21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene-maleic anhydride copolymers. 177.1820 Section 177.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use...

A new process for the valorisation of a bio-alcohol. The oxidehydration of 1-butanol into maleic anhydride

Energy Technology Data Exchange (ETDEWEB)

Caldarelli, A.; Cavani, F.; Garone, O.; Pavarelli, G. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; Bologna Univ. (Italy). CIRCC, Research Unit; Dubois, J.L. [ARKEMA, Colombes (France); Mitsova, I.; Simeonova, L. [JSC, Russe (Bulgaria). Orgachim

2012-07-01

This paper deals with a study on the gas-phase transformation of 1-butanol into maleic anhydride, using different types of catalysts. Indeed, catalytic acid properties are needed to dehydrate 1-butanol into 1-butene, whereas redox-type properties are required for the oxidation of the olefin into maleic anhydride. The two types of active sites can be combined in bifunctional systems, showing both acid and redox-type properties. We found that vanadyl pyrophosphate catalyzes the one-pot reaction, giving a maximum selectivity to maleic anhydride of 28%. In fact, various side reactions contributed to the formation of by-products, eg, 1-butanol (oxidative) dehydrogenation into butyraldehyde, formation of light carboxylic acids and carbon oxides, and condensation of unsaturated C{sub 4} intermediates (butenes and butadiene) with the formed maleic anhydride to yield heavier compounds. (orig.)

Comparative Study Of The Preparation Of Maleic Anhydride-g-Polypropylene By Two Grafting Processes Using Peroxide

International Nuclear Information System (INIS)

Sakahara, R.M.; Wang, S.H.

2010-01-01

The Polypropylene grafting with Maleic anhydride is a thoroughly known technique. Its wide application is due, mainly,to the controlled changing in the polarity of this polymer, which increases the interfacial adhesion in blends and compounds. In this study, two grafting processes were compared. In the first, the maleic anhydride was grafted on polypropylene in a solution batch process, carried out in a round-bottom vessel. The second approach was carried out by reactive extrusion of polypropylene in the presence of peroxide and maleic anhydride. The samples thus prepared were characterized by DSC, TGA, FTIR, WAXS, EDS e SEM. It was possible to conclude that the solution technique was more efficient than the reactive extrusion; however the later was easier to accomplish due to the high viscosity of PP. (author)

Selective oxidation of n-butane to maleic anhydride under oxygen-deficient conditions over V-P-O mixed oxides

NARCIS (Netherlands)

Bosch, H.; Bruggink, A.A.; Ross, J.R.H.

1987-01-01

The selective oxidation of n-butane to maleic anhydride over V-P-O mixed oxides was studied under oxygen deficient conditions. The mixed oxides were prepared with P/V atomic ratios ranging from 0.7 to 1.0. Catalysts with P/V <1.0 did not show any selectivity to maleic anhydride formation, regardless

Maleic anhydride based copolymer dispersions for surface modification of polar substrates

NARCIS (Netherlands)

Gunbas, I.D.; Wouters, M.E.L.; Hendrix, M.M.R.M.; Benthem, R.A.T.M. van; Koning, C.E.; Noordover, B.A.J.

2012-01-01

In this article, we report the modification of poly(styrene-alt-maleic anhydride) (PSMA) with monofunctional amine-terminated poly(dimethyl siloxane) (PDMS-NH2) by thermal imidization, followed by the preparation and characterization of a surfactant-free artificial latex thereof and application of

Maleic anhydride based copolymer dispersions for surface modification of polar substrates

NARCIS (Netherlands)

Gunbas, I.D.; Wouters, M.E.L.; Hendrix, M.M.R.M.; Benthem, van R.A.T.M.; Koning, C.E.; Noordover, B.A.J.

2012-01-01

In this article, we report the modification of poly(styrene-alt-maleic anhydride) (PSMA) with monofunctional amine-terminated poly(dimethyl siloxane) (PDMS–NH2) by thermal imidization, followed by the preparation and characterization of a surfactant-free artificial latex thereof and application of

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

Science.gov (United States)

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

2017-02-01

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

Radiation-induced cationic curing of vinyl ethers

International Nuclear Information System (INIS)

Lapin, S.C.

1992-01-01

Recently there has been an increasing interest in nonacrylate radiation-curable coatings. Vinyl ethers are particularly reactive under cationic polymerization reaction conditions. The high efficiency of the photoacid initiators combined with the high reactivity of vinyl ether monomers makes this a potentially very useful system. This chapter discusses the preparation of vinyl ethers, introduces vinyl ether-functional monomers and oligomers, describes radiation-induced cationic polymerization of vinyl ethers, and discusses various coating systems. Throughout the chapter, an emphasis is placed on radiation-curable coating applications. 64 refs., 5 figs., 11 tabs

Hydrolysis and stability of thin pulsed plasma polymerised maleic anhydride coatings

DEFF Research Database (Denmark)

Drews, Joanna Maria; Launay, Héléne; Hansen, Charles M.

2008-01-01

Abstract The stability of plasma polymerised layers has become important because of their widespread use. This study explored the hydrolysis and degradation stability of coatings of plasma polymerised maleic anhydride. Coatings made with different plasma parameters were exposed to aqueous media...... of different pH as a function of time. ATR-FTIR was used for structure analysis and a toluidine blue staining method allowed quantitative analysis of the hydrolysis of anhydride groups to acid groups. Coatings with constant thickness were obtained at different plasma powers and layers with varying thickness...

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

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, from ammonium hydroxide... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... subject to reporting. (1) The chemical substance identified as amides, from ammonium hydroxide - maleic...

Urea- Hydrogen Peroxide (UHP Oxidation of Thiols to the Corresponding Disulfides Promoted by Maleic Anhydride as Mediator

Directory of Open Access Journals (Sweden)

M. H. Habibi

2005-10-01

Full Text Available Urea-hydrogen peroxide (UHP was used in the presence of maleic anhydride as mediator in a simple and convenient method for the oxidation in high yield of some thiols to the corresponding disulfides. Peroxymaleic acid formed in situ from the reaction of UHP with maleic anhydride has a key role in this oxidation. Performance of the reaction in various solvents showed that methanol was the solvent of choice at 0 oC. The products were isolated by simple filtration on silica gel.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

) andMn(II) complexes of poly(methyl vinyl ether-alt-maleic anhydride). Synthesis, characterization and thermodynamic parameters. Hidayet Mazi Ali Gulpinar. Volume 126 Issue 1 January 2014 pp 239-245 ...

THE GRAFTING OF MALEIC-ANHYDRIDE ON HIGH-DENSITY POLYETHYLENE IN AN EXTRUDER

NARCIS (Netherlands)

GANZEVELD, KJ; JANSSEN, LPBM

The grafting of maleic anhydride (MAH) on high density polyethylene in a counter-rotating twin screw extruder has been studied. As the reaction kinetics appear to be affected by mass transfer, good micro mixing in the extruder is important. Due to the competing mechanisms of increasing mixing and

1-O-vinyl glycosides via Tebbe olefination, their use as chiral auxiliaries and monomers.

Science.gov (United States)

Yuan, Jialong; Lindner, Kristof; Frauenrath, Holger

2006-07-21

A series of anomerically pure 1-O-formyl glycosides 1 was prepared and converted into the corresponding 1-O-vinyl glycosides 2 by Tebbe olefination. The unsubstituted vinyl glycosides were obtained as anomerically pure compounds in good yields, and the method of preparation was compatible with the presence of a variety of functional groups. Remarkably, the anomeric formate group was regioselectively converted into the corresponding olefin in the presence of acetate and benzoate protecting groups. With the perspective to use the 1-O-vinyl glycosides as monomers for the preparation of glycosylated poly(vinyl alcohol) derivatives with controlled tacticity, their scope as chiral auxiliaries for a stereodifferentiation in addition reactions to the olefin function was investigated by using the [2+2] cycloaddition to dichloroketene as a model reaction. In particular, vinyl 2,3,4,6-tetra-O-benzoyl-alpha-d-mannopyranoside (2i) exhibited excellent diastereoselectivity. Finally, the 1-O-vinyl glycosides were successfully subjected to radical homopolymerization in bulk or used as electron-rich comonomers in radical copolymerizations with maleic anhydride, yielding alternating, glycosylated poly(vinyl alcohol-alt-maleic anhydride).

Réaction du polyisobutène chloré sur l'anhydride maléique : mécanisme. Catalyse par l'anhydride dichloromaléique Reaction of Chlorinated Polyisobutene on Maleic Anhydride. Mechanism. Catalysis by Dichloromaleic Anhydride

Directory of Open Access Journals (Sweden)

Sillion B.

2006-11-01

Full Text Available Dans cet article le mécanisme de la réaction de condensation du polyisobutène chloré sur l'anhydride maléique, qui sert dans la synthèse d'additif pour lubrifiant, est étudié par une cinétique globale et par un travail sur composés modèles. Il est montré que, dans cette réaction, l'anhydride maléique joue un double rôle : de catalyseur de déshydrochloration par une réactivité de type acide de Lewis organique, de réactif comme diénophile. Grâce à ces résultats, il est proposé une catalyse par l'anhydride dichloromaléique, qui permet une amélioration sensible du procédé. This article examines the mechanism of the chlorinated-polyisobutene condensation reaction on maleic anhydride. The overall kinetics and model compounds are investigated for this reaction which is used in the synthesis of lubricant additives. Maleic anhydride is shown to play the dual role of a dehydrochlorination catalyst by having a reactivity of the organic Lewis acid type and of a reactant like dienophile. These results are used to propose a catalysis by dichloromaleic anhydride which appreciably improves the process.

Blends of Styrene-Butadiene-Styrene Triblock Copolymer with Random Styrene-Maleic Anhydride Copolymers

NARCIS (Netherlands)

Piccini, Maria Teresa; Ruggeri, Giacomo; Passaglia, Elisa; Picchioni, Francesco; Aglietto, Mauro

2002-01-01

Blends of styrene-butadiene-styrene triblock copolymer (SBS) with random styrene-maleic anhydride copolymers (PS-co-MA), having different MA content, were prepared in a Brabender Plastigraph mixer. The presence of polystyrene (PS) blocks in the SBS copolymer and the high styrene content (93 and 86

Tensile and morphology properties of PLA/LNR blends modified with maleic anhydride grafted-polylactic acid and -natural rubber

Science.gov (United States)

Ruf, Mohd Farid Hakim Mohd; Ahmad, Sahrim; Chen, Ruey Shan; Shahdan, Dalila; Zailan, Farrah Diyana

2018-04-01

This research was carried out to investigate the addition of grafted copolymers of maleic anhydride grafted-polylactic acid(PLA-g-MA) and maleic anhydride grafted-natural rubber (NR-g-MA) on the tensile and morphology properties of polylactic acid/ liquid natural rubber (PLA/LNR) blends. Prior to blend preparation, the PLA-g-MA and NR-g-MA was first self-synthesized using maleic anhydride (MA) and dicumyl peroxide (DCP) as initiator together with the PLA and NR respectively. The PLA/LNR, PLA/LNR/PLA-g-MA and PLA/LNR/NR-g-MA blends were prepared via melt-blending method. The loading of PLA-g-MA and NR-g-MA was varied by 5, 10 and 15 wt% respectively. The addition of PLA-g-MA led to increment in tensile strength with 5 and 10 wt% while NR-g-MA gives lower than controlled sample (PLA/LNR blend). Scanning electron microscope (SEM) showed the interaction of the components in the blends. The PLA/LNR compatibilized with PLA-g-MA and NR-g-MA shows greater dispersion and adhesion.

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

Directory of Open Access Journals (Sweden)

J. Varshosaz

2014-01-01

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

Towards anti-corrosion coatings from surfactant-free latexes based on maleic anhydride containing polymers

NARCIS (Netherlands)

Soer, W.J.; Ming, W.; Koning, C.E.; Benthem, van R.A.T.M.

2008-01-01

We report on the film formation of surfactant-free, artificial latexes based on copolymers containing maleic anhydride. Different metallic substrates, such as aluminum, steel and magnesium alloys, were coated with three different latexes. A commercial polyester based coating was used as a

Development of chitosan derivatives with anhydride maleic; Desenvolvimento de derivados de quitosana com anidrido maleico

Energy Technology Data Exchange (ETDEWEB)

Silva, Solranny C.C.C.; Braz, Elton Marks de A.; Brito, Carla Adriana R. de S.; Silva, Durcilene A. da; Junior, Luiz de S.S.; Silva Filho, Edson C. da, E-mail: solbiologa@hotmail.com [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil)

2015-07-01

Chitosan was chemically modified with maleic anhydride in ratios of 1/2, 1/5 and 1/10 in the absence of solvents. The obtained derivatives were characterized by elemental analysis, FTIR, thermal analysis (TGA / DTG) and XRD where it was possible to prove the chemical modification. Elemental analysis showed an increase of the relation C / N with the increasing of the proportion of anhydrides. The FTIR showed the incorporation of the anhydride in the biopolymer structure. The thermal stability of the derivatives was lower in comparison to the polysaccharide and by XRD the modified materials were less crystalline. (author)

Samarium-modified vanadium phosphate catalyst for the selective oxidation of n-butane to maleic anhydride

International Nuclear Information System (INIS)

Wu, Hua-Yi; Wang, Hai-Bo; Liu, Xin-Hua; Li, Jian-Hui; Yang, Mei-Hua; Huang, Chuan-Jing; Weng, Wei-Zheng; Wan, Hui-Lin

2015-01-01

Graphical abstract: The addition of a small amount of Sm into VPO catalyst brought about great changes in its physicochemical properties such as surface area, surface morphology, phase composition and redox property, thus leading to a higher catalytic performance in the selective oxidation of n-butane to maleic anhydride, as compared to the undoped VPO catalyst. - Highlights: • The addition of Sm leads to great changes in the structure of VPO catalyst. • Sm improves performance of VPO for oxidation of n-butane to maleic anhydride. • Catalytic performance is closely related to structure of VPO catalyst. - Abstract: A series of samarium-modified vanadium phosphate catalysts were prepared and studied in selective oxidation of n-butane to maleic anhydride. The catalytic evaluation showed that Sm modification significantly increased the overall n-butane conversion and intrinsic activity. N 2 -adsorption, XRD, SEM, Raman, XPS, EPR and H 2 -TPR techniques were used to investigate the intrinsic difference among these catalysts. The results revealed that the addition of Sm to VPO catalyst can increase the surface area of the catalyst, lead to a significant change in catalyst morphology from plate-like structure into rosette-shape clusters, and largely promote the formation of (VO) 2 P 2 O 7 . All of these were related to the different catalytic performance of Sm-doped and undoped VPO catalysts. The roles of the different VOPO 4 phases and the influence of Sm were also described and discussed

Highly Efficient Gas-Phase Oxidation of Renewable Furfural to Maleic Anhydride over Plate Vanadium Phosphorus Oxide Catalyst.

Science.gov (United States)

Li, Xiukai; Ko, Jogie; Zhang, Yugen

2018-02-09

Maleic anhydride (MAnh) and its acids are critical intermediates in chemical industry. The synthesis of maleic anhydride from renewable furfural is one of the most sought after processes in the field of sustainable chemistry. In this study, a plate vanadium phosphorus oxide (VPO) catalyst synthesized by a hydrothermal method with glucose as a green reducing agent catalyzes furfural oxidation to MAnh in the gas phase. The plate catalyst-denoted as VPO HT -has a preferentially exposed (200) crystal plane and exhibited dramatically enhanced activity, selectivity and stability as compared to conventional VPO catalysts and other state-of-the-art catalytic systems. At 360 °C reaction temperature with air as an oxidant, about 90 % yield of MAnh was obtained at 10 vol % of furfural in the feed, a furfural concentration value that is much higher than those (<2 vol %) reported for other catalytic systems. The catalyst showed good long-term stability and there was no decrease in activity or selectivity for MAnh during the time-on-stream of 25 h. The high efficiency and catalyst stability indicate the great potential of this system for the synthesis of maleic anhydride from renewable furfural. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic porous high-density polyethylene/polyethylene- grafted-maleic anhydride scaffold with improved in vitro cytocompatibility.

Science.gov (United States)

Sharma, Swati; Bhaskar, Nitu; Bose, Surjasarathi; Basu, Bikaramjit

2018-05-01

A major challenge for tissue engineering is to design and to develop a porous biocompatible scaffold, which can mimic the properties of natural tissue. As a first step towards this endeavour, we here demonstrate a distinct methodology in biomimetically synthesized porous high-density polyethylene scaffolds. Co-extrusion approach was adopted, whereby high-density polyethylene was melt mixed with polyethylene oxide to form an immiscible binary blend. Selective dissolution of polyethylene oxide from the biphasic system revealed droplet-matrix-type morphology. An attempt to stabilize such morphology against thermal and shear effects was made by the addition of polyethylene- grafted-maleic anhydride as a compatibilizer. A maximum ultimate tensile strength of 7 MPa and elastic modulus of 370 MPa were displayed by the high-density polyethylene/polyethylene oxide binary blend with 5% maleated polyethylene during uniaxial tensile loading. The cell culture experiments with murine myoblast C2C12 cell line indicated that compared to neat high-density polyethylene and high-density polyethylene/polyethylene oxide, the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride scaffold significantly increased muscle cell attachment and proliferation with distinct elongated threadlike appearance and highly stained nuclei, in vitro. This has been partly attributed to the change in surface wettability property with a reduced contact angle (∼72°) for 5% PE- g-MA blends. These findings suggest that the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride can be treated as a cell growth substrate in bioengineering applications.

Reactive compatibilization of ethylene-co-vinyl acetate/starch blends

NARCIS (Netherlands)

Ma, P.; Hristova - Bogaerds, D.G.; Schmit, P.; Goossens, J.G.P.; Lemstra, P.J.

2012-01-01

The dispersion of starch as a filler in hydrophobic ethylene-co-vinyl acetate (EVA) rubber is an issue. To obtain a fine dispersion of starch in EVA rubber, EVA/starch blends were prepared by reactive extrusion in the pres- ence of maleic anhydride (MA), benzoyl peroxide (BPO), and glycerol. MA,

A novel reverse osmosis membrane modified by polyvinyl alcohol with maleic anhydride crosslinking

Science.gov (United States)

Samnani, Mohit; Rathod, Harshad; Raval, Hiren

2018-03-01

In the era of increasing energy crisis, it is inevitable to decrease process energy consumption to increase process viability and curtail green-house gas emission. The Reverse Osmosis plant requires significant energy to transfer water overcoming the osmotic pressure. This paper focuses on increasing the water flux for Thin Film Composite Reverse Osmosis (TFC RO) membrane without compromising salt rejection performance leading to the environmentally friendly and economically attractive process. The virgin TFC RO membrane was exposed to solution of sodium hypochlorite of concentration 2000 mg l-1 for 1 h to activate the surface of the membrane, followed by the treatment with the mixture of polyvinyl alcohol and maleic anhydride with varying concentrations for 1 h and curing in the oven at 80 °C temperature for 10 min. Out of all the treated membranes, the membrane treated with 2000 mg l-1 polyvinyl alcohol and 1000 mg l-1 maleic anhydride demonstrated the highest salt rejection of 96.83 % with 2% increase as compared to the virgin TFC RO membrane. The water flux of the membrane was around 44% higher than the virgin TFC RO membrane. The membrane samples were characterized by atomic force micrographs, ATR-FTIR, Nuclear magnetic resonance and Dynamic mechanical analysis.

Williamson alkylation approach to the synthesis of poly(alkyl vinyl ether) copolymers

International Nuclear Information System (INIS)

Markova, D.; Christova, D.; Velichkova, R.

2008-01-01

A method for synthesis of poly(alkyl vinyl ether-co-vinyl alcohol) copolymers was developed based on the Williamson's alkylation of poly(vinyl acetate) (PVAc) with alkyl iodides. The influence of the alkylating agent and the reaction conditions on the efficiency of the modification reaction was investigated. The copolymers obtained were characterized by means of 1 H NMR and GPC. It was proved that by applying the proposed method copolymers of different composition and properties containing methyl vinyl ether, ethyl vinyl ether as well as n-butyl vinyl ether units could be prepared. Poly(methyl vinyl ether-co-vinyl alcohol)s of high degree of methylation exhibit sharp temperature response at 38-39 deg C in aqueous solution typical of the so-called smart polymers. (authors)

Synthesis of Poly(vinyl ether) Thermoplastic Elastomers Having Functional Soft Segments

OpenAIRE

今枝, 嗣人; 漆崎, 美智遠; 阪口, 壽一; 橋本, 保; Tsuguto, IMAEDA; Michio, URUSHISAKI; Toshikazu, SAKAGUCHI; Tamotsu, HASHIMOTO

2013-01-01

The ABA-type triblock copolymers consisting of poly(2-adarnantyl vinyl ether) [poly(2-AdVE) as outer hard segments and poly(6-acetoxyhexyl vinyl ether) [poly(AcHVE)] poly(6-hydroxyhexyl vinyl ether) [poly(H HVE)], or poly(2-(2-methoxyethoxy)ethyl vinyl ether [poly(MOEOVE)] as inner soft segments were synthesized by sequential living cationic polymerization. Despite the presence of polar functional groups such as ester, hydroxy, and oxyethylene units in their soft segments, the two polymer seg...

Partial oxidation of D-xylose to maleic anhydride and acrylic acid over vanadyl pyrophosphate

International Nuclear Information System (INIS)

Ghaznavi, Touraj; Neagoe, Cristian; Patience, Gregory S.

2014-01-01

Xylose is the second most abundant sugar after glucose. Despite its tremendous potential to serve as a renewable feedstock, few commercial processes exploit this resource. Here, we report a new technology in which a two-fluid nozzle atomizes a xylose-water solution into a capillary fluidized bed operating above 300 °C. Xylose-water droplets form at the tip of the injector, vaporize then react with a heterogeneous mixed oxide catalyst. A syringe pump metered the solution to the reactor charged with 1 g of catalyst. Product yield over vanadyl pyrophosphate was higher compared to molybdenum trioxide-cobalt oxide and iron molybdate; it reached 25% for maleic anhydride, 17% for acrylic acid and 11% for acrolein. Gas residence time was 0.2 s. The catalyst was free of coke even after operating for 4 h – based on a thermogravimetric analysis of catalyst withdrawn from the reactor. Below 300 °C, powder agglomerated at the tip of the injector at 300 °C; it also agglomerated with a xylose mass fraction of 7% in water. - Highlights: • D-xylose reacts to form maleic anhydride and acrylic acid above 250 °C. • Vanadyl pyrophosphate is both active and selective for maleic and acrylic acid. • Acid and acrolein yield approaches 50% for a xylose mass fraction of 3% in water. • Catalyst agglomerates at low temperatures and high xylose aqueous mass fraction. • Atomization quality is a determining factor to minimize agglomeration

Thermogravimetric analysis of the polymer acrylate-vinyl ether mixture cured by radiation

International Nuclear Information System (INIS)

Danu, Sugiarto

1998-01-01

An experiment on thermal stability of the polymer acrylate-vinyl ether mixture cured by radiation have been done using thermogravimetric analysis. Three kinds of acrylic oligomers i.e., epoxy acrylate, urethane acrylate, and polypropylene glycol diacrylate, and vinyl ether monomers i.e., triethylene glycol divinyl ether (DVE-3), 1,4-cyclohexane dimethanol divinyl ether (CHVE), and butanediol monovinyl ether (HBVE) were used in the experiment. Reaction was taken via radical and cationic polymerisation. In case of cationic polymerisation, diphenyliodonium hexafluorophosphate fotoinisiator was used in the formulation. Thermogravimetric analysis was conducted in a nitrogen atmosphere at a flow rate of 40 ml/minute with a constant heating rate 10 o C and evaluation range were done from 25 to 500 o C. The results of thermogravimetric analysis showed that acrylate and DVE-3 mixture produced the polymer films with higher thermal stability than the mixture of acrylate with CHVE or HBVE. The composition of acrylate-vinyl ether mixture and degree of unsaturation of vinyl ether monomers influenced the thermal stability of polymer. The mixture of epoxy acrylate-vinyl ether and polypropylene glycol diacrylate-vinyl ether have 1 initial decomposition temperature whereas the urethane acrylate-vinyl ether mixture has 2 initial decomposition temperatures. (authors)

Controlled Release of Damascone from Poly(styrene-co-maleic anhydride-based Bioconjugates in Functional Perfumery

Directory of Open Access Journals (Sweden)

Andreas Herrmann

2013-02-01

Full Text Available Poly(styrene-co-maleic anhydrides were modified with poly(propylene oxide (PO-co-ethylene oxide (EO side chains (Jeffamine® with different EO/PO molar ratios, varying between 0.11 and 3.60. These copolymers were then further functionalized with a β-mercapto ketone of δ-damascone. The obtained poly(maleic acid monoamide-based β-mercapto ketones were then studied as delivery systems for the controlled release of δ-damascone by retro 1,4-addition. The release of δ-damascone, a volatile, bioactive molecule of the family of rose ketones, was studied by dynamic headspace analysis above a cotton surface after deposition of a cationic surfactant containing fabric softening formulation, as a function of the ethylene oxide (EO/propylene oxide (PO molar ratio of the grafted copolymer side chains. The polarity of the EO/PO side chain influenced the release efficiency of the damascone in a typical fabric softening application. PO-rich copolymers and the corresponding poly(styrene-co-maleic anhydride without Jeffamine® side chains were found to be less efficient for the desired fragrance release than the corresponding bioconjugate with a EO/PO ratio of 3.60 in the side chain. This copolymer conjugate seemed to represent a suitable balance between hydrophilicity and hydrophobicity to favor the release of the δ-damascone and to improve the deposition of the conjugate from an aqueous environment onto a cotton surface.

The use of maleic anhydride-modified polypropylene for performance enhancement in continuous glass fiber-reinforced polypropylene composites

NARCIS (Netherlands)

Rijsdijk, H.A.; Contant, M.; Peijs, A.A.J.M.; Miravete, A.

1993-01-01

The influence of maleic anhydride-modified polypropylene (m-PP) on static mech. properties of continuous glass fiber-reinforced polypropylene (PP) composites was studied. M-PP was added to the PP homopolymer to improve the adhesion between the matrix and the glass fiber. Three-point bending tests

Effects of Different Types of Clays and Maleic Anhydride Modified Polystyrene on Polystyrene/Clay Nanocomposites

Directory of Open Access Journals (Sweden)

M. Mehrabzadeh

2013-01-01

Full Text Available Polymer/clay nanocomposites are considered as a new subject of research in Iran and the world. Addition of a minimum amount of clay (2-5wt% can improve the mechanical properties, enhance barrier properties and reduce flammability dramatically. Polystyrene (PS exhibits high strength, high modulus and excellent dimensional stability, but it has poor ductility, elongation, and flexural modulus. By incorporating clay into polystyrene these properties can be improved. In this study preparation of polystyrene/clay nanocomposite, effects of different types of clays (Cloisite 10A andNanomer I.30TC and maleic anhydride modified polystyrene on mechanical properties of the prepared polystyrene/clay nanocomposites were evaluated. Samples were prepared by a twin screw extruder. Transmission electron microscopy (TEM and X-ray diffraction (XRD techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Mechanical tests show that by addition of clay and maleic anhydride modified polystyrene the flexural modulus (~30% and elongation-at-break (~40% of prepared nanocomposites have been improved. XRD and TEM results show that nanocomposite have an intercalated structure with ability to change to further exfoliation structure.

21 CFR 177.1970 - Vinyl chloride-lauryl vinyl ether copolymers.

Science.gov (United States)

2010-04-01

... in powder form having a particle size such that 100 percent will pass through a U.S. Standard Sieve No. 40 and such that not more than 10 percent will pass through a U.S. Standard Sieve No. 200. (1... analysis. (e) Other specifications and limitations. The vinyl chloride-lauryl vinyl ether copolymers...

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

Energy Technology Data Exchange (ETDEWEB)

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.

A maleic anhydride grafted sugarcane bagasse adsorbent and its performance on the removal of methylene blue from related wastewater

Energy Technology Data Exchange (ETDEWEB)

Ge, Mingliang; Du, Mingyi; Zheng, Luoyun [Key Laboratory of Polymer Processing Engineering of Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Bingying; Zhou, Xiangyang [College of Chemistry and Chemical Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225 (China); Jia, Zhixin [College of Material Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Hu, Guoqing [Key Laboratory of Polymer Processing Engineering of Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Jahangir Alam, S.M., E-mail: mejahangir@scut.edu.cn [Key Laboratory of Polymer Processing Engineering of Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640 (China)

2017-05-01

Sugarcane bagasse (SCB) was selected as the supporting material for grafting maleic anhydride (MA) to obtain sugarcane-bagasse-grafting-maleic-anhydride (SCB-g-MA), which was used as an adsorbent for the removal of methylene blue (MB) in the dye-containing wastewater. The granular morphology and functional groups of the material were characterized by the scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), and solid-state analysis (13C NMR) methods. The effect(s) of the adsorbent dosage, adsorption time, initial concentration of MB, and the pH of solution on the MB adsorption performance of the material have been also investigated. The results showed that the adsorption capacity and removal rate of MB were found to be 82 mg/g and 98%, respectively. It has also showed that the adsorption behavior on the MB could be well described by the pseudo-second-order model integrated with Langmuir model. - Highlights: • Using solid phase grafting method to graft the maleic anhydride (MA) onto the Sugarcane bagasse (SCB) and get the SCB-g-MA. • SEM, FTIR and 13C NMR analysis were used to characterize the grafting of MA on to the SCB by the solid phase grafting method. • The adsorption capacity and removal rate of MB were to be 82 mg/g and 98% respectively, to show an excellent adsorption effect. • Pseudo-second-order model and Langmuir model are better fitted the adsorption kinetics and isotherms in this research.

PREPARATION AND CHARACTERIZATION OF COMPOSITES COMPRISING MODIFIED HARDWOOD AND WOOD POLYMERS/POLY(VINYL CHLORIDE

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Ruxanda Bodîrlău

Full Text Available Chemical modification of hardwood sawdust from ash-tree species was carried out with a solution of maleic anhydride in acetone. Wood polymers, lignin, and cellulose were isolated from the wood sawdust and modified by the same method. Samples were characterized by Fourier transform infrared spectroscopy (FTIR, providing evidence that maleic anhydride esterifies the free hydroxyl groups of the wood polymer components. Composites comprising chemically modified wood sawdust and wood polymers (cellulose, lignin-as variable weight percentages-, and poly (vinyl chloride were obtained and further characterized by using FTIR spectroscopy and scanning electron microscopy (SEM. The thermal behavior of composites was investigated by using the thermogravimetric analysis (TGA. In all cases, thermal properties were affected by fillers addition.

Using maleic anhydride functionalized graphene oxide for improving the interfacial properties of carbon fiber/BMI composites

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W. Li

2016-11-01

Full Text Available Maleic anhydride functionalized graphene oxide (MAH-GO was synthesized and then introduced into carbon fiber (CF reinforced bismaleimide (BMI composites, with the aim of improving the interfacial adhesion strength between CF and BMI resin. Various characterization techniques including Fourier transform infrared spectroscopy (FT-IR, X-ray photoelectron spectra (XPS and thermogravimetric analysis (TGA demonstrated that the maleic anhydride has been successfully grafted onto the GO surfaces. The study showed that the interlaminar shear strength (ILSS and flexural properties of CF/BMI composites were all improved by the incorporation of GO and MAH-GO, and the MAH-GO showed the substantially improved effect due to the strong interaction between the MAH-GO and the resin matrix. The maximum increment of the ILSS, flexural strength and flexural modulus of composites were 24.4, 28.7 and 49.7%, respectively. Scanning electron microscope (SEM photographs of the fracture surfaces revealed that the interfacial bonding between CF and resin matrix was significantly strengthened by the addition of MAH-GO. The results suggest that this feasible method may be an ideal substitute for the traditional method in the interfacial modification of composites.

Comparative Study Of The Preparation Of Maleic Anhydride-g-Polypropylene By Two Grafting Processes Using Peroxide; Estudo comparativo de dois processos de graftizacao de polipropileno com anidrido maleico utilizando peroxidos

Energy Technology Data Exchange (ETDEWEB)

Sakahara, R.M.; Wang, S.H., E-mail: sakahara@usp.b, E-mail: wangshui@usp.b [Universidade de Sao Paulo (EPUSP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

2010-07-01

The Polypropylene grafting with Maleic anhydride is a thoroughly known technique. Its wide application is due, mainly,to the controlled changing in the polarity of this polymer, which increases the interfacial adhesion in blends and compounds. In this study, two grafting processes were compared. In the first, the maleic anhydride was grafted on polypropylene in a solution batch process, carried out in a round-bottom vessel. The second approach was carried out by reactive extrusion of polypropylene in the presence of peroxide and maleic anhydride. The samples thus prepared were characterized by DSC, TGA, FTIR, WAXS, EDS e SEM. It was possible to conclude that the solution technique was more efficient than the reactive extrusion; however the later was easier to accomplish due to the high viscosity of PP. (author)

Interpolymer complexses of vinyl ether copolymer with polyacrylic and polymethacrylic acids

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E. Shaikhutdinov

2012-03-01

Full Text Available The interactions between macromolecules of copolymers based on vinyl ethers (vinyl ether of monoethanolamine and vinyl buthyl ether and 2-acryloilamido-2-methylpropanesulphonic acid with polyacrylic and polymethacrylic acid and, as well as study the effect of interpolymer interactions in the adsorption of polymers at the aqueous solution-air interface were investigated. The observed synergistic increase in surface activity of macromolecules into polyelectrolyte mixtures explained by the formation of interpolymer complexes polyacid - copolymer.

MECHANICAL, ELECTRICAL, AND THERMAL PROPERTIES OF MALEIC ANHYDRIDE MODIFIED RICE HUSK FILLED PVC COMPOSITES

OpenAIRE

Navin Chand; Bhajan Das Jhod

2008-01-01

Unmodified and modified rice husk powder filled PVC composites were prepared having different amounts of rice husk powder. Mechanical, thermal, and electrical properties of these composites were determined. The tensile strength of rice husk powder PVC composites having 0, 10, 20, 30, and 40 weight percent of rice husk powder was found to be 33.9, 19.4, 18.1, 14.6, and 9.5 MPa, respectively. Adding of maleic anhydride- modified rice husk powder improved the tensile strength of rice husk powder...

Tailoring the morphology and properties of poly(lactic acid)/poly(ethylene-co-vinyl acetate)/starch blends via reactive compatibilization

NARCIS (Netherlands)

Ma, P.; Hristova - Bogaerds, D.G.; Schmit, P.; Goossens, J.G.P.; Lemstra, P.J.

