading frame of this gene encoded 622 amino acid residues. It was cloned, fused with the oleosin gene and over expressed in Escherichia coli to prepare immobilized lipase artificial oil body AOB-sole-lip-1. The monomeric Sole-lip-1 fusion protein presented a molecular mass of 102.4 kDa. Enzyme assays using olive oil and methanol as the substrates in petroleum ether confirmed its transesterification activity. Hexadecanoic acid methyl ester, 8,11-Octadecadienoic acid methyl ester, 8-Octadecenoic acid methyl ester, and Octadecanoic acid methyl ester were detected. It showed favorable transesterification activity with optimal temperature 45 °C. Besides, the maximal biodiesel yield was obtained when the petroleum ether system as the organic solvent and the substrate methanol in 350 mmol/L (at a molar ratio of methanol of 10.5:1) and the water content was 1%. In light of these advantages, this lipase presents a promising resource for biodiesel production.

Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

PubMed

Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

2014-10-01

Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211.

Free volume study on the miscibility of PEEK/PEI blend using positron annihilation and dynamic mechanical thermal analysis

NASA Astrophysics Data System (ADS)

Ramani, R.; Alam, S.

2015-06-01

High performance polymer blend of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) was examined for their free volume behaviour using positron annihilation lifetime spectroscopy and dynamic mechanical thermal analysis methods. The fractional free volume obtained from PALS shows a negative deviation from linear additivity rule implying good miscibility between PEEK and PEI. The dynamic modulus and loss tangent were obtained for the blends at three different frequencies 1, 10 and 100 Hz at temperatures close to and above their glass transition temperature. Applying Time-Temperature-Superposition (TTS) principle to the DMTA results, master curves were obtained at a reference temperature To and the WLF coefficients c01 and c02 were evaluated. Both the methods give similar results for the dependence of fractional free volume on PEI content in this blend. The results reveal that free volume plays an important role in determining the visco-elastic properties in miscible polymer blends.

Polymer grafted magnetic nanoparticles for delivery of anticancer drug at lower pH and elevated temperature.

PubMed

Dutta, Sujan; Parida, Sheetal; Maiti, Chiranjit; Banerjee, Rakesh; Mandal, Mahitosh; Dhara, Dibakar

2016-04-01

Efficient and controlled delivery of therapeutics to tumor cells is one of the important issues in cancer therapy. In the present work, a series of pH- and temperature-responsive polymer grafted iron oxide nanoparticles were prepared by simple coupling of aminated iron oxide nanoparticle with poly(N-isopropylacrylamide-ran-poly(ethylene glycol) methyl ether acrylate)-block-poly(acrylic acid) (P(NIPA-r-PEGMEA)-b-PAA). For this, three water soluble block polymers were prepared via reversible addition fragmentation transfer (RAFT) polymerization technique. At first, three different block copolymers were prepared by polymerizing mixture of NIPA and PEGMEA (with varying mole ratio) in presence of poly(tert-butyl acrylate) (PtBA) macro chain transfer agent. Subsequently, P(NIPA-r-PEGMEA)-b-PAA copolymers were synthesized by hydrolyzing tert-butyl acrylate groups of the P(NIPA-r-PEGMEA)-b-PtBA copolymers. The resulting polymers were then grafted to iron oxide nanoparticles, and these functionalized nanoparticles were thoroughly characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), zeta potential measurements, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and Fourier transform infrared spectroscopy (FTIR). Doxorubicin (DOX), an anti-cancer drug, was loaded into the polymer coated nanoparticles and its release behavior was subsequently studied at different pH and temperatures. The drug release pattern revealed a sustained release of DOX preferentially at the desired lysosomal pH of cancer cells (pH 5.0) and slightly above the physiological temperature depending upon the composition of the copolymers. The potential anticancer activity of the polymer grafted DOX loaded nanoparticles were established by MTT assay and apoptosis study of cervical cancer ME 180cells in presence of the nanoparticles. Thus, these particles can be utilized for controlled delivery of anticancer drugs at the desired lysosomal pH and/or by slightly heating the cells using magnetic hyperthermia. Copyright © 2016 Elsevier Inc. All rights reserved.

Transgene Delivery using Poly(amino ether)-Gold Nanorod Assemblies

PubMed Central

Ramos, James; Rege, Kaushal

2012-01-01

Gold nanorods (GNRs) have emerged as promising nanomaterials for biosensing, imaging, photothermal treatment and therapeutic delivery for several diseases, including cancer. We have generated poly(amino ether)-functionalized gold nanorods (PAE-GNRs) using a layer-by-layer deposition approach; polymers from a poly(amino ether) library recently synthesized in our laboratory were employed to generate the PAE-GNR assemblies. PAE-GNR assemblies demonstrate long-term colloidal stability as well as the capacity to bind plasmid DNA by means of electrostatic interactions. Sub-toxic concentrations of PAE-GNRs were employed to deliver plasmid DNA to prostate cancer cells in vitro. PAE-GNRs generated using 1,4C-1,4Bis, a cationic polymer from our laboratory demonstrated significantly higher transgene expression and exhibited lower cytotoxicities when compared to similar assemblies generated using 25 kDa poly(ethylene imine) (PEI25k-GNRs), a current standard for polymer-mediated gene delivery. The roles of polyelectrolyte chemistry and zeta-potential in determining transgene expression efficacies of PAE-GNR assemblies were investigated. Our results indicate that stable and effective PAE-GNR assemblies are a promising engineered platform for transgene delivery. PAE-GNRs also have the potential to be used simultaneously for photothermal ablation, photothermally enhanced drug and gene delivery, and biological imaging, thus making them a powerful theranostic platform. PMID:22170455

Anti-Helicobacter pylori activity of bioactive components isolated from Hericium erinaceus.

PubMed

Liu, Jian-Hui; Li, Liang; Shang, Xiao-Dong; Zhang, Jun-Ling; Tan, Qi

2016-05-13

The fungus Hericium erinaceus (Bull.) Pers is used in Chinese traditional medicine to treat symptoms related to gastric ulcers. Different extracts from the fungus were assessed for anti-Helicobacter pylori activity to investigate the antibacterial activity of the ethanol extracts from H. erinaceus and verify the traditional indication of use. The fruiting bodies of H. erinaceus were concentrated with ethanol by HPD-100 macroporous resin and the whole extract was partitioned by petroleum ether and chloroform to afford fractions with using a silica gel column. Several pure compounds of petroleum ether extracts were obtained and analyzed using nuclear magnetic resonance (NMR). The activity of the extracts and fractions towards H. pylori was assessed by the microdilution assay and by the disk diffusion assay in vitro. From the most active fraction, two pure compounds were isolated and identified as the main components with anti-H. pylori activity from the fungus H. erinaceus. The cytotoxicity of these two compounds against the human erythroleu-kemia cell line K562 was also evaluated. The crude ethanol extracts from the fungus H. erinaceus were inhibitory to H. pylori. The petroleum ether extracts (PE1s, PE2s) and the chloroform extracts (TEs) demonstrated strong inhibition to H. pylori. The inhibition of H. pylori was observed through an agar dilution test with minimal inhibition concentration (MIC) values from 400μg/mL to 12.5µg/mL. Two pure compounds, 1-(5-chloro-2-hydroxyphenyl)-3-methyl-1-butanone and 2,5-bis(methoxycarbonyl)terephthalic acid were isolated from the petroleum ether fractions and identified using (1)H NMR and (13)C NMR spectra analysis. The MIC value for 1-(5-chloro-2-hydroxyphenyl)-3-methyl-1-butanone was 12.5-50µg/mL and the MIC value for 2,5-bis(methoxycarbonyl)terephthalic acid was 6.25-25µg/mL. Both two compounds showed weak cytotoxicity against K562 with IC50<200mM. This study revealed that the extracts from petroleum ether contribute to the anti-H. pylori activity. The compounds obtained from petroleum ether extracts, 1-(5-chloro-2-hydroxyphenyl)-3-methyl-1-butanone and 2,5-bis(methoxycarbonyl)terephthalic acid, inhibit the growth of H. pylori. Copyright © 2016. Published by Elsevier Ireland Ltd.

Molecular dynamics simulation of low dielectric constant polymer electrolytes

NASA Astrophysics Data System (ADS)

Wheatle, Bill; Lynd, Nathaniel; Ganesan, Venkat

Recent experimental studies measured the ionic conductivities of a series of poly(glycidyl ether)s with varying neat dielectric constants (ɛ), viscosities (η), and glass transition temperatures (Tg), as hosts for lithium bistrifluoromethanesulfonimide (LiTFSI) salt. In such a context, it was demonstrated that the ionic conductivity of these polymer electrolytes was a function of ɛ rather than Tg or η, suggesting that there may exist regimes in which ionic conductivity is not limited by slow segmental dynamics but rather by low ionic dissociation. Motivated by such results, we used atomistic molecular dynamics to study the structure and transport characteristics of the same set of host polymers. We found that the coordination number of TFSI- about Li+ in the first solvation shell and the total fraction of free ions increased as a function of ɛ, implying the polymer hosts enhanced ion dissociation. In addition, we found that increasing the dielectric constant of the host polymer enhanced self-correlated ion transport, as evidenced by an increase in the diffusion coefficients of each ion species. Overall, we confirmed that limited ion dissociation in low- ɛ polymer electrolyte hosts hampers ionic conductivity. We would like to thank the National Science Foundation Graduate Research Fellowship Program for funding this research endeavor.

Hydration Differences Explain the Large Variations in the Complexation Thermodynamics of Modified γ-Cyclodextrins with Bile Salts.

PubMed

Køhler, Jonatan; Schönbeck, Christian; Westh, Peter; Holm, René

2016-01-28

The structure and thermodynamics of inclusion complexes of seven different γ-cyclodextrins (γCDs) and three biologically relevant bile salts (BS) were investigated in the present study. Natural γCD and six modified γCDs [two methyl-γCDs, one sulfobutyl ether-γCD (SBEγCD), and three 2-hydroxypropyl-γCDs (HPγCD)] and their complexes with BS were investigated by isothermal titration calorimetry, NMR, and molecular dynamics simulations. With the exception of the fully methylated γCD, which did not bind the BSs investigated, all of the γCDs formed 1:1 complexes with the BS, and the structures were similar to those with natural γCD; i.e., the modifications of the γCD had limited structural impact on the formation of complexes. Isothermal titration calorimetry was carried out over in the temperature interval 5-55 °C to enable the calculation of the stability constant (K) and the thermodynamic parameters enthalpy (ΔH°), entropy (ΔS°), and heat capacity (ΔCp°). The stability constants decreased with an increased degree of substitution (DS), with methyl substituents having a lower effect on the stability constant than the sulfobutyl ether and hydroxypropyl substituents on the stability constants. Enthalpy-entropy compensation was observed, since both enthalpy and entropy increased with the degree of substitution, which may reflect dehydration of the hydrophobic surface on both CD and BS. Calculations based on ΔCp° data suggested that each of the substituents dehydrated 10-20 (hydroxypropyl), 22-33 (sulfobutyl ether), and 10-15 Å(2) (methyl) of the BS surface area, in reasonable agreement with estimates from the molecular dynamics simulations. Combined with earlier investigations on modified βCDs, these results indicate general trends of the substituents on the thermodynamics of complex formation.