2012-01-01

Poly(lactic acid)/poly(ethylene-co-vinyl acetate)/starch (PLA/EVA/starch) ternary blends were prepared by multi-step melt processing (reactive extrusion) in the presence of maleic anhydride (MA), benzoyl peroxide and glycerol. The effects of MA and glycerol concentration on the morphology and

Fabrication and properties of poly(polyethylene glycol n-alkyl ether vinyl ether)s as polymeric phase change materials

International Nuclear Information System (INIS)

Pei, Dong-fang; Chen, Sai; Li, Shu-qin; Shi, Hai-feng; Li, Wei; Li, Xuan; Zhang, Xing-xiang

2016-01-01

A series of poly(polyethylene glycol n-alkyl ether vinyl ether)s (PC m E n VEs) with various lengths of alkyl chains and polyethylene glycol spacers as side chain (m = 16,18; n = 1,2) were synthesized via two steps. First, monomers-ethylene glycol hexadecyl ether vinyl ether (C 16 E 1 VE), ethylene glycol octadecyl ether vinyl ether (C 18 E 1 VE), diethylene glycol hexadecyl ether vinyl ether (C 16 E 2 VE) and diethylene glycol octadecyl ether vinyl ether (C 18 E 2 VE) were synthesized by a modified Williamson etherification. Then, four new types of phase change materials were successfully fabricated by a living cationic polymerization. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were employed to characterize their composition, thermal properties and crystallization behavior. The results show that, the side chains of PC 16 E 1 VE, PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are in a hexagonal lattice, and the onset temperatures for melting of PC 16 E 1 VE, PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are 39.8 °C, 37.4 °C, 51.0 °C and 48.9 °C, the onset temperatures for crystallization are 36.7 °C, 35.2 °C, 47.4 °C and 46.3 °C, respectively. The enthalpy changes of PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are higher than 100 J/g; on the contrary, it is 96 J/g for PC 16 E 1 VE. The enthalpy decrease is no more than 11% after 10 heating and cooling cycles. The 5 wt% mass loss temperatures of PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are higher than 300 °C; on the contrary, it’s 283 °C for PC 16 E 1 VE. Using a weak polarity, flexible alkyl ether chain (-OCH 2 CH 2 O-) as a spacer to link the main chain and side chain is conducive to the crystallization of the alkyl side chain. These new phase change materials can be applied in heat storage, energy conservation, and environmental protection.

Hydrolysis of strained bridgehead bicyclic vinyl ethers and sulfides

International Nuclear Information System (INIS)

Chwang, W.K.; Kresge, A.J.; Wiseman, J.R.

1979-01-01

Rates of hydrolysis of the bridgehead bicyclic vinyl ether 9-oxabicyclo[3.3.1]non-1-ene(6) and its vinyl sulfide counterpart 9-thiabicyclo[3.3.1]non-1-ene(7), catalyzed by the hydronium ion, were measured in H 2 O and in D 2 O solution. These data give isotope effects, k/sub H//k/sub D/ = 2.4 and 1.9 respectively, which show that these reactions occur by the normal, rate-determining carbon protonation, mechanism. The vinyl ether 6 is less reactive than its olefin analogue, bicyclo[3.3.1]non-1-ene (relative rate 1:1/1400), as may have been expected for a constrained bicyclic system such as this, where stabilization of the bridgehead carbocation intermediate by conjugation with oxygen is severely impaired. The vinyl sulfide 7, however, is even less reactive than the vinyl ether (relative rates 1:1/140); this is a remarkable result in view of the fact that conjugation between the sulfur atom and the cationic center is presumably also strongly inhibited. 1 figure, 3 tables

Method for production of dicarbonic acid anhydrides

International Nuclear Information System (INIS)

Mistr, A.; Necas, J.; Polak, V.

1975-01-01

A method is described of producing dicarboxylic acid anhydrides by the reaction of maleic acid anhydride with olefins. The synthesis is initiated by gamma radiation at a total dose of 10 4 to 10 6 rads in the presence of an organic solvent. The addition reactions of maleic acid anhydride to 1-hexadecene, 1-octene and cyclohexene with yields of 43%, 17% and 11%, respectively, are specified. (L.K.)

Convenient procedures for the α-metallation of vinylic ethers and thioethers

NARCIS (Netherlands)

Verkruijsse, H.D.; Brandsma, L.; Schleyer, P. von R.

1987-01-01

Ethyl vinyl ether H2C=CHOC2H5 and the analogous cyclic vinylic ethers dehydrofuran and 2,3-dihydropyran can be potassiated at −20°C in the α-position with a 1/1/1 molar mixture of BuLi, t-BuOK and TMEDA in hexane. Methyl vinyl sulfide is potassiated very smoothly by a 1/1 molar mixture of BuLi and

The breakdown of vinyl ethers as a two-center synchronous reaction

Science.gov (United States)

Pokidova, T. S.; Shestakov, A. F.

2009-11-01

The experimental data on the molecular decomposition of vinyl ethers of various structures to alkanes and the corresponding aldehydes or ketones in the gas phase were analyzed using the method of intersecting parabolas. The enthalpies and kinetic parameters of decomposition were calculated for 17 reactions. The breakdown of ethers is a two-center concerted reaction characterized by a very high classical potential barrier to the thermally neutral reaction (180-190 kJ/mol). The kinetic parameters (activation energies and rate constants) of back reactions of the formation of vinyl ethers in the addition of aldehydes or ketones to alkanes were calculated using the method of intersecting parabolas. The factors that influenced the activation energy of the decomposition and formation of ethers were discussed. Quantum-chemical calculations of several vinyl ether decomposition reactions were performed. Ether formation reactions were compared with the formation of unsaturated alcohols as competitive reactions, which can occur in the interaction of carbonyl compounds with alkenes.

Blends of nitrile butadiene rubber/poly (vinyl chloride: The use of maleated anhydride castor oil based plasticizer

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Indiah Ratna Dewi

2016-06-01

Full Text Available Recently, much attention has been focused on research to replace petroleum-based plasticizers, with biodegradable materials, such as biopolymer which offers competitive mechanical properties. In this study, castor oil was modified with maleic anhydride (MAH to produce bioplasticizer named maleated anhydride castor oil (MACO, and used in nitrile butadiene rubber (NBR/poly vinyl chloride (PVC blend. The effect of MACO on its cure characteristics and mechanical properties of NBR/PVC blend has been determined. The reactions were carried out at different castor oil (CO/xylene ratios, i.e. 1:0 and 1:1 by weight, and fixed CO/MAH ratio, 1:3 by mole. DOP, CO, and MACO were added into each NBR/PVC blend according to the formula. It was found that the viscosity and safe process level of NBR/PVC blend is similar from all plasticizer, however, MACO (1:0 showed the highest cure rate index (CRI. MACO-based plasticizer gave a higher value of the mechanical properties of the NBR/PVC blend as compared to DOP based plasticizer. MACO (1:1 based plasticizer showed a rather significance performance compared to another type of plasticizers both before and after aging. The value of hardness, elongation at break, tensile strength, and tear strength were 96 Shore A, 155.91 %, 19.15 MPa, and 74.47 MPa, respectively. From this result, NBR/PVC blends based on MACO plasticizer can potentially replace the DOP, and therefore, making the rubber blends eco-friendly.

Maleic anhydride as an additive to γ-butyrolactone solutions for Li-ion batteries

International Nuclear Information System (INIS)

Ufheil, Joachim; Baertsch, Martin C.; Wuersig, Andreas; Novak, Petr

2005-01-01

The effect of maleic anhydride (MA) as a new film-forming additive in γ-butyrolactone (GBL)-based electrolytes for use in Li-ion batteries has been studied to advance the understanding of the solid electrolyte interphase (SEI) formation on graphite electrodes. Cyclic voltammetry measurements showed that even small amounts of MA (up to 4 wt.%) improved the lithium intercalation into graphite. The effect of MA was also verified by electrochemical impedance spectroscopy. In situ subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS) and differential electrochemical mass spectrometry (DEMS) allowed identification of gas formation and decomposition products during the SEI formation. GBL-based electrolytes with MA showed both, higher cycling efficiency and cycle life of graphite electrodes

Grafting amino drugs to poly(styrene-alt-maleic anhydride) as a potential method for drug release

Energy Technology Data Exchange (ETDEWEB)

Khazaei, Ardeshir; Saednia, Shahnaz; Saien, Javad; Abbasi, Fatemeh, E-mail: Khazaei_1326@yahoo.com, E-mail: ssaednia@gmail.com [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Kazem-Rostami, Masoud [Young Researchers Club and Elite, Takestan Branch, Islamic Azad University, Takestan (Iran, Islamic Republic of); Sadeghpour, Mahdieh [Department of Chemistry, Takestan Branch, Islamic Azad University, Takestan (Iran, Islamic Republic of); Borazjani, Maryam Kiani [Faculty of Science, Department of Chemistry, Bushehr Payame Noor University (PNU), Bushehr (Iran, Islamic Republic of)

2013-07-15

Drug delivery systems based on polymer-drug conjugates give an improved treatment with lower toxicity or side effects and be used for the treatment of different diseases. Conjugates of biodegradable poly(styrene-alt-maleic anhydride) (PSMA), with a therapeutic agents such as amantadine hydrochloride, amlodipine, gabapentin, zonisamide and mesalamine, were afforded by the formation of the amide bonds of the amino drugs that reacted with the PSMA anhydride groups. The amounts of covalently conjugated drugs were determined by a {sup 1}H NMR spectroscopic method, and the in vitro release rate in buffer solution (pH 1.3) was studied at body temperature 37 Degree-Sign C. In kinetic studies, different dissolution models were examined to obtain drug release data and the collected data were well-fitted to the Korsmeyer-Peppas equation, revealing a dominant Fickian diffusion mechanism for drug release under the in vitro conditions. (author)

Ambient gold-catalyzed O-vinylation of cyclic 1,3-diketone: A vinyl ether synthesis

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Yumeng Xi

2013-11-01

Full Text Available Gold-catalyzed O-vinylation of cyclic 1,3-diketones has been achieved for the first time, which provides direct access to various vinyl ethers. A catalytic amount of copper triflate was identified as the significant additive in promoting this transformation. Both aromatic and aliphatic alkynes are suitable substrates with good to excellent yields.

Amphiphilic poly{[α-maleic anhydride-ω-methoxypoly(ethylene glycol]-co-(ethyl cyanoacrylate} graft copolymer nanoparticles as carriers for transdermal drug delivery

Directory of Open Access Journals (Sweden)

Jinfeng Xing

2009-10-01

Full Text Available Jinfeng Xing, Liandong Deng, Jun Li, Anjie DongDepartment of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People’s Republic of ChinaAbstract: In this study, the transdermal drug delivery properties of D,L-tetrahydropalmatine (THP-loaded amphiphilic poly{[α-maleic anhydride-ω-methoxy-poly(ethylene glycol]-co-(ethyl cyanoacrylate} (PEGECA graft copolymer nanoparticles (PEGECAT NPs were evaluated by skin penetration experiments in vitro. The transdermal permeation experiments in vitro were carried out in Franz diffusion cells using THP-loaded PEGECAT NPs as the donor system. Transmission electron microscopy and Fourier transform infrared spectroscopy were used to characterize the receptor fluid. The results indicate that the THP-loaded PEGECAT NPs are able to penetrate the rat skin. Fluorescent microscopy measurements demonstrate that THP-loaded PEGECAT NPs can penetrate the skin not only via appendage routes but also via epidermal routes. This nanotechnology has potential application in transdermal drug delivery. Keywords: poly{[α-maleic anhydride-ω-methoxy-poly(ethylene glycol]-co-(ethyl cyanoacrylate}, nanoparticles, transdermal drug delivery, D,L-tetrahydropalmatine

Short-chain grafting of tetrahydrofuran and 1,4-dioxane cycles on vinylchloride-maleic anhydride copolymer

Directory of Open Access Journals (Sweden)

2009-01-01

Full Text Available Mass increase of vinylchloride-maleic anhydride (VC-MA copolymer samples aged in tetrahydrofuran (THF or in 1,4-dioxane results from chemical interaction of VC-MA macromolecules with 1,4-dioxane or THF. Microstructure of the products of such modification was proved by infrared spectroscopy (IR- and nuclear magnetic resonance spectroscopy (13C NMR and 1H NMR. Mechanism of modification has been proposed. The results of microstructure research of VC-MA samples aged in THF and in 1,4-dioxane coincide with already known data on the reactions of opening of these and other oxygen-containing cycles under mild conditions.

Barrier and adhesion properties of anti-corrosion coatings based on surfactant-free latexes from anhydride-containing polymers

NARCIS (Netherlands)

Soer, W.J.; Ming, W.; Koning, C.E.; Benthem, van R.A.T.M.; Mol, J.M.C.; Terryn, H.

2009-01-01

We have successfully obtained surfactant-free latexes from anhydride-containing polymers, including poly(styrene-alt-maleic anhydride) (PSMA), maleinized polybutadiene (PBDMA), and poly(octadecene-alt-maleic anhydride) (POMA). Here we report barrier and adhesion properties of the coatings made from

Designing maleic anhydride-{alpha}-olifin copolymeric combs as wax crystal growth nucleators

Energy Technology Data Exchange (ETDEWEB)

Soni, Hemant P. [Department of Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390 002 (India); Kiranbala; Bharambe, D.P. [Department of Applied Chemistry, Faculty of Technology and Engineering, The Maharaja Sayajirao University of Baroda, Vadodara-390 001 (India); Agrawal, K.S. [Department of Petrochemical Technology, Polytechnic, The Maharaja Sayajirao University of Baroda, Vadodara-390 002 (India); Nagar, A. [MH ASSET, ONGC, Mumbai (India)

2010-09-15

Modification of the wax crystal habit is of great practical interest during transportation and processing of crude oil at low temperature. Various pour point depressant (PPD) additives can facilitate this modification by different mechanisms. Comb shaped polymer additives are known to depress the pour point of crude oil by providing different nucleation sites for the precipitation of wax. This paper describes performance based design, synthesis, characterization and evaluation of comb shaped polymeric diesters. Copolymers of maleic anhydride with different unsaturated C{sub 22} esters were synthesized and copolymers then reacted with two unsaturated fatty alcohols. All products were characterized by Fourier Transform Infra Red (FTIR) spectroscopy and Gel Permeation Chromatography (GPC). Rheological properties of crude (with and without additive) were studied by Advance Rheometer AR-500. In this study the additive based on oleic acid was evaluated as good PPD and rheology modifier. (author)

Controlled radical copolymerization of styrene and maleic anhydride and the synthesis of novel polyolefin-based block copolymers by reversible addition-fragmentation chain-transfer (RAFT) polymerization

NARCIS (Netherlands)

Brouwer, de J.A.M.; Schellekens, M.A.J.; Klumperman, B.; Monteiro, M.J.; German, A.L.

2000-01-01

Reversible addn.-fragmentation chain transfer (RAFT) was applied to the copolymn. of styrene and maleic anhydride. The product had a low polydispersity and a predetd. molar mass. Novel, well-defined polyolefin-based block copolymers were prepd. with a macromol. RAFT agent prepd. from a com.

Amphiphilic graft copolymer based on poly(styrene-co-maleic anhydride with low molecular weight polyethylenimine for efficient gene delivery

Directory of Open Access Journals (Sweden)

Duan XP

2012-09-01

Full Text Available Xiaopin Duan,1,2 Jisheng Xiao,2 Qi Yin,2 Zhiwen Zhang,2 Shirui Mao,1 Yaping Li21School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 2Center of Pharmaceutics, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, ChinaBackground and methods: A new amphiphilic comb-shaped copolymer (SP was synthesized by conjugating poly(styrene-co-maleic anhydride with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, 1H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer.Results: The buffering capability of SP was similar to that of polyethyleneimine within the endosomal pH range. The copolymer could condense DNA effectively to form complexes with a positive charge (13–30 mV and a small particle size (130–200 nm at N/P ratios between 5 and 20, and protect DNA from degradation by DNase I. In addition, SP showed much lower cytotoxicity than polyethyleneimine 25,000. Importantly, the gene transfection activity and cellular uptake of SP-DNA complexes were all markedly higher than that of complexes of polyethyleneimine 25,000 and DNA in MCF-7 and MCF-7/ADR cell lines.Conclusion: This work highlights the promise of SP as a safe and efficient synthetic vector for DNA delivery.Keywords: poly(styrene-co-maleic anhydride, polyethylenimine, DNA, gene delivery

Improved performance of Nb-doped vanadyl pyrophosphate, catalyst for n-butane oxidation to maleic anhydride

Energy Technology Data Exchange (ETDEWEB)

Pavarelli, G.; Caldarelli, A.; Cavani, F. [Bologna Univ. (Italy). Dipt. di Chimica Industriale ' Toso Montanari' ; Cortelli, C.; Luciani, S. [Polynt SpA, Scanzorosciate (Italy)

2013-11-01

We report here about an investigation on the role of Nb{sup 5+} when used as a promoter for vanadyl pyrophosphate, catalyst for the oxidation of n-butane to maleic anhydride. The effect of Nb was very complex, a function of both its amount and the reaction temperature used. The optimal catalytic behavior was shown for very low Nb contents, i.e., for a V/Nb atomic ratio as low as 150. The main role of Nb was that of accelerating the formation of a limited amount of {gamma}-VOPO{sub 4} on the surface of vanadyl pyrophosphate, by accelerating the oxidation of V{sup 4+} into V{sup 5+} under reaction conditions. (orig.)

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

Science.gov (United States)

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

2017-07-01

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

Effect of surface modified kaolin on properties of polypropylene grafted maleic anhydride

Science.gov (United States)

Yang, Ni; Zhang, Zuo-Cai; Ma, Ning; Liu, Huan-Li; Zhan, Xue-Qing; Li, Bing; Gao, Wei; Tsai, Fang-Chang; Jiang, Tao; Chang, Chang-Jung; Chiang, Tai-Chin; Shi, Dean

To achieve reinforcement of mechanical and thermal performances of polypropylene (PP) product, this work aimed at fabrication of surface modified kaolin (M-kaolin) filled polypropylene grafted maleic anhydride (PP-g-MAH) composites with varying contents of fillers and investigation of their mechanical and thermal properties. And the prepared PP-g-MAH/M-kaolin composites were characterized by means of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Fracture analysis by SEM showed M-kaolin particles were well dispersed in the PP-g-MAH matrix. Mechanical behaviors were determined by tensile strength, tensile strain at break and impact strength analysis. Impact strength of PP-g-MAH/2 wt% M-kaolin composites was improved up to 30% comparing with unfilled composites. Thermostability had been found enhanced when M-kaolin added. The results revealed PP-g-MAH/M-kaolin composites showed the optimal thermal and mechanical properties when 2 wt% of M-kaolin was added.

nanocomposites of PA6/ABS blends compatibilized with styrene-maleic anhydride copolymer

International Nuclear Information System (INIS)

Oliveira, Amanda D. de; Pessan, Luiz A.

2009-01-01

To achieve a balance between stiffness and toughness, ternary nanocomposites based on blends of polyamide 6 (PA6) and acrylonitrile-butadiene-styrene (ABS) were prepared by the melt intercalation using the organoclay Cloisite R 30B (OMMT) and the styrene-maleic anhydride copolymer (SMA) as compatibilizer. Four blending sequences were used to prepare studied systems and their mechanical properties studied through the Young's modulus and notched Izod impact. It was observed that the materials prepared by all blending sequences studied showed an increase in the Young's modulus compared to the neat PA6. However, a decrease in the toughness was observed for the systems with the addition of the organoclay. The DRX results showed an intercalated structure for the some systems that used ABS in their compositions. HDT measurements of the nanocomposites showed an increase in this property compared to the neat PA6. The use of nanoclay lead to a reinforcement of the polymeric matrix. (author)

Two-step modification of poly(D, L-lactic acid) by ethylenediamine-maleic anhydride

International Nuclear Information System (INIS)

Cao Chengbo; Zhu Fanglian; Yu Xueli; Wang Qin; Wang Chuandong; Li Baolu; Lv Ronghui; Li Musen

2008-01-01

Poly(lactic acid) (PLA) was modified by maleic anhydride (MAH), then the resultant MAH modified PLA (MPLA) was acylated with ethylenediamine (EDA), so EDA-MAH modified PLA (EMPLA) was prepared. The results of DSC, FT-IR and NMR testified that MAH and EAD were successfully introduced into the original polymer. The hydrophilicity of EMPLA was considerably increased compared with that of PLA. The degradation experiment showed that the introduction of EDA into the original polymer could neutralize the carboxyl end groups of the degradation products. The results of SEM and MTT of rat osteoblasts cultured in vitro showed that the cytocompatibility and cell adhesion of the modified materials were significantly increased compared with the original polymer, especially EMPLA; the number of cells were obviously increased and cells attached firmly to the material; these were ascribed to the EDA neutralizing the carboxyl end groups of the degradation products

Effect of maleic anhydride on the physico-mechanical properties of NR/PE blends

International Nuclear Information System (INIS)

Yehia, A.A.; El Elnashar, D.

2005-01-01

Blending of two or more polymers is considered as a new technique to produce new materials with new properties at low production cost and investment. Rubber / Rubber blends are well known in tire industry. In the last decade rubber and plastic blending attract the interest of many researchers and technologists. In the present work NR and LLDPE was blended in presence of maleic anhydride (MA) on a Brabender premixed at different conditions and namely temperature and time. The obtained blends were cured with sulphur and peroxide curing systems. Peroxide can crosslink both NR and PE, but the sulphur system crosslinks only the rubber phase in the blend. The data showed also that the addition of MA greatly improved the physico-mechanical properties of NR/PE blends. The surface morphology of the blends under investigation was studied by SEM. The results will be presented and discussed in detail

Study of maleic anhydride and styrene grafted onto polypropylene induced by UV irradiation

International Nuclear Information System (INIS)

Li Zhenzhong; He Wei; Guo Hongjun; Zhang Wenxiong; Ma Yalin

2007-01-01

Maleic anhydride (MAH) and styrene (St) grafted onto polypropylene (PP) were prepared by UV irradiation. Effects of the irradiation time, monomer and initiator content on the grafting rate and melt flow rate (MFR) were studied. The results show that the optimal duration of UV irradiation is 30s. The grafting rate increases with initiator content when initiator content less than 0.6 phr, the MFR value of grafted PP reaches the highest point when benzophenone (BP) content is 0.4 phr. The content of MAH and St have an effect on the grafting rate and MFR value of the grafted PP, and the optimal contents of monomer is 4 phr. The existence of St as a comonomer reduces apparently the MFR value of grafted PP greatly. Grafted PP present significant changes in crystallization and fusion peaks, indicating differences in crystal size and formation after grafting reaction. (authors)

Tailoring magnetic properties of self-biased hexaferrites using an alternative copolymer of isobutylene and maleic anhydride

Science.gov (United States)

Wu, Chuanjian; Yu, Zhong; Sokolov, Alexander S.; Yu, Chengju; Sun, Ke; Jiang, Xiaona; Lan, Zhongwen; Harris, Vincent G.

2018-05-01

Discussed is a novel self-biased hexaferrite gelling system based on a nontoxic and water-soluble copolymer of isobutylene and maleic anhydride. This copolymer simultaneously acts as a dispersant and gelling agent, and recently received much attention from the ceramics community. Herein its effects on the rheological conditions throughout magnetic-field pressing, and consequently, orientation, density and magnetic properties of textured hexaferrites were investigated. Ka-band FMR linewidths were measured, and the crystalline anisotropy and porosity induced linewidth broadening were estimated according to Schlömann's theory. The copolymer allowed to reduce the friction between micron-sized magnetic particulates, resulting in higher density and degree of crystalline orientation, and lower FMR linewidth.

Effect of hydrostatic pressure, temperature, and solvent on the rate of the Diels-Alder reaction between 9,10-anthracenedimethanol and maleic anhydride

Science.gov (United States)

Kiselev, V. D.; Kornilov, D. A.; Anikin, O. V.; Latypova, L. I.; Konovalov, A. I.

2017-03-01

The rate of the reaction between 9,10-anthracenedimethanol and maleic anhydride in 1,4-dioxane, acetonitrile, trichloromethane, and toluene is studied at 25, 35, 45°C in the pressure range of 1-1772 bar. The rate constants, enthalpies, entropies and activation volumes are determined. It is shown that the rate of reaction with 9,10-anthracenedimethanol is approximately one order of magnitude higher than with 9-anthracenemethanol.

Partial oxidation of Raffinate II and other mixtures of n-Butane and n-Butenes to maleic anhydride in a fixed-bed reactor

OpenAIRE

Brandstädter, Willi Michael

2008-01-01

The utilisation of the C4 streams of steamcrackers by converting raffinate II to maleic anhydride was studied. The oxidation reactions were investigated in a laboratory-scale fixed-bed reactor to determine reaction kinetics. The effects of pore diffusional resistance were investigated and explained. A two-dimensional pseudo-homogeneous reactor model was used for the simulation of a production-scale fixed-bed reactor. A flow scheme of the reactor section including a recycle was proposed.

γ-Rays-induced synthesis of hydrogels of vinyl ethers with stimuli-sensitive behavior

International Nuclear Information System (INIS)

Nam, I.K.; Mun, G.A.; Urkimbaeva, P.I.; Nurkeeva, Z.S.

2003-01-01

γ-Radiation method was applied to synthesize novel water-soluble and water-swelling polymers. Vinyl ether of ethylene glycol (VEEG), vinyl butyl (VBE) and vinyl isobutyl (VIBE) ethers were used as monomers. The synthesis of VEEG-VBE and VEEG-VIBE copolymers was carried out in a wide range of feed composition and absorbed dose. It was found that the hydrophobic-hydrophilic balance of the copolymers could be delicately varied by the copolymer composition as well as by the chemical structure of the alkyl substitute in the hydrophobic moiety. The copolymers exhibit thermo-sensitive behavior in water solutions. The value of transition temperature is considerably decreased at a higher concentration of the hydrophobic component in the copolymer composition

Poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers with Various Molecular Weights as Phase Change Materials

Directory of Open Access Journals (Sweden)

Dongfang Pei

2018-02-01

Full Text Available At present, research on the relationship of comb-like polymer phase change material structures and their heat storage performance is scarce. Therefore, this relationship from both micro and macro perspectives will be studied in this paper. In order to achieve a high phase change enthalpy, ethylene glycol segments were introduced between the vinyl and the alkyl side chains. A series of poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers (PC14EnVEs (n = 1, 2 with various molecular weights were polymerized by living cationic polymerization. The results of PC14E1VE and PC14E2VE showed that the minimum number of carbon atoms required for side-chain crystallization were 7.7 and 7.2, which were lower than that reported in the literature. The phase change enthalpy 89 J/g (for poly(mono ethylene glycol n-tetradecyl ether vinyl ethers and 86 J/g (for poly(hexadecyl acrylate were approximately equal. With the increase of molecular weight, the melting temperature, the melting enthalpy, and the initial thermal decomposition temperature of PC14E1VE changed from 27.0 to 28.0 °C, from 95 to 89 J/g, and from 264 to 287 °C, respectively. When the number average molar mass of PC14EnVEs exceeded 20,000, the enthalpy values remained basically unchanged. The introduction of the ethylene glycol chain was conducive to the crystallization of alkyl side chains.

A computational study of the Diels-Alder reactions between 2,3-dibromo-1,3-butadiene and maleic anhydride

Science.gov (United States)

Rivero, Uxía; Meuwly, Markus; Willitsch, Stefan

2017-09-01

The neutral and cationic Diels-Alder-type reactions between 2,3-dibromo-1,3-butadiene and maleic anhydride have been computationally explored as the first step of a combined experimental and theoretical study. Density functional theory calculations show that the neutral reaction is concerted while the cationic reaction can be either concerted or stepwise. Further isomerizations of the Diels-Alder products have been studied in order to predict possible fragmentation pathways in gas-phase experiments. Rice-Ramsperger-Kassel-Marcus (RRKM) calculations suggest that under single-collision experimental conditions the neutral product may reform the reactants and the cationic product will most likely eliminate CO2.

Procedure and composition for secondary recovery of petroleum

Energy Technology Data Exchange (ETDEWEB)

Sullivan, F F

1968-03-04

A copolymer of vinyl methyl ether and maleic anhydride in a brine (sodium bicarbonate, sodium chloride, calcium chloride) was proposed, for secondary oil recovery in the presence of clays. The ratio of copolymer to salts should be 20 : 1 to 1 : 1500. The ratio between the multivalent salts and sodium bicarbonate is 5 : 1 to 1 : 600. The concentration of salts of multivalent cations should be present in the range of 0.0025 to 0.25% by weight. Alkali metal halides comprise 0.1 to 1% of the polymer solution.

Radiation grafting from binary monomer mixtures. II. Vinyl ether of monoethanolamine and N-vinylpyrrolidone

International Nuclear Information System (INIS)

Nurkeeva, Zauresh S.; Abdel Aal, A.-S.; Kupchishin, Anatoliy I.; Khutoryanskiy, Vitaliy V.; Mun, Grigoriy A.; Beksyrgaeva, Aida G.

2003-01-01

Radiation grafting from binary monomer mixtures of vinyl ether of monoethanolamine and N-vinylpyrrolidone onto polyethylene films has been studied. The structure of the grafted films was characterized by FTIR spectroscopy. Water uptake and contact angle measurements confirmed that the grafting leads to a considerable hydrophilization of the films surface. The presence of the more active N-vinylpyrrolidone enhances the grafting of the less active vinyl ether of monoethanolamine. Sorption properties of grafted films with respect to copper (II) ions have been studied

Radiation grafting from binary mixtures of vinyl ether of mono ethanol amine with N-vinylpyrrolidone and vinyl ether of ethylene glycol onto polyolefins films and metallization of obtained films

International Nuclear Information System (INIS)

Al'-Saed Abdel' Aal'; Nurkeeva, Z.; Khutoryanskij, V.; Mun, G.; Sangajlo, M.

2003-01-01

Radiation grafting from binary mixtures of vinyl ether of mono ethanol amine with N-vinylpyrrolidone and vinyl ether of ethylene glycol onto polyolefins films using γ-radiation and accelerated electrons has been studied. IR-spectroscopy is used to confirm the structure of grafted films. A combination of and metallization of obtained films. A combination of gravimetric and potentiometric techniques is applied to determine the fraction of each monomer in graft copolymer. Water uptake and contact angle measurements confirmed that the grafting process improve the hydrophilic properties of obtained films. The obtained materials are metallized by electroless copper plating. The metallized films have good electro conductive properties. (author)

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

Science.gov (United States)

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

2017-01-01

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

Preparation of vinyl chloride – vinyl ether copolymers via partial etherification from PVC

Directory of Open Access Journals (Sweden)

2007-08-01

Full Text Available The chemical modifications of poly (vinyl chloride with aliphatic and aromatic alcohols compounds have been investigated at room temperature and atmospheric pressure, catalysed by a new green basic catalyst, the Maghnite-K+. The presence of ether groups in the products is proven by infra red spectroscopy (IR as well as by nuclear magnetic resonance spectroscopy (1H NMR, and characterized by intrinsic viscosity as well as by gel permeation chromatography (GPC.

Grafting of copolymer styrene maleic anhydride on poly(ethylene terephthalate) film by chemical reaction and by plasma method

Energy Technology Data Exchange (ETDEWEB)

Bigan, Muriel; Bigot, Julien [Laboratoire de Chimie Organique et Macromoleculaire (UMR 8009), Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France); Mutel, Brigitte [Laboratoire de Genie des Procedes d' Interactions Fluides reactifs-Materiaux (UPRES-EA 3751), Batiment C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: Brigitte.mutel@univ-lille1.fr; Coqueret, Xavier [Laboratoire Reactions Selectives et Applications (UMR-CNRS 6519) Universite de Reims Champagne-Ardennes, B.P. 1039, 51687 Reims Cedex 2 (France)

2008-02-15

This work deals with the chemical grafting of a styrene maleic anhydride copolymer on the surface of a previously hydrolyzed polyethylene terephthalate (PET) film 12 {mu}m thick via covalent bond. Two different ways are studied. The first one involves an activation of the hydrolyzed PET by the triethylamine before the grafting step. In the second one, the copolymer reacts with the 4-dimethylaminopyridine in order to form maleinyl pyridinium salt which reacts with alcohol function of the hydrolyzed PET. Characterization and quantification of the grafting are performed by Fourier transform infrared spectroscopy. Factorial experiment designs are used to optimize the process and to estimate experimental parameters effects. The opportunity to associate the chemical process to a cold remote nitrogen plasma one is also examined.

Effect of polypropylene maleic anhydride (PPMAH) on mechanical and morphological properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr)/empty fruit bunch (EFB) composites

Science.gov (United States)

Othman, Nurul Syazwani; Santiagoo, Ragunathan; Abdillahi, Khalid Mohamed; Ismail, Hanafi

2017-07-01

The fabrication of polypropylene (PP)/ recycled acrylonitrile butadiene rubber (NBRr)/ empty fruit bunch (EFB) composites were investigated. The effects of polypropylene maleic anhydride (PPMAH) as a compatibilizer on the mechanical and morphological properties of PP/NBRr/EFB composites were studied. Composites were prepared through melt mixing using heated two roll mill at 180 °C for 9 minutes and rotor speed of 15 rpm. NBRr loading were varied from 0 to 60 phr and PPMAH was fixed for 5 phr. The composites were moulded into a 1 mm thin sheet using hot press machine and then cut into dumbbell shape. The mechanical and morphological properties of composites were examined using universal tensile machine (UTM) and scanning electron microscope (SEM), respectively. Tensile strength and Young's modulus of PP/NBRr/EFB composites decreased with increasing NBRr loading, whilst increasing the elongation at break. However, PPMAH compatibilized composites have resulted 27% to 40% and 25% to 42% higher tensile strength and Young's modulus, respectively, higher compared to uncompatibilized composites. This was due to the better adhesion between PP/NBRr matrices and EFB filler with the presence of maleic anhydride moieties. From the morphological study, the micrograph of PPMAH compatibilized composites has proved the well bonded and good attachments of EFB filler with PP/NBRr matrices which results better tensile strength to the PP/NBRr/EFB composites.

Solid polymer electrolytes based on alternating copolymers of vinyl ethers with methoxy oligo(ethyleneoxy)ethyl groups and vinylene carbonate

International Nuclear Information System (INIS)

Itoh, Takahito; Fujita, Katsuhito; Inoue, Kentaro; Iwama, Hiroki; Kondoh, Kensaku; Uno, Takahiro; Kubo, Masataka

2013-01-01

Graphical abstract: - Highlights: • Synthesis of alternating copolymers of vinyl ethers and vinylene carbonate. • Preparation of polymer electrolytes based on the alternating copolymers with LiTFSI. • Structure-property relationship for alternating copolymers-based electrolytes. • Interfacial stability between polymer electrolytes with lithium metal electrode. - Abstract: Alternating copolymers (poly(1a-g-alt-VC)) of vinyl ethers with various methoxy oligo(ethyleneoxy)ethyl groups and vinylene carbonate (VC) were prepared, and the thermal and electrochemical properties of their polymer electrolytes with LiTFSI and interfacial stability between the polymer electrolyte and Li metal electrode were investigated. T g 's increased linearly with salt contents, and decreased with an increase in the chain length of methoxy oligo(ethyleneoxy)ethyl groups in the vinyl ethers at constant salt concentration. The slopes of T g vs. [Li]/[O] were identical, independent of the polymer structure. The ionic conductivities of the polymer electrolytes increased with increasing the side-chain ethyleneoxy (EO) unit length of the vinyl ether unit in the alternating copolymers, and also their temperature dependences became relatively smaller in the polymer electrolytes having longer EO units in the vinyl ethers. The highest ionic conductivity, 1.2 × 10 −4 S/cm at 30 °C, was obtained in the alternating copolymer with a side-chain EO unit length of 23.5 in the vinyl ether unit. Ion transport coupled with the segmental motion of the polymer is dominant in these polymer electrolytes. Interfacial resistance increased gradually with contact time, indicative of the formation of passivation films on the Li metal electrode. These polymer electrolytes are thermally stable and have large electrochemical windows of use

Grafting of Maleic Anhydride onto Polyethylene by Blend Process forEnvironmentally Friendly Plastics

International Nuclear Information System (INIS)

Hendrana, Sunit; Retno-Yusiasih; Sudirman; Ipit-Karyaningsih; Djimat-Lisnawati

2000-01-01

Grafting maleic anhydride (MAH) onto polyethylene is one of the route tomake plastics which can be consumed by microbe in the soil. High temperaturesolution process is one of the method to perform grafting. This method is notreally handy since it involves many steps. Therefore, in this work a simplemethod is performed to graft MAH onto polyethylene, i.e., blending process.As the process occurs in melt, the reaction is more likely to be diffusioncontrol rather than chemical control. Therefore, there are many parameterscan affect the grafting such as temperature of the blending, speed of therotation, concentration of MAH and concentration of dicumyl peroxide (DCP).Preliminary work in our laboratorium found an optimum condition for the firsttwo parameters. Thus, in this work the effect of concentration of MAH and DCPis studied into the effectiveness of grafting process. One of the indicationof unexpected reaction is formation of gel, or in other words the formationof X-link among polyethylene molecules. The grafted polyethylene ischaracterized by calculation of gel content, thermal properties by TG/DTA andFourier Transform Infrared (FTIR). The results show the concentration of MAHand DCP play roles. However, initiator DCP has more significance effect thanthe MAH. (author)

The Free-Radical Copolymerization of Difurylmethane with Maleic

African Journals Online (AJOL)

Prof. Jo Michael

Reaction feeds containing 85 mol % and higher of difurylmethane ... Keywords: difurylmethane; maleic anhydride; copolymerization; thermodecomposition ... delivery apparatus set at 500 psi for a flow rate of 1 cm3 min-1; a Waters model U6K.

Influence of Maleic Anhydride/Glycidyl Methacrylate Cografted Polylactic Acid on Properties of Wood Flour/PLA Composites

Directory of Open Access Journals (Sweden)

DU Jun

2017-12-01

Full Text Available Graft copolymers of PLA-g-MAH, PLA-g-GMA and PLA-co-MAH/GMA were prepared by means of melt grafting. The structure of the graft copolymers were characterized by FTIR.Wood flour/PLA composites were prepared by injection molding with three kinds of graft copolymers as compatibilizers, and the fractured morphology of composites was investigated by scanning electron microscope (SEM. Results show that there is no obvious phase interface between wood flour and PLA,which indicating the interfacial compatibility of wood flour/PLA composites is improved after adding different graft copolymers. The determination results of mechanical properties, processing flowability and dynamic rheological property of composites prepared with different graft copolymers reveal that, compared to the composite without compatibilizer, the tensile strength and impact strength of wood flour/PLA composites are increased by 9.54% and 7.23% respectively, and the equilibrium torque, shear heat, storage modulus and complex viscosity are all increased after adding maleic anhydride/glycidyl methacrylate cografted polylactic acid.

Study on thermal properties and crystallization behavior of electron beam irradiated ethylene vinyl acetate (EVA)/waste tyre dust (WTD) blends in the presence of polyethylene graft maleic anhydride (PEgMAH)

Energy Technology Data Exchange (ETDEWEB)

Ramli, Syuhada; Ahmad, S. H. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan (Malaysia); Ratnam, C. T. [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang (Malaysia); Athirah, Nurul [School of Materials and Mineral Resources, USM Engineering Campus (Malaysia)

2013-11-27

The aim of this article is to show the effects of the electron beam irradiation dose and presence of a compatibiliser on the thermal properties and crystallinity of EVA/WTD blends. The purpose of applying electron beam radiation with doses range 50 to 200 kGy and adding a compatibiliser was to enhance the compatibility of the studied blends and at the same time to investigate the possibility of using this technique in the process of recycling polymeric materials. As the compatibilisers, the polyethylene grafted maleic anhydride (PEgMAH) was utilized, they were added at the amounts of 1-5 phr respectively. The enhancement of thermal properties was accompanied by the following effects, discussed in this article: i) an irradiated EVA/WTD blend at 200kGy was found to improve the thermal properties of EVA, ii) the addition of PEgMAH in EVA/WTD blends and the subsequent irradiation allowed prevention of degradation mechanism. iii) the ΔH{sub f} and crystallinity percentage decrease at higher PEgMAH content.

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

International Nuclear Information System (INIS)

Klinpituksa, P; Kongkalai, P; Kaesaman, A

2014-01-01

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

Structure of pyridine and quinoline vinyl ethers according to data from 1H and 13C NMR spectra and quantum-chemical calculations

International Nuclear Information System (INIS)

Afonin, A.V.; Voronov, V.K.; Andriankov, M.A.; Danovich, D.K.

1987-01-01

A systematic investigation of the structure of the vinyl ethers of heterocyclic compounds has not been undertaken. The present work was devoted to investigation of the stereochemical and electronic structure of the vinyl ethers of pyridine and quinoline. The PMR spectra of the samples were recorded for 5% solutions in deuterochloroform on a Tesla BS-497 spectrometer at 100 MHz. The 13 C NMR spectra were recorded on a Tesla BS-567A spectrometer at 25.1 MHz in deuterochloroform with the samples at concentrations of 30%. The internal standard was HMDS. The vinyl ethers of pyridine and quinoline exist preferentially in the nonplanar S-trans conformation. In the vinyl esters of pyridine and quinoline the p-π conjugation is concurrent in nature and depends on the position of the vinyloxy group in the heterocycle

Compatibility analysis of Nylon 6 and poly(ethylene-n-butyl acrylate-maleic anhydride) elastomer blends using isothermal crystallization kinetics

Energy Technology Data Exchange (ETDEWEB)

Biber, Erkan, E-mail: ebiber@cankaya.edu.tr [Middle East Technical University, Polymer Science and Technology Department, Ankara (Turkey); Cankaya University, Industrial Engineering Department, Ankara (Turkey); Guenduez, Guengoer [Middle East Technical University, Polymer Science and Technology Department, Ankara (Turkey); Middle East Technical University, Chemical Engineering Department, Ankara (Turkey); Mavis, Bora [Hacettepe University, Mechanical Engineering Department, Ankara (Turkey); Colak, Uner [Hacettepe University, Nuclear Energy Engineering Department, Ankara (Turkey)

2010-07-01

Nylon 6 is a widely used engineering polymer, and has relatively poor impact strength. Ethylene, n-Butyl acrylate, maleic anhydride (E-nBA-MAH) terpolymer is blended with Nylon 6 to enhance its impact strength. Mixture should be compatible to be used in applications. The bare interaction energy between Nylon 6 and E-nBA-MAH terpolymer is calculated according to melting point depression approach using both Flory-Huggins (FH) Theory and Sanchez-Lacombe Equation of State (SL EOS). It demonstrates that blends are thermodynamically favorable to any arrangements. Yet, isothermal crystallization kinetics and WAXS crystallization peaks of blends reveal that mixtures of various compositions have different crystallization behaviors and require alternating crystallization energy due to crystalline structures of individual polymers. Also, SEM images support that after 5% addition of elastomeric terpolymer, interaction loosens due to strong crystalline structure of Nylon 6.

Kaolinite Nanocomposite Platelets Synthesized by Intercalation and Imidization of Poly(styrene-co-maleic anhydride

Directory of Open Access Journals (Sweden)

Pieter Samyn

2015-07-01

Full Text Available A synthesis route is presented for the subsequent intercalation, exfoliation and surface modification of kaolinite (Kln by an imidization reaction of high-molecular weight poly(styrene-co-maleic anhydride or SMA in the presence of ammonium hydroxide. In a first step, the intercalation of ammonolyzed SMA by guest displacement of intercalated dimethylsulfoxide has been proven. In a second step, the imidization of ammonolyzed SMA at 160 °C results in exfoliation of the kaolinite layers and deposition of poly(styrene-co-maleimide or SMI nanoparticles onto the kaolinite surfaces. Compared with a physical mixture of Kln/SMI, the chemically reacted Kln/SMI provides more efficient exfoliation and hydrogen bonding between the nanoparticles and the kaolinite. The kaolinite nanocomposite particles are synthesized in aqueous dispersion with solid content of 65 wt %. The intercalation and exfoliation are optimized for a concentration ratio of Kln/SMI = 70:30, resulting in maximum intercalation and interlayer distance in combination with highest imide content. After thermal curing at 135 °C, the imidization proceeds towards a maximum conversion of the intermediate amic acid moieties. The changes in O–H stretching and kaolinite lattice vibrations have been illustrated by infrared and FT-Raman spectroscopy, which allow for a good quantification of concentration and imidization effects.

Additive effects on phase transition and interactions in poly(vinyl methyl ether) solutions

Czech Academy of Sciences Publication Activity Database

Starovoytova, Larisa; Šťastná, J.; Šturcová, Adriana; Konefal, Rafal; Dybal, Jiří; Velychkivska, Nadiia; Radecki, M.; Hanyková, L.

2015-01-01

Roč. 7, č. 12 (2015), s. 2572-2583 ISSN 2073-4360 R&D Projects: GA ČR(CZ) GA13-23392S Institutional support: RVO:61389013 Keywords : additives * LCST * poly(vinyl methyl ether) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.944, year: 2015

Irradiation grafting of natural rubber latex with maleic anhydride and its compatibilization of poly(lactic acid)/natural rubber blends

Science.gov (United States)

Pongsathit, Siriwan; Pattamaprom, Cattaleeya

2018-03-01

Maleic anhydride (MA) is an interesting monomer to be grafted onto natural rubber(NR) due to its potential as a compatibilizer of hydrophobic rubbers and polymers with higher polarity. So far, radiation grafting of MA onto NR in latex state has not been reported. In this study, the grafting of NR with MA in latex state was investigated by exposing the latex to cobalt-60 gamma irradiation at a fixed MA content of 9% and a varied absorbed doses from 2 to 10 kGy. The FTIR spectrometer, 1H NMR spectrometer and gel content analysis have confirmed successful grafting of MA onto NR after irradiation. The grafted NRs were then used to increase the compatibility and the impact property of PLA/NR blends. It was found that the highest impact strength of the blends was achieved when the grafting was carried out at the absorbed dose of 4 kGy.

Preparation of a Sepia Melanin and Poly(ethylene-alt-maleic Anhydride Hybrid Material as an Adsorbent for Water Purification

Directory of Open Access Journals (Sweden)

Guido Panzarasa

2018-01-01

Full Text Available Meeting the increasing demand of clean water requires the development of novel efficient adsorbent materials for the removal of organic pollutants. In this context the use of natural, renewable sources is of special relevance and sepia melanin, thanks to its ability to bind a variety of organic and inorganic species, has already attracted interest for water purification. Here we describe the synthesis of a material obtained by the combination of sepia melanin and poly(ethylene-alt-maleic anhydride (P(E-alt-MA. Compared to sepia melanin, the resulting hybrid displays a high and fast adsorption efficiency towards methylene blue (a common industrial dye for a wide pH range (from pH 2 to 12 and under high ionic strength conditions. It is easily recovered after use and can be reused up to three times. Given the wide availability of sepia melanin and P(E-alt-MA, the synthesis of our hybrid is simple and affordable, making it suitable for industrial water purification purposes.

An additive for a petroleum coke and water suspension

Energy Technology Data Exchange (ETDEWEB)

Khiguti, K.; Igarasi, T.; Isimura, Y.; Kharaguti, S.; Tsudzina, T.

1983-03-04

The patent covers an additive for a petroleum coke and watersuspension which contains soap of an aliphatic acid (AM) and or a salt of a maleic acid copolymer (SMK). The aliphatic acid soap is a salt of an alkaline earth metal of C6 to C22 aliphatic acid, an ammonium salt or a salt of a lower amine. The maleic acid copolymer is a salt (sodium, NH4) of a lower amine of a maleic anhydride copolymer with a copolymerizing vinyl additive. Capric acid, lauric acid, palmatic acid, aleic and other acids may be used as the aliphatic acid, while methylamine, trimethylamine, diethanolamine, morpholine and so on may be used as the lower amine salt. Ethylene, vinylchloride, methyl(meta)acrylate and so on are used as the polymerizing vinyl compound. The molar ratio of the maleic anhydride to the polymerizing vinyl compound is in a range from 1 to 1 to 1 to 10 (preferably 1 to 1 to 1 to 3). The maleic acid copolymer has a mean molecular mass within 1,000 to 5,000. The additive with the optimal composition contains a solvent, a thickener, an anticorrosion substance, anticoagulants, surfacants (PAV) and so on. A highly concentrated suspension of oil coke and water with a 50 to 75 percent concentration of powder form petroleum coke may be produced using the patented additive. Such a suspension is characterized by low viscosity, high stability and forms no foam during processing.

13C n.m.r. study of solvation mechanisms in the radiation-induced polymerization of vinyl ethers

International Nuclear Information System (INIS)

Deffieux, A.; Subira, F.; Stannett, V.T.

1984-01-01

A 13 C n.m.r. study of the microstructure of ethyl vinyl ether (EVE) and isopropyl vinyl ether (IPVE) polymers prepared under various experimental conditions and using chemical or γ-ray initiation has been made. Long stereo-sequence assignments were conducted for poly EVE allowing determination of the configurational statistics of propagation in the radiation-induced polymerization of EVE in low polar solvents. Stereo-sequence intensities are found in good agreement with the Markovian model. The results are considered as further support for the occurrence of a specific interaction between the growing active centres and the polymer chains. In the case of IPVE polymers much more important overlappings of the resonance patterns are observed thus preventing any similar detailed study. (author)

Optimal oxygen feeding policy to maximize the production of Maleic anhydride in unsteady state fixed bed catalytic reactors

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E. Ali

2017-07-01

Full Text Available The effect of different oxygen feeding scenarios in a fixed bed reactor for the production of Maleic anhydride (MA is studied. Two reactor configurations were examined. In the first configuration, a cross flow reactor (CFR with 4 discrete feeding points is considered. Another configuration is the conventional packed-bed reactor (PBR with a single feed. Nonlinear Model Predictive Controller (NLMPC was used as optimal controller to operate the CFR in dynamic mode and to optimize the multiple feed dosages in order to enhance the MA yield. The simulation results indicated that different combinations of the four feed ratios can operate the reactor at the best value for the yield provided the first feeding point is kept as low as possible. For the packed bed reactor configuration, a single oxygen feed is considered and is optimized transiently by NLMPC. The simulation outcomes showed that the reactor performance in terms of the produced MA mole fraction can also be enhanced to the same magnitude obtained by CFR configuration. This improvement requires decreasing the oxygen ratio in the reactor single feed by 70%.

High performances unsaturated polyester based nanocomposites: Effect of vinyl modified nanosilica on mechanical properties

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J. D. Rusmirovic

2016-02-01

Full Text Available Influences of the vinyl modified nanosilica Aerosil® 380, i.e./i>, vinyl and methacryloyl silane coupling agent and linseed oil fatty acids (BD reactive residues, on the mechanical properties of the unsaturated polyester resins (UPes based nanocomposites, was studied. The polycondensation of maleic anhydride and products of poly(ethylene terephthalate (PET depolymerization with propylene glycol, with and without separation of ethylene glycol, yields UPe1 and UPe2 resin, respectively. The hydroxyl terminated PET depolymerization products (glycolyzates and UPes were characterized by acid and hydroxyl values, Fourier Transform Infrared (FTIR and nuclear magneti resonance (NMR spectroscopies. Transmission electron microscopy (TEM confirmed that silica nanoparticles formed domains of aggregates in the polymer matrix. An increase from 195 to 247% of stress at break (σb, and from 109 to 131% of impact strength (σi of UPes based nanocomposites was obtained for 1 wt% addition of vinyl modified silica. Flexural strength (σf increase from 106 to 156% for both UPes based nanocomposites with 1 wt% addition of BD modified silica. Cross-linking density (ν, storage modulus (G', tanδ and Tg of the nanocomposite were determined from the dynamic mechanical testing and discussed in relation to the structure of silica modification.

Acrylic composition

International Nuclear Information System (INIS)

Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Meda, Yutaka.

1969-01-01

An acrylic composition and a process for the production of an easily hardenable coating material by irradiating with active energy, particularly electron beams and ultraviolet light, are provided using a mixture of 10%-100% by weight of an unsaturated compound and 90%-0% of a vinyl monomer. The composition has a high degree of polymerization, low volatility, low viscosity and other properties similar to thermosetting acrylic or amino alkyd resins. The aforesaid unsaturated compound is produced by primarily reacting saturated cyclocarboxylic anhydride and/or alpha-, beta-ethylene unsaturated carboxylic anhydride and by secondarily reacting an epoxy radical-containing vinyl monomer by addition reaction with polyhydric alcohols. Each reaction is conducted in the presence of a tertiary amino radical-containing vinyl monomer as a catalyst. The cross-linking is effected generally with an electron beam accelerator of 0.1-2.0 MeV or with a light beam in the 2,000-8,000A range in the presence of a photosensitive agent. In one example, 62 parts of ethylene glycol and 196 parts of maleic anhydride were dissolved in a mixture consisting of 100 parts of n-butyl methacrylate and 30 parts of styrene. To the mixture were added 5 parts of 2-methyl 5 vinyl piridine and 0.005 part of hydroquinone monomethyl ether. After the reaction at 90 0 C for 3 hours, a compound HOC:O-CH=CHC:OCH 2 CH 2 C:OOH was produced. To this solution were added 285 parts of glycidyl methacrylate. After the reaction at 90 0 C for 6 hours, 95% of the carboxylic acids reacted with epoxy radicals. Fourteen examples are given. (Iwakiri, K.)

Morphology, rheology and electrical resistivity of PLLA/HDPE/CNT nanocomposites: Effect of maleic anhydride

Energy Technology Data Exchange (ETDEWEB)

Shao, Li-na; Chen, Jie; Dai, Jian; Chen, Hai-ming; Yang, Jing-hui [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Wang, Yong, E-mail: yongwang1976@163.com [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Zhang, Chao-liang [State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041 (China)

2015-02-15

As a part of serial work about tuning the selective location of carbon nanotubes (CNTs) in immiscible polymer blends, this work reports the effects of component polarity and viscosity ratio between components on the selective location of CNTs and the resultant electrical resistivity of the nanocomposites. To achieve the research aim, maleic anhydride (MA) was grafted onto poly(L-lactide) (PLLA) main chain through a reactive compounding processing. After that, different contents of CNTs were incorporated into blends of high density polyethylene (HDPE) and PLLA (or PLLA-g-MA). The morphologies of the ternary nanocomposites and the selective location of CNTs in the nanocomposites were characterized using scanning electron microscope (SEM) and transmission electron microscope (TEM). The microstructure of nanocomposites and the dispersion of CNTs were further proved by rheological measurement. Finally, the electrical resistivity of nanocomposites containing different CNT contents was measured. The results showed that through increasing the polarity of PLLA and decreasing the melt viscosity, CNTs were kinetically trapped at the blend interface region. Consequently, largely decreased percolation threshold was achieved for the PLLA-g-MA/HDPE/CNT nanocomposites. The morphological changes as well as the rheological properties were also comparatively analyzed. - Highlights: • PLLA/HDPE/CNT and PLLA-g-MA/HDPE/CNT composites were prepared. • Different selective location states of CNTs were achieved in different composites. • Selectively located CNTs at the interface resulted in lower percolation threshold.

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

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Jong-Seok Park

2015-04-01

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

Carbon Nanotubes Reinforced Maleic Anhydride-Modified Xylan-g-Poly(N-isopropylacrylamide) Hydrogel with Multifunctional Properties

Science.gov (United States)

Liu, Xinxin; Song, Tao; Chang, Minmin; Meng, Ling; Wang, Xiaohui; Sun, Runcang; Ren, Junli

2018-01-01

Introducing multifunctional groups and inorganic material imparts xylan-based hydrogels with excellent properties, such as responsiveness to pH, temperature, light, and external magnetic field. In this work, a composite hydrogel was synthesized by introducing acid treated carbon nanotubes (AT-CNTs) into the maleic anhydride modified xylan grafted with poly(N-isopropylacrylamide) (MAX-g-PNIPAM) hydrogels network. It was found that the addition of AT-CNTs affected the MAX-g-PNIPAM hydrogel structure, the swelling ratio and mechanical properties, and imparted the hydrogel with new properties of electrical conductivity and near infrared region (NIR) photothermal conversion. AT-CNTs could reinforce the mechanical properties of MAX-g-PNIPAM hydrogels, being up to 83 kPa for the compressive strength when the amount was 11 wt %, which was eight times than that of PNIPAM hydrogel and four times than that of MAX-g-PNIPAM hydrogel. The electroconductibility was enhanced by the increase of AT-CNTs amounts. Meanwhile, the composite hydrogel also exhibited multiple shape memory and NIR photothermal conversion properties, and water temperature was increased from 26 °C to 56 °C within 8 min under the NIR irradiation. Thus, the AT-CNTs reinforced MAX-g-PNIPAM hydrogel possessed promising multifunctional properties, which offered many potential applications in the fields of biosensors, thermal-arrest technology, and drug-controlled release. PMID:29495611

Morphology in binary blends of poly(vinyl methyl ether) and epsilon-caprolactone-trimethylene carbonate diblock copolymer

NARCIS (Netherlands)

Luyten, MC; Bogels, EJF; vanEkenstein, GORA; tenBrinke, G; Bras, W; Komanschek, BE; Ryan, AJ

The morphology of symmetric diblock copolymer of epsilon-caprolactone (PCL) and trimethylene carbonate (PTMC), in blends with poly(vinyl methyl ether) (PVME) is investigated with (modulated) differential scanning calorimetry (d.s.c.), time resolved small angle (SAXS) and wide angle (WAXS) X-ray

Morphology in binary blends of poly(vinyl methyl ether) and ε-caprolactone-trimethylene carbonate diblock copolymer

NARCIS (Netherlands)

Luyten, M.C.; Bögels, E.J.F.; Alberda van Ekenstein, G.O.R.; Brinke, G. ten; Bras, W.; Komanschek, B.E.; Ryan, A.J.

1997-01-01

The morphology of symmetric diblock copolymer of ε-caprolactone (PCL) and trimethylene carbonate (PTMC), in blends with poly(vinyl methyl ether) (PVME) is investigated with (modulated) differential scanning calorimetry (d.s.c.), time resolved small angle (SAXS) and wide angle (WAXS) X-ray

Compatibility of polyvinyl alcohol and poly(methyl vinyl ether-co-maleic acid) blends estimated by molecular dynamics

CSIR Research Space (South Africa)

Moolman, FS

2005-07-25

Full Text Available are not dissociated (ionized). At pH below pKa (negative logarithm of acid dissociation constant) of maleic acid (first and second dissociation constants at 25 8C are pKa1Z1.91 and pKa 2Z6.33, respectively [22]), ioniz- ation of the carboxylic acid groups in the PMVE...-MA. Decreasing pH also reduces absolute viscosities and broadens the optimum blend ratio peak. Fig. 2. Density of a selected number of runs (11?15) as a function of time. F.S. Moolman et al. / Polymer 46 (2005) 6192?6200 6195 The cohesive energy densities display...

A self-crosslinking thermosetting monomer with both epoxy and anhydride groups derived from Tung oil fatty acids: Synthesis and properties

Science.gov (United States)

A self-crosslinking compound with epoxy groups and anhydride groups (GEMA) has been successfully synthesized from Tung oil fatty acid by reacting with maleic anhydride via the Diels-Alder reaction. GEMA has very good storage stability and can be cured with trace amounts of tertiary amine. This advan...

Radiation grafting of styrene and maleic anhydride onto PTFE membranes and sequent sulfonation for applications of vanadium redox battery

International Nuclear Information System (INIS)

Qiu Jingyi; Ni Jiangfeng; Zhai Maolin; Peng Jing; Zhou Henghui; Li Jiuqiang; Wei Genshuan

2007-01-01

Using γ-radiation technique, poly(tetrafluoroethylene) (PTFE) membrane was grafted with styrene (St) (PTFE-graft-PS) or binary monomers of St and maleic anhydride (MAn) (PTFE-graft-PS-co-PMAn), respectively. Then grafted membranes were further sulfonated with chlorosulfonic acid into ion-exchange membranes (denoted as PTFE-graft-PSSA and PTFE-graft-PSSA-co-PMAc, respectively) for application of vanadium redox battery (VRB). Micro-FTIR analysis indicated that PTFE was successfully grafted and sulfonated at the above two different conditions. However, a higher degree of grafting (DOG) was obtained in St/MAn binary system at the same dose due to a synergistic effect. Comparing with PTFE-graft-PSSA, PTFE-graft-PSSA-co-PMAc membrane showed higher water uptake and ion-exchange capacity (IEC) and lower area resistance (AR) at the same DOG. In addition, PTFE-graft-PSSA-co-PMAc with 6% DOG also showed a higher IEC and higher conductivity compared to Nafion membrane. Radiation grafting of PTFE in St/MAn binary system and sequent sulfonation is an appropriate method for preparing ion-exchange membrane of VRB

Amphiphilic graft copolymer based on poly(styrene-co-maleic anhydride) with low molecular weight polyethylenimine for efficient gene delivery

Science.gov (United States)

Duan, Xiaopin; Xiao, Jisheng; Yin, Qi; Zhang, Zhiwen; Mao, Shirui; Li, Yaping

2012-01-01

Background and methods A new amphiphilic comb-shaped copolymer (SP) was synthesized by conjugating poly(styrene-co-maleic anhydride) with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, 1H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer. Results The buffering capability of SP was similar to that of polyethyleneimine within the endosomal pH range. The copolymer could condense DNA effectively to form complexes with a positive charge (13–30 mV) and a small particle size (130–200 nm) at N/P ratios between 5 and 20, and protect DNA from degradation by DNase I. In addition, SP showed much lower cytotoxicity than polyethyleneimine 25,000. Importantly, the gene transfection activity and cellular uptake of SP-DNA complexes were all markedly higher than that of complexes of polyethyleneimine 25,000 and DNA in MCF-7 and MCF-7/ADR cell lines. Conclusion This work highlights the promise of SP as a safe and efficient synthetic vector for DNA delivery. PMID:23028224

Solid-phase synthesis of isoxazoles using vinyl ethers as chameleon catches.

Science.gov (United States)

Barrett, A G; Procopiou, P A; Voigtmann, U

2001-10-04

[reaction: see text] Regioselective 1,3-dipolar cycloadditions of supported vinyl ethers R(1)C(=CH(2))O-CH(2)-polymer, prepared by the Tebbe olefination of R(1)CO(2)-CH(2)-polymer, with ethyl cyanoformate N-oxide gave supported isoxazoline derivatives. Release from the support under mild acidic conditions gave the isoxazoles ethyl 5-R(1)-isoxazole-3-carboxylates. Alternatively, further on-resin functionalization of the R(1) substituent using Suzuki coupling reactions and release from the support under acidic conditions gave more structurally diverse isoxazoles.

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

Science.gov (United States)

Setiawan, A. H.; Aulia, F.

2017-05-01

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

Vinyl ether hydrolysis. VII. Isotope effects on catalysis by aqueous hydrofluoric acid

International Nuclear Information System (INIS)

Kresge, A.J.; Chen, H.J.; Chiang, Y.

1977-01-01

Comparison of rates of hydrolysis of three vinyl ethers catalyzed by HF in H 2 O and DF in D 2 O at 25 0 C gives primary isotope effects in the range k/sub H//k/sub D/ = 3.3 to 3.5. The unexpectedly small size of these effects may be attributed to strong, ω = 1325 to 1450 cm -1 , hydrogenic bending vibrations in the proton transfer transition states of these reactions along with the lack of compensatory bending vibrations in the diatomic proton donor

Styrene-Assisted Maleic Anhydride Grafted Poly(lactic acid as an Effective Compatibilizer for Wood Flour/Poly(lactic acid Bio-Composites

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Jun Du

2017-11-01

Full Text Available This study aimed to evaluate the effect of styrene-assisted maleic anhydride-grafted poly(lactic acid (PLA-g-St/MAH on the interfacial properties of wood flour/poly(lactic acid (PLA bio-composites. PLA-g-St/MAH was synthesized by free-radical melt grafting using styrene as a comonomer and dicumyl peroxide as an initiator. The structure of PLA-g-St/MAH was characterized by Fourier transform infrared spectroscopy. Wood flour/PLA composites were prepared by compression molding using PLA-g-St/MAH as a compatibilizer. The effects of PLA-g-St/MAH on the rheological and mechanical properties, as well as on the fractured surface morphology of the composites were investigated. Results indicated that storage modulus, complex viscosity, equilibrium torque, and shear heat were significantly increased. The mechanical properties of the wood flour/PLA composites were also significantly increased after the addition of PLA-g-St/MAH. The maximum values were achieved at the loading rate of 3 wt % because of the improved interfacial adhesion between the wood flour and the PLA matrix.

Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE Addition

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Yun Lu

2013-06-01

Full Text Available This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs. The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE) Addition.

Science.gov (United States)

Chen, Jinxiang; Wang, Yong; Gu, Chenglong; Liu, Jianxun; Liu, Yufu; Li, Min; Lu, Yun

2013-06-18

This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE) enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs). The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%-8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

/sup 13/C-/sup 13/C spin-spin coupling constants in structural investigations. II. Conformational structure of vinyl ethers

Energy Technology Data Exchange (ETDEWEB)

Krivdin, L.B.; Shcherbakov, V.V.; Bzhezovskii, V.M.; Kalabin, G.A.

1986-10-10

The /sup 13/C-/sup 13/C spin-spin coupling constants between the carbon nuclei of the vinyl group were measured for a series of vinyl ethers. It was established that the unshared electron pairs of the oxygen atom can make a substantial stereospecific contribution to the direct /sup 13/C-/sup 13/C constants of the adjacent nuclei. The observed effect was used to establish the conformational structure of the compounds.

Intranasal Administration of Maleic Anhydride-Modified Human Serum Albumin for Pre-Exposure Prophylaxis of Respiratory Syncytial Virus Infection

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Zhiwu Sun

2015-02-01

Full Text Available Respiratory syncytial virus (RSV is the leading cause of pediatric viral respiratory tract infections. Neither vaccine nor effective antiviral therapy is available to prevent and treat RSV infection. Palivizumab, a humanized monoclonal antibody, is the only product approved to prevent serious RSV infection, but its high cost is prohibitive in low-income countries. Here, we aimed to identify an effective, safe, and affordable antiviral agent for pre-exposure prophylaxis (PrEP of RSV infection in children at high risk. We found that maleic anhydride (ML-modified human serum albumin (HSA, designated ML-HSA, exhibited potent antiviral activity against RSV and that the percentages of the modified lysines and arginies in ML- are correlated with such anti-RSV activity. ML-HSA inhibited RSV entry and replication by interacting with viral G protein and blocking RSV attachment to the target cells, while ML-HAS neither bound to F protein, nor inhibited F protein-mediated membrane fusion. Intranasal administration of ML-HSA before RSV infection resulted in significant decrease of the viral titers in the lungs of mice. ML-HSA shows promise for further development into an effective, safe, affordable, and easy-to-use intranasal regimen for pre-exposure prophylaxis of RSV infection in children at high risk in both low- and high-income countries.

Separation and recovery of lead from a low concentration solution of lead(II) and zinc(II) using the hydrolysis production of poly styrene-co-maleic anhydride

Energy Technology Data Exchange (ETDEWEB)

Liang, Xing; Su, Yibing [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou (China); Yang, Ying, E-mail: Yangying@lzu.edu.cn [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou (China); Qin, Wenwu [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou (China)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Separation and recovery of Pb(II) from a solution of Pb(II) and Zn(II) was performed. Black-Right-Pointing-Pointer Pb(II) can be recovered using the hydrolysis production of poly styrene-co-maleic anhydride. Black-Right-Pointing-Pointer The adsorption capacity of the PSMA resin for Pb(II) is 641.62 mg g{sup -1}. Black-Right-Pointing-Pointer Pb(II) can be recovered through desorption of Pb-PSMA into Pb(II) ion and the solid PSMA resin. Black-Right-Pointing-Pointer The resin can be repeatedly used through desorption by an inorganic acid condition (6 M H{sub 2}SO{sub 4}). - Abstract: The Pb-Zn separation/preconcentration technique, based on the complex formation reaction of Pb(II) and Zn(II), using a copolymer poly(styrene-co-maleic anhydride) (PSMA), without adding any carrier element was developed. The effects of several experimental parameters such as solution pH, temperature and adsorption time were studied. The experimental results show that the PSMA resin-Pb equilibrium was achieved in 2 min and the Pb(II) loading capacity is up to 641.62 mg g{sup -1} in aqueous solution under optimum conditions, which is much higher than the Zn(II) loading capacity within 80 min. The adsorption test for Pb(II) indicates that PSMA can recover Pb(II) from a mixed solution of Pb(II), Zn(II) and light metals such as Ca(II) and Mg(II) with higher adsorption rate and larger selective coefficient. A further study indicates that PSMA as chelating resins recovering Pb(II) can be regenerated via mineral acid (6 M H{sub 2}SO{sub 4}). PSMA was synthesized by radical polymerization and tested as an adsorbent for the selective recovery of Pb(II). In addition, the formation procedure and structure of Pb-PSMA complex were also studied. Both the PSMA and the Pb-PSMA complex were characterized by means of FTIR spectroscopy, elemental analysis, gel permeation chromatography (GPC) and atomic absorption spectrometry (AAS).