Dielectric Constant and Loss Data. Part 4

DTIC Science & Technology

1980-12-01

Fluorinated ethers, Organic Chemicals Dept., P.R.-194Dow Chemical "Dowtherm" A, P.R.-194 T ORg C a p - Dew Corning Corp., IV-26, 27, 41, 42, "HVITON...Esso "Teresso" oil, V-78; P.R.-195 and MFl16, V-15 "Estawax", IV-57 "Eccosorb" MFll7, V-15, 242 Ethers, fluorinated , P.R.-194 Eggwhite. P.R.-202 "Ethocel...PPG, 8-20 Flourglas laminate, 9-33 "Gafite" cast polymer, IV-34 Fluorinated ethers, P.R.-194 Gasoline, aviation, 100 and 91 octane, Fluorcarbon

Synthesis and Characterization of Perfluoroalkyl Heterocyclic Elastomers

DTIC Science & Technology

Perfluoroalkyl bibenzoxazole polymers containing a (CF2)8 between heterocyclic rings have been prepared by the reaction of dihydroxybenzidine and...methyl perfluorosebacimidate . Through preparation of this polymer, the basic polymerization system has been significantly improved and polymers with...C. (TGA). Copolymers of dihydroxybenzidine and methyl perfluoro -4,9,14,19- tetraoxadocosanediimidate, which are tacky and resilient, have been

Alkyl Azides, Diazides, Haloazides and Bridged Polycyclic Diazides

DTIC Science & Technology

1991-05-16

temperature. Most of the methyl ether was removed during this process. The ehtyl ether was distilled from the reaction mixture using a water aspirator into a...Street PROGRAM IPROJECT ITASK IWORK li1111? ArliiqIoh, VA 22217-5000 EILIMENT NO I NO. I oACCESSION P10) Alkyl Azides, Dlazides, laloazides and...REPRODUCE LEGIBLY. ALKYL AZIDES, DIAZIDES, HALOAZIDES AND BRIDGED POLYCYCLIC DIAZIDES Final REPORTe July 1, 1989-November 14, 1990 A6jd.%4gi0 F’or

Health assessment of gasoline and fuel oxygenate vapors: neurotoxicity evaluation.

PubMed

O'Callaghan, James P; Daughtrey, Wayne C; Clark, Charles R; Schreiner, Ceinwen A; White, Russell

2014-11-01

Sprague-Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess potential neurotoxicity of evaporative emissions. Test articles included vapor condensates prepared from "baseline gasoline" (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000mg/mg(3) and exposures were for 6h/day, 5days/week for 13weeks. The functional observation battery (FOB) with the addition of motor activity (MA) testing, hematoxylin and eosin staining of brain tissue sections, and brain regional analysis of glial fibrillary acidic protein (GFAP) were used to assess behavioral changes, traditional neuropathology and astrogliosis, respectively. FOB and MA data for all agents, except G/TBA, were negative. G/TBA behavioral effects resolved during recovery. Neuropathology was negative for all groups. Analyses of GFAP revealed increases in multiplebrain regions largely limited to males of the G/EtOH group, findings indicative of minor gliosis, most significantly in the cerebellum. Small changes (both increases and decreases) in GFAP were observed for other test agents but effects were not consistent across sex, brain region or exposure concentration. Copyright © 2014 Elsevier Inc. All rights reserved.

Direct screening of ground water samples for fuel oxygenates by headspace liquid phase microextraction-gas chromatography.

PubMed

Kaykhaii, Massoud; Mirbaloochzahi, Mohammad Reza

2008-12-01

The applicability of the headspace liquid phase microextraction and gas chromatography (HS-LPME/GC) for the expeditious and reliable screening of 68 well water samples for selected fuel oxygenates compounds, viz. methyl tertiary-butyl ether (MTBE), tertiary-amyl methyl ether (TAME), ethyl tertiary-butyl ether (ETBE) and n-butyl ethyl ether (n-BEE) has been evaluated. The method used 3 microl of 1:1 benzyl alcohol/1-octanol as extraction solvent, 20 min extraction time with stirring at 1,250 rpm, at 20 degrees C and salt addition of a mixture of 0.3 g ml(-1) sodium sulphate/0.1 g ml(-1) sodium chloride. The enrichment factors of this method were from 171 to 571. Limits of detection were in the range of 77-110 ng l(-1). The relative standard deviations (RSDs) at 0.05, 0.50 and 10.0 mg l(-1) of spiking levels were in the range of 1.28-6.80% with recoveries between 96.2 and 106.0%. Sixty-eight groundwater wells that were located near different gasoline reservoirs in eight largest cities of the Sistan and Balouchestan province were screened by the method. Eight contaminated wells were identified contained MTBE at levels between 0.3 and 1.7 mg l(-1). In all cases, other target analytes were at low concentrations or not detected.

Health assessment of gasoline and fuel oxygenate vapors: subchronic inhalation toxicity.

PubMed

Clark, Charles R; Schreiner, Ceinwen A; Parker, Craig M; Gray, Thomas M; Hoffman, Gary M

2014-11-01

Sprague Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess whether their use in gasoline influences the hazard of evaporative emissions. Test substances included vapor condensates prepared from an EPA described "baseline gasoline" (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000mg/m(3) and exposures were for 6h/day, 5days/week for 13weeks. A portion of the animals were maintained for a four week recovery period to determine the reversibility of potential adverse effects. Increased kidney weight and light hydrocarbon nephropathy (LHN) were observed in treated male rats in all studies which were reversible or nearly reversible after 4weeks recovery. LHN is unique to male rats and is not relevant to human toxicity. The no observed effect level (NOAEL) in all studies was 10,000mg/m(3), except for G/MTBE (<2000) and G/TBA (2000). The results provide evidence that use of the studied oxygenates are unlikely to increase the hazard of evaporative emissions during refueling, compared to those from gasoline alone. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Health assessment of gasoline and fuel oxygenate vapors: Neurotoxicity evaluation

PubMed Central

O’Callaghan, James P.; Daughtrey, Wayne C.; Clark, Charles R.; Schreiner, Ceinwen A.; White, Russell

2016-01-01

Sprague–Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess potential neurotoxicity of evaporative emissions. Test articles included vapor condensates prepared from “baseline gasoline” (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000 mg/mg3 and exposures were for 6 h/day, 5 days/week for 13 weeks. The functional observation battery (FOB) with the addition of motor activity (MA) testing, hematoxylin and eosin staining of brain tissue sections, and brain regional analysis of glial fibrillary acidic protein (GFAP) were used to assess behavioral changes, traditional neuropathology and astrogliosis, respectively. FOB and MA data for all agents, except G/TBA, were negative. G/TBA behavioral effects resolved during recovery. Neuropathology was negative for all groups. Analyses of GFAP revealed increases in multiple brain regions largely limited to males of the G/EtOH group, findings indicative of minor gliosis, most significantly in the cerebellum. Small changes (both increases and decreases) in GFAP were observed for other test agents but effects were not consistent across sex, brain region or exposure concentration. PMID:24879970

Hyperbranched PEGmethacrylate linear pDMAEMA block copolymer as an efficient non-viral gene delivery vector.

PubMed

Mathew, Asha; Cao, Hongliang; Collin, Estelle; Wang, Wenxin; Pandit, Abhay

2012-09-15

A unique hyperbranched polymeric system with a linear poly-2-dimethylaminoethyl methacrylate (pDMAEMA) block and a hyperbranched polyethylene glycol methyl ether methacrylate (PEGMEMA) and ethylene dimethacrylate (EGDMA) block was designed and synthesized via deactivation enhanced atom transfer radical polymerisation (DE-ATRP) for efficient gene delivery. Using this unique structure, with a linear pDMAEMA block, which efficiently binds to plasmid DNA (pDNA) and hyperbranched polyethylene glycol (PEG) based block as a protective shell, we were able to maintain high transfection levels without sacrificing cellular viability even at high doses. The transfection capability and cytotoxicity of the polymers over a range of pDNA concentration were analysed and the results were compared to commercially available transfection vectors such as polyethylene imine (branched PEI, 25 kDa), partially degraded poly(amido amine)dendrimer (dPAMAM; commercial name: SuperFect(®)) in fibroblasts and adipose tissue derived stem cells (ADSCs). Copyright © 2012 Elsevier B.V. All rights reserved.

Sequence control of phase separation and dewetting in PS/PVME blend thin films by changing molecular weight of PS.

PubMed

Xia, Tian; Qin, Yaping; Huang, Yajiang; Huang, Ting; Xu, Jianhui; Li, Youbing

2016-11-28

The morphology evolution mechanism of polystyrene (PS)/poly (vinyl methyl ether) (PVME) blend thin films with different PS molecular weights (M w ) was studied. It was found that the morphology evolution was closely related to the molecular weight asymmetry between PS and PVME. In the film where M w (PS) ≈ M w (PVME), dewetting happened at the interface between the bottom layer and substrate after SD phase separation. While in the film where M w (PS) > M w (PVME), dewetting happened at the interface between the middle PS/PVME blend layer and bottom PVME layer near the substrate prior to phase separation. The different sequences of phase separation and dewetting and different interface for dewetting occurrence were studied by regarding the competitive effects of viscoelasticity contrast between polymer components and preferential wetting between PVME and the substrate. The viscoelastic nature of the PS component played a crucial role in the sequence of phase separation and dewetting.

Effect of Polyhedral Oligomeric Silsesquioxane (POSS) Substituents on the Rheological Behavior in Butyl Methacrylate/POSS Copolymers

DTIC Science & Technology

2008-10-27

was repeated twice, dissolving the product in chloroform and diethyl ether, respectively. The polymer was dried at 60 °C under vacuum overnight...the Tg of the i Bu remains the same. Table 1. Tg for Butyl Methacrylate-co- Propyl Methacryl POSS Polymers with Various POSS Substituents

Thermal and Optical Properties of New Poly(amide-imide)/Nanocomposite Reinforced by Layer Silicate Containing Diphenyl Ether Moieties

NASA Astrophysics Data System (ADS)

Faghihi, Khalil; Faramarzi, Ellahe; Shabanian, Meisam

2011-04-01

New poly(amide-imide)-montmorillonite reinforced nanocomposites containing Bis(4-N-trimellitylimido) diphenyl ether moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 4 was synthesized by the direct polycondensation reaction of Bis(4-N-trimellitylimido) diphenyl ether 3 with 4,4'-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 10 and 20 mass% silicate particles respectively, were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The properties of nanocomposites films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

76 FR 63282 - Foreign-Trade Zone 140-Flint, Michigan; Application for Subzone; Dow Corning Corporation (Silicon...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-12

..., allylglycol, allyl glycidyl ether, methyl ethyl ketone, diacetone alcohol, octanoic acid, undecylenic acid, monoplex dos, ethyl silicate, sparc base, dimethylethanolamine, vinyltriacetoxysilane, dimethyl me...

Ether bond effects in quaternary ammonium and phosphonium ionic liquid-propanol solutions

NASA Astrophysics Data System (ADS)

Kishimura, Hiroaki; Kohki, Erica; Nakada, Ayumu; Tamatani, Kentaro; Abe, Hiroshi

2018-03-01

The liquid-liquid equilibria (LLE) of quaternary ammonium and phosphonium ionic liquid (IL)-propanol solutions were examined. The ILs contained cations with or without ether bonds; the anion in all the ILs was bis(trifluoromethanesulfonyl)imide (TFSI-). The cations without ether groups are tributylmethyl ammonium (N4441+), triethylpentyl phosphonium (P2225+), triethyloctyl phosphonium (P2228+), and tributylmethyl phosphonium (P4441+). The cations containing ether groups are N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium, (N122(2O1)+), triethyl(methoxymethyl) phosphonium (P222(1O1)+), and triethyl(2-methoxyethyl) phosphonium, (P222(2O1)+). Propanol isomer effect was observed to affect the LLEs, reflecting the geometrical factors and hydrophobicities of 1-propanol and 2-propanol. According to Raman spectroscopy, the TFSI- anion conformers in the mixtures were altered in the presence of ether bonds in the cations. The universal quasichemical (UNIQUAC) interaction parameters are consistent with significant factors affecting IL-propanol solutions, such as the type of cation (ammonium or phosphonium), ether bonds, TFSI- conformers, and propanol isomer effects.

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.

Hierarchical assembly of branched supramolecular polymers from (cyclic Peptide)-polymer conjugates.

PubMed

Koh, Ming Liang; Jolliffe, Katrina A; Perrier, Sébastien

2014-11-10

We report the synthesis and assembly of (N-methylated cyclic peptide)-polymer conjugates for which the cyclic peptide is attached to either the α- or both α- and ω- end groups of a polymer. A combination of chromatographic, spectroscopic, and scattering techniques reveals that the assembly of the conjugates follows a two-level hierarchy, initially driven by H-bond formation between two N-methylated cyclic peptides, followed by unspecific, noncovalent aggregation of this peptide into small domains that behave as branching points and lead to the formation of branched supramolecular polymers.

A Visible Light Initiating System for Free Radical Promoted Cationic Polymerization

DTIC Science & Technology

1994-02-02

identify the end groups in the polymer of cyclohexene oxide. N,N-Dimethylnaphthyl amine (DNA), a compound with high fluorescence quantum yield, was used...candidates to be polymerized via a cationic mechanism include cyclic ethers, cyclic formals and acetals, vinyl ethers, and epoxy compounds . Of these...reported sensitizer, bears two dimethylamino groups, is direct evidence that an aromatic amine can be present in a cationically photopolymerizable system

Sulfonated poly(ether ether ketone)/poly(vinyl alcohol) sensitizing system for solution photogeneration of small Ag, Au, and Cu crystallites.

PubMed

Korchev, A S; Shulyak, T S; Slaten, B L; Gale, W F; Mills, G

2005-04-28

Illumination of air-free aqueous solutions containing sulfonated poly(ether ether ketone) and poly(vinyl alcohol) with 350 nm light results in benzophenone ketyl radicals of the polyketone. The polymer radicals form with a quantum yield 0.02 and decay with a second-order rate constant 6 orders of magnitude lower than that of typical alpha-hydroxy radicals. Evidence is presented that the polymeric benzophenone ketyl radicals reduce Ag+, Cu2+, and AuCl4- to metal particles of nanometer dimensions. Decreases in the reduction rates with increasing Ag(I), Cu(II), and Au(III) concentrations are explained using a kinetic model in which the metal ions quench the excited state of the polymeric benzophenone groups, which forms the macromolecular radicals. Quenching is fastest for Ag+, whereas Cu2+ and AuCl4- exhibit similar rate constants. Particle formation becomes more complex as the number of equivalents needed to reduce the metal ions increases; the Au(III) system is an extreme case where the radical reactions operate in parallel with secondary light-initiated and thermal reduction channels. For each metal ion, the polymer-initiated photoreactions produce crystallites possessing distinct properties, such as a very strong plasmon in the Ag case or the narrow size distribution exhibited by Au particles.

Proton Conduction in Tröger's Base Linked Poly(crown ether)s.

PubMed

Patel, Hasmukh A; Selberg, John; Salah, Dhafer; Chen, Haoyuan; Liao, Yijun; Nalluri, Siva Krishna Mohan; Farha, Omar K; Snurr, Randall Q; Rolandi, Marco; Stoddart, J Fraser

2018-06-05

Exactly 50 years ago, the ground-breaking discovery of dibenzo[18]crown-6 (DB18C6) by Charles Pedersen, led to the use of DB18C6 as a receptor in supramolecular chemistry and a host in host‒guest chemistry. We have demonstrated proton conductivity in Tröger's base-linked polymers through hydrogen-bonded networks formed from adsorbed water molecules on the oxygen atoms of DB18C6 under humid conditions. Tröger's base-linked polymers - poly(TBL‒DB18C6)-t and poly(TBL‒DB18C6)-c - synthesized by the in situ alkylation and cyclization of either trans- or cis-di(aminobenzo) [18]crown-6 at room temperature have been isolated as high molecular weight polymers. The macromolecular structures of the isomeric poly(TBL‒DB18C6)s have been established by spectroscopic techniques and size-exclusion chromatography. The excellent solubility of these polymers in chloroform allows the formation of free-standing membranes which are thermally stable and also show stability under aqueous conditions. The hydrophilic nature of the DB18C6 building blocks in the polymer facilitates retention of the water as confirmed by water-vapor adsorption isotherms which show a 23 wt% water uptake. The adsorbed water is retained even after reducing the relative humidity to 25 %. The proton conductivity of poly(TBL‒DB18C6)-t which is found to be 1.4 x 10‒4 mS cm‒1 in a humid environment, arises from the hydrogen bonding and the associated proton hopping mechanism, as supported by a modeling study. In addition to proton conductivity, the Tröger's base-linked polymers reported here promise a wide range of applications where the sub-nanometer-sized cavities of the crown ethers and the robust film-forming ability are the governing factors in dictating their properties.

Low-temperature radiation copolymerization of tetrafluoroethylene with perfluorovinyl ethers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, I.P.; Pirozhnaya, L.N.; Loginova, N.N.

1986-12-01

The copolymerization of perfluorovinyl ethers with tetrafluoroethylene at low temperature was studied and compared with the process conducted with chemical initiation in bulk or aqueous medium. A calorimetric method was used for studying the kinetics of copolymerization, the phase state of the system, and the phase transition dynamics. Ampules containing the samples of monomers and mixtures were irradiated at 77/sup 0/K with /sup 60/Co ..gamma.. rays with a dose rate of 25 kGy/h. Radiolysis in the solid phase at 77/sup 0/K with a 130 kGy dose resulted in the formation of 0.5-1.0 wt.% of a polymer, and this polymer wasmore » soluble in the monomer.« less

Synthetic Polymers as Gasoline Thickening Agents

DTIC Science & Technology

1944-10-02

Polyvinyl Ethers —---- 71 2. Vistanex and Synthetic Rubbers — 73 3. Ethyl Cellulose 7* a. Solubility Studies 75 b. Gel Preparation — 75 c...Surveillance Tests —- 77 d. Static Firing Tests 78 e. Ethyl Cellulose as a Methacrylate Extender 78 f. Modification of Ethyl Cellulose 78 4...Miscellaneous Polymers 79 5. Emulsions 81 6. Pactices 81 B. Preparation of Polymers not nov in Commercial Production— ---——--— 81 1. Cellulose Esters

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

DOEpatents

Liepins, R.; Aldissi, M.

1984-07-27

Polymers with conjugated backbones, both polyacetylene and polyaromatic heterocyclic types, are doped with electron-donor agents to increase their electrical conductivity. The electron-donor agents are either electride dopants made in the presence of lithium or dopants derived from alkalides made in the presence of lithium. The dopants also contain a metal such as cesium and a trapping agent such as a crown ether.

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

DOEpatents

Liepins, Raimond; Aldissi, Mahmoud

1988-01-01

Polymers with conjugated backbones, both polyacetylene and polyaromatic heterocyclic types, are doped with electron-donor agents to increase their electrical conductivity. The electron-donor agents are either electride dopants made in the presence of lithium or dopants derived from alkalides made in the presence of lithium. The dopants also contain a metal such as cesium and a trapping agent such as a crown ether.

Oxime Ethers of (E)-11-Isonitrosostrychnine as Highly Potent Glycine Receptor Antagonists.

PubMed

Mohsen, Amal M Y; Mandour, Yasmine M; Sarukhanyan, Edita; Breitinger, Ulrike; Villmann, Carmen; Banoub, Maha M; Breitinger, Hans-Georg; Dandekar, Thomas; Holzgrabe, Ulrike; Sotriffer, Christoph; Jensen, Anders A; Zlotos, Darius P

2016-12-23

A series of (E)-11-isonitrosostrychnine oxime ethers, 2-aminostrychnine, (strychnine-2-yl)propionamide, 18-oxostrychnine, and N-propylstrychnine bromide were synthesized and evaluated pharmacologically at human α1 and α1β glycine receptors in a functional fluorescence-based and a whole-cell patch-clamp assay and in [ 3 H]strychnine binding studies. 2-Aminostrychnine and the methyl, allyl, and propargyl oxime ethers were the most potent α1 and α1β antagonists in the series, displaying IC 50 values similar to those of strychnine at the two receptors. Docking experiments to the strychnine binding site of the crystal structure of the α3 glycine receptor indicated the same orientation of the strychnine core for all analogues. For the most potent oxime ethers, the ether substituent was accommodated in a lipophilic receptor binding pocket. The findings identify the oxime hydroxy group as a suitable attachment point for linking two strychnine pharmacophores by a polymethylene spacer and are, therefore, important for the design of bivalent ligands targeting glycine receptors.