Insight into the informational-structure behavior of the Diels-Alder reaction of cyclopentadiene and maleic anhydride.

Science.gov (United States)

Molina-Espíritu, Moyocoyani; Esquivel, Rodolfo O; Kohout, Miroslav; Angulo, Juan Carlos; Dobado, José A; Dehesa, Jesús S; LópezRosa, Sheila; Soriano-Correa, Catalina

2014-08-01

The course of the Diels-Alder reactions of cyclopentadiene and maleic anhydride were studied. Two reaction paths were modelled: endo- and exo-selective paths. All structures within the transient region were characterized and analyzed by means of geometrical descriptors, physicochemical parameters and information-theoretical measures in order to observe the linkage between chemical behavior and the carriage of information. We have shown that the information-theoretical characterization of the chemical course of the reaction is in complete agreement with its phenomenological behavior in passing from reactants to products. In addition, we were able to detect the main differences between the two reaction mechanisms. This type of informational analysis serves to provide tools to help understand the chemical reactivity of the two simplest Diels-Alder reactions, which permits the establishment of a connection between the quantum changes that molecular systems exert along reaction coordinates and standard physicochemical phenomenology. In the present study, we have shown that every reaction stage has a family of subsequent structures that are characterized not solely by their phenomenological behavior but also by informational properties of their electronic density distribution (localizability, order, uniformity). Moreover, we were able to describe the main differences between endo-adduct and exo-adduct pathways. With the advent of new experimental techniques, it is in principle possible to observe the structural changes in the transient regions of chemical reactions. Indeed, through this work we have provided the theoretical concepts needed to unveil the concurrent processes associated with chemical reactions.

Effect of Surface Modification of Palygorskite on the Properties of Polypropylene/Polypropylene-g-Maleic Anhydride/Palygorskite Nanocomposites

Directory of Open Access Journals (Sweden)

David Cisneros-Rosado

2017-01-01

Full Text Available The effect of surface modification of palygorskite (Pal on filler dispersion and on the mechanical and thermal properties of polypropylene (PP/polypropylene grafted maleic anhydride (PP-g-MAH/palygorskite (Pal nanocomposites was evaluated. A natural Pal mineral was purified and individually surface modified with hexadecyl tributyl phosphonium bromide and (3-Aminopropyltrimethoxysilane; the pristine and modified Pals were melt-compounded with PP to produce nanocomposites using PP-g-MAH as compatibilizer. The grafting of Pal surface was verified by FT-IR and the change in surface hydrophilicity was estimated by the contact angle of sessile drops of ethylene glycol on Pal tablets. The extent of Pal dispersion and the degree of improvement in both the mechanical and thermal properties were related to the surface treatment of Pal. Modified Pals were better dispersed during melt processing and improved Young’s modulus and strength; however, maximum deformation tended to decrease. The thermal stability of PP/PP-g-MAH/Pal nanocomposites was considerably improved with the content of modified Pals. The degree of crystallinity increased with Pal content, regardless of the surface modification. Surfactant modified Pal exhibited better results in comparison with silane Pal; it is possible that longer alkyl chains from surfactant molecules promoted interactions with polymer chains, thereby improving nanofiller dispersion and enhancing the properties.

Reactivity of vinyl ethers and vinyl ribosides in UV-initiated free radical copolymerization with acceptor monomers.

Science.gov (United States)

Pichavant, Loic; Guillermain, Céline; Coqueret, Xavier

2010-09-13

The reactivity of various vinyl ethers and vinyloxy derivatives of ribose in the presence of diethyl fumarate or diethyl maleate was investigated for evaluating the potential of donor-acceptor-type copolymerization applied to unsaturated monomers derived from renewable feedstock. The photochemically induced polymerization of model monomer blends in the bulk state was monitored by infrared spectroscopy. The method allowed us to examine the influence of monomer pair structure on the kinetic profiles. The simultaneous consumption of both monomers was observed, supporting an alternating copolymerization mechanism. A lower reactivity of the blends containing maleates compared with fumarates was confirmed. The obtained kinetic data revealed a general correlation between the initial polymerization rate and the Hansen parameter δ(H) associated with the H-bonding aptitude of the donor monomer.

Photo- and radiation chemical cycloaddition of maleic acid derivatives to ethylene and acetylene under elavated pressure

International Nuclear Information System (INIS)

Mirbach, M.

1975-01-01

Based on spectroscopic and kinetic measurements the influence of high pressure on some selected photochemical cycloaddition-reactions is studied. The photo-cycloaddition-reaction of maleic acid anhydride with ethylen has been performed under high ethylen pressures ( 90%). Surprisingly the quantum yield of the cyclo aduct decreases with increasing ethylene pressure from PHI = 0.06 at p = 1 bar to PHI = 0.022 at p = 42 bar. Based on Stern-Volmer quenching experiments, the decrease in ring formation with increasing ethylene concentrations could be explained by an endoergic triplet energy transfer from maleic acid anhydride to ethylene. The type II dissociation of butyrophenone has been quenched also with ethylene. With a lifetime for the first excited butyrophenone triplett state of tau = 6.8 x 10 -8 sec, obtained from kinetic data, the velocity constant can be calculated for this reaction with the result k 5 = 3 x 10 6 M -1 sec -1 . (orig./HK) [de

Fabrication of Poly(styrene-co-maleic anhydride)@Ag Spheres with High Surface Charge Intensity and their Self-Assembly into Photonic Crystal Films.

Science.gov (United States)

Bi, Jiajie; Fan, Genrui; Wu, Suli; Su, Xin; Xia, Hongbo; Zhang, Shu-Fen

2017-10-01

Herein, we developed a method to prepare monodisperse poly(styrene-co-maleic anhydride)@Ag (PSMA@Ag) core-shell microspheres with high surface charge intensity by using an in situ reduction method. In this method, ethylenediamine tetraacetic acid tetrasodium salt (Na 4 EDTA) was used as a reducing agent to promote the growth of Ag, and at the same time endowed the PSMA@Ag spheres with a surface charge. The monodispersity of PSMA and PSMA@Ag and the ordered array of the photonic crystal films were characterized by using SEM. The formation of Ag nanoparticles was confirmed by using TEM, HR-TEM, and XRD characterizations. Due to the existence of surface charges, the obtained PSMA@Ag microspheres easily self-assembled to form photonic crystal structures. In addition, the surface-enhanced Raman scattering (SERS) activity of the PSMA@Ag photonic crystal films was evaluated by detecting the signal from Raman probe molecules, 4-aminothiophenol (4-ATP). The PSMA@Ag photonic crystal films exhibited a high SERS effect, a low detection limit of up to 10 -8 for 4-ATP, good uniformity, and reproducibility.

Extraction of Micro- and Nano-Fibrils from Nylon 6/Polypropylene Grafted with Maleic Anhydride/Polypropylene Blended Films

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E. Bagheban Kochak

2013-01-01

Full Text Available Atechnical feasibility study has been conducted on production of nano- and micro-fibrils from nylon 6/polypropylene grafted with maleic anhydride/polypropylene blended films. Fibrils are prepared in four consecutive steps.In the first step the polymers melt blended in an extruder with and without compatibilizers to produce chips; in the second step films are extruded from polymer blends chips, in the third step films are cold drawn with different draw ratios at room temperature and in the forth step fibrils are extracted by Soxhlet extraction with formic acid as solvent for nylon 6.  The films and fibrils were examined by scanning electron microscope and FTIR spectroscopy. It is found that the polypropylene dispersed phase deforms and coalesces into elongated fibrils during drawing  operation. The  fibrils’ diameters in the blends containing compatibilizer are more uniform and are smaller than those from films without compatibilizers. The thinnest polypropylene fibril observed has a diameter around 300 nm with the aspect ratio above 150. The stress-elongation curves show three distinctive regions, elastic, yield and hardening-leading to breakage. The elastic region is short and follows by necking and yield, i.e., elongation without increase in load. The hardening region is accompanied by the increase in the slope. The deformations of the polypropylene particles are noticed during the last regions of the extension; the fibril deformations seem to be more severe during breakage.

Development and Applications of Fluorogenic Probes for Mercury(II) Based on Vinyl Ether Oxymercuration

OpenAIRE

Ando, Shin; Koide, Kazunori

2011-01-01

Mercury is a major threat to the environment and to human health. It is highly desirable to develop a user-friendly kit for on-site mercury detection. Such a method must be able to detect mercury below the threshold levels for drinking water, 1–2 ppb. We developed a fluorescence method based on the oxymercuration of vinyl ethers to detect mercury in dental and environmental samples. Chloride ions interfered with the oxymercuration reaction, but the addition of AgNO3 solved this problem. Fine ...

Triblock and pentablock terpolymers by sequential base-assisted living cationic copolymerization of functionalized vinyl ethers

KAUST Repository

Bouchekif, Hassen; Sulhami, A. I.; AlGhamdi, Rayed D.; Gnanou, Yves; Hadjichristidis, Nikolaos

2015-01-01

A series of novel, well-defined triblock (PnBVE-b-PCEVE-b-PSiDEGVE) and pentablock (PSiDEGVE-b-PCEVE-b-PnBVE-b-PCEVE-b-PSiDEGVE) terpolymers of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiEGVE) were synthesized by sequential base-assisted living cationic polymerization. The living character of the homopolymerization of the three VE monomers and the crossover reaction resulting in the formation of well-defined block copolymers were investigated in various solvents (toluene, dichloromethane and n-hexane) using either a monofunctional [nBVE-acetic acid adduct (nBEA), CEVE-acetic acid adduct (CEEA) and SiDEGVE-acetic acid adduct (SiDEGEA)] or a difunctional [1,4-cyclohexane-1,4-diyl bis(2-methoxyethyl acetate) (cHDMEA)] initiator. All initiators are structurally equivalent to the dormant species of the corresponding monomers in order to achieve fast initiation. The optimal conditions of polymerization were achieved in n-hexane at -20 °C, in the presence of 1 M AcOEt (base). Good control over the number average molecular weight (Mn) and the polydispersity index (PDI) was obtained only at [Et3Al2Cl3]0 = [Chain-end]0 ≤ 10 mM. 2,6-Di-tert-butylpyridine (DtBP) was used as a non-nucleophilic proton trap to suppress any protonic initiation from moisture (i.e., Et3Al2Cl3·H2O). Well-defined PnBVEn-b-PCEVEp-b-PSiDEGVEq and PSiDEGVEq-b-PCEVEp-b-PnBVEn-b-PCEVEp-b-PSiDEGVEq terpolymers with a high crossover efficiency, no PCEVE-induced physical gelation, and predictable Mn and PDI < 1.15 were synthesized successfully provided that the targeted DPCEVE/DPnBVE ratio (i.e., p/n) did not exceed 2 and 0.2, respectively. The quantitative desilylation of the PSiEGVE by n-Bu4N+F- in THF at 0 °C led to triblock and pentablock terpolymers in which the PCEVE is the central block and the polyalcohol is the outer block. The thermal properties of the synthesized materials were examined by differential scanning

VOLUME 8 (2003) Sada and J. Guthrie ABSTRACT

African Journals Online (AJOL)

denise

Conjugated dienes tend to form 1:1 Diels. Alder adducts instead of copolymerizing while non - conjugated dienes can react to form 1:1 or 1:2 copolymers with vinyl groups which are cyclic15. A more extensive description of the current knowledge on the kinetics of copolymerization of maleic anhydride with dienes is found in ...

Removal of Copper ions from aqueous solutions using polymer derivations of poly (styrene-alt-maleic anhydride

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Naser Samadi

2017-06-01

Full Text Available In this study chelating resins have been considered to be suitable materials for the recovery of Copper (II ions in water treatments. Furthermore, these modified resins were reacted with 1,2-diaminoethane in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin on the Nano scale for the recovery of Copper (II ions from aqueous solutions. This method which is used for removing and determining Copper (II ions using copolymers derived resins of poly (styrene-alternative-maleic anhydride (SMA and atomic absorption spectroscopy. The method is simple, sensitive, inexpensive and fast. The various parameters such as pH, contact time, concentrations of metal ions, mass of resin, and agitation speed were investigated on adsorption effect. The adsorption behavior of Copper (II ions were investigated by the synthesis of chelating resins at various pHs. The prepared resins showed a good tendency for removing the selected metal ions from aqueous solution, even at an acidic pH. Also, the prepared resins were examined for the removal of Copper (II ions from real samples such as industrial wastewater and were shown to be very efficient at adsorption in the cases of Copper (II ions. The pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetics equations were used for modeling of adsorption data and it was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The intra-particle diffusion study revealed that external diffusion might be involved in this case. The resins were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis.

Adsorption of heavy metal ions and azo dyes by crosslinked nanochelating resins based on poly(methylmethacrylate-co-maleic anhydride

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M. Ghaemy

2014-03-01

Full Text Available Chelating resins are suitable materials for the removal of heavy metals in water treatments. A copolymer, Poly(MMA-co-MA, was synthesized by radical polymerization of maleic anhydride (MA and methyl methacrylate (MMA, characterized and transformed into multifunctional nanochelating resin beads (80–150 nm via hydrolysis, grafting and crosslink reactions. The resin beads were characterized by swelling studies, field emission scanning electron microscopy (FESEM and Fourier transform infrared spectroscopy (FTIR. The main purpose of this work was to determine the adsorption capacity of the prepared resins (swelling ratio ~55% towards metal ions such as Hg2+, Cd2+, Cu2+ from water at three different pH values (3, 6 and 9. Variations in pH and types of metal ions have not significantly affected the chelation capacity of these resins. The maximum chelation capacity of one of the prepared resin beads (Co-g-AP3 for Hg2+ was 63, 85.8 and 71.14 mg/g at pH 3, 6 and 9, respectively. Approximately 96% of the metal ions could be desorbed from the resin. Adsorption capacity of these resins towards three commercial synthetic azo dyes was also investigated. The maximum adsorption of dye AY42 was 91% for the resin Co-g-AP3 at room temperature. This insures the applicability of the synthesized resins for industrial applications.

Syntheses and properties of complex resins obtained by the reaction of polyethyleneimine with maleic anhydride-isobutene copolymer

International Nuclear Information System (INIS)

Usami, Shiro; Hasegawa, Kiyoshi; Takata, Kyoko; Naito, Ryunosuke; Uchida, Hiroshi; Kozuka, Hiroshi.

1985-01-01

Complex resins obtained by the reaction of polyethyleneimine with maleic anhydride-isobutene copolymer around 100 0 C revealed selective ion adsorption depending on the equivalent ratio of nitrogen to carboxyl group (N/COOH). In detail, polyanion-excess complex resins (N/COOH 2+ , Pb 2+ , Zn 2+ and Ni 2+ , and resins containing excess polycation (N/COOH > 1) for metal complex anions such as [CrO 4 ] 2- , [Ag(S 2 O 3 ) 2 ] 3- and [Fe(CN) 6 ] 4- . Furthermore, the polycation-excess complex resins had high adsorption capacity for uranium in solution, for example, a polycationic resin (N/COOH = 1.79) had an adsorption capacity of more than 100 mg U/g-dry base resin in a 75 ppm uranium solution. It also adsorbed and recovered uranium from solution contatining such infinitesimal amounts of uranium as sea water. The results from electron probe X-ray microanalyser (EPMA) of a polycationic resin (N/COOH = 1.79) indicated that cations such as Ca 2+ and Mg 2+ , abundant in sea water, were not adsorbed at all while such anions as Cl - and S 2- were adsorbed. It was found that Br - , I - , etc. were not adsorbed from sea water while these anions were adsorbed from the solutions containing them independently. The result indicated that Cl - in sea water probably interfered the adsorption of Br - , I - , etc. However, uranium was adsorbed from sea water in spite of its extremely low concentration without any disturbance of other co-existing ions. It was found that Ni 2+ and Cu 2+ were also adsorbed. (author)

Radiation induced ionic polymerisation and grafting of vinyl monomers

International Nuclear Information System (INIS)

Stannett, V.T.

1981-01-01

Some special aspects of the radiation induced ionic polymerisation and grafting of vinyl monomers will be described. In particular the effects of solvents on the cationic polymerisation of the vinyl ethers will be discussed in detail. The unequivocal free ion nature of the polymerisation makes such information of considerable general interest. Estimates of the propagation rate constants with free cation polymerisation in solvents of different dielectric constants and solvation powers will be presented. Finally, some observations on the radiation induced graft polymerisation of ethyl vinyl ether to poly(vinyl chloride) and to polypropylene will be presented. (author)

Identifying airway sensitizers: cytokine mRNA profiles induced by various anhydrides

International Nuclear Information System (INIS)

Plitnick, L.M.; Loveless, S.E.; Ladics, G.S.; Holsapple, M.P.; Smialowicz, R.J.; Woolhiser, M.R.; Anderson, P.K.; Smith, C.; Selgrade, M.J.K.

2003-01-01

Exposure to low molecular weight (LMW) chemicals in the workplace has been linked to a variety of respiratory effects. Within the LMW chemicals, one of the major classes involved in these effects are the acid anhydrides. The immunological basis of respiratory hypersensitivity involves CD4+ cells. By virtue of their induction of cytokines typical of CD4+ T-helper type 2 (Th2) cells--interleukin (IL)-4, 10, and 13--respiratory sensitizers may be identified and differentiated from contact sensitizers which induce Th1 cytokines (IL-2 and IFN-γ). Our previous work suggested that the ribonuclease protection assay (RPA) was useful in identifying the respiratory sensitizer, trimellitic anhydride (TMA), based on quantitative differences in Th2 cytokine mRNA as compared to the contact sensitizer dinitrochlorobenzene (DNCB). Therefore, the purpose of the studies described in this report was to expand the chemicals tested in the RPA. To this end, four acid anhydrides with known respiratory sensitization potential, TMA, maleic anhydride (MA), phthalic anhydride (PA) and hexahydrophthalic anhydride (HHPA), were tested. Although previously determined to induce immunologically equivalent responses in a local lymph node assay (LLNA), the initial dose chosen (2.5%) failed to induce Th2 cytokine mRNA expression. To determine if the lack of cytokine expression was related to dose, LLNAs were conducted at higher doses for each of the anhydrides. The highest doses evaluated (four- to six-fold higher than those used in the initial RPA) gave equivalent proliferative responses for the various anhydrides and were used for subsequent RPA testing. At these higher doses, significant increases in Th2 versus Th1 cytokine mRNA were observed for all anhydrides tested. These results suggest that the RPA has the potential to serve as a screen for the detection of LMW airway sensitizing chemicals. However, the basis for selecting immunologically equivalent doses may require some modification

A Tetrazine-Labile Vinyl Ether Benzyloxycarbonyl Protecting Group (VeZ): An Orthogonal Tool for Solid-Phase Peptide Chemistry.

Science.gov (United States)

Staderini, Matteo; Gambardella, Alessia; Lilienkampf, Annamaria; Bradley, Mark

2018-06-01

The vinyl ether benzyloxycarbonyl (VeZ) protecting group is selectively cleaved by treatment with tetrazines via an inverse electron-demand Diels-Alder reaction. This represents a new orthogonal protecting group for solid-phase peptide synthesis, with Fmoc-Lys(VeZ)-OH as a versatile alternative to Fmoc-Lys(Alloc)-OH and Fmoc-Lys(Dde)-OH, as demonstrated by the synthesis of two biologically relevant cyclic peptides.

The Causes of Blistering in Boat Building Materials

Science.gov (United States)

1986-08-01

acrylate units (MET) Ethylene glycol (MET) Propylene glycol (MET) Neopentyl glycol (NET) Maleic acid or anhydride (unsaturated) (NET) lumaric acid...PROPYLENE GLYCOL OPA ORTHOPHTHALIC ACID VINYL - URETHANE BASED POLYESTER IqPG NEOPENTYL GLYCOL RESIN EG - ETHYLENE GLYCOL TMPD - 22,, - TRiMETHY...IPA Isophthalic acid WSN Low molecular weight water soluble material NPG Neopentyl glycol OPA Orthophthalio acid PG Propylene glycol MEKP Hethyl

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

Science.gov (United States)

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

Synthesis of Terpolymers with Homogeneous Composition by Free Radical Copolymerization of Maleic Anhydride, Perfluorooctyl and Butyl or Dodecyl Methacrylates: Application of the Continuous Flow Monomer Addition Technique

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Marian Szkudlarek

2017-11-01

Full Text Available Terpolymers of homogeneous composition were prepared by free radical copolymerization of butyl or dodecyl methacrylate, 1H,1H,2H,2H-perfluorodecyl methacrylate and maleic anhydride using the continuous monomer addition technique. The copolymerization reactions were performed at 65 °C in the presence of azobisisobutyronitrile as an initiator in a mixture of methyl ethyl ketone and 1,3-bis (trifluoromethylbenzene. The monomers and initiator are added to the reaction mixture with the same rate they are consumed in 5- and 10-fold excess compared to the initial monomer stock. The obtained terpolymers with molecular weights Mn = 50,000–70,000 are of uniform composition, close to the composition determined in low conversion experiments, proving the principle of the chosen concept. The kinetic data necessary for the design of the continuous addition experiment were obtained from binary copolymerization experiments at low monomer conversion (to avoid compositional drift. In addition, the so-called terpolymerization parameter was determined from ternary copolymerization experiments.

Accumulation of long-chain bases in yeast promotes their conversion to a long-chain base vinyl ether

OpenAIRE

Martínez-Montañés, Fernando; Lone, Museer A.; Hsu, Fong-Fu; Schneiter3, Roger

2017-01-01

Long-chain bases (LCBs) are the precursors to ceramide and sphingolipids in eukaryotic cells. They are formed by the action of serine palmitoyl-CoA transferase (SPT), a complex of integral membrane proteins located in the endoplasmic reticulum. SPT activity is negatively regulated by Orm proteins to prevent the toxic overaccumulation of LCBs. Here we show that overaccumulation of LCBs in yeast results in their conversion to a hitherto undescribed LCB derivative, an LCB vinyl ether. The ...

Responsive copolymers for enhanced petroleum recovery. Second annual report

Energy Technology Data Exchange (ETDEWEB)

McCormick, C.; Hester, R.

1995-05-01

The authors describe second year efforts in synthesis, characterization, and rheology to develop polymers with significantly improved efficiency in mobility control and conformance. These advanced polymer systems would maintain high viscosities or behave as virtual gels under low shear conditions and at elevated electrolyte concentrations. At high fluid shear rates, associates would deaggregate yielding low viscosity solutions, reducing problems of shear degradation or face plugging during injection. Polymeric surfactants were also developed with potential for use in higher salt, higher temperature reservoirs for mobilization of entrapped oil. Chapters include: Ampholytic terpolymers of acrylamide with sodium 3-acrylamido-3-methylbutanoate and 2-acrylamido-2-methylpropanetrimethylammonium chloride; Hydrophilic sulfobetaine copolymers of acrylamide and 3-(2-acrylamido-methylpropane-dimethylammonio)-1-propanesulfonate; Copolymerization of maleic anhydride and N-vinylformamide; Reactivity ratio of N-vinylformamide with acrylamide, sodium acrylate, and n-butyl acrylate; Effect of the distribution of the hydrophobic cationic monomer dimethyldodecyl(2-acrylamidoethyl)ammonium bromide on the solution behavior of associating acrylamide copolymers; Effect of surfactants on the solution properties of amphipathic copolymers of acrylamide and N,N-dimethyl-N-dodecyl-N-(2-acrylamidoethyl)ammonium bromide; Associative interactions and photophysical behavior of amphiphilic terpolymers prepared by modification of maleic anhydride/ethyl vinyl ether copolymers; Copolymer compositions of high-molecular-weight functional acrylamido water-soluble polymers using direct-polarization magic-angle spinning {sup 13}C NMR; Use of factorial experimental design in static and dynamic light scattering characterization of water soluble polymers; and Porous medium elongational rheometer studies of NaAMB/AM copolymer solutions.

Anhydric maleic functionalization and polyethylene glycol grafting of lactide-co-trimethylene carbonate copolymers

Energy Technology Data Exchange (ETDEWEB)

Díaz, A.; Valle, L.; Franco, L. del [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Sarasua, J.R. [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain); Estrany, F. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J., E-mail: Jordi.Puiggali@upc.es [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain)

2014-09-01

Lactide and trimethylene carbonate copolymers were successfully grafted with polyethylene glycol via previous functionalization with maleic anhydride and using N,N′-diisopropylcarbodiimide as condensing agent. Maleinization led to moderate polymer degradation. Specifically, the weight average molecular weight decreased from 36,200 to 30,200 g/mol for the copolymer having 20 mol% of trimethylene carbonate units. Copolymers were characterized by differential scanning calorimetry, thermogravimetry and X-ray diffraction. Morphology of spherulites and lamellar crystals was evaluated with optical and atomic force microscopies, respectively. The studied copolymers were able to crystallize despite the randomness caused by the trimethylene carbonate units and the lateral groups. Contact angle measurements indicated that PEG grafted copolymers were more hydrophilic than parent copolymers. This feature justified that enzymatic degradation in lipase medium and proliferation of both epithelial-like and fibroblast-like cells were enhanced. Grafted copolymers were appropriate to prepare regular drug loaded microspheres by the oil-in-water emulsion method. Triclosan release from loaded microspheres was evaluated in two media. - Highlights: • Pegylated copolymers of lactide and trimethylene carbonate have been synthesized. • Grafting with polyethylene glycol was able via maleic anhydride functionalization. • Drug-loaded microspheres could be prepared from new pegylated copolymers. • Hydrophilicity of lactide/trimethylene carbonate copolymers increased by pegylation. • New pegylated copolymers supported cell adhesion and proliferation.

Highly Carboxylated Cellulose Nanofibers via Succinic Anhydride Esterification of Wheat Fibers and Facile Mechanical Disintegration.

Science.gov (United States)

Sehaqui, H; Kulasinski, K; Pfenninger, N; Zimmermann, T; Tingaut, P

2017-01-09

We report herein the preparation of 4-6 nm wide carboxyl-functionalized cellulose nanofibers (CNF) via the esterification of wheat fibers with cyclic anhydrides (maleic, phtalic, and succinic) followed by an energy-efficient mechanical disintegration process. Remarkable results were achieved via succinic anhydride esterification that enabled CNF isolation by a single pass through the microfluidizer yielding a transparent and thick gel. These CNF carry the highest content of carboxyl groups ever reported for native cellulose nanofibers (3.8 mmol g -1 ). Compared to conventional carboxylated cellulose nanofibers prepared via Tempo-mediated oxidation of wheat fibers, the present esterified CNF display a higher molar-mass and a better thermal stability. Moreover, highly carboxylated CNF from succinic anhydride esterification were effectively integrated into paper filters for the removal of lead from aqueous solution and are potentially of interest as carrier of active molecules or as transparent films for packaging, biomedical or electronic applications.

Thermodynamic and kinetic analysis of phase separation of temperature-sensitive poly(vinyl methyl ether) in the presence of hydrophobic tert-butyl alcohol

Czech Academy of Sciences Publication Activity Database

Velychkivska, Nadiia; Bogomolova, Anna; Filippov, Sergey K.; Starovoytova, Larisa; Labuta, J.

2017-01-01

Roč. 295, č. 8 (2017), s. 1419-1428 ISSN 0303-402X R&D Projects: GA ČR(CZ) GC15-10527J Institutional support: RVO:61389013 Keywords : phase separation * coil-globule transition * poly(vinyl methyl ether) Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.723, year: 2016

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

Science.gov (United States)

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.

NMR study of temperature-induced phase separation and polymer-solvent interactions in poly(vinyl methyl ether)/D.sub.2./sub.O/ethanol solutions

Czech Academy of Sciences Publication Activity Database

Hanyková, L.; Labuta, J.; Spěváček, Jiří

2006-01-01

Roč. 47, č. 17 (2006), s. 6107-6116 ISSN 0032-3861 Grant - others:GA UK 294/2004/B Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(vinyl methyl ether)/D2O/ ethanol solutions * temperature-induced phase separation * 1H and 13C NMR spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.773, year: 2006

Evaluation of a water-soluble bioadhesive patch for photodynamic therapy of vulval lesions.

Science.gov (United States)

McCarron, Paul A; Donnelly, Ryan F; Zawislak, Agnieszka; Woolfson, A David; Price, John H; McClelland, Raymond

2005-04-11

An innovative bioadhesive patch intended primarily as a vulval drug delivery system and, specifically, as a means to deliver photosensitisers, or their prodrugs, for photodynamic purposes is described. The patch was formulated with a copolymer of methyl vinyl ether and maleic anhydride (PMVE/MA) as a bioadhesive matrix and poly(vinyl chloride) as a drug-impervious backing layer. Adhesive strength to neonate porcine skin, as a model substrate, was evaluated using peel and tensile testing measurements. Acceptabilities of non-drug loaded patches were appraised using human volunteers and visual-analogue scoring devices. An optimal formulation, with water uptake and peel strengths appropriate for vulval drug delivery, was cast from a 20% (w/w) PMVE/MA solution and adhered with a strength of approximately 1.7 Ncm(-2). Patient evaluation demonstrated comfort and firm attachment for up to 4h in mobile patients. Aminolevulinic acid, a commonly used photosensitiser, was formulated into the candidate formulation and applied to vulval intraepithelial neoplastic lesions. Fluorescence under ultraviolet illumination revealed protoporphyrin synthesis. The patch achieves the extended application times obligatory in topical photodynamic therapy of vulval lesions, thereby contributing to potential methods for the eradication of neoplastic lesions in the lower female reproductive tract.

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

Science.gov (United States)

Van Zee, Nathan J; Coates, Geoffrey W

2015-02-23

The alternating copolymerization of propylene oxide with terpene-based cyclic anhydrides catalyzed by chromium, cobalt, and aluminum salen complexes is reported. The use of the Diels-Alder adduct of α-terpinene and maleic anhydride as the cyclic anhydride comonomer results in amorphous polyesters that exhibit glass transition temperatures (Tg ) of up to 109 °C. The polymerization conditions and choice of catalyst have a dramatic impact on the molecular weight distribution, the relative stereochemistry of the diester units along the polymer chain, and ultimately the Tg of the resulting polymer. The aluminum salen complex exhibits exceptional selectivity for copolymerization without transesterification or epimerization side reactions. The resulting polyesters are highly alternating and have high molecular weights and narrow polydispersities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrogels Prepared from Cross-Linked Nanofibrillated Cellulose

Science.gov (United States)

Sandeep S. Nair; J.Y. Zhu; Yulin Deng; Arthur J. Ragauskas

2014-01-01

Nanocomposite hydrogels were developed by cross-linking nanofibrillated cellulose with poly(methyl vinyl ether-co-maleic acid) and polyethylene glycol. The cross-linked hydrogels showed enhanced water absorption and gel content with the addition of nanocellulose. In addition, the thermal stability, mechanical strength, and modulus increased with an increase in the...

Application of Computational Methods Mm2 and Gussian for Studing Unimolecular Decomposition of Vinil Ethers based on the Mechanism of Hydrogen Bonding

OpenAIRE

Behnaz Shahrokh; Garnik N. Sargsyan; Arkadi B. Harutyunyan

2012-01-01

Investigations of the unimolecular decomposition of vinyl ethyl ether (VEE), vinyl propyl ether (VPE) and vinyl butyl ether (VBE) have shown that activation of the molecule of a ether results in formation of a cyclic construction - the transition state (TS), which may lead to the displacement of the thermodynamic equilibrium towards the reaction products. The TS is obtained by applying energy minimization relative to the ground state of an ether under the program MM2 when...

Structure and thermal performance of poly(styrene-co-maleic anhydride)-g-alkyl alcohol comb-like copolymeric phase change materials

International Nuclear Information System (INIS)

Wang, Haixia; Shi, Haifeng; Qi, Miao; Zhang, Lingjian; Zhang, Xingxiang; Qi, Lu

2013-01-01

Graphical abstract: SMA-g-CnOH comb-like PCMs exhibit the better thermal stability against 1-alcohols due to the protection of SMA backbones, and the degradation temperature is dependent on the side-chain length, where at 5 wt% weight loss T d increased from 193 to 257 °C with n changing from 14 to 26. SMA-g-CnOH PCMs can be widely used under 300 °C for preparation of energy-saving products and materials. - Highlights: • The length of alkyl side-chains determines the thermal energy storage ability. • SMA backbone restricts the crystallization of alkyl side groups. • SMA-g-CnOH PCMs have the better thermal stability against 1-alcohols. - Abstract: A series of comb-like copolymeric phase change materials (SMA-g-CnOH) composed of poly(styrene-co-maleic anhydride) (SMA) and 1-alcohols CnOH with n = 14, 16, 18 or 26, respectively, was synthesized through grafting reaction. The structure and thermal properties of SMA-g-CnOH were investigated by 1 H nuclear magnetic resonance ( 1 H NMR), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and wide-angle X-ray diffraction (WAXD). The DSC analysis indicates that SMA-g-CnOH exhibit good structure stability with phase change enthalpies changing from 37.9 to 110.7 J g −1 . The results showed that the low thermal efficiency of SMA-g-CnOH was ascribed to the small CH 2 segments of side chains participating in the assembled structure of side-chain crystallites. Their advantageous structural stability and thermal performance of SMA-g-CnOH were favorable for phase change materials in the thermal energy storage systems. Additionally, the influence of side-chain length on thermal properties of SMA-g-CnOH also was discussed in detail in combination with the published results

Effects of single and double bonds in linkers on colorimetric and fluorescent sensing properties of polyving akohol grafting rhodamine hydrazides.