Stable carbon and hydrogen isotope analysis of methyl tert-butyl ether and tert-amyl methyl ether by purge and trap-gas chromatography-isotope ratio mass spectrometry: method evaluation and application.

PubMed

Kujawinski, Dorothea M; Stephan, Manuel; Jochmann, Maik A; Krajenke, Karen; Haas, Joe; Schmidt, Torsten C

2010-01-01

In order to monitor the behaviour of contaminants in the aqueous environment effective enrichment techniques often have to be employed due to their low concentrations. In this work a robust and sensitive purge and trap-gas chromatography-isotope ratio mass spectrometry method for carbon and hydrogen isotope analysis of fuel oxygenates in water is presented. The method evaluation included the determination of method detection limits, accuracy and reproducibility of deltaD and delta(13)C values. Lowest concentrations at which reliable delta(13)C values could be determined were 5 microg L(-1) and 28 microg L(-1) for TAME and MTBE, respectively. Stable deltaD values for MTBE and TAME could be achieved for concentrations as low as 25 and 50 microg L(-1). Good long-term reproducibility of delta(13)C and deltaD values was obtained for all target compounds. But deltaD values varying more than 5 per thousand were observed using different thermal conversion tubes. Thus, a correction of deltaD values in the analysis of groundwater samples was necessary to guarantee comparability of the results. The applicability of this method was shown by the analysis of groundwater samples from a gasoline contaminated site. By two dimensional isotope analysis two locations within this site were identified at which anaerobic and aerobic degradation of methyl tert-butyl ether occurred.

Sulfobutyl ether β-cyclodextrin (Captisol(®) ) and methyl β-cyclodextrin enhance and stabilize fluorescence of aqueous indocyanine green.

PubMed

DeDora, Daniel J; Suhrland, Cassandra; Goenka, Shilpi; Mullick Chowdhury, Sayan; Lalwani, Gaurav; Mujica-Parodi, Lilianne R; Sitharaman, Balaji

2016-10-01

As the only FDA-approved near-infrared fluorophore, indocyanine green (ICG) is commonly used to image vasculature in vivo. ICG degrades rapidly in solution, which limits its usefulness in certain applications, including time-sensitive surgical procedures. We propose formulations that address this shortcoming via complexation with β-cyclodextrin derivatives (β-CyD), which are known to create stabilizing inclusion complexes with hydrophobic molecules. Here, we complexed ICG with highly soluble methyl β-CyD and FDA-approved sulfobutyl ether β-CyD (Captisol(®) ) in aqueous solution. We measured the fluorescence of the complexes over 24 h. We found that both CyD+ICG complexes exhibit sustained fluorescence increases of >2.0× versus ICG in water and >20.0× in PBS. Using transmission electron microscopy, we found evidence of reduced aggregation in complexes versus ICG alone. We thus conclude that this reduction in aggregation helps mitigate fluorescence autoquenching of CyD+ICG complexes compared in ICG alone. We also found that while ICG complexed with methyl β-CyD severely reduced the viability of MRC-5 fibroblasts, ICG complexed with sulfobutyl ether β-CyD had no effect on viability. These results represent an important first step toward enhancing the utility of aqueous ICG by reducing aggregation-dependent fluorescence degradation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1457-1464, 2016. © 2015 Wiley Periodicals, Inc.

Ionic-liquid-mediated poly(dimethylsiloxane)- grafted carbon nanotube fiber prepared by the sol-gel technique for the head space solid-phase microextraction of methyl tert-butyl ether using GC.

PubMed

Vatani, Hossein; Yazdi, Ali Sarafraz

2014-01-01

A headspace solid-phase microextraction method was developed for the preconcentration and extraction of methyl tert-butyl ether. An ionic-liquid-mediated multiwalled carbon nanotube-poly(dimethylsiloxane) hybrid coating, which was prepared by covalent functionalization of multiwalled carbon nanotubes with hydroxyl-terminated poly(dimethylsiloxane) using the sol-gel technique, was used as solid-phase microextraction adsorbent. This innovative fiber exhibited a highly porous surface structure, high thermal stability (at least 320°C) and long lifespan (over 210 uses). Potential factors affecting the extraction efficiency were optimized. Under the optimum conditions, the method LOD (S/N = 3) was 0.007 ng/mL and the LOQ (S/N = 10) was 0.03 ng/mL. The calibration curve was linear in the range of 0.03-200 ng/mL. The RSDs for one fiber (repeatability, n = 5) at three different concentrations (0.05, 1, and 150 ng/mL) were 5.1, 4.2, and 4.6% and for the fibers obtained from different batches (reproducibility, n = 3) were 6.5, 5.9, and 6.3%, respectively. The developed method was successfully applied to the determination of methyl tert-butyl ether in different real water samples on three consecutive days. The relative recoveries for the spiked samples with 0.05, 1, and 150 ng/mL were between 94-104%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cannabidiol-2',6'-dimethyl ether, a cannabidiol derivative, is a highly potent and selective 15-lipoxygenase inhibitor.

PubMed

Takeda, Shuso; Usami, Noriyuki; Yamamoto, Ikuo; Watanabe, Kazuhito

2009-08-01

The inhibitory effect of nordihydroguaiaretic acid (NDGA) (a nonselective lipoxygenase (LOX) inhibitor)-mediated 15-LOX inhibition has been reported to be affected by modification of its catechol ring, such as methylation of the hydroxyl group. Cannabidiol (CBD), one of the major components of marijuana, is known to inhibit LOX activity. Based on the phenomenon observed in NDGA, we investigated whether or not methylation of CBD affects its inhibitory potential against 15-LOX, because CBD contains a resorcinol ring, which is an isomer of catechol. Although CBD inhibited 15-LOX activity with an IC(50) value (50% inhibition concentration) of 2.56 microM, its monomethylated and dimethylated derivatives, CBD-2'-monomethyl ether and CBD-2',6'-dimethyl ether (CBDD), inhibited 15-LOX activity more strongly than CBD. The number of methyl groups in the resorcinol moiety of CBD (as a prototype) appears to be a key determinant for potency and selectivity in inhibition of 15-LOX. The IC(50) value of 15-LOX inhibition by CBDD is 0.28 microM, and the inhibition selectivity for 15-LOX (i.e., the 5-LOX/15-LOX ratio of IC(50) values) is more than 700. Among LOX isoforms, 15-LOX is known to be able to oxygenate cholesterol esters in the low-density lipoprotein (LDL) particle (i.e., the formation of oxidized LDL). Thus, 15-LOX is suggested to be involved in development of atherosclerosis, and CBDD may be a useful prototype for producing medicines for atherosclerosis.

Study on the molecularly imprinted polymers with methyl-testosterone as the template.

PubMed

Yang, Minli; Gu, Wancheng; Sun, Li; Zhang, Feng; Ling, Yun; Chu, Xiaogang; Wang, Daning

2010-04-15

Molecularly imprinted polymers (MIPs) using methyl-testosterone as the template, methacrylic acid (MAA) as the monomer and ethylene glycol dimethacrylate (EDMA) as the crosslinker were prepared by precipitation polymerization. The morphology of the obtained particles was characterized by scanning electron microscopy (SEM) and the pore size was measured by BET. Then, the specificity and selectivity of the MIPs were evaluated using the equilibrium rebinding experiments. Besides, the MIPs were also used as the stationary phase of HPLC column and the retention behaviour to the template and analogues was confirmed using HPLC-MS-MS. Finally, the real application of the methyl-testosterone imprinted polymers was evaluated using SPE procedure with the spiked tap water and lake water. The results indicated that the prepared methyl-testosterone imprinted polymer showed specific rebinding ability to its template and could retain the template strongly compared with other structural analogues. At the same time, the MIPs could be used as SPE column to enrich methyl-testosterone in the lake water and show broad prospects in real samples. (c) 2009 Elsevier B.V. All rights reserved.

Self-assembly of BODIPY based pH-sensitive near-infrared polymeric micelles for drug controlled delivery and fluorescence imaging applications

NASA Astrophysics Data System (ADS)

Liu, Xiaodong; Chen, Bizheng; Li, Xiaojun; Zhang, Lifen; Xu, Yujie; Liu, Zhuang; Cheng, Zhenping; Zhu, Xiulin

2015-10-01

Responsive block copolymer micelles emerging as promising imaging and drug delivery systems show high stability and on-demand drug release activities. Herein, we developed self-assembled pH-responsive NIR emission micelles entrapped with doxorubicin (DOX) within the cores by the electrostatic interactions for fluorescence imaging and chemotherapy applications. The block copolymer, poly(methacrylic acid)-block-poly[(poly(ethylene glycol) methyl ether methacrylate)-co-boron dipyrromethene derivatives] (PMAA-b-P(PEGMA-co-BODIPY)), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, and the molecular weight distribution of this copolymer was narrow (Mw/Mn = 1.31). The NIR fluorescence enhancement induced by the phenol/phenolate interconversion equilibrium works as a switch in response to the intracellular pH fluctuations. DOX-loaded PMAA-b-P(PEGMA-co-BODIPY) micelles can detect the physiological pH fluctuations with a pKa near physiological conditions (~7.52), and showed pH-responsive collapse and an obvious acid promoted anticancer drug release behavior (over 58.8-62.8% in 10 h). Real-time imaging of intracellular pH variations was performed and a significant chemotherapy effect was demonstrated against HeLa cells.Responsive block copolymer micelles emerging as promising imaging and drug delivery systems show high stability and on-demand drug release activities. Herein, we developed self-assembled pH-responsive NIR emission micelles entrapped with doxorubicin (DOX) within the cores by the electrostatic interactions for fluorescence imaging and chemotherapy applications. The block copolymer, poly(methacrylic acid)-block-poly[(poly(ethylene glycol) methyl ether methacrylate)-co-boron dipyrromethene derivatives] (PMAA-b-P(PEGMA-co-BODIPY)), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, and the molecular weight distribution of this copolymer was narrow (Mw/Mn = 1.31). The NIR fluorescence enhancement induced by the phenol/phenolate interconversion equilibrium works as a switch in response to the intracellular pH fluctuations. DOX-loaded PMAA-b-P(PEGMA-co-BODIPY) micelles can detect the physiological pH fluctuations with a pKa near physiological conditions (~7.52), and showed pH-responsive collapse and an obvious acid promoted anticancer drug release behavior (over 58.8-62.8% in 10 h). Real-time imaging of intracellular pH variations was performed and a significant chemotherapy effect was demonstrated against HeLa cells. Electronic supplementary information (ESI) available: GPC, UV/vis, fluorescence, and MTT data of the as-prepared polymers; 1H NMR, 13C NMR, HRMS and FT-IR of organic molecules and polymers. See DOI: 10.1039/c5nr04655f

Molecular structure impacts on secondary organic aerosol formation from glycol ethers

NASA Astrophysics Data System (ADS)

Li, Lijie; Cocker, David R.

2018-05-01

Glycol ethers, a class of widely used solvents in consumer products, are often considered exempt as volatile organic compounds based on their vapor pressure or boiling points by regulatory agencies. However, recent studies found that glycol ethers volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents indicating the potential of glycol ethers to form secondary organic aerosol (SOA). This is the first work on SOA formation from glycol ethers. The impact of molecular structure, specifically -OH, on SOA formation from glycol ethers and related ethers are investigated in the work. Ethers with and without -OH, with methyl group hindrance on -OH and with -OH at different location are studied in the presence of NOX and under "NOX free" conditions. Photooxidation experiments under different oxidation conditions confirm that the processing of ethers is a combination of carbonyl formation, cyclization and fragmentation. Bulk SOA chemical composition analysis and oxidation products identified in both gas and particle phase suggests that the presence and location of -OH in the carbon bond of ethers determine the occurrence of cyclization mechanism during ether oxidation. The cyclization is proposed as a critical SOA formation mechanism to prevent the formation of volatile compounds from fragmentation during the oxidation of ethers. Glycol ethers with -CH2-O-CH2CH2OH structure is found to readily form cyclization products, especially with the presence of NOx, which is more relevant to urban atmospheric conditions than without NOx. Glycol ethers are evaluated as dominating SOA precursors among all ethers studied. It is estimated that the contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources. The contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources and will play a more important role in future anthropogenic SOA formation.

Lewis acid catalyzed ring-opening polymerization of natural epoxy oil (Euphorbia oil) in carbon dioxide media

USDA-ARS?s Scientific Manuscript database

In an attempt to build up useful application of plant oil based polymers, natural epoxy oil (euphorbia oil-EuO) was polymerized in liquid carbon dioxide in the presence of Lewis acid catalyst [Boron trifluoride diethyl etherate (BF3•OEt2)]. The resulting polymers (RPEuO) were characterized by FTIR ...

Development of a category approach to predict the testicular toxicity of chemical substances structurally related to ethylene glycol methyl ether.

PubMed

Yamada, Takashi; Tanaka, Yushiro; Hasegawa, Ryuichi; Sakuratani, Yuki; Yamazoe, Yasushi; Ono, Atsushi; Hirose, Akihiko; Hayashi, Makoto

2014-12-01

We propose a category approach to assessing the testicular toxicity of chemicals with a similar structure to ethylene glycol methyl ether (EGME). Based on toxicity information for EGME and related chemicals and accompanied by adverse outcome pathway information on the testicular toxicity of EGME, this category was defined as chemicals that are metabolized to methoxy- or ethoxyacetic acid, a substance responsible for testicular toxicity. A Japanese chemical inventory was screened using the Hazard Evaluation Support System, which we have developed to support a category approach for predicting the repeated-dose toxicity of chemical substances. Quantitative metabolic information on the related chemicals was then considered, and seventeen chemicals were finally obtained from the inventory as a shortlist for the category. Available data in the literature shows that chemicals for which information is available on the metabolic formation of EGME, ethylene glycol ethyl ether, methoxy- or ethoxyacetic acid do in fact possess testicular toxicity, suggesting that testicular toxicity is a concern, due to metabolic activation, for the remaining chemicals. Our results clearly demonstrate practical utility of AOP-based category approach for predicting repeated-dose toxicity of chemicals. Copyright © 2014 Elsevier Inc. All rights reserved.

Alkyl ether lipids, ion channels and lipid raft reorganization in cancer therapy.

PubMed

Jaffrès, Paul-Alain; Gajate, Consuelo; Bouchet, Ana Maria; Couthon-Gourvès, Hélène; Chantôme, Aurélie; Potier-Cartereau, Marie; Besson, Pierre; Bougnoux, Philippe; Mollinedo, Faustino; Vandier, Christophe

2016-09-01

Synthetic alkyl lipids, such as the ether lipids edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine) and ohmline (1-O-hexadecyl-2-O-methyl-rac-glycero-3-β-lactose), are forming a class of antitumor agents that target cell membranes to induce apoptosis and to decrease cell migration/invasion, leading to the inhibition of tumor and metastasis development. In this review, we present the structure-activity relationship of edelfosine and ohmline, and we point out differences and similarities between these two amphiphilic compounds. We also discuss the mechanisms of action of these synthetic alkyl ether lipids (involving, among other structures and molecules, membrane domains, Fas/CD95 death receptor signaling, and ion channels), and highlight a key role for lipid rafts in the underlying process. The reorganization of lipid raft membrane domains induced by these alkyl lipids affects the function of death receptors and ion channels, thus leading to apoptosis and/or inhibition of cancer cell migration. The possible therapeutic use of these alkyl lipids and the clinical perspectives for these lipids in prevention or/and treatment of tumor development and metastasis are also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Synthesis and Characterization of Perfluoroalkyl Heterocyclic Elastomers

DTIC Science & Technology

Perfluoro -4,9,14,19-tetraoxadocosane diimidate-dihydroxybenzidine polymers have been prepared from carefully purified monomers. DTA measurements show...attained was 0.28. Polymers prepared from dihydroxybenzidine and methyl perfluoro -4,9-dioxadodecanediimidate soften at about 65C. with a Tg near 21C...of 3,3’-diamino-4,4’-dihydroxybenzophenone with methyl perfluorosebacimidate . The polymer softens at 205C., forms films and has excellent thermal

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.

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.

Slow-Releasing Oxygen Source

EPA Science Inventory

Subsurface pollution is an environmental issue of great concern in the United States and around the world. Bioremediation has proven to be an effective and environmentally preferable treatment for biodegradable pollutants, such as methyl tertiary butyl ether, toluene, ethylbenze...

Effect of Methyl Substitution on the N-H···O Interaction in Complexes of Pyrrole with Water, Methanol, and Dimethyl Ether: Matrix Isolation Infrared Spectroscopy and ab Initio Computational Studies.

PubMed

Sarkar, Shubhra; Ramanathan, N; Sundararajan, K

2018-03-08

Hydrogen-bonded interactions of pyrrole with water and methanol have been studied using matrix isolation infrared spectroscopy and compared with the calculation performed on dimethyl ether. Computations carried out at MP2/aug-cc-pVDZ level of theory yielded two minima for the pyrrole-water and pyrrole-methanol complexes. The global and local minima correspond to the N-H···O and O-H···π complexes, respectively, where the N-H group of pyrrole interacts with oxygen of water/methanol and O-H of water and methanol interacts with the π cloud of pyrrole. Computations performed on the pyrrole-dimethyl ether gave only N-H···O type complex. From the experimental vibrational wavenumber shifts in the N-H stretching and N-H bending modes of pyrrole, as well as in the O-H stretching modes of water and methanol, the 1:1 N-H···O complexes were discerned. The strength of the N-H···O hydrogen bond and the corresponding shift in the N-H stretching vibrational wavenumbers increases in the order pyrrole-water < pyrrole-methanol < pyrrole-dimethyl ether, where a proton is successively replaced by a methyl group. Apart from the 1:1 complexes, higher clusters of 2:1 and 1:2 pyrrole-water and pyrrole-methanol complexes were also generated in N 2 matrix. Atoms in molecules and natural bond orbital analyses were carried out at the MP2/aug-cc-pVDZ level to understand the nature of interaction in the 1:1 pyrrole-water, pyrrole-methanol and pyrrole-dimethyl ether complexes.

Hydroperoxide Traces in Common Cyclic Ethers as Initiators for Controlled RAFT Polymerizations.

PubMed

Eggers, Steffen; Abetz, Volker

2018-04-01

Herein, a reversible addition-fragmentation chain transfer (RAFT) polymerization is introduced for reactive monomers like N-acryloylpyrrolidine or N,N-dimethylacrylamide working without a conventional radical initiator. As a very straightforward proof of principle, the method takes advantage of the usually inconvenient radical-generating hydroperoxide contaminations in cyclic ethers like tetrahydrofuran or 1,4-dioxane, which are very common solvents in polymer sciences. The polymerizations are surprisingly well controlled and the polymers can be extended with a second block, indicating their high livingness. "Solvent-initiated" RAFT polymerizations hence prove to be a feasible access to tailored materials with minimal experimental effort and standard laboratory equipment, only requiring the following ingredients: hydroperoxide-contaminated solvent, monomer, and RAFT agent. In other respects, however, the potential coinitiating ability of the used solvent is to be considered when investigating the kinetics of RAFT polymerizations or aiming for the synthesis of high-livingness polymers, e.g., multiblock copolymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design, synthesis, and characterization of new phosphazene related materials, and study the structure property correlations

NASA Astrophysics Data System (ADS)