Science.gov (United States)

Geng, Tong-Mou; Wang, Xie; Wang, Zhu-Qing; Chen, Tai-Jie; Zhu, Hai; Wang, Yu

2015-03-01

Two rhodamine derivatives, N-mono-maleic acid amide-N'-rhodamine B hydrazide (MRBH) and N-mono-succinic acid amide-N'-rhodamine 6G hydrazide (SR6GH), were synthesized by amidation with maleic anhydride (MAH), succinic anhydride (SAH) and rhodamine B hydrazide, rhodamine 6G hydrazide, which were identified by FTIR, (1)H NMR and elemental analysis. Two water-soluble fluorescent materials (PVA-MRBH and PVA-SR6GH) were prepared via esterification reaction with N-mono-maleic acyl chloride amide-N'-rhodamine B hydrazide (MRBHCl) or N-mono-maleic acyl chloride amide-N'-rhodamine 6G hydrazide (SR6GHCl) and poly(vinyl alcohol) (PVA) in DMSO solution. The sensing behaviors of PVA-MRBH and PVA-SR6GH were explored by recording the fluorescence spectra in completely aqueous solution. Upon the addition of Cu(2+) and Fe(3+) ions to the aqueous solution of PVA-MRBH, visual color change from rose pink to amaranth and orange for Cu(2+) and Fe(3+) ions, respectively, and fluorescence quenching were observed. Titration of Cu(2+), Fe(3+), Cr(3+) or Hg(2+) into the aqueous solution of PVA-SR6GH, although they induced fluorescence enhancement, only Fe(3+) made the color changing from colorless to yellow. Moreover, other metal ions did not induce obvious changes to color and the fluorescence spectra.

Role of distonic dimer radical cations in the radiation-induced polymerisation of vinyl ethers

International Nuclear Information System (INIS)

Naumov, Sergej; Janovsky, Igor; Knolle, Wolfgang; Mehnert, Reiner

2005-01-01

The experimental low-temperature EPR results and the quantum chemical calculations suggest that dimer radical cations of cyclic and aliphatic vinyl ethers (VE) plays a key role in starting of radiation-induced polymerisation. The main species observed at high 2,3-dihydrofuran (DHF), 2,3-dihydropyran (DHP) and VE concentration is the dimer radical cation. In the case of cyclic VE the dimer radical cation transforms through H-abstraction from neutral molecule into a carbocation and radical, which could start both cationic and free-radical polymerisation. However, in the case of aliphatic VE no further reactive species, which could start polymerisation, were observed. This is caused (in agreement with experiment and quantum chemical calculations) by the very high stability of dimer radical cation and calculated endothermity of H-abstraction reaction by dimer radical cation from monomer

Actinic-radiation curable polymers prepared from a reactive polymer, halogenated cyclic anhydride and glycidyl ester

International Nuclear Information System (INIS)

Pastor, S.D.

1979-01-01

A novel class of photosensitive polymers are disclosed which are prepared by the reaction, preferably in the presence of a catalyst, of a reactive polymer, a halogenated cyclic anhydride and glycidyl ester of an alpha, beta-unsaturated carboxylic acid. These polymers are capable of undergoing vinyl-type polymerization when exposed to actinic radiation

Synthesis, characterization, and assessment of cytotoxic, antiproliferative, and antiangiogenic effects of a novel procainamide hydrochloride-poly(maleic anhydride-co-styrene) conjugate.

Science.gov (United States)

Karakus, Gulderen; Akin Polat, Zubeyde; Sahin Yaglıoglu, Ayse; Karahan, Mesut; Yenidunya, Ali Fazil

2013-01-01

Poly(maleic anhydride-co-styrene) (MAST) was synthesized by a free-radical polymerization reaction. A bioactive molecule, procainamide hydrochloride (PH), was then conjugated to MAST. The conjugation product was named as MAST/PH. Structural characterization of MAST and MAST/PH was carried out by Fourier Transform Infrared and Nuclear Magnetic Resonance spectroscopy. Their molecular weights were determined by size-exclusion chromatography. A mechanism was then suggested for the conjugation reaction. The results of the cytotoxicity assay, employing a mouse fibroblast cell line (L929), indicated that MAST/PH had no cytotoxicity at concentrations [Formula: see text] 62 μg mL(-1) (p > 0.05). Antiproliferative activities of MAST/PH and PH were determined by the BrdU cell proliferation ELISA assay, using C6 and HeLa cell lines. In the experiment, two anticancer chemotherapy drugs, cisplatin and 5-fluorouracil, were included as positive control. Antiproliferative activity results demonstrated that MAST/PH yielded the highest suppression profile (approximately 42%) at 20 μg/ml, while free PH exerted the same activity at 100 μg/ml. Interestingly, both MAST/PH and PH suppressed the proliferation of only one of the cell lines, C6 cells. Both cisplatin and 5-fluorouracil yielded approximately 60% antiproliferative activity on C6 cells at 20 and 100 μg/ml concentrations. Antiangiogenic capacity of both MAST and MAST/PH was also investigated by using the chicken chorioallantoic membrane assay. Results obtained indicated that while MAST/PH could be included into the category of good antiangiogenic substances, the activity score of MAST was within the weak category.

Cyclic α-Alkoxyphosphonium Salts from (2-(Diphenylphosphino)phenyl)methanol and Aldehydes and Their Application in Synthesis of Vinyl Ethers and Ketones via Wittig Olefination.

Science.gov (United States)

Huang, Wenhua; Rong, Hong-Ying; Xu, Jie

2015-07-02

Cyclic α-alkoxyphosphonium salts have been synthesized from (2-(diphenylphosphino)phenyl)methanol and aldehydes in 36-89% yields. These phosphonium salts are bench-stable solids and undergo Wittig olefination with aldehydes under basic conditions (K2CO3 or t-BuOK) to form benzylic vinyl ethers, which are readily hydrolyzed to 1,2-disubstituted ethanones under acidic conditions. The formation mechanism of these phosphonium salts via hemiacetal is also proposed.

Structure and thermal performance of poly(styrene-co-maleic anhydride)-g-alkyl alcohol comb-like copolymeric phase change materials

Energy Technology Data Exchange (ETDEWEB)

Wang, Haixia; Shi, Haifeng, E-mail: haifeng.shi@gmail.com; Qi, Miao; Zhang, Lingjian; Zhang, Xingxiang; Qi, Lu

2013-07-20

Graphical abstract: SMA-g-CnOH comb-like PCMs exhibit the better thermal stability against 1-alcohols due to the protection of SMA backbones, and the degradation temperature is dependent on the side-chain length, where at 5 wt% weight loss T{sub d} increased from 193 to 257 °C with n changing from 14 to 26. SMA-g-CnOH PCMs can be widely used under 300 °C for preparation of energy-saving products and materials. - Highlights: • The length of alkyl side-chains determines the thermal energy storage ability. • SMA backbone restricts the crystallization of alkyl side groups. • SMA-g-CnOH PCMs have the better thermal stability against 1-alcohols. - Abstract: A series of comb-like copolymeric phase change materials (SMA-g-CnOH) composed of poly(styrene-co-maleic anhydride) (SMA) and 1-alcohols CnOH with n = 14, 16, 18 or 26, respectively, was synthesized through grafting reaction. The structure and thermal properties of SMA-g-CnOH were investigated by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and wide-angle X-ray diffraction (WAXD). The DSC analysis indicates that SMA-g-CnOH exhibit good structure stability with phase change enthalpies changing from 37.9 to 110.7 J g{sup −1}. The results showed that the low thermal efficiency of SMA-g-CnOH was ascribed to the small CH{sub 2} segments of side chains participating in the assembled structure of side-chain crystallites. Their advantageous structural stability and thermal performance of SMA-g-CnOH were favorable for phase change materials in the thermal energy storage systems. Additionally, the influence of side-chain length on thermal properties of SMA-g-CnOH also was discussed in detail in combination with the published results.

Separation and recovery of lead from a low concentration solution of lead(II) and zinc(II) using the hydrolysis production of poly styrene-co-maleic anhydride.

Science.gov (United States)

Liang, Xing; Su, Yibing; Yang, Ying; Qin, Wenwu

2012-02-15

The PbZn separation/preconcentration technique, based on the complex formation reaction of Pb(II) and Zn(II), using a copolymer poly(styrene-co-maleic anhydride) (PSMA), without adding any carrier element was developed. The effects of several experimental parameters such as solution pH, temperature and adsorption time were studied. The experimental results show that the PSMA resin-Pb equilibrium was achieved in 2 min and the Pb(II) loading capacity is up to 641.62 mg g(-1) in aqueous solution under optimum conditions, which is much higher than the Zn(II) loading capacity within 80 min. The adsorption test for Pb(II) indicates that PSMA can recover Pb(II) from a mixed solution of Pb(II), Zn(II) and light metals such as Ca(II) and Mg(II) with higher adsorption rate and larger selective coefficient. A further study indicates that PSMA as chelating resins recovering Pb(II) can be regenerated via mineral acid (6M H(2)SO(4)). PSMA was synthesized by radical polymerization and tested as an adsorbent for the selective recovery of Pb(II). In addition, the formation procedure and structure of Pb-PSMA complex were also studied. Both the PSMA and the Pb-PSMA complex were characterized by means of FTIR spectroscopy, elemental analysis, gel permeation chromatography (GPC) and atomic absorption spectrometry (AAS). Copyright © 2011 Elsevier B.V. All rights reserved.

Preparation, characterization and thermal properties of styrene maleic anhydride copolymer (SMA)/fatty acid composites as form stable phase change materials

International Nuclear Information System (INIS)

Sari, Ahmet; Alkan, Cemil; Karaipekli, Ali; Onal, Adem

2008-01-01

Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA) and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the major drawback of them, limiting their utility area in thermal energy storage. The use of fatty acids as form stable PCMs will increase their feasibilities in practical applications due to the reduced cost of the LHTES system. In this regard, a series of styrene maleic anhydride copolymer (SMA)/fatty acid composites, SMA/SA, SMA/PA, SMA/MA, and SMA/LA, were prepared as form stable PCMs by encapsulation of fatty acids into the SMA, which acts as a supporting material. The encapsulation ratio of fatty acids was as much as 85 wt.% and no leakage of fatty acid was observed even when the temperature of the form stable PCM was over the melting point of the fatty acid in the composite. The prepared form stable composite PCMs were characterized using optic microscopy (OM), viscosimetry and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the SMA was physically and chemically compatible with the fatty acids. In addition, the thermal characteristics such as melting and freezing temperatures and latent heats of the form stable composite PCMs were measured by using the differential scanning calorimetry (DSC) technique, which indicated they had good thermal properties. On the basis of all the results, it was concluded that form stable SMA/fatty acid composite PCMs had important potential for practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floors impregnated with a form stable PCM due to their satisfying thermal properties, easy preparation in desired dimensions, direct usability without needing additional encapsulation thereby eliminating the thermal resistance caused by the shell and, thus, reducing the cost of

Fatigue mechanisms in unidirectional glass-fibre-reinforced polypropylene

DEFF Research Database (Denmark)

Gamstedt, E.K.; Berglund, L.A.; Peijs, T.

1999-01-01

Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects of interfac......Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects...... of interfacial strength on fatigue performance and on the underlying micromechanisms have been studied for these composite systems. Tension-tension fatigue tests (R = 0.1) were carried out on 0 degrees glass-fibre/PP and glass-fibre/ MA-PP coupons. The macroscopic fatigue behaviour was characterized in terms...

Facile and Efficient Acetylation of Primary Alcohols and Phenols with Acetic Anhydride Catalyzed by Dried Sodium Bicarbonate

Directory of Open Access Journals (Sweden)

Fulgentius Nelson Lugemwa

2013-12-01

Full Text Available A variety of primary alcohols and phenols were reacted with acetic anhydride at room temperature in the presence of sodium bicarbonate to produce corresponding esters in good to excellent yields. The acetylation of 4-nitrobenzyl alcohol was also carried out using other bicarbonates and carbonates. The reaction in the presence of cesium bicarbonate and lithium carbonate gave 4-nitrobenzyl acetate in excellent yield, while in the presence of Na2CO3, K2CO3, Cs2CO3, or KHCO3 the yield was in the range of 80%–95%. Calcium carbonate and cobaltous carbonate did not promote the acetylation of 4-ntirobenzyl alcohol using acetic anhydride. The acetylation of 4-nitrobenzyl alcohol was carried out using ethyl acetate, THF, toluene, diethyl ether, dichloromethane and acetonitrile, and gave good yields ranging from 75%–99%. Toluene was the best solvent for the reaction, while diethyl ether was the poorest.

Modification of montmorillonite fillers by ionizing radiation

International Nuclear Information System (INIS)

Zimek, Z.; Przybytniak, G.; Nowicki, A.; Mirkowski, K.

2006-01-01

The mineral fillers can be modified by using unsaturated compounds: styrene, methacrylic acid and maleic anhydride (MA), following by irradiation with high energy electron beam. In presented paper the authors have used this method to change properties of bentonite S pecjal , containing about 70% of pure montmorillonite. It has been shown that: (a) the particles obtained in this process can be good fillers for the production of composites; (b) maleic anhydride reacts via anhydride group with active ionic sites of bentonite, forming a salt-like compound. Irradiation with electron beam leads to the breakage of double bond in maleic anhydride and to the production of new organic phases

Resonance energy transfer from quinolinone modified polystyrene-block-poly(styrene-alt-maleic anhydride) copolymer to terbium(III) metal ions

Energy Technology Data Exchange (ETDEWEB)

Výprachtický, Drahomír, E-mail: vyprachticky@imc.cas.cz [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovský Sq. 2, 162 06 Prague 6 (Czech Republic); Mikeš, František [New York University Polytechnic School of Engineering, Polymer Research Institute, 6 MetroTech Center, Brooklyn, NY 11201 (United States); Lokaj, Jan; Pokorná, Veronika; Cimrová, Věra [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovský Sq. 2, 162 06 Prague 6 (Czech Republic)

2015-04-15

Polystyrene-block-poly(styrene-alt-maleic anhydride) was synthesized by nitroxide mediated radical polymerization and modified with 7-amino-4-methylquinolin-2(1H)-one (I) and methanol. The formed block polymer ligand contained a quinolinone fluorophore (Ω) and carboxyl (III) or sodium carboxylate (IV) binding sites. The ligand-to-metal resonance energy transfer (RET) and ligand binding properties of [III–Tb{sup 3+}] and [IV–Tb{sup 3+}] complexes were investigated by steady-state and time-resolved luminescence spectroscopy in tetrahydrofuran/methanol and/or tetrahydrofuran/deuterated methanol mixtures and compared with those of a low-molecular-weight model ligand, i.e. the sodium salt of N-(4-methyl-2-oxo-1,2-dihydroquinolin-7-yl)succinamic acid (II). The long-lived emission intensities of Tb{sup 3+} at 490, 545, 585, and 620 nm corresponding to the {sup 5}D{sub 4}→{sup 7}F{sub 6}, {sup 5}D{sub 4}→{sup 7}F{sub 5}, {sup 5}D{sub 4}→{sup 7}F{sub 4}, and {sup 5}D{sub 4}→{sup 7}F{sub 3} transitions, respectively, were strongly increased by the addition of ligands in the order [II-Tb{sup 3+}]⪡[III-Tb{sup 3+}]<[IV-Tb{sup 3+}]. The efficiency of energy transfer (E) was evaluated from the emission intensity of the donor (Ω) in the presence or absence of the acceptor (Tb{sup 3+}) depending on the acceptor concentration and ligand neutralization. It was concluded that the macromolecular ligand structural properties (polymer coil and supramolecular structures, e.g. micelles) were responsible for the increase in RET. The time-resolved luminescence measurements revealed that the binding affinity of the ligands II, III, and IV increased in the order II

The properties of poly(lactic acid)/starch blends with a functionalized plant oil: tung oil anhydride.

Science.gov (United States)

Xiong, Zhu; Li, Chao; Ma, Songqi; Feng, Jianxian; Yang, Yong; Zhang, Ruoyu; Zhu, Jin

2013-06-05

Bio-sourced polymers, polylactide (PLA) and starch, have been melt-blended by lab-scale co-extruder with tung oil anhydride (TOA) as the plasticizer. The ready reaction between the maleic anhydride on TOA and the hydroxyl on starch led TOA molecules to accumulate on starch and increased the compatibility of PLA/starch blends, which was confirmed by FT-IR analyses and SEM. The TOA could change the mechanical properties and physical behaviors of PLA/starch blends. DSC and DMA analysis show that the TOA layer on starch has an effect on the thermal behavior of PLA in the ternary blend. The enrichment of TOA on starch improves the toughness and impact strength of the PLA/starch blends. The adding amount of TOA in PLA/starch blends primarily determined the compatibility and mechanical properties of the resulted ternary blends. The tensile and impact fracture modes of the PLA/starch blend with or without TOA has also been investigated by SEM analysis. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

CF3+ fragmentation by electron impact ionization of perfluoro-propyl-vinyl-ethers, C5F10O, in gas phase

Science.gov (United States)

Kondo, Yusuke; Ishikawa, Kenji; Hayashi, Toshio; Miyawaki, Yudai; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

2015-04-01

The gas phase fragmentations of perfluoro-propyl-vinyl ether (PPVE, C5F10O) are studied experimentally. Dominant fragmentations of PPVE are found to be the result of a dissociative ionization reaction, i.e., CF3+ via direct bond cleavage, and C2F3O- and C3F7O- via electron attachment. Regardless of the appearance energy of around 14.5 eV for the dissociative ionization of CF3+, the observed ion efficiency for the CF3+ ion was extremely large the order of 10-20 cm-2, compared with only 10-21 cm-2 for the other channels. PPVE characteristically generated CF3+ as the largest abundant ion are advantageous for use of feedstock gases in plasma etching processes.

Properties and quality verification of biodiesel produced from tobacco seed oil

Energy Technology Data Exchange (ETDEWEB)

Usta, N., E-mail: n_usta@pau.edu.t [Pamukkale University, Mechanical Engineering Department, 20070 Denizli (Turkey); Aydogan, B. [Pamukkale University, Mechanical Engineering Department, 20070 Denizli (Turkey); Con, A.H. [Pamukkale University, Food Engineering Department, 20070 Denizli (Turkey); Uguzdogan, E. [Pamukkale University, Chemical Engineering Department, 20070 Denizli (Turkey); Ozkal, S.G. [Pamukkale University, Food Engineering Department, 20070 Denizli (Turkey)

2011-05-15

Research highlights: {yields} High quality biodiesel fuel can be produced from tobacco seed oil. {yields} Pyrogallol was found to be effective antioxidant improving the oxidation stability. {yields} The iodine number was reduced with a biodiesel including more saturated fatty acids. {yields} Octadecene-1-maleic anhydride copolymer was an effective cold flow improver. {yields} The appropriate amounts of the additives do not affect the properties negatively. -- Abstract: Tobacco seed oil has been evaluated as a feedstock for biodiesel production. In this study, all properties of the biodiesel that was produced from tobacco seed oil were examined and some solutions were derived to bring all properties of the biodiesel within European Biodiesel Standard EN14214 to verify biodiesel quality. Among the properties, only oxidation stability and iodine number of the biodiesel, which mainly depend on fatty acid composition of the oil, were not within the limits of the standard. Six different antioxidants that are tert-butylhydroquinone, butylated hydroxytoluene, propyl gallate, pyrogallol, {alpha}-tocopherol and butylated hydroxyanisole were used to improve the oxidation stability. Among them, pyrogallol was found to be the most effective antioxidant. The iodine number was improved with blending the biodiesel produced from tobacco seed oil with a biodiesel that contains more saturated fatty acids. However, the blending caused increasing the cold filter plugging point. Therefore, four different cold flow improvers, which are ethylene-vinyl acetate copolymer, octadecene-1-maleic anhydride copolymer and two commercial cold flow improvers, were used to decrease cold filter plugging point of the biodiesel and the blends. Among the improvers, the best improver is said to be octadecene-1-maleic anhydride copolymer. In addition, effects of temperature on the density and the viscosity of the biodiesel were investigated.

Synthesis of water-soluble poly [acrylic acid-co-vinyl butyl ether] and its applications in cement admixtures

International Nuclear Information System (INIS)

Negim, S.M.; Mun, G.A.; Nurkeeva, Z.S.; Danveesh, H.H.M.

2005-01-01

Three composition ratios of poly[acrylic acid (AA)-co-vinyl butyl ether)] were prepared in alcoholic solution using azo-bis-isobutyro-nitrile as initiator (ABIN). The water-soluble copolymers were characterized through FT-IR, 1 H NMR, Mass spectra, ESEM as well as viscosity. The effect of water-soluble copolymers and their sodium salts on the physico-mechanical properties of Ordaniary Portland Cement (O.P.C) pastes was investigated. The results showed that the addition of aqueous solutions from the prepared copolymers and their sodium salts to the cement improve most of the specific characteristics of (O.P.C). As the concentration of the water-soluble copolymer increases, the setting time increases. The combined water content enhances the addition of copolymer to the mixing water. The compressive strength was she increased at all any hydration. The results of the solution of the prepared sodium salt copolymers are better than its copolymers. (author)

Post irradiation effects on the graft of poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) films

International Nuclear Information System (INIS)

Geraldes, Adriana N.; Zen, Heloisa A.; Ribeiro, Geise; Ferreira, Henrique P.; Souza, Camila P.; Parra, Duclerc F.; Lugao, Ademar B.

2009-01-01

Radiation induced grafting of monomers into fluorinated polymers was designed as an alternative route to polymer modification. In this work, grafting of styrene onto poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) was studied. Radiation-induced grafting of styrene onto PFA films was investigated after simultaneous irradiation (in post-irradiation condition) using a 60 Co source. The films of PFA were irradiated at 20, 40, 80 and 100 kGy doses at room temperature and chemical changes were monitored after contact with styrene for grafting. The post-irradiation time was established between 7 and 28 days when films of PFA were maintained in styrene/toluene 1:1 v/v solution at room temperature. After these periods the grafting degrees were evaluated in the samples. The highest degree of grafting was achieved after 14 days. Chemical modifications were evaluated by infrared spectroscopic analysis (FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC) and also by scanning electron microscopy (SEM). The degree of grafting (DOG) was determined gravimetrically. The results showed that irradiated PFA films at 100 kGy exhibited higher grafting degree. Surface analysis by SEM technique of irradiated, grafted and original films have presented an homogeneous surface. (author)

Silver-containing polymer composition used in spacecraft and semiconductor optoelectronics control systems

Energy Technology Data Exchange (ETDEWEB)

Ivanov, A. A., E-mail: alexchemtsu@rambler.ru; Tuev, V. I., E-mail: tvi-retem@main.tusur.ru [Tomsk State University of Control Systems and Radioelectronics, Tomsk, 634050 (Russian Federation)

2015-10-27

The copolymer of the vinyl chloride-maleic anhydride and silver nano- and microparticle (70 wt %) composition is offered as a conductive adhesive for fixing various chips on the dielectric substrate. The wiring volume resistivity is up to 3.1×10{sup −8} Ohm×m. The adhesive strength of the silver-containing polymer composition (70% of Ag) applied under a shear on the dielectric substrate is 106 N/mm{sup 2}. Adhesive layers obtained from these substances have a high thermal conductivity up to λ = 199.93 W/m×K that depends on the amount of Ag in the polymer composition.

Hybrid thermosets from vinyl ester resin and acrylated epoxidized soybean oil (AESO

Directory of Open Access Journals (Sweden)

2011-01-01

Full Text Available A series of hybrids composed of styrene crosslinkable vinyl ester (VE and acrylated epoxidized soybean oil (AESO were produced via free radical-induced crosslinking. The VE/AESO ratio was changed between 75/25 and 25/75 wt%. Moreover, to support phase grafting the VE/AESO = 50/50 wt% hybrid was modified with phthalic anhydride in various amounts (1, 5 and 10 wt%. The structure of the hybrid systems was investigated by dynamic mechanical thermal analysis (DMTA, differential scanning calorimetry (DSC, and atomic force microscopy (AFM. The properties of the systems were assessed by static flexural and fracture mechanical tests. The resistance to thermal degradation was inspected by thermogravimetric analysis (TGA. The results suggested that the hybrids have an interpenetrating network (IPN structure. With increasing AESO content the stiffness (modulus, strength and glass transition temperature (Tg of the hybrids decreased, whereas their ductility increased. Phthalic anhydride caused an adverse trend. Both the fracture toughness and fracture energy increased with increasing AESO content. They were less affected by adding phthalic anhydride phase couplant. Interestingly, the hybrids outperformed the parent VE and AESO in respect to resistance to thermal degradation.

α-Costic anhydride

Directory of Open Access Journals (Sweden)

Moha Berraho

2010-03-01

Full Text Available The title compound [systematic name: 2-(4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-ylacrylic acid anhydride], C30H42O3, is a new isocostic anhydride which was synthesized from the aerial part of Inula Viscosa (L Aiton [or Dittrichia Viscosa (L Greuter]. The molecule adopts an essentially linear shape with two terminal fused-rings bridged by the anhydride group. The external rings have the same conformation (half-chair while each of the two inner rings has an almost ideal chair conformation. In the crystal, intermolecular C—H...O interactions link the molecules into a two-dimensional array in the bc plane.

Densities and derived thermodynamic properties of the binary systems of 1,1-dimethylethyl methyl ether with allyl methacrylate, butyl methacrylate, methacrylic acid, and vinyl acetate at T = (298.15 and 308.15) K

International Nuclear Information System (INIS)

Wisniak, Jaime; Peralta, Rene D.; Infante, Ramiro; Cortez, Gladis

2005-01-01

Densities of the binary systems of 1,1-dimethylethyl methyl ether (MTBE) with allyl methacrylate, butyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 and 308.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are negative for the binaries of MTBE + methacrylates; the system MTBE with vinyl acetate presents near ideal behavior. The excess coefficient of thermal expansion is positive for all the systems studied here; the value of the coefficient for the system MTBE + allyl methacrylate is at least three times larger than that for the other systems

Synthesis and Characterization of Poly (ether imide)s Containing Phthalazinone and Isopropyl Moieties

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-l-one and bisphenol-A diphthalic anhydride was synthesized by one-step solution condensation polymerization in m-cresol. The polymer was characterized by FTIR, NMR, molecular weights, glass transition temperature,thermal degradation temperature and WAXD.

Radiation-induced trioxane postpolymerization in the liquid phase

International Nuclear Information System (INIS)

Kapustina, I.B.; Starchenko, T.V.

1979-01-01

Radiation-induced trioxane postpolymerization in the presence of maleic anhydride and different solvents in the liquid phase has been studied. It has been found that addition of small quantities of different solvents inhibits the trioxane polymerization process both in the presence of maleic anhydride and in the absence of it. Trioxane postpolymerization in a solvent-nonsolvent mixture gives fibrous polyoxymethylene with high molecular mass and high yield

Effect of temperature and ph on the drug release rate from a polymer conjugate system

International Nuclear Information System (INIS)

Kenawy, E.; Abdel-Hay, F.I.; El-Newehy, M.H.; Ottenbrite, R.M.

2005-01-01

Hydroximide and A-methylhydroxamic acid of poly(ethylene-altmaleic anhydride) (average MW 100-500 k) were used as a carrier for a new drug delivery system. The synthesis of the hydroximide and N methylhydroxamic acid of poly(ethylene-alt-maleic anhydride) were carried out by chemical modification of poly(ethylene-alt-maleic anhydride) with hydroxylamine and N-methyl hydroxylamine, respectively, in N,N- dimethylformamide at room temperature to yield water soluble copolymer. Ketoprofen was reacted with hydroximide and N-methylhydroxamic acid derivatives of poly(ethylene-alt-maleic anhydride) using dicyclohexylcarbodiimide as condensation agent at -5 degree C to yield water insoluble ketoprofen conjugates. All products were characterized by elemental analysis, FTIR and 1HNMR spectra. The in-vitro ketoprofen release was carried out by UV spectrophotometer at max =260 nm. The results demonstrated the effectiveness of hydroximide and N-methylhydroxamic acid of polyethylene-alt-maleic anhydride) as a drug delivery system. The release rates were studied at various ph and temperatures. The copolymer-drug adducts released the drug very slowly at the low ph found in the stomach thus protecting the drug from the action of high concentrations of digestive acids. These results showed the usefulness of hydroxamic acid polymer-drug conjugates as a new drug delivery system for drugs to be targeted to sites in the GI system

Acidolysis small molecular phenolic ether used as accelerator in photosensitive diazonaphthaquinone systems

Science.gov (United States)

Zhou, Haihua; Zou, Yingquan

2006-03-01

The photosensitive compounds in the photosensitive coatings of positive PS plates are the diazonaphthaquinone derivatives. Some acidolysis small molecular phenolic ethers, which were synthesized by some special polyhydroxyl phenols with vinyl ethyl ether, are added in the positive diazonaphthaquinone photosensitive composition to improve its sensitivity, composed with photo-acid-generators. The effects to the photosensitivity, anti-alkali property, anti-isopropyl alcohol property, dot resolution and line resolution of the coatings are studied with different additive percent of the special phenolic ethers. In the conventional photosensitive diazonaphthaquinone systems for positive PS plates, the photosensitivity is improved without negative effects to resolution, anti-alkali and anti-isopropyl alcohol properties when added about 5% of the special acidolysis phenolic ethers, EAAE or DPHE, composed with photo-acid-generators.

Interaction parameters of poly(vinyl methyl ether) in 2-propanol-water mixture as determined by small-angle neutron scattering

International Nuclear Information System (INIS)

Takada, Masako; Kurita, Kimio; Okano, Koji; Furusaka, Michihiro.

1994-01-01

The small-angle neutron scattering from semidilute solutions of poly(vinyl methyl ether)(PVME) in a 2-propanol-water mixture has been measured, the volume concentration of 2-propanol in the aqueous solvent being 10%, in the temperature range just below the lower critical solution temperature(LCST). The binary and ternary cluster integrals of polymer segments were determined from the concentration dependence of the correlation length at each temperature. We have calculated the contribution of segment-segment interaction to the entropy, S int and enthalpy, U int from the measured temperature dependences of these interaction parameters and found that both values are positive in accordance with the previously measured PVME-water system and PVME-(water+methanol) system. However, the value of S int for PVME-(water+2-propanol) system is larger than that for PVME-(water+methanol) system having the same alcohol concentration, and it is even larger than that for PVME-water system. This anomalous behavior is explained as due to the preferential solvation of 2-propanol molecules to the segments of PVME. (author)

Development of functionalized hydroxyapatite/poly(vinyl alcohol) composites

Science.gov (United States)

Stipniece, Liga; Salma-Ancane, Kristine; Rjabovs, Vitalijs; Juhnevica, Inna; Turks, Maris; Narkevica, Inga; Berzina-Cimdina, Liga

2016-06-01

Based on the well-known pharmaceutical excipient potential of poly(vinyl alcohol) (PVA) and clinical success of hydroxyapatite (HAp), the objective of this work was to fabricate functionalized composite microgranules. PVA was modified with succinic anhydride to introduce carboxyl groups (-COOH), respectively, by reaction between the -OH groups of PVA and succinic anhydride, for attachment of drug molecules. For the first time, the functionalized composite microgranules containing HAp/PVA in the ratio of 1:1 were prepared through in situ precipitation of HAp in modified PVA aqueous solutions followed by spray drying of obtained suspensions. The microgranules were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and differential scanning calorimetry (DSC). The presence of -COOH groups was verified by FT-IR, and the amount of functional groups added to PVA molecules (averaging 15 mol%) was determined by nuclear magnetic resonance spectroscopy (NMR). DSC results showed that modification with -COOH groups slightly decreased the thermal stability of PVA. FT-IR and XRD analysis confirmed that the resulting composites contain mainly nanocrystalline HAp and PVA. Moreover, the images taken by FE-SEM revealed that the microgranules consisted of nanosized HAp crystallites homogenously embedded in the PVA matrix. DSC measurements indicated that decomposition mechanism of the HAp/PVA differs from that of pure PVA and occurs at lower temperatures. However, the presence of HAp had minor influence on the thermal decomposition of the PVA modified with succinic anhydride. The investigation of composite microgranules confirmed interaction and integration between the HAp and PVA.

Influence of reaction medium during synthesis of Gantrez AN 119 nanoparticles for oral vaccination.

Science.gov (United States)

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.

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

Science.gov (United States)

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

2015-03-01

Cellulose modified with maleic (M) and phthalic (P) anhydride, to be named CMA and CPA, were tested as feasible adsorbents for the removal of malachite green from aqueous solution. At the same time, the uptake ability of natural cellulose was also studied for comparison. The structure of material was characterized by FT-IR and XRD. The effects of solution pH, initial dye concentration, contact time and temperature were investigated in detail by batch adsorption experiments. The kinetic and isotherm studies suggested that the adsorption followed the pseudo-second-order model and Langmuir isotherm. The maximum adsorption capacity on CMA and CPA were 370 mg g(-1) and 111 mg g(-1), respectively. Furthermore, the thermodynamics studies indicated the spontaneous nature of adsorption of malachite green on adsorbents. All the studied results showed that the modified cellulose could be used as effective adsorption material for the removal of malachite green from aqueous solutions. Copyright © 2014 Elsevier B.V. All rights reserved.

One-Pot Catalytic Enantio- and Diastereoselective Syntheses of anti-, syn-cis-Disubstituted, and syn-Vinyl Cyclopropyl Alcohols

Science.gov (United States)

Kim, Hun Young; Salvi, Luca; Carroll, Patrick J.; Walsh, Patrick J.

2009-01-01

Highly enantio- and diastereoselective methods for the synthesis of a variety of cyclopropyl alcohols are reported. These methods represent the first one-pot approaches to syn-vinyl cyclopropyl alcohols, syn-cis-disubstituted cyclopropyl alcohols, and anti-cyclopropyl alcohols from achiral precursors. The methods begin with enantioselective C–C bond formations promoted by a MIB-based zinc catalyst to generate allylic alkoxide intermediates. The intermediates are then subjected to in situ alkoxide-directed cyclopropanation to provide cyclopropyl alcohols. In the synthesis of vinyl cyclopropyl alcohols, hydroboration of enynes is followed by transmetalation of the resulting dienylborane to zinc to provide dienylzinc reagents. Enantioselective addition to aldehydes generates the requisite dienyl zinc alkoxides, which are then subjected to in situ cyclopropanation to furnish vinyl cyclopropyl alcohols. Cyclopropanation occurs at the double bond allylic to the alkoxide. Using this method, syn-vinylcyclopropyl alcohols are obtained in 65–85% yield, 76–93% ee, and >19:1 dr. To prepare anti-cyclopropanols, enantioselective addition of alkylzinc reagents to conjugated enals provides allylic zinc alkoxides. Because direct cyclopropanation provides syn-cyclopropyl alcohols, the intermediate allylic alkoxides were treated with TMSCl/Et3N to generate intermediate silyl ethers. In situ cyclopropanation of the allylic silyl ether resulted in cyclopropanation to form the anti-cyclopropyl silyl ether. Workup with TBAF affords the anti-cyclopropyl alcohols in one-pot in 60–82% yield, 89–99% ee, and ≥10:1 dr. For the synthesis of cis-disubstituted cyclopropyl alcohols, in situ generated (Z)-vinyl zinc reagents were employed in asymmetric addition to aldehydes to generate (Z)-allylic zinc alkoxides. In situ cyclopropanation provides syn-cis-disubstituted cyclopropyl alcohols in 42–70% yield, 88–97% ee, and >19:1 dr. These one-pot procedures enable the synthesis of a

Hybrid composites

CSIR Research Space (South Africa)

Jacob John, Maya

2009-04-01

Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

α-Diazo oxime ethers for N-heterocycle synthesis.