Tian, Zhicheng

The work described in this thesis is divided into three major parts, and all of which involve the exploration of the chemistry of polyphosphazenes. The first part (chapters 2 and 3) of my research is synthesis and study polyphoshazenes for biomedical applications, including polymer drug conjugates and injectable hydrogels for drug or biomolecule delivery. The second part (chapters 4 and 5) focuses on the synthesis of several organic/inorganic hybrid polymeric structures, such as diblock, star, brush and palm tree copolymers using living cationic polymerization and atom transfer radical polymerization techniques. The last part (chapters 6 and 7) is about exploratory synthesis of new polymeric structures with fluorinated side groups or cycloaliphatic side groups, and the study of new structure property relationships. Chapter 1 is an outline of the fundamental concepts for polymeric materials, as such the history, important definitions, and some introductory material for to polymer chemistry and physics. The chemistry and applications of phopshazenes is also briefly described. Chapter 2 is a description of the design, synthesis, and characterization of development of a new class of polymer drug conjugate materials based on biodegradable polyphosphazenes and antibiotics. Poly(dichlorophosphazene), synthesized by a thermal ring opening polymerization, was reacted with up to 25 mol% of ciprofloxacin or norfloxacin and three different amino acid esters (glycine, alanine, or phenylalanine) as cosubstituents via macromolecular substitutions. Nano/microfibers of several selected polymers were prepared by an electrospinning technique. Chapter 3 is concerned with the development of a class of injectable and biodegradable hydrogels based on water-soluble poly(organophosphazenes) containing oligo(ethylene glycol) methyl ethers and glycine ethyl esters. The hydrogels can be obtained by mixing alpha-cyclodextrin aqueous solution and poly(organophosphazenes) aqueous solution in various gelation rates depending on the polymer structures and the concentrations. The rheological measurements of the supramolecular hydrogels indicate a fast gelation process and flowable character under a large stain. Chapter 4 outlines the preparation of a number of amphiphilic diblock copolymers based on poly[bis(trifluoroethoxy)phosphazene] (TFE) as the hydrophobic block and poly(dimethylaminoethylmethacrylate) (PDMAEMA) as the hydrophilic block. The TFE block was synthesized first by the controlled living cationic polymerization of a phosphoranimine, followed by replacement of all the chlorine atoms using sodium trifluoroethoxide. To allow for the growth of the PDMAEMA block, 3-azidopropyl-2-bromo-2-methylpropanoate, an atom transfer radical polymerization (ATRP) initiator, was grafted onto the endcap of the TFE block via the 'click' reaction followed by the ATRP of 2-(dimethylamino)ethyl methacrylate (DMAEMA). Chapter 5 is a report on the design and assembly of polyphosphazene materials based on the non-covalent "host--guest" interactions either at the terminus of the polymeric main-chains or the pendant side-chains. The supramolecular interaction at the main chain terminus was used to produce amphiphilic palm-tree like pseudo-block copolymers via host-guest interactions between an adamantane end-functionalized polyphosphazene and a 4-armed beta-cyclodextrin (beta-CD) initiated poly[poly(ethylene glycol) methyl ether methacylate] branched-star type polymer. The formation of micelles of the obtained amphiphiles was analyzed by fluorescence technique, dynamic light scattering, transmission electron microscopy, and atomic force microscopy. Chapter 6 is an investigation of the influence of bulky fluoroalkoxy side groups on the properties of polyphosphazenes. A new series of mixed-substituent high polymeric poly(fluoroalkoxyphosphazenes) containing trifluoroethoxy and branched fluoroalkoxy side groups was synthesized and characterized by NMR and GPC methods. These polymers contained 19--29 mol% of di-branched hexafluoropropoxy groups or 4mol% of tri-branched tert-perfluorobutoxy groups, which serve as regio-irregularities to reduce the macromolecular microcrystallinity. The structure--property correlations of the polymers were then analyzed and interpreted by several techniques: specifically by the thermal behavior by DSC and TGA methods, the crystallinity by wide-angle X-ray diffraction, and the surface hydrophobicity/oleophobicity by contact angle measurements. (Abstract shortened by UMI.). Chapter 7 is an outline of the exploratory synthesis of a new series of phosphazene model cyclic trimers and single- and mixed- substituent high polymers containing cyclic aliphatic rings, --CnH2n-1 (where n = 4--8). The cylco-aliphatic side group containing phosphazenes expand the structural and property boundaries of phosphazene chemistry, and suggest additional approaches for studying slow macromolecular substitution reactions and substituent exchange reactions.

Role of sulfonation in the stability, reactivity, and selectivity of poly(ether imide) used to develop ion exchange membranes: DFT study with application to fuel cells.

PubMed

López-Chávez, Ernesto; Peña-Castañeda, Yésica A; de la Portilla-Maldonado, L César; Guzmán-Pantoja, Javier; Martínez-Magadán, José Manuel; Oviedo-Roa, Raúl; de Landa Castillo-Alvarado, Fray; Cruz-Torres, Armando

2014-07-01

The design of polymer electrolyte membranes for fuel cells must satisfy two equally important fundamental principles: optimization of the reactivity and the selectivity in order to improve the ion transport properties of the membrane as well as its long-term stability in the hydrated state at high temperature (above 100 °C). A study utilizing density functional theory (DFT) to elucidate the effect of the degree of sulfonation on the chemical stability, reactivity, and selectivity of poly(ether imide) (PEI), which allows the ionic transport properties of the membrane to be predicted, is reported here. Sulfonated poly(ether imide) (SPEI) structures with (-SO3H) n (n = 1-6) groups were built and optimized in order to calculate the above properties as functions of the number of sulfonyl groups. A comparative study demonstrated that the SPEI with four sulfonyl groups in its backbone is the polymer with the properties best suited for use in fuel cells.

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 Na 3 V 2 (PO 4 ) 3 cathode, MoS 2 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 Na 3 V 2 (PO 4 ) 3 /MoS 2 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.

Organic arsenicals as efficient and highly specific linkers for protein/peptide-polymer conjugation.

PubMed

Wilson, Paul; Anastasaki, Athina; Owen, Matthew R; Kempe, Kristian; Haddleton, David M; Mann, Sarah K; Johnston, Angus P R; Quinn, John F; Whittaker, Michael R; Hogg, Philip J; Davis, Thomas P

2015-04-01

The entropy-driven affinity of trivalent (in)organic arsenicals for closely spaced dithiols has been exploited to develop a novel route to peptide/protein-polymer conjugation. A trivalent arsenous acid (As(III)) derivative (1) obtained from p-arsanilic acid (As(V)) was shown to readily undergo conjugation to the therapeutic peptide salmon calcitonin (sCT) via bridging of the Cys(1)-Cys(7) disulfide, which was verified by RP-HPLC and MALDI-ToF-MS. Conjugation was shown to proceed rapidly (t < 2 min) in situ and stoichiometrically through sequential reduction-conjugation protocols, therefore exhibiting conjugation efficiencies equivalent to those reported for the current leading disulfide-bond targeting strategies. Furthermore, using bovine serum albumin as a model protein, the trivalent organic arsenical 1 was found to demonstrate enhanced specificity for disulfide-bond bridging in the presence of free cysteine residues relative to established maleimide functional reagents. This specificity represents a shift toward potential orthogonality, by clearly distinguishing between the reactivity of mono- and disulfide-derived (vicinal or neighbors-through-space) dithiols. Finally, p-arsanilic acid was transformed into an initiator for aqueous single electron-transfer living radical polymerization, allowing the synthesis of hydrophilic arsenic-functional polymers which were shown to exhibit negligible cytotoxicity relative to a small molecule organic arsenical, and an unfunctionalized polymer control. Poly(poly[ethylene glycol] methyl ether acrylate) (PPEGA480, DPn = 10, Mn,NMR = 4900 g·mol(-1), Đ = 1.07) possessing a pentavalent arsenic acid (As(V)) α-chain end was transformed into trivalent As(III) post-polymerization via initial reduction by biological reducing agent glutathione (GSH), followed by binding of GSH. Conjugation of the resulting As(III)-functional polymer to sCT was realized within 35 min as indicated by RP-HPLC and verified later by thermodynamically driven release of sCT, from the conjugate, in the presence of strong chelating reagent ethanedithiol.

Bright conjugated polymer nanoparticles containing a biodegradable shell produced at high yields and with tuneable optical properties by a scalable microfluidic device.

PubMed

Abelha, T F; Phillips, T W; Bannock, J H; Nightingale, A M; Dreiss, C A; Kemal, E; Urbano, L; deMello, J C; Green, M; Dailey, L A

2017-02-02

This study compares the performance of a microfluidic technique and a conventional bulk method to manufacture conjugated polymer nanoparticles (CPNs) embedded within a biodegradable poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG 5K -PLGA 55K ) matrix. The influence of PEG 5K -PLGA 55K and conjugated polymers cyano-substituted poly(p-phenylene vinylene) (CN-PPV) and poly(9,9-dioctylfluorene-2,1,3-benzothiadiazole) (F8BT) on the physicochemical properties of the CPNs was also evaluated. Both techniques enabled CPN production with high end product yields (∼70-95%). However, while the bulk technique (solvent displacement) under optimal conditions generated small nanoparticles (∼70-100 nm) with similar optical properties (quantum yields ∼35%), the microfluidic approach produced larger CPNs (140-260 nm) with significantly superior quantum yields (49-55%) and tailored emission spectra. CPNs containing CN-PPV showed smaller size distributions and tuneable emission spectra compared to F8BT systems prepared under the same conditions. The presence of PEG 5K -PLGA 55K did not affect the size or optical properties of the CPNs and provided a neutral net electric charge as is often required for biomedical applications. The microfluidics flow-based device was successfully used for the continuous preparation of CPNs over a 24 hour period. On the basis of the results presented here, it can be concluded that the microfluidic device used in this study can be used to optimize the production of bright CPNs with tailored properties with good reproducibility.

Health assessment of gasoline and fuel oxygenate vapors: reproductive toxicity assessment.

PubMed

Gray, Thomas M; Steup, David; Roberts, Linda G; O'Callaghan, James P; Hoffman, Gary; Schreiner, Ceinwen A; Clark, Charles R

2014-11-01

Vapor condensates of baseline gasoline (BGVC), or gasoline-blended with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA) were evaluated for reproductive toxicity in rats at target concentrations of 2000, 10,000, or 20,000mg/m(3), 6h/day, 7days/week. BGVC and G/MTBE were assessed over two generations, the others for one generation. BGVC and G/MTBE F1 offspring were evaluated for neuropathology and changes in regional brain glial fibrillary acidic protein content. No neurotoxicity was observed. Male kidney weight was increased consistent with light hydrocarbon nephropathy. In adult rats, decreased body weight gain and increased liver weight were seen. Spleen weight decreased in adults and pups exposed to G/TBA. No pathological changes to reproductive organs occurred in any study. Decreased food consumption was seen in G/TAME lactating females. Transient decreases in G/TAME offspring weights were observed during lactation. Except for a minor increase in time to mating in G/TBA which did not affect other reproductive parameters, there were no adverse reproductive findings. The NOAEL for reproductive and offspring parameters was 20,000mg/m(3) for all vapor condensates except for lower offspring NOAELs of 10,000mg/m(3) for G/TBA and 2000mg/m(3) for G/TAME. Copyright © 2014 Elsevier Inc. All rights reserved.

Health assessment of gasoline and fuel oxygenate vapors: immunotoxicity evaluation.

PubMed

White, Kimber L; Peachee, Vanessa L; Armstrong, Sarah R; Twerdok, Lorraine E; Clark, Charles R; Schreiner, Ceinwen A

2014-11-01

Female Sprague Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess potential immunotoxicity of evaporative emissions. Test articles included vapor condensates prepared from "baseline gasoline" (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000mg/mg(3) administered for 6h/day, 5days/week for 4weeks. The antibody-forming cell (AFC) response to the T-dependent antigen, sheep erythrocyte (sRBC), was used to determine the effects of the gasoline vapor condensates on the humoral components of the immune system. Exposure to BGVC, G/MTBE, G/TAME, and G/TBA did not result in significant changes in the IgM AFC response to sRBC, when evaluated as either specific activity (AFC/10(6) spleen cells) or as total spleen activity (AFC/spleen). Exposure to G/EtOH and G/DIPE resulted in a dose-dependent decrease in the AFC response, reaching the level of statistical significance only at the high 20,000mg/m(3) level. Exposure to G/ETBE resulted in a statistically significant decrease in the AFC response at the middle (10,000mg/m(3)) and high (20,000mg/m(3)) exposure concentrations. Copyright © 2014 Elsevier Inc. All rights reserved.