Science.gov (United States)

Choi, Subin; Ha, Sujin; Park, Cheol-Min

2017-06-01

This Feature Article introduces the preparation and synthetic utility of α-diazo oxime ethers. α-Oximino carbenes are useful synthons for N-heterocycles, and can be easily prepared from α-diazo oxime ethers as precursors. We begin with the preparation of α-diazo oxime ethers and their application in [3+2] cycloaddition. It turns out that the nature of metals bound to carbenes plays a crucial role in modulating the reactivity of α-oximino carbenes, in which copper carbenes smoothly react with enamines, whereas the less reactive enol ethers and nitriles require gold carbenes. In Section 3.2, a discussion on N-O and C-H bond activation is presented. Carbenes derived from diazo oxime ethers show unique reactivity towards N-O and C-H bond activation, in which the proximity of the two functionalities, carbene and oxime ether, dictates the preferred reaction pathways toward pyridines, pyrroles, and 2H-azirines. In Section 3.3, the development of tandem reactions based on α-diazo oxime ethers is discussed. The nature of carbenes in which whether free carbenes or metal complexes are involved dissects the pathway and forms different types of 2H-azirines. The 2H-azirine formation turned out to be an excellent platform for the tandem synthesis of N-heterocycles including pyrroles and pyridines. In the last section, we describe the electrophilic activation of 2H-azirines with vinyl carbenes and oximino carbenes. The resulting azirinium species undergo rapid ring expansion rearrangements to form pyridines and pyrazines.

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

Science.gov (United States)

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

2014-10-01

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

Polyethylene organo-clay nanocomposites: the role of the interface chemistry on the extent of clay intercalation/exfoliation.

Science.gov (United States)

Mainil, Michaël; Alexandre, Michaël; Monteverde, Fabien; Dubois, Philippe

2006-02-01

High density polyethylene (HDPE)/clay nanocomposites have been prepared using three different functionalized polyethylene compatibilizers: an ethylene/vinyl acetate copolymer, a polyethylene grafted with maleic anhydride functions and a (styrene-b-ethylene/butylene-b-styrene) block copolymer. The nanocomposites were prepared via two different routes: (1) the dispersion in HDPE of a masterbatch prepared from the compatibilizer and the clay or (2) the direct melt blending of the three components. For each compatibilizer, essentially intercalated nanocomposites were formed as determined by X-ray diffraction and transmission electron microscopy. With the ethylene/vinyl acetate copolymer, a significant delamination of the intercalated clay in thin stacks was observed. This dispersion of thin intercalated stacks within the polymer matrix allowed increasing significantly the stiffness and the flame resistance of the nanocomposite. A positive effect of shear rate and blending time has also been put into evidence, especially for the process based on the masterbatch preparation, improving both the formation of thin stacks of intercalated clay and the mechanical properties and the flame resistance of the formed nanocomposites.

Certain laws governing the influence of high molecular polymer additives on specific electrical conductivity and viscosity of zincate alkaline solution

Energy Technology Data Exchange (ETDEWEB)

Dmitrenko, V.Ye.; Toropetsera, T.N.; Zubov, M.S.

1983-01-01

A study was made of the influence of polymer additives of different nature: polyelectrolyte, copolymer of ethylene with maleic anhydride, polymethacrylic acid and nonpolyectrolyte copolymer of vinyl alcohol with vinyleneglycol and polyvinyleneglycol on specific electrical conductance and viscosity of the zincate alkaline solution. It is indicated that with an increase in the content of additives, the specific conductance of the solution diminishes according to a linear law, while the viscosity rises. The additives of polyelectrolyte nature reduce more strongly the specific conductance and increase the viscosity than the nonpolyelectrolyte additives. From a comparison of the data on specific conductance and viscosity the following conclusion is drawn: the more the polymer ''structures'' the zincate alkaline solution, the more strongly it reduces its specific electrical conductance.

Cytotoxicity of S-conjugates of the sevoflurane degradation product fluoromethyl-2,2-difluoro-1-(trifluoromethyl) vinyl ether (Compound A) in a human proximal tubular cell line

International Nuclear Information System (INIS)

Altuntas, T. Gul; Zager, Richard A.; Kharasch, Evan D.

2003-01-01

Fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE) is a fluorinated alkene formed by degradation of the volatile anesthetic sevoflurane in anesthesia machines. FDVE is nephrotoxic in rats but not humans. Rat FDVE nephrotoxicity is attributed to FDVE glutathione conjugation and bioactivation of subsequent FDVE-cysteine S-conjugates, in part by renal β-lyase. Although FDVE conjugation and metabolism occur in both rats and humans, the mechanism for selective toxicity in rats and lack of effect in humans is incompletely elucidated. This investigation measured FDVE S-conjugate cytotoxicity in cultured human proximal tubular HK-2 cells, and compared this with known cytotoxic S-conjugates. HK-2 cells were incubated with FDVE and its GSH, cysteine S-mercapturic acid, cysteine S-sulfoxide, and mercapturic acid sulfoxide conjugates (0.1-2.7 mM) for 24 h. Cytotoxicity was determined by lactate dehydrogenase (LDH) release, total LDH, and the ability of viable cells to reduce a tetrazolium-based compound (MTT). FDVE was cytotoxic only at concentrations ≥0.9 mM. No increase in LDH release was observed with either FDVE-GSH conjugate. The FDVE-cysteine conjugates S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine (DFEC) and (Z)-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-FFVC) caused significant differences in LDH release and MTT reduction only at 2.7 mM; (Z)-FFVC was slightly more cytotoxic. Both S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine sulfoxide (DFEC-SO) and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine sulfoxide ((Z)-N-Ac-FFVC-SO) caused slightly greater changes in LDH release or total LDH than the corresponding equimolar DFEC and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-N-Ac-FFVC) conjugates. In contrast to FDVE S-conjugates, S-(1,2-dichlorovinyl)-L-cysteine was markedly cytotoxic, at concentrations as low as 0

A novel sulfonated poly(ether ether ketone) and cross-linked membranes for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Li, Hongtao; Zhang, Gang; Wu, Jing; Zhao, Chengji; Zhang, Yang; Shao, Ke; Han, Miaomiao; Lin, Haidan; Zhu, Jing; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, Jilin (China)

2010-10-01

A novel poly(ether ether ketone) (PEEK) containing pendant carboxyl groups has been synthesized by a nucleophilic polycondensation reaction. Sulfonated polymers (SPEEKs) with different ion exchange capacity are then obtained by post-sulfonation process. The structures of PEEK and SPEEKs are characterized by both FT-IR and {sup 1}H NMR. The properties of SPEEKs as candidates for proton exchange membranes are studied. The cross-linking reaction is performed at 140 C using poly(vinyl alcohol) (PVA) as the cross-linker. In comparison with the non-cross-linked membranes, some properties of the cross-linked membranes are significantly improved, such as water uptake, methanol resistance, mechanical and oxidative stabilities, while the proton conductivity decreases. The effect of PVA content on proton conductivity, water uptake, swelling ratio, and methanol permeability is also investigated. Among all the membranes, SPEEK-C-8 shows the highest selectivity of 50.5 x 10{sup 4} S s cm{sup -3}, which indicates that it is a suitable candidate for applications in direct methanol fuel cells. (author)

Diclofenac sodium (DS) loaded bioerodible polymer based constructs

Science.gov (United States)

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

2008-02-01

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

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry

NARCIS (Netherlands)

Polgar, Lorenzo Massimo; van Duin, Martin; Picchioni, Francesco

2016-01-01

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ethylene-propylene rubber, grafted with maleic anhydride, is thermo-reversibly cross-linked in two steps. The pending anhydride moieties are first modified

Use of Diels-Alder Chemistry for Thermoreversible Cross-Linking of Rubbers : The Next Step toward Recycling of Rubber Products?

NARCIS (Netherlands)

Polgar, L. M.; van Duin, M.; Broekhuis, A. A.; Picchioni, F.

2015-01-01

A proof of principle for the use of Diels-Alder chemistry as a thermoreversible cross-linking tool for rubber products is demonstrated. A commercial ethylene-propylene rubber grafted with maleic anhydride has been thermoreversibly cross-linked in two steps. The pending anhydride rings were first

21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1360 Ethylene-vinyl acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2...

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-04-16

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

Pharmacokinetics of Maleic Acid as a Food Adulterant Determined by Microdialysis in Rat Blood and Kidney Cortex

Directory of Open Access Journals (Sweden)

Mei-Ling Hou

2016-03-01

Full Text Available Maleic acid has been shown to be used as a food adulterant in the production of modified starch by the Taiwan Food and Drug Administration. Due to the potential toxicity of maleic acid to the kidneys, this study aimed to develop an analytical method to investigate the pharmacokinetics of maleic acid in rat blood and kidney cortex. Multiple microdialysis probes were simultaneously inserted into the jugular vein and the kidney cortex for sampling after maleic acid administration (10 or 30 mg/kg, i.v., respectively. The pharmacokinetic results demonstrated that maleic acid produced a linear pharmacokinetic phenomenon within the doses of 10 and 30 mg/kg. The area under concentration versus time curve (AUC of the maleic acid in kidney cortex was 5-fold higher than that in the blood after maleic acid administration (10 and 30 mg/kg, i.v., respectively, indicating that greater accumulation of maleic acid occurred in the rat kidney.

Preparation of epoxy/zirconia hybrid materials via in situ polymerization using zirconium alkoxide coordinated with acid anhydride

International Nuclear Information System (INIS)

Ochi, Mitsukazu; Nii, Daisuke; Harada, Miyuki

2011-01-01

Highlights: → Novel epoxy/zirconia hybrid materials were synthesized via in situ polymerization using zirconium alkoxide coordinated with acid anhydride. → The half-ester compound of acid anhydride desorbed from zirconium played as curing agent of epoxy resin. → The zirconia was uniformly dispersed in the epoxy matrix on the nanometer or sub-nanometer scale by synchronizing the epoxy curing and sol-gel reactions. → The refractive indices of the hybrid materials significantly improved with an increase in the zirconia content. - Abstract: Novel epoxy/zirconia hybrid materials were synthesized using a bisphenol A epoxy resin (diglycidyl ether of bisphenol A; DGEBA), zirconium(IV)-n-propoxide (ZTNP), and hexahydrophthalic anhydride (HHPA) via in situ polymerization. HHPA played two roles in this system: it acted as a modifier to control the hydrolysis and condensation reactions of zirconium alkoxide and also as a curing agent - the half-ester compound of HHPA desorbed from zirconium reacted with the epoxy resin to form the epoxy network. As a result, both the sol-gel reaction and epoxy curing occurred simultaneously in a homogeneous solution, and organic-inorganic hybrid materials were readily obtained. Further, the zirconia produced by the in situ polymerization was uniformly dispersed in the epoxy matrix on the nanometer or sub-nanometer scale; thus, hybrid materials that exhibited excellent optical transparency were obtained. Furthermore, the heat resistance of the hybrid materials could be improved by hybridization with zirconia. And, the refractive indices of the hybrid materials significantly improved with an increase in the zirconia content.

Effect of wood filler treatment and EBAGMA compatibilizer on morphology and mechanical properties of low density polyethylene/olive husk flour composites

Directory of Open Access Journals (Sweden)

2007-07-01

Full Text Available This paper deals with plastic-wood composites based on low density polyethylene (LDPE and olive husk flour (OHF. The problem of incompatibility between the hydrophilic wood filler and the LDPE hydrophobic matrix was treated by two methods: a chemical modification of the olive husk flour with maleic anhydride to esterify the free hydroxyl groups of the wood components and the use of a compatibilizer agent, i.e. an ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA terpolymer. The changes in the structure, the morphology, and the properties resulting from these treatments were followed by various techniques, especially FTIR spectroscopy, scanning electron microscopy (SEM, tensile measurements and water absorption. The experimental results indicated that both methods, i.e. the chemical treatment of the olive husk flour with maleic anhydride and the inclusion of EBAGMA terpolymer, improved the interactions between the two composite components and promoted better dispersion of the filler in the matrix. Moreover, ultimate tensile properties were also increased. However, the use of EBAGMA terpolymer as compatibilizer produced better enhancement of the properties of LDPE/OHF composites compared to those treated with maleic anhydride.

Structural studies of 4-aminoantipyrine derivatives

Science.gov (United States)

Cunha, Silvio; Oliveira, Shana M.; Rodrigues, Manoel T.; Bastos, Rodrigo M.; Ferrari, Jailton; de Oliveira, Cecília M. A.; Kato, Lucília; Napolitano, Hamilton B.; Vencato, Ivo; Lariucci, Carlito

2005-10-01

Reaction of 4-aminoantipyrine with acetylacetone, ethyl acetoacetate, benzoyl isothiocyanate, phenyl isothiocyanate, maleic anhydride and methoxymethylene Meldrum's acid afforded a series of new antipyrine derivatives. The antibacterial activity of the synthesized compounds against Micrococcus luteus ATCC 9341, Staphilococcus aureus ATCC 29737, and Escherichia coli ATCC 8739 was evaluated and the minimal inhibitory concentration determined. Modest activity was found only to the maleamic acid obtained from the reaction of 4-aminoantipyrine and maleic anhydride. 1H NMR investigation of this maleamic acid showed that it is slowly converted to the corresponding toxic maleimide. The structures of three derivatives were determined by X-ray diffraction analysis.

A glassy carbon electrode modified with an amphiphilic, electroactive and photosensitive polymer and with multi-walled carbon nanotubes for simultaneous determination of dopamine and paracetamole

International Nuclear Information System (INIS)

Liu, Ren; Zeng, Xuebiao; Liu, Jingcheng; Luo, Jing; Zheng, Yuanyi; Liu, Xiaoya

2016-01-01

The article describes an electrochemical sensor for simultaneous determination of dopamine (DA) and paracetamole (PAT). It is based on the use of an electroactive polymer (referred to as BPVCM) to functionalize multi-walled carbon nanotubes. BPVCM is a branched amphiphilic photo-sensitive and electroactive polymer that was obtained by copolymerization of a vinyl benzyl carbazole, maleic acid anhydride, 4-vinyl benzylthiol and a vinylbenzyl oxycoumarin. BPVCM efficiently disperses MWCNT in aqueous solution. The electropolymerization of the carbazole moieties of the BPVCM enhances the current response. It also facilitates electron transfer in the MWCNT-BPVCM hybrid as evidenced by cyclic voltammetry and electrochemical impedance spectroscopy. A glassy carbon electrode modified with the nanocomposite displays outstanding electrocatalytic activity towards DA and PAT. DA can be determined, best at a working voltage of 0.2 V (vs. SCE), in the 5 to 1000 μM concentration range with a 2.3 μM detection limit. PAT can be determined in parallel, at a working voltage of 0.39 V (vs. SCE), in the same concentration range with a 3.5 μM detection limit. This analytical range of this method is wider than that of most alternative methods. (author)

46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and pipe...

Molecular modeling of interactions in electronic nose sensors for environmental monitoring

Science.gov (United States)

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.

Effects of electric fields in polymerization on enthalpy of PMAA anhydridization

Energy Technology Data Exchange (ETDEWEB)

Chang Zhenqi; Liu Gang; Zhang Zhicheng

2004-02-19

PMAA (polymethacrylic acid) polymerized by {gamma}-irradiation in electric field forms six-membered cyclic anhydride during heating process and the enthalpy of PMAA anhydridization was determined by DSC. Why the endothermic peak of PMAA anhydridization in DSC curve between 200 and 300 deg. C appears is particularly explained by calculation. The relations between applied electric field and the enthalpy of PMAA anhydridization are studied. The results show that, with the increases of the intensity of electric field in polymerization, the enthalpy of PMAA forming anhydrides nonlinearly increase, which might be related to orientation of carboxylic acid groups of the PMAA in an electric field.

Modification of (DGEBA epoxy resin with maleated depolymerised natural rubber

Directory of Open Access Journals (Sweden)

2008-04-01

Full Text Available In this work, diglycidyl ether of bisphenol A (DEGBA type epoxy resin has been modified with maleated depolymerised natural rubber (MDPR. MDPR was prepared by grafting maleic anhydride onto depolymerised natural rubber. MDPR has been characterized by Fourier transform infrared (FT-IR spectroscopy and nuclear magnetic resonance spectroscopy. MDPR was blended with epoxy resin at three different ratios (97/3, 98/2 and 99/1, by keeping the epoxy resin component as the major phase and maleated depolymerised natural rubber component as the minor phase. The reaction between the two blend components took place between the acid/anhydride group in the MDPR and the epoxide group of the epoxy resin. The proposed reaction schemes were supported by the FT-IR spectrum of the uncured Epoxy/MDPR blends. The neat epoxy resin and Epoxy/MDPR blends were cured by methylene dianiline (DDM at 100°C for three hours. Thermal, morphological and mechanical properties of the neat epoxy and the blends were investigated. Free volume studies of the cured, neat epoxy and Epoxy/MDPR blends were correlated with the morphological and mechanical properties of the same systems using Positron Annihilation Lifetime Studies.

Preparation and characterization of sulfonated amine-poly(ether sulfone)s for proton exchange membrane fuel cell

Energy Technology Data Exchange (ETDEWEB)

Seo, Dong-Wan; Lim, Young-Don; Lee, Soon-Ho; Jeong, Young-Gi; Kim, Whan-Gi [Department of Applied Chemistry/RIC-ReSEM, Konkuk University, Chungju-si, Chungbuk 380-701 (Korea, Republic of); Hong, Tae-Whan [Department of Materials Sci and Engineering/RIC-ReSEM, Chungju National University, Chungju, Chungbuk (Korea, Republic of)

2010-12-15

Sulfonated amine-poly(ether sulfone)s (S-APES)s were prepared by nitration, reduction and sulfonation of poly(ether sulfone) (ultrason {sup registered} -S6010). Poly(ether sulfone) was reacted with ammonium nitrate and trifluoroacetic anhydride to produce the nitrated poly(ether sulfone), and was followed by reduction using tin(II)chloride and sodium iodide as reducing agents to give the amino-poly(ether sulfone). The S-APES was obtained by reaction of 1,3-propanesultone and the amino-poly(ether sulfone) (NH{sub 2}-PES) with sodium methoxide. The different degrees of nitration and reduction of poly(ether sulfone) were successfully synthesized by an optimized process. The reduction of nitro group to amino was done quantitatively, and this controlled the contents of the sulfonic acid group. The films were converted from salt to acid forms with dilute hydrochloric acid. Different contents of sulfonated unit of the S-APES were studied by FT-IR, {sup 1}H NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion exchange capacity (IEC), a measure of proton conductivity, was evaluated. The S-APES membranes exhibit conductivities (25 C) from 1.05 x 10{sup -3} to 4.83 x 10{sup -3} S/cm, water swell from 30.25 to 66.50%, IEC from 0.38 to 0.82 meq/g, and methanol diffusion coefficients from 3.10 x 10{sup -7} to 4.82 x 10{sup -7} cm{sup 2}/S at 25 C. (author)

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

Science.gov (United States)

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

1997-05-01

Damage to the enamel surface during bonding and debonding of orthodontic brackets is a clinical concern. Alternative bonding methods that minimize enamel surface damage while maintaining a clinically useful bond strength is an aim of current research. The purpose of this study was to compare the effects on bond strength and bracket failure location of two adhesives (System 1+ and Scotchbond Multipurpose, 3M Dental Products Division) and two enamel conditioners (37% phosphoric acid and 10% maleic acid). Forty-eight freshly extracted human premolars were pumiced and divided into four groups of 12 teeth, and metal orthodontic brackets were attached to the enamel surface by one of four protocols: (1) System 1+ and phosphoric acid, (2) Scotchbond and phosphoric acid, (3) System 1+ and maleic acid, and (4) Scotchbond and maleic acid. After bracket attachment, the teeth were mounted in phenolic rings and stored in deionized water at 37 degrees C for 72 hours. A Zwick universal testing machine (Zwick GmbH & Co.) was used to determine shear bond strengths. The residual adhesive on the enamel surface was evaluated with the Adhesive Remnant Index. The analysis of variance was used to compare the four groups. Significance was predetermined at p adhesives on the enamel surfaces, revealed significant differences among the four groups (mean 2 = 0.005). A Duncan multiple range test revealed the difference occurred between the phosphoric acid and maleic acid groups, with maleic acid having bond failures at the enamel-adhesive interface. In conclusion, the use of Scotchbond Multipurpose and/or maleic acid does not significantly effect bond strength, however, the use of maleic acid resulted in an unfavorable bond failure location.

QDs Supported on Langmuir-Blodgett Films of Polymers and Gemini Surfactant

Directory of Open Access Journals (Sweden)

T. Alejo

2013-01-01

Full Text Available Different LB films of poly(octadecene-co-maleic anhydride, PMAO, poly(styrene-co-maleic anhydride partial 2 butoxy ethyl ester cumene terminated, PS-MA-BEE, and Gemini surfactant ethyl-bis(dimethyl octadecylammonium bromide, 18-2-18, have been used to study the effect of the substrate coating on the surface self-assembly of CdSe quantum dots (QDs. Results show that all the “coating molecules” avoid the 3D aggregation of QDs observed when these nanoparticles are directly deposited on mica. Different morphologies were observed depending on the molecules used as coatings, and this was related to the surface properties, such as wetting ability, and the morphology of the coating LB films.

Crosslinked poly(vinyl alcohol)/sulfonated poly(ether ether ketone) blend membranes for fuel cell applications - Surface energy characteristics and proton conductivity

Energy Technology Data Exchange (ETDEWEB)

Kanakasabai, P.; Vijay, P.; Deshpande, Abhijit P.; Varughese, Susy [Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India)

2011-02-01

Ionic polymers, their blends and composites are considered potential candidates for application as electrolytes in fuel cells. While developing new materials for membranes, it is important to understand the interactions of these electrolytic materials with electrodes/catalysts and with reactants/products. Some of these interactions can be understood by estimating the surface energy and wettability of the membrane materials. In this work, polyvinyl alcohol with varying degrees of sulfonation and its blend with sulfonated poly(ether ether ketone) are prepared and studied for their wettability characteristics using goniometry. The surface energy and its components are estimated using different approaches and compared. Properties such as the ion-exchange capacity, the proton conductivity and the water sorption/desorption behaviour are also investigated to understand the relationship with wettability and surface energy and its components. Among the different methods, the van Oss acid-base and the modified Berthelot approaches yield comparable estimates for the total surface energy. (author)

Gas-Phase Infrared Spectra of Vinyl Selenol and Vinyl Tellurol

Science.gov (United States)

Benidar, Abdessamad; Khater, Brahim; Guillemin, Jean-Claude; Gámez, José A.; Yáñez, Manuel

2009-10-01

The infrared spectra (3500-500 cm-1) of gaseous vinyl selenol and vinyl tellurol have been recorded at 0.1 cm-1 resolution. For the latter the spectra were obtained at room temperature, but for the former a temperature of -40 °C was required because of the chemical instability of vinyl selenol at room temperature. To compensate the very weak vapor pressure of vinyl tellurol at room temperature, a long optical path up to 136 m was necessary to record its spectrum. B3LYP density functional theory (DFT) calculations have been performed to assign the different absorption bands. Since an unambiguous assignment of the absorption bands requires a precise knowledge on the relative abundance of the syn and gauche rotamers of these compounds, their relative energies and their anharmonic vibrational frequencies were obtained using a very extended Def2-QZVP basis set. Two rotamers, the syn, which is planar, and a nonplanar gauche, were found to be local minima for both compounds. The gauche rotamer presents two degenerate conformers, which differ by the position of the SeH (TeH) hydrogen atom above or below the molecular plane. Our theoretical results are in good agreement with the main features of the experimental spectra. Fundamental bands and some combination bands of vinyl selenol and vinyl tellurol were assigned and compared with those of vinyl alcohol and vinyl thiol, whose spectra had been reported previously in the literature.

Poly(ester-anhydride):poly(beta-amino ester) micro- and nanospheres: DNA encapsulation and cellular transfection.

Science.gov (United States)

Pfeifer, Blaine A; Burdick, Jason A; Little, Steve R; Langer, Robert

2005-11-04

Poly(ester-anhydride) delivery devices allow flexibility regarding carrier dimensions (micro- versus nanospheres), degradation rate (anhydride versus ester hydrolysis), and surface labeling (through the anhydride functional unit), and were therefore tested for DNA encapsulation and transfection of a macrophage P388D1 cell line. Poly(l-lactic acid-co-sebacic anhydride) and poly(l-lactic acid-co-adipic anhydride) were synthesized through melt condensation, mixed with 25 wt.% poly(beta-amino ester), and formulated with plasmid DNA (encoding firefly luciferase) into micro- and nanospheres using a double emulsion/solvent evaporation technique. The micro- and nanospheres were then characterized (size, morphology, zeta potential, DNA release) and assayed for DNA encapsulation and cellular transfection over a range of poly(ester-anhydride) copolymer ratios. Poly(ester-anhydride):poly(beta-amino ester) composite microspheres (6-12 microm) and nanospheres (449-1031 nm), generated with copolymers containing between 0 and 25% total polyanhydride content, encapsulated plasmid DNA (>or=20% encapsulation efficiency). Within this polyanhydride range, poly(adipic anhydride) copolymers provided DNA encapsulation at an increased anhydride content (10%, microspheres; 10-25%, nanospheres) compared to poly(sebacic anhydride) copolymers (1%, microspheres and nanospheres) with cellular transfection correlating with the observed DNA encapsulation.

Water-Soluble Polymers with Strong Photoluminescence through an Eco-Friendly and Low-Cost Route.

Science.gov (United States)

Guo, Zhaoyan; Ru, Yue; Song, Wenbo; Liu, Zhenjie; Zhang, Xiaohong; Qiao, Jinliang

2017-07-01

Photoluminescence (PL) of nonconjugated polymers brings a favorable opportunity for low-cost and nontoxic luminescent materials, while most of them still exhibit relatively weak emission. Strong PL from poly[(maleic anhydride)-alt-(vinyl acetate)] (PMV) from low-cost monomer has been found in organic solvents, yet the necessity of noxious solvents would hinder its practical applications. Herein, through a novel, eco-friendly, and one-step route, PMV-derived PL polymers can be fabricated with the highest quantum yield of 87% among water-soluble nonconjugated PL polymers ever reported. These PMV-derived polymers emit strong blue emission in both solutions and solids, and can be transformed into red-emission agents easily. These PL polymers exhibit application potentials in light-conversion agricultural films. It is assumed that this work not only puts forward a convenient preparation routine for nonconjugated polymers with high PL, but also provides an industrial application possibility for them. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enzyme-Catalyzed Regioselective Modification of Starch Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Soma [Polytechnic Univ., Brooklyn, NY (United States). National Science Foundation (NSF) Center for Biocatalysis and Bioprocessing of Macromolecules, Othmer Dept. of Chemical and Biological Science and Engineering; Sahoo, Bishwabhusan [Polytechnic Univ., Brooklyn, NY (United States). National Science Foundation (NSF) Center for Biocatalysis and Bioprocessing of Macromolecules, Othmer Dept. of Chemical and Biological Science and Engineering; Teraoka, Iwao [Polytechnic Univ., Brooklyn, NY (United States). National Science Foundation (NSF) Center for Biocatalysis and Bioprocessing of Macromolecules, Othmer Dept. of Chemical and Biological Science and Engineering; Miller, Lisa M. [Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source (NSLS); Gross, Richard A. [Polytechnic Univ., Brooklyn, NY (United States). National Science Foundation (NSF) Center for Biocatalysis and Bioprocessing of Macromolecules, Othmer Dept. of Chemical and Biological Science and Engineering

2004-12-13

The selective esterification of starch nanoparticles was performed using as catalyst Candida antartica Lipase B (CAL-B) in its immobilized (Novozym 435) and free (SP-525) forms. The starch nanoparticles were made accessible for acylation reactions by formation of Aerosol-OT (AOT, bis(2-ethylhexyl)sodium sulfosuccinate) stabilized microemulsions. Starch nanoparticles in microemulsions were reacted with vinyl stearate, ε-caprolactone, and maleic anhydride at 40 °C for 48 h to give starch esters with degrees of substitution (DS) of 0.8, 0.6, and 0.4, respectively. Substitution occurred regioselectively at the C-6 position of the glucose repeat units. Infrared microspectroscopy (IRMS) revealed that AOT-coated starch nanoparticles diffuse into the outer 50 μm shell of catalyst beads. Thus, even though CAL-B is immobilized within a macroporous resin, CAL-B is sufficiently accessible to the starch nanoparticles. When free CAL-B was incorporated along with starch within AOT-coated reversed micelles, CAL-B was also active and catalyzed the acylation with vinyl stearate (24 h, 40 °C) to give DS = 0.5. After removal of surfactant from the modified starch nanoparticles, they were dispersed in DMSO or water and were shown to retain their nanodimensions.

Characteristic of Irradiation Result Film of Poly-Propylene-Co-Ethylene/Poly-ε-Caprolactone and Poly-Propylene Grafted Maleic Anhydrate Blend

International Nuclear Information System (INIS)

Nikham

2004-01-01

The effect of gamma rays irradiation to film of melt-blending polypropylene-co-ethylene (CPP) and poly-ε-caprolactone (PCL) with polypropylene grafted maleic anhydride (PP-g-MAH) blend as compatibilizer has been studied. The objective of the research is to prepare the biodegradable polyblend. The composition blend of CPP/PCL with 0, 10, 15, 20 wt % PP-g-MAH i.e. 100/0, 75/25, 50/50, 25/75 and 0/100 were irradiated by using gamma rays 60 Co with activity 420 kCi at doses; 0, 50, 100, 150, 200 kGy, at dose rate 8.2 kGy/hrs and temperature 90 o C. The elongation at break, tensile strength, gel fraction, enzymatic degradation and heat resistance were evaluated. The results showed that the compatibility of PP-g-MAH to reach good enough polyblend is 20 % weight. Elongation at break film of CPP/PCL 50/50 blend which irradiated at dose 200 kGy decreased, whereas the tensile strength increased. Gel fraction and heat resistance of the film irradiated increased. Enzyme of lipase AK can degraded either without irradiated or irradiated film. Thus quality of the polyblend can be called as biodegradable plastic material. (author)

Vinyl Record

DEFF Research Database (Denmark)

Bartmanski, Dominik; Woodward, Ian

2018-01-01

. This relational process means that both the material affordances and entanglements of vinyl allow us to feel, handle, experience, project, and share its iconicity. The materially mediated meanings of vinyl enabled it to retain currency in independent and collector’s markets and thus resist the planned......In this paper, we use the case of the vinyl record to show that iconic objects become meaningful via a dual process. First, they offer immersive engagements which structure user interpretations through various material experiences of handling, use, and extension. Second, they always work via...

Hydrolysis of Acetic Anhydride in a CSTR

Directory of Open Access Journals (Sweden)

Veronica N. Coraci

2016-05-01

Full Text Available To find the optimal reactor volume and temperature for the hydrolysis of acetic anhydride at the lowest possible cost with a 90% conversion of acetic anhydride, a formula for the total cost of the reaction was created. Then, the first derivative was taken to find a value for the temperature. This value was then inputted into the second derivative of the equation to find the sign of the value which would indicate whether that point was a minima or maxima value. The minima value would then be the lowest total cost for the optimum reaction to take place.

Low-Cost and High-Impact Environmental Solutions for Military Composite Structures

Science.gov (United States)

2005-12-15

moduli of UPE polymers are considerably increased when neopentyl glycol is used as the polyol instead of ethylene glycol in the formulations [56...general purpose unsaturated polyester based on phthalic anhydride, ethylene glycol , and maleic anhydride. The VIAPAL 570G was a colorless solid in the...modulus. In this case, the neopentyl center of the Bisphenol A backbone of the VE 828 polymer may be responsible for increased modulus values. The

Trifluoromethanesulfonic Anhydride as a Low-Cost and Versatile Trifluoromethylation Reagent.

Science.gov (United States)

Ouyang, Yao; Xu, Xiu-Hua; Qing, Feng-Ling

2018-04-19

A large number of reagents have been developed for the synthesis of trifluoromethylated compounds. However, an ongoing challenge in trifluoromethylation reaction is the use of less expensive and practical trifluoromethyl sources. We report herein the unprecedented direct trifluoromethylation of (hetero)arenes using trifluoromethanesulfonic anhydride as a radical trifluoromethylation reagent by merging photoredox catalysis and pyridine activation. Furthermore, introduction of both the CF 3 and OTf groups of the trifluoromethanesulfonic anhydride into internal alkynes to access tetrasubstituted trifluoromethylated alkenes was achieved. Since trifluoromethanesulfonic anhydride is a low-cost and abundant chemical, this method provides a cost-efficient and practical route to trifluoromethylated compounds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analisis sifat fisika pemanfaatan pati tandan kosong sawit dan limbah plastik LDPE sebagai bahan pembuatan plastik biodegradabel

Directory of Open Access Journals (Sweden)

Tengku Rachmi Hidayani

2017-06-01

Full Text Available This research aimed to overcome the issue of plastic packaging waste that accumulates in nature because synthetic polymers cannot be easily unraveled by bacteria. Biodegradable plastics were produced by mixing waste of plastics of the low density polyethylene (LDPE with starch of empty palm fruit bunches, modified with the addition of maleic anhydride as a crosslinking agent. To produce biodegradable plastics, different compositions of LDPE waste, starch of empty palm fruit bunch, maleic anhydride, and benzoyl peroxide were used, namely (90: 10: 1: 1, (80: 20: 1: 1, (70: 30: 1: 1, and (60: 40: 1: 1. Research stages consisted of extraction of starch from palm empty fruit bunch (PEFB; preparation of biodegradable plastic powder with the reflux method and xylene solvents; and making of biodegradable plastics using the press molding method. Based on the results of characterization, it was revealed that the optimum condition was generated by biodegradable plastics with the composition of LDPE waste, starch of empty palm bunches, maleic anhydride, and benzoyl peroxide was equal to 60: 40: 1: 1, which generated the tensile strength value of 6.9410 N/m2, the elongation at break of 3.1875%, the the melting point temperature of 103oC, and the decomposition temperature of 384oC. Besides, the thermal gravimetric test generated a residue of 12.6% and results of the analysis on morphological properties suggested that the starch distributed evenly.

Dimethylthioarsinic anhydride: A standard for arsenic speciation

International Nuclear Information System (INIS)

Fricke, Michael; Zeller, Matthias; Cullen, William; Witkowski, Mark; Creed, John

2007-01-01

Dimethylthioarsinic acid (DMTA V ) has recently been identified in biological, dietary and environmental matrices. The relevance of this compound to the toxicity of arsenic in humans is unknown and further exposure assessment and metabolic studies are difficult to conduct because of the unavailability of a well characterized standard. The synthesis of DMTA V was accomplished by the reaction of dimethylarsinic acid (DMA V ) with hydrogen sulfide. The initial reaction product produced is DMTA V but multiple products over the course of the reaction are also observed. Therefore, a chromatographic separation was developed to monitor the reaction progress via LC-ICP-MS. In this synthesis, conversion of DMA V to DMTA V was not taken to completion to avoid the production of side products. The product was isolated from the starting material by standard organic techniques. Single crystal diffraction demonstrated that solid DMTA V is present in the form of the oxygen-bridged dimethylthioarsinic anhydride. Dissolution of the anhydride in water produces the acid form of DMTA V and the aqueous phase DMTA V provided a characteristic molecular ion of m/z 155 by LC-ESI-MS. The synthesis and isolation of dimethylthioarsinic anhydride provides a stable crystalline standard suitable for identification, toxicological study and exposure assessment of dimethylthioarsinic acid

Catalyst activity maintenance study for the liquid phase dimethyl ether process

Energy Technology Data Exchange (ETDEWEB)

Peng, X.D.; Toseland, B.A.; Underwood, R.P. [Air Products and Chemicals, Inc., Allentown, PA (United States)

1995-12-31

The co-production of dimethyl ether (DME) and methanol from syngas is a process of considerable commercial attractiveness. DME coproduction can double the productivity of a LPMEOH process when using coal-derived syngas. This in itself may offer chemical producers and power companies increased flexibility and more profitable operation. DME is also known as a clean burning liquid fuel; Amoco and Haldor-Topsoe have recently announced the use of DME as an alternative diesel fuel. Moreover, DME can be an interesting intermediate in the production of chemicals such as olefins and vinyl acetate. The current APCl liquid phase dimethyl ether (LPDME) process utilizes a physical mixture of a commercial methanol synthesis catalyst and a dehydration catalyst (e.g., {gamma}-alumina). While this arrangement provides a synergy that results in much higher syngas conversion per pass compared to the methanol-only process, the stability of the catalyst system suffers. The present project is aimed at reducing catalyst deactivation both by understanding the cause(s) of catalyst deactivation and by developing modified catalyst systems. This paper describes the current understanding of the deactivation mechanism.

Synthesis and property characterization of cassava starch grafted poly(acrylamide-co-(maleic acid)) superabsorbent via γ-irradiation

International Nuclear Information System (INIS)

Kiatkamjornwong, Suda; Mongkolsawat, Kanlaya; Sonsuk, Manit

2004-01-01

Graft copolymerizations of acrylamide and maleic acid onto cassava starch by a simultaneous irradiation technique using γ-rays as a initiator were carried out. Various important parameters of total dose, dose rate, monomer-to-cassava starch ratio and maleic acid content were studied. Addition of 2% ww -1 diprotic acid of maleic acid into the reaction mixture yields a saponified starch graft copolymer with a water absorption in distilled water as high as 2256g g -1 of its dried weight. The water absorption of these saponified graft copolymers insaline and buffer solutions was also measured. The water absorption depends largely on the cationic type and concentration of these solutions in terms of ionic strength. This research explains a charge transfer mechanism for graft copolymerization of maleic acid and acrylamide onto cassava starch, and describes the influential parameters that affect grafting efficiency and water absorption. (author)

Nicotine-selective radiation-induced poly(acrylamide/maleic acid) hydrogels

International Nuclear Information System (INIS)

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

2001-01-01

Nicotine-selective poly(acrylamide/maleic acid) (AAm/MA) hydrogels prepared by γ-irradiation were used in experiments on swelling, diffusion, and interactions of the pharmaceuticals nicotine, nicotinic acid, nicotinamide, and nikethamide. For AAm/MA hydrogel containing 60 mg maleic acid and irradiated at 5.2 kGy, the studies indicated that swelling increased in the following order; nicotine>nicotinamide>nikethamide>nicotinic acid>water. Diffusions of water and the pharmaceuticals within the hydrogels were found to be non-Fickian in character. AAm/MA hydrogel sorbed only nicotine and did not sorb nicotinamide, nikethamide and nicotinic acid in the binding experiments. S-type adsorption in Giles's classification system was observed. Some binding and thermodynamic parameters for AAm/MA hydrogel-nicotine system were calculated using the Scatchard method. The values of adsorption heat and free energy of this system were found to be negative whereas adsorption entropy was found to be positive. (author)

Novel synthesis on poly (vinyl alcohol): characterization, complexation a biological activity

International Nuclear Information System (INIS)

El-Sawy, N.M.; Elassar, A.Z.; Al-Fulaij, O.

2002-01-01

Poly(vinyl alcohol), PVA, readily condensed with phenyl hydrazine and malononitrile in basic medium to give the hydrazone and pyran derivatives, respectively. PVA reacted with chloroacetonitrile, biuet and thiophene carbonyl chloride to give modified polymeric materials. While addition of PVA to acrylonitrile and phenyl isothiocyanate gives the ether and thiocarbamate ester derivatives, respectively. Hydroxylamine hydrochloride reacted with the modified, carbonitrile containing, polymer to give the amidoxime derivative. The amidoximated products of PVA and carbamate ester of polymeric material were complexed with CUCL2 solution. The complex materials were confirmed by using UV and ESDS measurements. The morphology of PVA and complex with CUII was observed by SEM. Biological activity of some of the prepared compounds was investigated toward bacteria and fungi

Process for hardening an alkyd resin composition using ionizing radiation. [electron beams, gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Watanabe, T; Murata, K; Maruyama, T

1969-11-27

In an alkyd resin composition having free hydroxide radicals and containing a conjugated unsaturated fatty acid and/or oil as a component thereof, a process for hardening an alkyd resin composition comprises the steps of dissolving into a vinyl monomer, the product obtained by the semi-esterification reaction of said hydroxide radicals with acid anhydrides having polymerizable radicals and hardening by ionizing radiation to provide a coating with a high degree of cross-linking, with favorable properties such as toughness, hardness, chemical resistance and resistance to weather and with the feasibility of being applied as the ground and finish coat on metals, wood, paper, outdoor construction or the like. Any kind of ionization radiation, particularly accelerated electron beams, ..gamma.. radiation can be used at 50/sup 0/C to -5/sup 0/C for a few seconds or minutes, permitting continuous operation. In one example, 384 parts of phthalic anhydride, 115 parts of pentaerythritol, 233 parts of trimethylol ethane, 288 parts of tung fatty acid and 49 parts of para-tertiary-butyl benzoic acid are mixed and heated with 60 parts of xylene to an acid value of 12. In addition, 271 parts of maleic anhydride and 0.6 parts of hydroquinone are admixed with the content and heated to terminate the reaction. 100 parts of a 50% stylene solution of this alkyd resin are mixed with 1 part of a 60% toluene solution of cobalt naphthenate, and then coated on a glass plate and irradiated with high energy electron beams of 300 kV with a dose of 5 Mrad for 1 sec.

Curing behaviors and properties of an extrinsic toughened epoxy/anhydride system and an intrinsic toughened epoxy/anhydride system

International Nuclear Information System (INIS)

Fan, Mengjin; Liu, Jialin; Li, Xiangyuan; Cheng, Jue; Zhang, Junying

2013-01-01

Highlights: ► Two curing systems (ETRS and ITRS) with similar chemical composite were prepared. ► The curing kinetics of the ETRS and the novel ITRS were comparatively studied. ► Crosslinking density can affect the kinetic schemes of the two curing systems. ► Their mechanical properties and thermal stabilities were also comparatively studied. ► Crosslinking density may play an influential role in mechanical properties. - Abstract: The curing kinetics of an extrinsic toughened epoxy (mixture of diglycidyl ether of bisphenol-A and 1,4-butanediol epoxy resin, DGEBA/DGEBD) and an intrinsic toughened epoxy (ethoxylated bisphenol-A epoxy resin with two oxyethylene units, DGEBAEO-2) using hexahydrophthalic anhydride (HHPA) as curing agent and tris-(dimethylaminomethyl) phenol (DMP-30) as accelerator were comparatively studied by non-isothermal DSC with a model-fitting Málek approach and a model-free advanced isoconversional method of Vyazovkin. The dynamic mechanical properties and thermal stabilities of the cured materials were investigated by DMTA and TGA, respectively. The results showed that Šesták–Berggren model can generally simulate well the reaction rates of these two systems. The activation energy of DGEBA/DGEBD/HHPA/DMP-30 at high fractional conversion changed much higher than that of DGEBAEO-2/HHPA/DMP-30, indicating the increased steric hindrance mainly affected the reaction kinetic scheme of DGEBA/DGEBD/HHPA/DMP-30. The T g and storage moduli of cured DGEBAEO-2/HHPA/DMP-30 were lower than those of cured DGEBA/DGEBD/HHPA/DMP-30 according to DMTA while TGA showed that the thermal stabilities of these two cured systems were similar

Curing behaviors and properties of an extrinsic toughened epoxy/anhydride system and an intrinsic toughened epoxy/anhydride system

Energy Technology Data Exchange (ETDEWEB)

Fan, Mengjin; Liu, Jialin; Li, Xiangyuan [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Cheng, Jue, E-mail: chengjue@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Junying, E-mail: zjybuct@gmail.com [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

2013-02-20

Highlights: ► Two curing systems (ETRS and ITRS) with similar chemical composite were prepared. ► The curing kinetics of the ETRS and the novel ITRS were comparatively studied. ► Crosslinking density can affect the kinetic schemes of the two curing systems. ► Their mechanical properties and thermal stabilities were also comparatively studied. ► Crosslinking density may play an influential role in mechanical properties. - Abstract: The curing kinetics of an extrinsic toughened epoxy (mixture of diglycidyl ether of bisphenol-A and 1,4-butanediol epoxy resin, DGEBA/DGEBD) and an intrinsic toughened epoxy (ethoxylated bisphenol-A epoxy resin with two oxyethylene units, DGEBAEO-2) using hexahydrophthalic anhydride (HHPA) as curing agent and tris-(dimethylaminomethyl) phenol (DMP-30) as accelerator were comparatively studied by non-isothermal DSC with a model-fitting Málek approach and a model-free advanced isoconversional method of Vyazovkin. The dynamic mechanical properties and thermal stabilities of the cured materials were investigated by DMTA and TGA, respectively. The results showed that Šesták–Berggren model can generally simulate well the reaction rates of these two systems. The activation energy of DGEBA/DGEBD/HHPA/DMP-30 at high fractional conversion changed much higher than that of DGEBAEO-2/HHPA/DMP-30, indicating the increased steric hindrance mainly affected the reaction kinetic scheme of DGEBA/DGEBD/HHPA/DMP-30. The T{sub g} and storage moduli of cured DGEBAEO-2/HHPA/DMP-30 were lower than those of cured DGEBA/DGEBD/HHPA/DMP-30 according to DMTA while TGA showed that the thermal stabilities of these two cured systems were similar.

Polyisobutenylsuccinimides as detergents and dispersants in fuel: infrared spectroscopy application

Energy Technology Data Exchange (ETDEWEB)

Aleman-Vazquez, L.O.; Villagomez-Ibarra, J.R. [Instituto Mexicano del Petrole, San Bartolo Atepehuacan (Mexico). Gerencia de Productos Quimicos

2001-05-01

Polyalkenylsuccinimides were synthesized and their dispersancy properties evaluated in an internal combustion engine. The synthesis is based on the reaction of polyisobutene with maleic anhydride as the first step. The polyisobutenylsuccinic anhydride obtained reacts with primary amines in the last step to give polyalkenylsuccinimides. The results of the evaluations showed that some polyisobutenylsuccinimides reduce the deposit formation in the intake system with good efficiency. Infrared spectra of the prepared compounds allowed their identification. 16 refs., 2 tabs.

Bridging adhesion and barrier properties with functional dispersions : towards waterborne anti-corrosion coatings

NARCIS (Netherlands)

Soer, W.J.

2008-01-01

The successful preparation of waterborne anti-corrosion coatings based on maleic anhydride containing copolymers is described in this thesis. To obtain good anticorrosion coatings, three different properties should be present in a coating system; they should display good mechanical properties, good

SHORT COMMUNICATION SOLVENT FREE PREPARATION OF N ...

African Journals Online (AJOL)

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KEYWORDS: Solvent free, Maleanilic acids, Maleic anhydride, Aniline derivatives ... associated with the carboxylic group between 3275-2877 cm-1, the weak –NH .... Chemical shifts (σ/ppm) relative to TMS*. O-H N-H Ha. Hb. Hc. Hd. He. Hf.

Preparation of Thermoplastic Poly (vinyl Alcohol), Ethylene Vinyl Acetate and Vinyl Acetate Versatic Ester Blends for Exterior Masonry Coating

International Nuclear Information System (INIS)

EL-Nahas, H.H.; Gad, Y.H.; Magida, M.M.

2013-01-01

Blend systems including ethylene vinyl acetate (EVA), poly (vinyl alcohol) (PVA) and vinyl acetate versatic copolymer latex (VAcVe) were prepared and used as exterior coatings. Mechanical and thermal properties of the blends were investigated using a testo meter, shore hardness tester, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The water resistance of the samples was measured. Effect of ionizing irradiation on gel content, tensile strength and surface hardness were also followed. The blend offers binder base for exterior masonry coating systems having superior water resistant and mechanical properties

Selective biocatalytic acylation studies on 5′-O-(4,4′-Dimethoxytrityl)-2′,3′-Secouridine

DEFF Research Database (Denmark)

Singh, Sunil K.; Reddy, L. Chandrashekhar; Srivastava, Smriti

2012-01-01

Lipozyme® TL IM (Theremomyces lanuginosus lipase immobilized on silica) in toluene catalyzes the acylation of the 2( )'-OH over the 3( )'-OH group in 5( )'-O-(4,4( )'-dimethoxytrityl)-2( )',3( )'-secouridine (5( )'-O-DMT-2( )',3( )'-secouridine) in a highly selective fashion in moderate to almost...... quantitative yields. The turn over during benzoyl transfer reactions mediated by vinyl benzoate or benzoic anhydride was faster than in acyl transfer reactions with vinyl acetate or C(1) to C(5) acid anhydrides; except in the case of butanoic anhydride. The 2( )'-O-benzoyl-5( )'-O-DMT-2( )',3( )'-secouridine...

Preparation and Surface Sizing Application of Sizing Agent Based on Collagen from Leather Waste

Directory of Open Access Journals (Sweden)

Xuechuan Wang

2015-09-01

Full Text Available Collagen extracted from leather waste was modified with maleic anhydride. Then, using ammonium persulfate as an initiator, by pre-modifying collagen reacted with styrene and ethyl acrylate monomers, a vinyl-grafted collagen sizing agent (VGCSA for paper was prepared. Before the experiment, the performance of VGCSA was tested and VGCSA emulsion was applied to the surface sizing of the corrugated paper. Effects of the amount of VGCSA, the compound proportion of VGCSA, and starch and styrene-acrylic emulsion were studied relative to paper properties. The morphological changes of the paper before and after sizing were characterized by SEM. It was found that the collagen reacted with styrene and ethyl acrylate monomers. Through the grafting of vinyl and collagen, the crystallinity and thermal stability of VGCSA increased. The structure of VGCSA was spherical with a uniform size, and the average particle size was approximately 350 to 400 nm. After being sized, the surface fibers of paper became smooth and orderly. The optimal sizing of VGCSA was 8 g/m2. The optimal proportion of VGCSA with starch was 4:6, and the optimal proportion of VGCSA with SAE was 2:8. The research indicates that collagen extracted from leather waste could be used as a biomaterial, and environmental and economic benefits could be created as well.

Dimethylthioarsinic anhydride: A standard for arsenic speciation

Energy Technology Data Exchange (ETDEWEB)

Fricke, Michael [United States Environmental Protection Agency, National Exposure Research Laboratory, Microbiological and Chemical Exposure Assessment Research Division, 26 W. Martin Luther King Drive, Cincinnati, OH 45268 (United States); Zeller, Matthias [STaRBURSTT-Cyberdiffraction Consortium, Department of Chemistry, Youngstown State University, One University Plaza, Youngstown, OH 44555-3663 (United States); Cullen, William [Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada); Witkowski, Mark [Food and Drug Administration, Forensic Chemistry Center, Vibrational Spectroscopy Laboratory, 6751 Steger Drive, Cincinnati, OH 45237 (United States); Creed, John [United States Environmental Protection Agency, National Exposure Research Laboratory, Microbiological and Chemical Exposure Assessment Research Division, 26 W. Martin Luther King Drive, Cincinnati, OH 45268 (United States)]. E-mail: creed.jack@epa.gov

2007-01-30

Dimethylthioarsinic acid (DMTA{sup V}) has recently been identified in biological, dietary and environmental matrices. The relevance of this compound to the toxicity of arsenic in humans is unknown and further exposure assessment and metabolic studies are difficult to conduct because of the unavailability of a well characterized standard. The synthesis of DMTA{sup V} was accomplished by the reaction of dimethylarsinic acid (DMA{sup V}) with hydrogen sulfide. The initial reaction product produced is DMTA{sup V} but multiple products over the course of the reaction are also observed. Therefore, a chromatographic separation was developed to monitor the reaction progress via LC-ICP-MS. In this synthesis, conversion of DMA{sup V} to DMTA{sup V} was not taken to completion to avoid the production of side products. The product was isolated from the starting material by standard organic techniques. Single crystal diffraction demonstrated that solid DMTA{sup V} is present in the form of the oxygen-bridged dimethylthioarsinic anhydride. Dissolution of the anhydride in water produces the acid form of DMTA{sup V} and the aqueous phase DMTA{sup V} provided a characteristic molecular ion of m/z 155 by LC-ESI-MS. The synthesis and isolation of dimethylthioarsinic anhydride provides a stable crystalline standard suitable for identification, toxicological study and exposure assessment of dimethylthioarsinic acid.

Graft polymerization of vinyl acetate onto starch. Saponification to starch-g-poly(vinyl alcohol)

International Nuclear Information System (INIS)

Fanta, G.F.; Burr, R.C.; Doane, W.M.; Russell, C.R.

1979-01-01

Graft polymerizations of vinyl acetate onto granular cornstarch were initiated by cobalt-60 irradiation of starch-monomer-water mixtures, and ungrafted poly(vinyl acetate) was separated from the graft copolymer by benzene extraction. Conversions of monomer to polymer were quantitative at a radiation dose of 1.0 Mrad. Over half of the polymer was present as ungrafted poly(vinyl acetate) (grafting efficiency less than 50%), and the graft copolymer contained only 34% grafted synthetic polymer (34% add-on). Lower irradiation doses produced lower conversions of monomer to polymer and gave graft copolymers with lower % add-on. Addition of minor amounts of acrylamide, methyl acrylate, and methacrylic acid as comonomers produced only small increases in % add-on and grafting efficency. Grafting efficiency was increased to 70% when a monomer mixture containing about 10% methyl methacrylate was used. Grafting efficiency could be increased to over 90% if the graft polymerization of vinyl acetate--methyl methacrylate was carried out near 0 0 C; although conversion of monomers to polymer was low and grafted polymer contained 40 to 50% poly(methyl methacrylate). Selected graft copolymers were treated with methanolic sodium hydroxide to convert starch-g-poly(vinyl acetate) to starch-g-poly(vinyl alcohol). The molecular weight of the poly(vinyl alcohol) moiety was about 30,000. The solubility of starch-g-poly(vinyl alcohol) in hot water was less than 50; however, solubility could be increased by substituting either acid-modified or hypochlorite-oxidized for unmodified starch in the graft polymerization reaction. Vinyl acetate was also graft polymerized onto acid-modified starch which had been dispersed and partially solubilized by heating in water. A total irradiation dose of either 1.0 or 0.5 Mrad gave starch-g-poly

Maleic acid treatment of biologically detoxified corn stover liquor.

Science.gov (United States)

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

2016-09-01

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

Antitumor activity and systemic effects of PVM/MA-shelled selol nanocapsules in lung adenocarcinoma-bearing mice

International Nuclear Information System (INIS)

De Souza, Ludmilla Regina; Muehlmann, Luis Alexandre; Matos, Lívia Carneiro; Lacava, Zulmira Guerreiro Marques; Báo, Sônia Nair; Azevedo, Ricardo Bentes; Simón-Vázquez, Rosana; González-Fernández, África; De-Paula, Alfredo Maurício Batista; Mosiniewicz-Szablewska, Ewa; Suchocki, Piotr; Morais, Paulo César

2015-01-01

Selol is a semi-synthetic compound containing selenite that is effective against cancerous cells and safer for clinical applications in comparison with other inorganic forms of selenite. Recently, we have developed a formulation of poly(methyl vinyl ether-co-maleic anhydride)-shelled selol nanocapsules (SPN), which reduced the proliferative activity of lung adenocarcinoma cells and presented little deleterious effects on normal cells in in vitro studies. In this study, we report on the antitumor activity and systemic effects induced by this formulation in chemically induced lung adenocarcinoma-bearing mice. The in vivo antitumor activity of the SPN was verified by macroscopic quantification, immunohistochemistry and morphological analyses. Toxicity analyses were performed by evaluations of the kidney, liver, and spleen; analyses of hemogram and plasma levels of alanine aminotransferase, aspartate transaminase, urea, and creatinine; and DNA fragmentation and cell cycle activity of the bone marrow cells. Furthermore, we investigated the potential of the SPN formulation to cause hemolysis, activate the complement system, provoke an inflammatory response and change the conformation of the plasma proteins. Our results showed that the SPN reduced the area of the surface tumor nodules but not the total number of tumor nodules. The biochemical and hematological findings were suggestive of the low systemic toxicity of the SPN formulation. The surface properties of the selol nanocapsules point to characteristics that are consistent with the treatment of the tumors in vivo: low hemolytic activity, weak inflammatory reaction with no activation of the complement system, and mild or absent conformational changes of the plasma proteins. In conclusion, this report suggests that the SPN formulation investigated herein exhibits anti-tumoral effects against lung adenocarcinoma in vivo and is associated with low systemic toxicity and high biocompatibility. (paper)

Gelatin–PMVE/MA composite scaffold promotes expansion of embryonic stem cells

International Nuclear Information System (INIS)

Chhabra, Hemlata; Gupta, Priyanka; Verma, Paul J.; Jadhav, Sameer; Bellare, Jayesh R.

2014-01-01

We introduce a new composite scaffold of gelatin and polymethyl vinyl ether-alt-maleic anhydride (PMVE/MA) for expansion of embryonic stem cells (ESCs) in an in vitro environment. To optimize the scaffold, we prepared a gelatin scaffold (G) and three composite scaffolds namely GP-1, GP-2, and GP-3 with varying PMVE/MA concentrations (0.2–1%) and characterized them by scanning electron microscopy (SEM), swelling study, compression testing and FTIR. SEM micrographs revealed interconnected porous structure in all the scaffolds. The permissible hemolysis ratio and activation of platelets by scaffolds confirmed the hemocompatibility of scaffolds. Initial biocompatibility assessment of scaffolds was conducted using hepatocarcinoma (Hep G2) cells and adhesion, proliferation and infiltration of Hep G2 cells in depth of scaffolds were observed, proving the scaffold's biocompatibility. Further Oct4B2 mouse embryonic stem cells (mESCs), which harbor a green fluorescence protein transgene under regulatory control of the Oct4 promotor, were examined for expansion on scaffolds with MTT assay. The GP-2 scaffold demonstrated the best cell proliferation and was further explored for ESC adherence and infiltration in depth (SEM and confocal), and pluripotent state of mESCs was assessed with the expression of Oct4-GFP and stage-specific embryonic antigen-1 (SSEA-1). This study reports the first demonstration of biocompatibility of gelatin–PMVE/MA composite scaffold and presents this scaffold as a promising candidate for embryonic stem cell based tissue engineering. - Highlights: • Composite scaffolds of gelatin and PMVE/MA were prepared by freeze-drying method. • SEM micrographs showed porous structure in all scaffolds of varying pore dimension. • GP-2 composite exhibited better cellular response in comparison to other scaffolds. • mESCs proliferated and expressed Oct-4 and SSEA-1, when cultured on GP-2 scaffold

Gelatin–PMVE/MA composite scaffold promotes expansion of embryonic stem cells

Energy Technology Data Exchange (ETDEWEB)

Chhabra, Hemlata [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (India); Gupta, Priyanka [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (India); IITB-Monash Research Academy, Mumbai (India); Department of Chemical Engineering, Monash University, Melbourne (Australia); Verma, Paul J. [Turretfield Research Centre, South Australian Research and Development Institute, Rosedale, South Australia (Australia); Jadhav, Sameer; Bellare, Jayesh R. [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai (India)

2014-04-01

We introduce a new composite scaffold of gelatin and polymethyl vinyl ether-alt-maleic anhydride (PMVE/MA) for expansion of embryonic stem cells (ESCs) in an in vitro environment. To optimize the scaffold, we prepared a gelatin scaffold (G) and three composite scaffolds namely GP-1, GP-2, and GP-3 with varying PMVE/MA concentrations (0.2–1%) and characterized them by scanning electron microscopy (SEM), swelling study, compression testing and FTIR. SEM micrographs revealed interconnected porous structure in all the scaffolds. The permissible hemolysis ratio and activation of platelets by scaffolds confirmed the hemocompatibility of scaffolds. Initial biocompatibility assessment of scaffolds was conducted using hepatocarcinoma (Hep G2) cells and adhesion, proliferation and infiltration of Hep G2 cells in depth of scaffolds were observed, proving the scaffold's biocompatibility. Further Oct4B2 mouse embryonic stem cells (mESCs), which harbor a green fluorescence protein transgene under regulatory control of the Oct4 promotor, were examined for expansion on scaffolds with MTT assay. The GP-2 scaffold demonstrated the best cell proliferation and was further explored for ESC adherence and infiltration in depth (SEM and confocal), and pluripotent state of mESCs was assessed with the expression of Oct4-GFP and stage-specific embryonic antigen-1 (SSEA-1). This study reports the first demonstration of biocompatibility of gelatin–PMVE/MA composite scaffold and presents this scaffold as a promising candidate for embryonic stem cell based tissue engineering. - Highlights: • Composite scaffolds of gelatin and PMVE/MA were prepared by freeze-drying method. • SEM micrographs showed porous structure in all scaffolds of varying pore dimension. • GP-2 composite exhibited better cellular response in comparison to other scaffolds. • mESCs proliferated and expressed Oct-4 and SSEA-1, when cultured on GP-2 scaffold.

Autophobicity and layering behavior of thin liquid-crystalline polymer films.

NARCIS (Netherlands)

Wielen, van der M.W.J.; Cohen Stuart, M.A.; Fleer, G.J.

1998-01-01

The stability against breaking-up of thin spin-coated films of liquid-crystalline polymers depends on the film thickness and annealing temperature. This study concerns side-chain liquid-crystalline polymers, based on alternating copolymers of maleic anhydride and mesogenic alkenes. The mesogenic

Solution blow spun nanocomposites of poly(lactic acid)/cellulose nanocrystals from Eucalyptus kraft pulp

Science.gov (United States)

Cellulose nanocrystals (CNCs) were extracted from Eucalyptus kraft pulp by sulfuric acid hydrolysis, and esterified with maleic anhydride (CNCMA). The incorporation of sulfate ester groups on the cellulose surface resulted in higher stability of the nanoparticles in aqueous suspensions and lower the...

76 FR 76259 - National Emissions Standards for Hazardous Air Pollutants: Primary Aluminum Reduction Plants

Science.gov (United States)

2011-12-06

... Emissions From Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene...). The rule is applicable to facilities with affected sources associated with the production of aluminum... are subject to the requirements of this NESHAP: 14 primary aluminum production plants and one carbon...

2,6-di-tert-butylphenylvinyl ether: effect of the unshared oxygen electron pair on the /sup 13/C-/sup 13/C spin-spin interaction constant

Energy Technology Data Exchange (ETDEWEB)

Krivdin, L.B.; Shcherbakov, V.V.; Glukhikh, N.G.; Sigalov, V.M.; Kalabin, G.A.

1987-07-10

Vinyl ethers were prepared by the well-known Favorskii-Shostakovskii method. The purity of the compounds was controlled by GLC and by the PMR and /sup 13/C NMR spectra. The proximity of sp/sup 7/-hybridized unshared pair of oxygen atoms result in a secondary, positive contribution in the constant of spin-spin interaction between neighboring carbon nuclei in the aromatic ring.

Pharmacokinetics of vinyl chloride in the rat

International Nuclear Information System (INIS)

Bolt, H.M.; Laib, R.J.; Kappus, H.; Buchter, A.

1977-01-01

When rats are exposed to [ 14 C]vinyl chloride in a closed system, the vinyl chloride present in the atmosphere equilibrates with the animals' organism within 15 min. The course of equilibration could be determined using rats which had been given 6-nitro-1,2,3-benzothiadiazole. This compound completely blocks metabolism of vinyl chloride. The enzymes responsible for metabolism of vinyl chloride are saturated at an atmospheric concentration of vinyl chloride of 250 ppm. Pharmacokinetic analysis shows that no significant cumulation of vinyl chloride or its major metabolites is to be expected on repeated administration of vinyl chlorides. This may be consistent with the theory that a reactive, shortly living metabolite which occurs in low concentration only, may be responsible for the toxic effects of vinyl chloride

Crystallo-chemistry of boric anhydride and of anhydrous borates

International Nuclear Information System (INIS)

Bernardin, Jacques

1968-01-01

After an overview of various aspects related to the atomic structure of boron and of its three-bind and four-bind compounds, this report briefly presents the different forms of boric anhydride (in solid, liquid, glassy and gaseous state), presents and comments the structure of these different forms, and addresses the molten boric anhydride which is used as oxide solvent. The next part addresses the structure of anhydrous borates. It presents some generalities on their structure, and describes examples of known structures: dimers, trimers, polymers with a degree higher than three like calcium metaborate, caesium tri-borate, lithium tetraborate, or potassium pentaborate

Synthesis and characterization of acrylated Parkia biglobosa ...

African Journals Online (AJOL)

The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum ...

In situ Raman spectroscopy studies of bulk and surface metal

NARCIS (Netherlands)

Weckhuysen, B.M.; Wachs, I.E.; Jehng, J.M.; Deo, G.; Guliants, V.V.; Benziger, J.B.

1996-01-01

Bulk V-P-O and model supported vanadia catalysts were investigated with in situ Raman spectroscopy during n-butane oxidation to maleic anhydride in order to determine the fundamental molecular structure-reactivity/selectivity insights that can be obtained from such experiments. The in situ Raman

Engineering Design Handbook Short Fiber Plastic Base Composites

Science.gov (United States)

1975-07-31

A adduct f. neopentyl glycol g. trimethyl pentanediol a. styrene b. methyl methacrylate c. vinyl toluene Characteristics a. lowest cost...dibasic acid or an unsaturated anhydride with a glycol . Most polyesters include as a third component a saturated dibasic acid or anhydride. The...anhydride, propylene glycol , and styrene monomer are used for lowest cost; isophthalic acid may be added for higher heat resistance and improved

Synthesis and evaluation of water-soluble poly(vinyl alcohol)-paclitaxel conjugate as a macromolecular prodrug

International Nuclear Information System (INIS)

Kakinoki, Atsufumi; Kaneo, Yoshiharu; Tanaka, Tetsuro; Hosokawa, Yoshitsugu

2008-01-01

Paclitaxel (PTX) is an antitumor agent for the treatment of various human cancers. Cremophor EL and ethanol are used to formulate PTX in commercial injection solutions, because of its poor solubility in water. However, these agents cause severe allergic reaction upon intravenous administration. The aim of this study is to synthesize water-soluble macromolecular prodrugs of PTX for enhancing the therapeutic efficacy. Poly (vinyl alcohol) (PVA, 80 kDa), water-soluble synthetic polymer, was used as a drug carrier which is safe and stable in the body. The 2'-hydroxyl group of PTX was reacted with succinic anhydride and then carboxylic group of the succinyl spacer was coupled to PVA via ethylene diamine spacer, resulting the water-soluble prodrug of poly (vinyl alcohol)-paclitaxel conjugate (PVA-SPTX). The solubility of PTX was greatly enhanced by the conjugation to PVA. The release of PTX from the conjugate was accelerated at the neutral to basic conditions in in vitro release experiment. [ 125 I]-labeled PVA-SPTX was retained in the blood circulation for several days and was gradually distributed into the tumorous tissue after intravenous injection to the tumor-bearing mice. PVA-SPTX inhibited the growth of sarcoma 180 cells subcutaneously inoculated in mice. It was suggested that the water-solubility of PTX was markedly enhanced by the conjugation to PVA, and PVA-SPTX effectively delivered PTX to the tumorous tissue due to the enhanced permeability and retention (EPR) effect. (author)

Vinyl Sulfonate/Vinyl Amide Copolymers and Different Surfactants As Suitable Systems in Eorat Higher Temperatures and Salinities Utilisation de mélanges de copolymères vinyl sulfonate/vinyl amide et de différents tensio-actifs en RAP dans des conditions de fortes salinités et de températures élevées

Directory of Open Access Journals (Sweden)

Von Halasz S. P.

2006-11-01

Full Text Available For enhanced oil recovery flooding processes there will be an increasing demand for polymers having high temperature and electrolyte stability. High molecular weight copolymers based on vinyl sulfonate, vinyl amide, and acryl amide show high performances in matching these demanding requirements. Surfactants are also known that are stable under these conditions, resulting in high deoiling rates. The aim of the present article is to demonstrate the influence of alkylphenol ethoxylates and their corresponding ether sulfonates on VS/VA/AM copolymer solutions. Aqueous solutions of such copolymers were added to varying quantities of nonionic and anionic surfactants at different temperatures using salinity scans. This article discusses the results of experiments with solutions of copolymers and surfactants in terms of compatibility, viscosity yield, flow properties, shear stability, injectability, thermostability, and oil recovery. Solutions of alkylphenol ethoxylates and/or ether sulfonates show nearly the same compatibility within a broad range of temperature and salinity, both with and without polymers. Relatively small amounts of surfactants are able to influence the EOR (Enhanced Oil Recovery properties of the polymer solutions, giving several interesting aspects for improved oil recovery. L'utilisation des polymères en récupération assistée du pétrole a fait apparaître un besoin croissant de polymères stables à haute température et à forte salinité. Les performances des terpolymères vinyl sulfonate/vinyl amide/acrylamide (VS/VA/VM ont montré que ces polymères remplissent de tels critères d'utilisation. On connaît également des tensio-actifs chimiquement stables dans ces mêmes conditions qui pourraient donc permettre d'obtenir des taux de récupération d'huile élevés. L'objectif de ce travail est de mettre en évidence l'influence de la présence d'alkylphénols éthoxyIates et des éthers sulfonates correspondants sur les

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

International Nuclear Information System (INIS)

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

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. (paper)

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

Science.gov (United States)

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

Alanine/epr pellet dosimeter using poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) copolymer as a binder for radiation dosimetry

International Nuclear Information System (INIS)

Beshir, W.B.; Ezz El-Din, H.M.; Abdel-fatth, A.A.; Ebraheem, S.