Health assessment of gasoline and fuel oxygenate vapors: Reproductive toxicity assessment

PubMed Central

Gray, Thomas M.; Steup, David; Roberts, Linda G.; O'Callaghan, James P.; Hoffman, Gary; Schreiner, Ceinwen A.; Clark, Charles R.

2016-01-01

Vapor condensates of baseline gasoline (BGVC), or gasoline-blended with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA) were evaluated for reproductive toxicity in rats at target concentrations of 2000, 10,000, or 20,000 mg/m3, 6 h/day, 7 days/week. BGVC and G/MTBE were assessed over two generations, the others for one generation. BGVC and G/MTBE F1 offspring were evaluated for neuropathology and changes in regional brain glial fibrillary acidic protein content. No neurotoxicity was observed. Male kidney weight was increased consistent with light hydrocarbon nephropathy. In adult rats, decreased body weight gain and increased liver weight were seen. Spleen weight decreased in adults and pups exposed to G/TBA. No pathological changes to reproductive organs occurred in any study. Decreased food consumption was seen in G/TAME lactating females. Transient decreases in G/TAME off-spring weights were observed during lactation. Except for a minor increase in time to mating in G/TBA which did not affect other reproductive parameters, there were no adverse reproductive findings. The NOAEL for reproductive and offspring parameters was 20,000 mg/m3 for all vapor condensates except for lower offspring NOAELs of 10,000 mg/m3 for G/TBA and 2000 mg/m3 for G/TAME. PMID:24813181

Health assessment of gasoline and fuel oxygenate vapors: micronucleus and sister chromatid exchange evaluations.

PubMed

Schreiner, Ceinwen A; Hoffman, Gary M; Gudi, Ramadevi; Clark, Charles R

2014-11-01

Micronucleus and sister chromatid exchange (SCE) tests were performed for vapor condensate of baseline gasoline (BGVC), or gasoline with oxygenates, methyl tert-butyl ether (G/MTBE), ethyl tert butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), t-butyl alcohol (TBA), or ethanol (G/EtOH). Sprague Dawley rats (the same 5/sex/group for both endpoints) were exposed to 0, 2000, 10,000, or 20,000mg/m(3) of each condensate, 6h/day, 5days/week over 4weeks. Positive controls (5/sex/test) were given cyclophosphamide IP, 24h prior to sacrifice at 5mg/kg (SCE test) and 40mg/kg (micronucleus test). Blood was collected from the abdominal aorta for the SCE test and femurs removed for the micronucleus test. Blood cell cultures were treated with 5μg/ml bromodeoxyuridine (BrdU) for SCE evaluation. No significant increases in micronucleated immature erythrocytes were observed for any test material. Statistically significant increases in SCE were observed in rats given BGVC alone or in female rats given G/MTBE. G/TAME induced increased SCE in both sexes at the highest dose only. Although DNA perturbation was observed for several samples, DNA damage was not expressed as increased micronuclei in bone marrow cells. Inclusion of oxygenates in gasoline did not increase the effects of gasoline alone or produce a cytogenetic hazard. Copyright © 2014 Elsevier Inc. All rights reserved.

Perfluorocyclobutane containing aromatic ether polymers as planarization materials for alternative magnetic media substrates

NASA Astrophysics Data System (ADS)

Perettie, Donald J.; Judy, Jack; Chen, Qixu; Keirstead, Rick

1994-11-01

Perfluorocyclobutane aromatic ether polymers (PFCB) are being researched as planarization materials for alternative magnetic media substrates allowing smoother surfaces for lower head flying recording. The results of current work reported herein have shown that PFCB can be used to affect surfaces on canasite with R(sub A)'s less than 2 nm. In addition, magnetic media can be produced of a quality comparative to that obtained on standard NiP-coated Al as well as that produced on regular canasite with equivalent coercivities at about 1500-1600 Oe and squarenesses of 0.8 or better. In addition to the above magnetic properties the recording performance was excellent with signal-to-noise ratios of planarized media 3.5 dB higher than that on regular canasite.

40 CFR Table 8 to Subpart Ffff of... - Partially Soluble Hazardous Air Pollutants

Code of Federal Regulations, 2011 CFR

2011-07-01

... acrylate 140885 34. Ethylbenzene 100414 35. Ethylene oxide 75218 36. Ethylidene dichloride 75343 37.... Methyl-t-butyl ether 1634044 42. Methylene chloride 75092 43. N-hexane 110543 44. N,N-dimethylaniline...

Ultrasound promoted N-alkylation of pyrrole using potassium superoxide as base in crown ether.

PubMed

Yim, E S; Park, M K; Han, B H

1997-04-01

Ultrasound accelerates the N-alkylation of pyrrole by alkylating reagents using potassium superoxide as base in the presence of 18-crown-6. A much lower yield of N-alkylated pyrrole was realized in the absence of ultrasound. N-alkylating reagents employed for pyrrole are methyl iodide, ethyl bromide, benzyl bromide, as well as acrylonitrile allyl cyanide and methyl acrylate. In an extension of this work, we have found that ultrasound was not necessary for the N-alkylation of indole and alkyl amine, such as diphenyl amine and piperidine with alkyl halides using our reagents. In all cases we observed that the 18-crown-6 catalyzed N-alkylation reaction gives higher yields of N-alkylated products than that without crown ether, when potassium superoxide was used as base. These observations are probably due to the potassium-crown complex which can be released when the reaction goes to completion.

The rapid detection of methyl tert-butyl ether (MtBE) in water using a prototype gas sensor system.

PubMed

de Lacy Costello, B P J; Sivanand, P S; Ratcliffe, N M; Reynolds, D M

2005-01-01

The gasoline additive Methyl-tertiary-Butyl Ether (MtBE) is the second most common contaminant of groundwater in the USA and represents an important soil contaminant. This compound has been detected in the groundwater in at least 27 states as a result of leaking underground storage facilities (gasoline storage tanks and pipelines). Since the health effects of MtBE are unclear the potential threat to drinking water supplies is serious. Therefore, the ability to detect MtBE at low levels (ppb) and on-line at high-risk groundwater sites would be highly desirable. This paper reports the use of 'commercial' and metal oxide sensor arrays for the detection of MtBE in drinking and surface waters at low ppb level (microg.L(-1) range). The output responses from some of the sensors were found to correlate well with MtBE concentrations under laboratory conditions.

A comparative study of biodiesel production using methanol, ethanol, and tert-butyl methyl ether (MTBE) under supercritical conditions.

PubMed

Farobie, Obie; Matsumura, Yukihiko

2015-09-01

In this study, biodiesel production under supercritical conditions among methanol, ethanol, and tert-butyl methyl ether (MTBE) was compared in order to elucidate the differences in their reaction behavior. A continuous reactor was employed, and experiments were conducted at various reaction temperatures (270-400 °C) and reaction times (3-30 min) and at a fixed pressure of 20 MPa and an oil-to-reactant molar ratio of 1:40. The results showed that under the same reaction conditions, the supercritical methanol method provided the highest yield of biodiesel. At 350 °C and 20 MPa, canola oil was completely converted to biodiesel after 10, 30, and 30 min in the case of - supercritical methanol, ethanol, and MTBE, respectively. The reaction kinetics of biodiesel production was also compared for supercritical methanol, ethanol, and MTBE. Copyright © 2015 Elsevier Ltd. All rights reserved.

The application of silicalite-1/fly ash cenosphere (S/FAC) zeolite composite for the adsorption of methyl tert-butyl ether (MTBE).

PubMed

Lu, Jia; Xu, Fang; Wang, Deju; Huang, Jue; Cai, Weimin

2009-06-15

Silicalite-1/fly ash cenosphere (S/FAC) zeolite composite has been applied for batch adsorption of methyl tert-butyl ether (MTBE) from water systems. Here the key experimental conditions, including the ratio of initial MTBE concentration to the amount weight of S/FAC, adsorption time and temperature, have been discussed in detail. The results show that approximately 93-95% MTBE could be adsorbed with initial concentration of MTBE solution 1000 microg l(-1). The column flow-through experiments also prove the high capacity of S/FAC composite for MTBE removal. The distinct advantages of S/FAC zeolite composite as adsorbent lie in (1) enhanced adsorption rate and capacity based on hierarchical micro and meso/macroporosity of S/FAC; (2) more easily operation and recycling process by assembly of nano-sized silicalite-1 zeolite on FAC support.

The failure of poly (ether ether ketone) in high speed contacts

NASA Astrophysics Data System (ADS)

Briscoe, B. J.; Stuart, B. H.; Sebastian, S.; Tweedale, P. J.

1993-04-01

The paper describes an experimental study, with an associated analysis incorporating supplementary data, of the anti-boundary lubricating action of an alkane-aliphatic carboxylic acid lubricant system in a poly (ether ether ketone)-mild steel contact. The experiments involve progressively increasing the load in a contact formed between a polymer plate and a rotating steel shaft and estimating the frictional work dissipated. Scuffing is identified when a rapid increase in frictional work is noted at a characteristic normal load. It is shown that the additive induces premature scuffing. Subsidiary data is provided using Raman spectroscopy and hardness probes, and confirms that certain additives such as decanoic acid and dodecylamine will induce surface plasticization in poly (ether ether ketone). The trends in the frictional data have been interpreted using the adhesive model of friction in conjunction with temperature-dependent interfacial theology and bulk mechanical property data. It is proposed that the scuffing process is induced prematurely as a consequence of excessive additive-induced subsurface plasticization. Restricted surface plasticization in this system provides an enhanced self-lubricating capacity.

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.

Nonaqueous polypyrrole colloids

DOEpatents

Armes, Steven P.; Aldissi, Mahmoud

1991-01-01

Processable conductive polymers including an oxidized, polymerized aromatic heterocyclic monomer, e.g., pyrrole, an stabilizing effective amount of a poly(vinyl acetate) and dopant anions, and a process of preparing said processable conductive polymers directly in a nonaqueous medium such as methyl acetate, methyl formate, ethyl formate, and propyl formate are disclosed.

Synthesis and characterization of polyphosphazene electrolytes including cyclic ether side groups

NASA Astrophysics Data System (ADS)

Fiedler, Carsten; Luerssen, Bjoern; Lucht, Brett; Janek, Juergen

2018-04-01

This paper presents the synthesis and detailed characterization of two polyphosphazene based polymers, including different cyclic ether side groups. The final polymers were obtained by a well-known method employing a living cationic polymerization and subsequent nucleophilic substitution. The synthesized polymers Poly [(1,3-dioxane-5-oxy) (1,3-dioxolane-4-methoxy)phosphazene] (DOPP) and Poly[bis(2-Tetrahydro-3-furanoxy)phosphazene] (THFPP) were mixed with varied amounts of lithium bis(trifluoromethane)sulfonamide (LiTFSI) and the interactions between the salt and the polymer chains were studied by Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) measurements. Electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS) and direct current polarization in the temperature range of 20-60 °C. These measurements were utilized to calculate the lithium transference number (t+), the lithium conductivity (σ) and its activation energy in order to elucidate the lithium transport behavior. Relatively high lithium transference numbers of 0.6 (DOPP) and 0.7 (THFPP) at 60 °C are found and reveal maximum lithium conductivities of 2.8·10-6 Sṡcm-1 and 9.0·10-7 Sṡcm-1 for DOPP and THFPP at 60 °C, respectively.

Hydroxystilbenes Are Monomers in Palm Fruit Endocarp Lignins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlos del Rio, Jose; Rencoret, Jorge; Gutierrez, Ana

Lignin, the plant cell wall polymer that binds fibers together but makes processing difficult, is traditionally formed from three monomers, the so-called monolignols (p-coumaryl, coniferyl, and sinapyl alcohols). Recently, we discovered, in grass lignins, a phenolic monomer that falls outside the canonical lignin biosynthetic pathway, the flavone tricin. As we show here, palm fruit (macaúba [Acrocomia aculeata], carnauba [Copernicia prunifera], and coconut [Cocos nucifera]) endocarps contain lignin polymers derived in part from a previously unconsidered class of lignin monomers, the hydroxystilbenes, including the valuable compounds piceatannol and resveratrol. Piceatannol could be released from these lignins upon derivatization followed by reductivemore » cleavage, a degradative method that cleaves b-ether bonds, indicating that at least a fraction is incorporated through labile ether bonds. Nuclear magnetic resonance spectroscopy of products from the copolymerization of piceatannol and monolignols confirms the structures in the natural polymer and demonstrates that piceatannol acts as an authentic monomer participating in coupling and cross-coupling reactions during lignification. Therefore, palm fruit endocarps contain a new class of stilbenolignin polymers, further expanding the definition of lignin and implying that compounds such as piceatannol and resveratrol are potentially available in what is now essentially a waste product.« less

Hydroxystilbenes Are Monomers in Palm Fruit Endocarp Lignins

DOE PAGES

Carlos del Rio, Jose; Rencoret, Jorge; Gutierrez, Ana; ...

2017-06-06

Lignin, the plant cell wall polymer that binds fibers together but makes processing difficult, is traditionally formed from three monomers, the so-called monolignols (p-coumaryl, coniferyl, and sinapyl alcohols). Recently, we discovered, in grass lignins, a phenolic monomer that falls outside the canonical lignin biosynthetic pathway, the flavone tricin. As we show here, palm fruit (macaúba [Acrocomia aculeata], carnauba [Copernicia prunifera], and coconut [Cocos nucifera]) endocarps contain lignin polymers derived in part from a previously unconsidered class of lignin monomers, the hydroxystilbenes, including the valuable compounds piceatannol and resveratrol. Piceatannol could be released from these lignins upon derivatization followed by reductivemore » cleavage, a degradative method that cleaves b-ether bonds, indicating that at least a fraction is incorporated through labile ether bonds. Nuclear magnetic resonance spectroscopy of products from the copolymerization of piceatannol and monolignols confirms the structures in the natural polymer and demonstrates that piceatannol acts as an authentic monomer participating in coupling and cross-coupling reactions during lignification. Therefore, palm fruit endocarps contain a new class of stilbenolignin polymers, further expanding the definition of lignin and implying that compounds such as piceatannol and resveratrol are potentially available in what is now essentially a waste product.« less

Hydroxystilbenes Are Monomers in Palm Fruit Endocarp Lignins1[OPEN

PubMed Central

2017-01-01

Lignin, the plant cell wall polymer that binds fibers together but makes processing difficult, is traditionally formed from three monomers, the so-called monolignols (p-coumaryl, coniferyl, and sinapyl alcohols). Recently, we discovered, in grass lignins, a phenolic monomer that falls outside the canonical lignin biosynthetic pathway, the flavone tricin. As we show here, palm fruit (macaúba [Acrocomia aculeata], carnauba [Copernicia prunifera], and coconut [Cocos nucifera]) endocarps contain lignin polymers derived in part from a previously unconsidered class of lignin monomers, the hydroxystilbenes, including the valuable compounds piceatannol and resveratrol. Piceatannol could be released from these lignins upon derivatization followed by reductive cleavage, a degradative method that cleaves β-ether bonds, indicating that at least a fraction is incorporated through labile ether bonds. Nuclear magnetic resonance spectroscopy of products from the copolymerization of piceatannol and monolignols confirms the structures in the natural polymer and demonstrates that piceatannol acts as an authentic monomer participating in coupling and cross-coupling reactions during lignification. Therefore, palm fruit endocarps contain a new class of stilbenolignin polymers, further expanding the definition of lignin and implying that compounds such as piceatannol and resveratrol are potentially available in what is now essentially a waste product. PMID:28588115

Searching for trans ethyl methyl ether in Orion KL★,★★

PubMed Central

Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

2015-01-01

We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm−2 and ≤(1.0 ± 0.2)× 1015 cm−2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. PMID:26869726

Searching for trans ethyl methyl ether in Orion KL.

PubMed

Tercero, B; Cernicharo, J; López, A; Brouillet, N; Kolesniková, L; Motiyenko, R A; Margulès, L; Alonso, J L; Guillemin, J-C

2015-10-01

We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH 3 CH 2 OCH 3 , through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH 3 CH 2 CH 2 OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 10 15 cm -2 and ≤(1.0 ± 0.2)× 10 15 cm -2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH 3 OCOH, CH 3 CH 2 OCOH, CH 3 OCH 3 , CH 3 OH, and CH 3 CH 2 OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N (CH 3 OCH 3 )/ N (tEME) ≥ 150 in the compact ridge of Orion.

Tribological properties of hydrophilic polymer brushes under wet conditions.

PubMed

Kobayashi, Motoyasu; Takahara, Atsushi

2010-08-01

This article demonstrates a water-lubrication system using high-density hydrophilic polymer brushes consisting of 2,3-dehydroxypropyl methacrylate (DHMA), vinyl alcohol, oligo(ethylene glycol)methyl ether methacrylate, 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTAC), 3-sulfopropyl methacrylate potassium salt (SPMK), and 2-methacryloyloxyethyl phosphorylcholine (MPC) prepared by surface-initiated controlled radical polymerization. Macroscopic frictional properties of brush surfaces were characterized by sliding a glass ball probe in water using a ball-on-plate type tribotester under the load of 0.1-0.49 N at the sliding velocity of 10(-5)-10(-1) m s(-1) at 298 K. A poly(DHMA) brush showed a relatively larger friction coefficient in water, whereas the polyelectrolyte brushes, such as poly(SPMK) and poly(MPC), revealed significantly low friction coefficients below 0.02 in water and in humid air conditions. A drastic reduction in the friction coefficient of polyelectrolyte brushes in aqueous solution was observed at around 10(-3)-10(-2) m s(-1) owing to the hydrodynamic lubrication effect, however, an increase in salt concentration in the aqueous solution led to the increase in the friction coefficients of poly(MTAC) and poly(SPMK) brushes. The poly(SPMK) brush showed a stable and low friction coefficient in water even after sliding over 450 friction cycles, indicating a good wear resistance of the brush film. Copyright 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Influence of reaction medium during synthesis of Gantrez AN 119 nanoparticles for oral vaccination.

PubMed

Vandamme, Katrien; Melkebeek, Vesna; Cox, Eric; Deforce, Dieter; Lenoir, Joke; Adriaens, Els; Vervaet, Chris; Remon, Jean Paul

2010-02-01

Two synthesis methods of poly(methyl vinyl ether-co-maleic anhydride) (Gantrez AN 119) nanoparticles (NP) (used for oral vaccination) were compared. Wheat germ agglutinin (WGA) was used as ligand to enhance the bioadhesive properties of NP and beta-galactosidase as antigen. The first method encapsulated beta-galactosidase in NP by co-precipitation in an acetone/water mixture containing 44% acetone. In the second method, antigen addition occurred in 100% acetone. To improve stability, NP were crosslinked with 1,3-diaminopropane. The stability of WGA-conjugated NP with encapsulated antigen diminished at lower pH and when decreasing the amount of crosslinker. The binding type between WGA and polymer depended on the synthesis method: predominantly ionic bonds were formed using the 44% acetone method, whereas synthesis via the 100% acetone method resulted in covalent bonds. The biological activity of the WGA coating, evaluated via a pig gastric mucin binding test, was lower in NP prepared via the 100% acetone method. No release of native antigen was detected after hydrolysis of NP, due to the covalent antigen binding during antigen encapsulation and the high reactivity of the polymer. Moreover, the mucosal irritation capacity was evaluated upon nanoparticle hydrolysis using a slug mucosal irritation assay. Herein, hydrolysed NP of the 44% acetone method were classified as mild irritative. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Palladium-Catalyzed Formal Cross-Coupling of Diaryl Ethers with Amines: Slicing the 4-O-5 Linkage in Lignin Models.

PubMed

Zeng, Huiying; Cao, Dawei; Qiu, Zihang; Li, Chao-Jun

2018-03-26

Lignin is the second most abundant organic matter on Earth, and is an underutilized renewable source for valuable aromatic chemicals. For future sustainable production of aromatic compounds, it is highly desirable to convert lignin into value-added platform chemicals instead of using fossil-based resources. Lignins are aromatic polymers linked by three types of ether bonds (α-O-4, β-O-4, and 4-O-5 linkages) and other C-C bonds. Among the ether bonds, the bond dissociation energy of the 4-O-5 linkage is the highest and the most challenging to cleave. To date, 4-O-5 ether linkage model compounds have been cleaved to obtain phenol, cyclohexane, cyclohexanone, and cyclohexanol. The first example of direct formal cross-coupling of diaryl ether 4-O-5 linkage models with amines is reported, in which dual C(Ar)-O bond cleavages form valuable nitrogen-containing derivatives. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.