2005-01-01

A new alanine pellet dosimeter was developed for gamma and electron beam radiation dosimetry. Alanine powder was mixed with a new binding material, poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) copolymer. Pellets were prepared by pressing fine powder alanine with 60% copolymer binder by using hydraulic press and a specially designed pressing die. The radiation-formed stable free radicals were analysed by using electron paramagnetic resonance (EPR) spectroscopy. The useful dose range of these pellets was found to ranges from 1 to 80 kGy. The stability of the radiation- induced response was also studied

Microbial reductive dehalogenation of vinyl chloride

Science.gov (United States)

Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Nannhein, DE; Meshulam-Simon, Galit [Los Altos, CA; McCarty, Perry L [Stanford, CA

2011-11-22

Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

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

Science.gov (United States)

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

2017-07-01

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

Safe design and operation of fluidized-bed reactors: Choice between reactor models

NARCIS (Netherlands)

Westerink, E.J.; Westerterp, K.R.

1990-01-01

For three different catalytic fluidized bed reactor models, two models presented by Werther and a model presented by van Deemter, the region of safe and unique operation for a chosen reaction system was investigated. Three reaction systems were used: the oxidation of benzene to maleic anhydride, the

Switchgrass (Panicum virgatum L.) as a reinforcing fibre in polypropylene composites

NARCIS (Netherlands)

Oever, van den M.J.A.; Elbersen, H.W.; Keijsers, E.R.P.; Gosselink, R.J.A.; Klerk-Engels, de B.

2003-01-01

In this study the switchgrass (Panicum virgatum L.), a biomass crop being developed in North America and Europe, was tested as a stiffening and reinforcing agent in polypropylene (PP) composites with and without maleic anhydride grafted PP (MAPP) as a compatibiliser and to evaluate the effect of

Surface Polymerisation Methods for Optimised Adhesion

DEFF Research Database (Denmark)

Drews, Joanna Maria

Arbejdet har fokuseret på muligheder for at forstærke kompositmaterialer til højteknologiske anvendelser fx til vindmøllevinger. Forskningen har derfor været centreret om plasma polymerisation af henholdsvis maleic anhydrid (MAH) og 1,2-methylenedioxybenzen til tynde film på modelkulstofsubstrate...

78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

Science.gov (United States)

2013-12-18

..., Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs.; Tolerance Exemption... an exemption from the requirement of a tolerance for residues of tall oil, polymer with polyethylene..., polymer with polyethylene glycol and succinic anhydride monopolyisobutylene derivs. on food or feed...

Electrical resistivity and thermal properties of compatibilized multi-walled carbon nanotube/polypropylene composites

Directory of Open Access Journals (Sweden)

A. Szentes

2012-06-01

Full Text Available The electrical resistivity and thermal properties of multi-walled carbon nanotube/polypropylene (MWCNT/PP composites have been investigated in the presence of coupling agents applied for improving the compatibility between the nanotubes and the polymer. A novel olefin-maleic-anhydride copolymer and an olefin-maleic-anhydride copolymer based derivative have been used as compatibilizers to achieve better dispersion of MWCNTs in the polymer matrix. The composites have been produced by extrusion followed by injection moulding. They contained different amounts of MWCNTs (0.5, 2, 3 and 5 wt% and coupling agent to enhance the interactions between the carbon nanotubes and the polymer. The electrical resistivity of the composites has been investigated by impedance spectroscopy, whereas their thermal properties have been determined using a thermal analyzer operating on the basis of the periodic thermal perturbation method. Rheological properties, BET-area and adsorption-desorption isotherms have been determined. Dispersion of MWCNTs in the polymer has been studied by scanning electron microscopy (SEM.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

... glass slides coated with polyvinyl alcohol (PVA) crosslinked with maleic anhydride (MA). FTIR and XRD studies of the coated film were also done. AFM studies further helped in the morphological study of the film deposited. Finally, conductivity and ammonia gas-sensing property of the polyaniline film were also studied.

C S Sanmathi

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. C S Sanmathi. Articles written in Bulletin of Materials Science. Volume 27 Issue 3 June 2004 pp 243-249 Polymers. Terpolymerization of 2-ethoxy ethylmethacrylate, styrene and maleic anhydride: determination of the reactivity ratios · C S Sanmathi S Prasannakumar B S ...

Synthesis and 1,3-Dipolar Cycloaddition Reactions of Chiral Maleimides

Directory of Open Access Journals (Sweden)

Lubor Fisera

1997-02-01

Full Text Available New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino acids 3a-f in the presence of Et3N with release of furan to give the requisite novel chiral imides 4a-f in good to moderate yields. The stereoselectivity of 1,3-dipolar cycloaddition of nitrile oxides with prepared chiral imides 4a-f is investigated.

Fire and heat resistant laminating resins based on maleimido substituted aromatic cyclotriphosphazene polymer

Science.gov (United States)

Kumar, Devendra (Inventor); Fohlen, George M. (Inventor); Parker, John A. (Inventor)

1987-01-01

4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g., hexakis amino or trisaminophenoxy trisphenoxy cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketones and Linear Poly(ether ketones

Directory of Open Access Journals (Sweden)

Atsushi Morikawa

2016-02-01

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

Acetylation of wood components and fourier transform infra-red ...

African Journals Online (AJOL)

In this study, the reactivity of wood components with acetic anhydride or vinyl acetate was studied. It was found that the reactivity of wood components was virgin wood flour > holocellulose >> a-cellulose. Acetylation of Turkish pine or cedar wood flour with acetic anhydride was significantly improved in the presence of ...

Gamma radiolysis and vinyl esters

International Nuclear Information System (INIS)

De Bruyn, H.; Balic, R.; Gilbert, R.G.

1998-01-01

The principle behind γ relaxation of free-radical polymerizations is that the source of initiating radicals can be switched off 'instantaneously'. In the absence of initiating radicals the only kinetic events remaining are propagation, transfer and termination. For monomers whose propagation rate coefficients have been determined, relaxation behaviour can be interpreted to determine radical-loss rate coefficients and test models of loss mechanisms. This technique has been employed successfully on styrene and MMA emulsion polymerizations. In the present study, vinyl acetate and vinyl neo-decanoate (a ten-carbon-branched homologue of vinyl acetate) were studied, with the propagation rate coefficients for both monomers being established by pulsed-laser polymerization. Both were found to exhibit rapid γ relaxation rates in emulsion polymerization. This is a surprising result because mechanisms for rapid relaxation in emulsion polymerizations require that chain transfer to monomer (which is rapid for both monomers) is followed by exit from the particle into the aqueous phase with subsequent re-entry into a radical-containing particle leading to bimolecular termination. It is not unreasonable to suppose that this may be possible for vinyl acetate which is fairly water soluble (∼0.3 M). However, vinyl neo-decanoate is virtually insoluble (∼0.00004 M) and hence desorption is extremely unlikely. The most likely explanation for the observed rapid relaxations is that some of the radicals produced by γ radiolysis are slow to initiate vinyl esters and hence act as radical traps. As vinyl esters are known to be particularly unreactive monomers. it is feasible that this experimental artifact affects them to a much greater extent than some of the monomers studied successfully with this technique in the past

Numerical analysis of spray characteristics of dimethyl ether and diethyl ether fuel

International Nuclear Information System (INIS)

Mohan, Balaji; Yang, Wenming; Yu, Wenbin; Tay, Kun Lin

2017-01-01

Highlights: • Thermo-physical properties of liquid DME and DEE are reported. • Ether fuels tend to cavitate higher compared to that of diesel fuel. • Spray tip penetration and SMD are found to be lesser for ether fuels. • Ether fuels shows excellent atomization behavior. - Abstract: In this work, the spray characteristics of ether fuels such as dimethyl ether (DME) and diethyl ether (DEE) have been numerically investigated using KIVA-4 CFD code. A new hybrid spray model developed by coupling the standard KHRT model to cavitation sub model was used. The detailed thermo-physical properties of ether fuels have been predicted and validated with experimental results available from literature. The cavitation inception inside the injector nozzle hole has been studied for ether fuels in comparison with diesel fuel. It was found that ether fuels cavitates higher compared to that of conventional diesel fuel because of its low viscosity. The spray tip penetration of diesel fuel was longer than that of ether fuels due to high viscosity and density of diesel fuel. Ether fuels characterized by low Ohnesorge number and high Reynolds number showed better atomization behavior compared to that of the diesel fuel.

Synthesis and Characterization of New ‎Copolymers as Asphalt Additives

Directory of Open Access Journals (Sweden)

Firyal M. ‎ A

2017-12-01

Full Text Available Rheological properties of asphalt S50  were improved by adding different prepared copolymers as additives with high homogeneity of asphalts  samples.  Three types of copolymers were prepared  Poly  (Indene –Co- maleic anhydride(A1 Poly (Acrylonitrile –Co- Maleic anhydride (A2 and Poly (Dipentine –Co-Maleic anhydride (A3, the cross linking of (A3 to (A3d. by using sulfur.              These copolymers  were designed by inserting Maleic anhydride as  rings  containing through backbone of polymer chains to be high potentially to react with water to protect the crack of pavement .And moisture with inhibit bonding of crack of pavement, Many factors should be considered when prepared the additives to enhanced performance to be convenience cost, beneficial thermal safety ,   extended life of the asphalt, preparing conditions which gave high thermal resistance with more stabilities, all these prepared copolymer have been characterized by FTIR and H-NMR spectroscopies .Intrinsic viscosities were calculated. softening point and penetration were observed for all asphalts blends which were  compared with the  asphalt samples, which gave high thermal resistance with more stabilities.                                          The results  showed high properties of these blends when  compared with the original asphalt. The physical properties of a specific polymers are determined by the sequence and chemical structure , When polymers are added to asphalt , the properties of the modified asphalt cement depend on polymer characteristic of asphalt and compatibility of polymer with asphalt. All these prepared copolymers were tested by softening points and penetration for all  asphalt blends which were compared with the asphalt sample. All the Improvements made by adding polymers to asphalt included the Increasing the viscosity of the binder service, the thermal susceptibility of the binder

Preparation of Syndiotactic Poly(vinyl alcohol)/Poly(vinyl pivalate/vinyl acetate) Microspheres with Radiopacity Using Suspension Copolymerization and Saponification

Science.gov (United States)

Seok Lyoo, Won; Wook Cha, Jin; Young Kwak, Kun; Jae Lee, Young; Yong Jeon, Han; Sik Chung, Yong; Kyun Noh, Seok

2010-06-01

To prepare Poly(vinyl pivalate/vinyl acetate) [P(VPi/VAc)] microspheres with radiopacity, the suspension copolymerization approach in the presence of aqueous radiopaque nanoparticles was used. After, The P(VPi/VAc) microspheres with radiopacity were saponified in heterogeneous system, and then P(VPi/VAc) microspheres without aggregates were converted to s-PVA/P(VPi/VAc) microspheres of skin/core structure through the heterogeneous surface saponification. Radiopacity of microspheres was confirmed with Computed tomography (CT).

Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

Science.gov (United States)

Homogeneous modification of cellulose with succinic anhydride was performed in tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU) and TBAA dosage were investigated as paramete...

Effect of boron and phosphate compounds on physical, mechanical, and fire properties of wood-polypropylene composites

Science.gov (United States)

Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Umit Buyuksari; Zeki Candan; Erkan Avci

2012-01-01

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites incorporated with different contents of boron compounds; borax/boric acid and zinc borate, and phosphate compounds; mono and diammonium phosphates were investigated. The effect of the coupling agent content, maleic anhydride-grafted polypropylene, on the properties of...

Amine modified polyethylenes, prepared in near critical propane, as adhesion promoting agents in multilayered HDPE/PET films

NARCIS (Netherlands)

Gooijer, de J.M.; Scheltus, M.; Koning, C.E.

2001-01-01

High d. polyethylene (HDPE) grafted with 0.13, 0.40 and 1.04 wt% maleic anhydride (abbreviation PEMA) was modified with an excess of a variety of diamines in near crit. propane. The resulting amic acid groups were quant. imidized to the corresponding imide (PEMI) in the melt. Increasing the

Thermochemistry of sarcosine and sarcosine anhydride: Theoretical and experimental studies

International Nuclear Information System (INIS)

Amaral, Luísa M.P.F.; Santos, Ana Filipa L.O.M.; Ribeiro da Silva, Maria das Dores M.C.; Notario, Rafael

2013-01-01

Highlights: ► Study on the Energetics of the sarcosine and sarcosine anhydride. ► Experimental and computational thermochemistry of sarcosine and its anhydride. ► Ab initio calculations for two amino acid derivatives by G3(MP2)//B3LYP method. -- Abstract: The standard molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, of sarcosine, −(388.0 ± 1.0) kJ · mol −1 , and sarcosine anhydride, −(334.5 ± 1.6) kJ · mol −1 , were calculated by combining, for each compound, the standard molar enthalpy of formation, in the crystalline phase, and the standard molar enthalpy of sublimation, derived from measurements of the standard massic energies of combustion by static bomb combustion calorimetry, and from measurements of vapour pressures by the Knudsen mass-loss effusion method, respectively. The standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs functions of sublimation, at T = 298.15 K, were also calculated. A theoretical study at the G3 and G4 levels has been carried out, and the calculated enthalpies of formation have been compared with the experimental ones

High performance oligomers: synthesis and photochemical properties of calix(n)arene containing various photoreactive groups

International Nuclear Information System (INIS)

Nishikubo, T.; Kameyama, A.

1999-01-01

Photoreactive calix(n)arenes containing radical polymerizable (meth)acrylate groups, and catatonically polymerizable vinyl ether, propargyl ether, oxirane and oxetane groups were synthesized by certain reactions of calix(n)arenes with the corresponding (meth)acrylic acid derivatives, vinyl ether compound, epibromohydrin and oxetane derivatives, respectively. The photochemical reaction of these calix(n)arene derivatives were also examined

Development of Transparent Materials Which Reduce Effects of Precipitation Static in Aircraft

Science.gov (United States)

1952-03-01

table shows the acid numbers of some available compounds: Polymer Acid Number Polyacrylic acid 780 Polymethacrylic acid 653 1:1 Styrene-maleic acid ...orthophosphoric acid in polymethyl methacrylate and analogous systems merit further detailed investigation. PUBLICATION REVIEW Manuscript Copy of this report...Resins 74 4.4 Polyacrylic Acid Films 76 4.5 Films of the Ammonium Salt of Styrene- Maleic Acid Copolymer 76 4.6 Imidization 80 4.7 Vinyl Addition 81 4.8

MECHANICAL PROPERTIES OF BLENDS OF PAMAM DENDRIMERS WITH POLY(VINYL CHLORIDE) AND POLY(VINYL ACETATE)

Science.gov (United States)

Hybrid blends of poly(amidoamine) PAMAM dendrimers with two linear high polymers, poly(vinyl chloride), PVC, and poly(vinyl acetate), PVAc, are reported. The interaction between the blend components was studied using dynamic mechanical analysis, xenon nuclear magnetic resonacne ...

Dynamic and Capillary Shear Rheology of Natural Fiber-Reinforced Composites

NARCIS (Netherlands)

Moigne, Le N.; Oever, van den M.J.A.; Budtova, T.

2013-01-01

An extended dynamic and capillary rheological study of molten flax and sisal polypropylene (PP) composites was performed. Fiber concentration varied from 20 to 50 wt% and shear rate from 0.1 rad s−1 to 10,000 s#142;−1. Maleic anhydride-grafted-PP was used as compatibilizer; it strongly reduces PP

Cosmic Ether

CERN Document Server

Tomaschitz, R

1998-01-01

A prerelativistic approach to particle dynamics is explored in an expanding Robertson-Walker cosmology. The receding galactic background provides a distinguished frame of reference and a unique cosmic time. In this context the relativistic, purely geometric space-time concept is criticized. Physical space is regarded as a permeable medium, the cosmic ether, which effects the world-lines of particles and rays. We study in detail a Robertson-Walker universe with linear expansion factor and negatively curved, open three-space; we choose the permeability tensor of the ether in such a way that the semiclassical approximation is exact. Galactic red-shifts depend on the refractive index of the ether. In the local Minkowskian limit the ether causes a time variation of mass, which scales inversely proportional to cosmic time. In the globally geodesic rest frames of galactic observers the ether manifests itself in an unbounded speed of signal transfer, in bifurcations of world-lines, and in time inversion effects.

Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

Science.gov (United States)

Ping-Ping Xin; Yao-Bing Huang; Chung-Yun Hse; Huai N. Cheng; Chaobo Huang; Hui. Pan

2017-01-01

Homogeneous modification of cellulose with succinic anhydride was performed using tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU), TBAA dosage, reaction temperature, and reaction time were investigated. The highest degree of substitution (DS)...

Design of amine modified polymer dispersants for liquid-phase exfoliation of transition metal dichalcogenide nanosheets and their photodetective nanocomposites

Science.gov (United States)

Lee, Jinseong; Hahnkee Kim, Richard; Yu, Seunggun; Babu Velusamy, Dhinesh; Lee, Hyeokjung; Park, Chanho; Cho, Suk Man; Jeong, Beomjin; Sol Kang, Han; Park, Cheolmin

2017-12-01

Liquid-phase exfoliation (LPE) of transition metal dichalcogenide (TMD) nanosheets is a facile, cost-effective approach to large-area photoelectric devices including photodetectors and non-volatile memories. Non-destructive exfoliation of nanosheets using macromolecular dispersing agents is beneficial in rendering the TMD nanocomposite films suitable for mechanically flexible devices. Here, an efficient LPE of molybdenum disulfide (MoS2) with an amine modified poly(styrene-co-maleic anhydride) co-polymer (AM-PSMA) is demonstrated, wherein the maleic anhydrides were converted into maleic imides with primary amines using N-Boc-(CH2) n -NH2. The exfoliation of nanosheets was facilitated through Lewis acid-base interaction between the primary amine and transition metal. The results demonstrate that the exfoliation depends upon both the fraction of primary amines in the polymer chain and their distance from the polymer backbone. Under optimized conditions of primary amine content and its distance from the backbone, AM-PSMA gave rise to a highly concentrated MoS2 nanosheet suspension that was stable for over 10 d. Exfoliation of several other TMDs was also achieved using the optimized AM-PSMA, indicating the scope of AM-PSMA applications. Furthermore, a flexible composite film of AM-PSMA and MoS2 nanosheets fabricated by vacuum-assisted filtration showed excellent photoconductive performances including a high I on/I off ratio of 102 and a fast photocurrent switching of 300 ms.

The Effects of Reaction Variables on Solution Polymerization of Vinyl Acetate and Molecular Weight of Poly(vinyl alcohol Using Taguchi Experimental Design

Directory of Open Access Journals (Sweden)

M.H. Navarchian

2009-12-01

Full Text Available Poly(vinyl acetate is synthesized via solution polymerization, and then it is converted to poly(vinyl alcohol by alkaline alcoholysis. The aim of the work study was to investigate statistically the  influence of reaction variables in vinyl acetate polymerization, the conversion of this monomer to polymer, degree of branching of acetyl group in poly(vinyl acetate, as well as the molecular weight of poly(vinyl alcohol, using Taguchi experimental design approach. The reaction variables were polymerization time, molar ratio of initiator to monomer, and volume ratio of monomer to solvent. The statistical analysis of variance of the results revealed that all factors have significantly influenced the conversion and degree of branching. Volume ratio of monomer to solvent is the only factor affecting the molecular weight of poly(vinyl alcohol, and has the greatest influence on all responses. By increasing this ratio, the conversion, degree of branching of acetyl group in poly(vinyl acetate, and molecular weight of poly(vinyl alcohol were increased.

Preparation, Physical-Chemical Characterization, and Cytocompatibility of Polymeric Calcium Phosphate Cements

Directory of Open Access Journals (Sweden)

Rania M. Khashaba

2011-01-01

Full Text Available Aim. Physicochemical mechanical and in vitro biological properties of novel formulations of polymeric calcium phosphate cements (CPCs were investigated. Methods. Monocalcium phosphate, calcium oxide, and synthetic hydroxyapatite were combined with either modified polyacrylic acid, light activated polyalkenoic acid, or polymethyl vinyl ether maleic acid to obtain Types I, II, and III CPCs. Setting time, compressive and diametral strength of CPCs was compared with zinc polycarboxylate cement (control. Specimens were characterized using X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. In vitro cytotoxicity of CPCs and control was assessed. Results. X-ray diffraction analysis showed hydroxyapatite, monetite, and brushite. Acid-base reaction was confirmed by the appearance of stretching peaks in IR spectra of set cements. SEM revealed rod-like crystals and platy crystals. Setting time of cements was 5–12 min. Type III showed significantly higher strength values compared to control. Type III yielded high biocompatibility. Conclusions. Type III CPCs show promise for dental applications.

Radical coupling of maleic anhydride onto graphite to fabricate ...

Indian Academy of Sciences (India)

graphene is oxidation of graphite to graphene oxide (GO) and subsequently modification of GO with modifiers [5,6]. However, oxidation process is performed under harsh condi- tions with different oxidizing agents such ..... Sci. 87 392. [20] Nakajima T, Žemva B and Tressaud A 2000 Advanced inor- ganic fluorides: synthesis ...

Preparation of poly (vinyl alcohol) membranes grafted with n-vinyl pyridine/ acrylic acid binary monomers

International Nuclear Information System (INIS)

Ajji, A.; Ali, A.

2014-03-01

Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl pyridine. The influence of different parameters on the grafting yield was investigated as: the comonomer concentration and composition, and irradiation dose. The suitable conditions of the process had been determined to prepare PVA membranes have both properties of the two monomers, acrylic acid and vinyl pyridine as comonomer concentration and composition, and irradiation dose. Some properties of the membranes had been investigated as maximum swelling and grafting. Also the ability of the grafted films to adsorb some heavy metals and dyes was elaborated and discussed.(author)

Antimalarial effects of vinyl sulfone cysteine proteinase inhibitors.

OpenAIRE

Rosenthal, P J; Olson, J E; Lee, G K; Palmer, J T; Klaus, J L; Rasnick, D

1996-01-01

We evaluated the antimalarial effects of vinyl sulfone cysteine proteinase inhibitors. A number of vinyl sulfones strongly inhibited falcipain, a Plasmodium falciparum cysteine proteinase that is a critical hemoglobinase. In studies of cultured parasites, nanomolar concentrations of three vinyl sulfones inhibited parasite hemoglobin degradation, metabolic activity, and development. The antimalarial effects correlated with the inhibition of falcipain. Our results suggest that vinyl sulfones or...

Synthesis and characterization of the polystyrene - asphaltene graft copolymer BY FT-IR spectroscopy

International Nuclear Information System (INIS)

Leo, Adan Yovani; Salazar Ramiro

2008-01-01

The creation of new polymer compounds to be added to asphalt has drawn considerable attention because these substances have succeeded in modifying the asphalt rheological characteristics and physical properties for the enhancement of its behavior during the time of use. This work explains the synthesis of a new graft copolymer based on an asphalt fraction called asphaltene, modified with maleic anhydride. Polystyrene functionalization is conducted in a parallel fashion in order to obtain polybenzylamine resin with an amine - NH2 free group that reacts with the anhydride graft groups in the asphaltene, thus obtaining the new Polystyrene/Asphaltene graft copolymer

Influence of polyvinyl alcohol amount on producing in situ photo-crosslinked thioamide functionalized nanofiber membranes

Directory of Open Access Journals (Sweden)

Zeytuncu Bihter

2015-01-01

Full Text Available Poly(vinyl alcohol/maleic anhydride/acryloyl thioamide monomer (PVA/MA/ATM photo-cured nanofiber membranes and pure PVA nanofiber membranes were produced by electrospinning technique. In situ UV radiation was applied during the electrospinning in order to provide polymerization during the jet flight and promote crosslinking of ATM and MA with PVA. The cross-linking was examined by Fourier-transform infrared spectroscopy (FTIR. The morphology and thermal behavior of electrospun nanofiber were characterized by scanning electron microscope (SEM and thermogravimetric analysis (TGA, respectively. The surface area of nanofiber membranes was measured by Brunauer-Emmert-Teller (BET analysis. Furthermore, water durability test was examined. Water durability test demonstrated that in situ photo-cured PVA/MA/ATM nanofiber membrane had the least average mass loss. The surface areas of PVA/MA/ATM nanofiber membranes were 160-280 m2/g. The surface area and diameter of PVA/MA/ATM nanofibers decreased as the PVA content increased. The diameter of nanofibers was obtained less than 100 nm. The results showed that the water-insoluble nanofiber membranes with better chemical and thermal resistance were obtained. These nanofiber membranes may be a promising candidate for the usage of water treatment.

Controlled sulfonation of poly(ether sulfone using phthalic anhydride as catalyst and its membrane performance for fuel cell application

Directory of Open Access Journals (Sweden)

Seikh Jiyaur Rahaman

2016-09-01

Full Text Available Proton exchange membrane (PEM fuel cells are one of the most emerging alternative energy technologies under development. A novel proton exchange membrane sulfonated polyethersulfone (SPES was developed by homogeneous method using phthalic anhydride as catalyst and chlorosulfonic acid as sulfonating agent to control the sulfonation reaction. The method of sulfonation was optimized by varying the reaction time and concentration of the catalyst. The structure of the SPES was studied by 1H-Nuclear Magnetic Resonance, Fourier Transform Infra Red Spectroscopy and X-ray diffraction. The extent of sulfonation was determined by ion exchange capacity studies. The thermal and mechanical stabilities were studied using thermogravimetric analysis (TGA and Dynamic Mechanical Analysis (DMA respectively. DMA results show that the storage modulus increased with increase in degree of sulfonation (DS and water uptake of SPES increased with DS. The proton conductivity of SPES (34% DS measured by impedance spectroscopy was found to be 0.03S/cm at 80%RH and 100°C. Also, current-voltage polarization characteristics of SPES membranes offer a favourable alternative PEM due to the thermal stability and cost effective than perfluorinated ionomers.

Misconceptions about the ether

International Nuclear Information System (INIS)

Duffy, M.C.

1980-01-01

Several misconceptions concerning the ether concept and ether models are reviewed and clarified so that the relationship between modern ether theory and orthodox relativity may be better understood. The question of the ether's supposed superfluidity as a concept, and its status in modern physics remains to be answered. (author)

Poly(imide benzimidazole)s for high temperature polymer electrolyte membrane fuel cells

DEFF Research Database (Denmark)

Yuan, Sen; Guo, Xiaoxia; Aili, David

2014-01-01

A series of poly(imide benzimidazole) random copolymers (PIBIs) was synthesized by condensation polymerization of biphenyl-4,4'-diyldi(oxo)-4,4'-bis(1,8-naphthalenedicarboxylic anhydride) (BPNDA), 2-(4-aminophenyl)-5-aminobenzimidazole (APABI) and 4,4'diaminodiphenyl ether (ODA) in m-cresol in th......A series of poly(imide benzimidazole) random copolymers (PIBIs) was synthesized by condensation polymerization of biphenyl-4,4'-diyldi(oxo)-4,4'-bis(1,8-naphthalenedicarboxylic anhydride) (BPNDA), 2-(4-aminophenyl)-5-aminobenzimidazole (APABI) and 4,4'diaminodiphenyl ether (ODA) in m...

Influence of natural fibers on the phase transitions in high-density polyethylene composites using dynamic mechanical analysis

Science.gov (United States)

Mehdi Tajvidi; Robert H. Falk; John C. Hermanson; Colin Felton

2003-01-01

Dynamic mechanical analysis was employed to evaluate the performance of various natural fibers in high-density polyethylene composites. Kenaf, newsprint, rice hulls, and wood flour were sources of fiber. Composites were made at 25 percent and 50 percent by weight fiber contents. Maleic anhydride modified polyethylene was also added at 1:25 ratio to the fiber....

Coir fiber reinforced polypropylene composite panel for automotive interior applications

Science.gov (United States)

Nadir Ayrilmis; Songklod Jarusombuti; Vallayuth Fueangvivat; Piyawade Bauchongkol; Robert H. White

2011-01-01

In this study, physical, mechanical, and flammability properties of coconut fiber reinforced polypropylene (PP) composite panels were evaluated. Four levels of the coir fiber content (40, 50, 60, and 70 % based on the composition by weight) were mixed with the PP powder and a coupling agent, 3 wt % maleic anhydride grafted PP (MAPP) powder. The water resistance and the...

Effects of fire retardants on physical, mechanical, and fire properties of flat-pressed WPCs

Science.gov (United States)

Nadir Ayrilmis; Jan T. Benthien; Heiko Thoemen; Robert H. White

2012-01-01

Physical, mechanical, and fire properties of the flat-pressed wood plastic composites (WPCs) incorporated with various fire retardants (10% by weight) at different levels of wood flour (WF) content, 40, 50, or 60 wt%, were investigated. The WPC panels were made from dry-blended WF, polypropylene (PP), and fire retardant (FR) powders with maleic anhydride-grafted PP (2...

Dynamic mechanical analysis of compatibilizer effect on the mechanical properties of wood flour/high-density polyethylene composites

Science.gov (United States)

Mehdi Behzad; Medhi Tajvidi; Ghanbar Ehrahimi; Robert H. Falk

2004-01-01

In this study, effect of MAPE (maleic anhydride polyethylene) as the compatibilizer on the mechanical properties of wood-flour polyethylene composites has been investigated by using Dynamic Mechanical Analysis (DMA). Composites were made at 25% and 50% by weight fiber contents and 1% and 2% compatibilizer respectively. Controls were also made at the same fiber contents...

Alternating copolymerization of epoxides with anhydrides initiated by organic bases

Czech Academy of Sciences Publication Activity Database

Hošťálek, Z.; Trhlíková, Olga; Walterová, Zuzana; Martinez, T.; Peruch, F.; Cramail, H.; Merna, J.

2017-01-01

Roč. 88, March (2017), s. 433-447 ISSN 0014-3057 Institutional support: RVO:61389013 Keywords : copolymerization * epoxides * anhydrides Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.531, year: 2016

Selective deoxygenation of stearic acid via an anhydride pathway

NARCIS (Netherlands)

Hollak, S.A.W.; Bitter, W.; Haveren, van J.; Es, van D.S.

2012-01-01

Stearic anhydride is proposed as reactive intermediate in the hydrogen free decarbonylation and ketonization of stearic acid over Pd/Al2O3 at 523 K. This information is crucial towards developing of a selective low temperature decarbonylation process of fatty acids towards olefins.

29 CFR 1910.1017 - Vinyl chloride.

Science.gov (United States)

2010-07-01

... employee exposure to vinyl chloride (chloroethene), Chemical Abstracts Service Registry No. 75014. (2) This section applies to the manufacture, reaction, packaging, repackaging, storage, handling or use of vinyl... this section by engineering, work practice, and personal protective controls as follows: (1) Feasible...

21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate copolymers. 177.1350 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1350 Ethylene-vinyl acetate copolymers. Ethylene-vinyl acetate copolymers may be safely used as articles or components of articles...

21 CFR 177.1950 - Vinyl chloride-ethylene copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-ethylene copolymers. 177.1950... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1950 Vinyl chloride-ethylene copolymers. The vinyl chloride-ethylene copolymers identified in paragraph (a) of this section may be safely...

Synthesis and characterisation of polymeric nanofibers poly (vinyl alcohol) and poly (vinyl alcohol)/silica using indigenous electrospinning set up

International Nuclear Information System (INIS)

Sasipriya, K.; Suriyaprabha, R.; Prabu, P.; Rajendran, V.

2013-01-01

Indigenous design and fabrication horizontal of electrospinning set up was developed to facilitate with double drum conveyor belt system to make ease in harvesting nanofibers rapidly. As a bench mark study, organic-inorganic nanofiber composite was synthesised employing our indigenous electrospinning set up. The aqueous solution of poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol were employed to produce nanofiber mats in order to vary the experimental parameters such as voltage, solvent effect and the effect of catalyst. The synthesised pure electro spun poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol fibers were characterized by Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and Fourier transform infra red spectroscopy (FTIR). According to the results, the fine polymeric nanofibers were achieved in the size range of 100-500 nm for pure poly (vinyl alcohol) fiber and 100-700 nm for polyvinyl alcohol/silica and the constitution of silica in rendering better fiber mats with this double drum set up. (author)

Synthesis and characterisation of polymeric nanofibers poly (vinyl alcohol) and poly (vinyl alcohol)/silica using indigenous electrospinning set up

Energy Technology Data Exchange (ETDEWEB)

Sasipriya, K.; Suriyaprabha, R.; Prabu, P.; Rajendran, V., E-mail: veerajendran@gmail.com [Centre for Nanoscience and Technology, K. S. Rangasamy College of Technology, Tamil Nadu (India)

2013-11-01

Indigenous design and fabrication horizontal of electrospinning set up was developed to facilitate with double drum conveyor belt system to make ease in harvesting nanofibers rapidly. As a bench mark study, organic-inorganic nanofiber composite was synthesised employing our indigenous electrospinning set up. The aqueous solution of poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol were employed to produce nanofiber mats in order to vary the experimental parameters such as voltage, solvent effect and the effect of catalyst. The synthesised pure electro spun poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol fibers were characterized by Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and Fourier transform infra red spectroscopy (FTIR). According to the results, the fine polymeric nanofibers were achieved in the size range of 100-500 nm for pure poly (vinyl alcohol) fiber and 100-700 nm for polyvinyl alcohol/silica and the constitution of silica in rendering better fiber mats with this double drum set up. (author)

Synthesis and characterisation of polymeric nanofibers poly (vinyl alcohol and poly (vinyl alcohol/silica using indigenous electrospinning set up

Directory of Open Access Journals (Sweden)

K. Sasipriya

2013-01-01

Full Text Available Indigenous design and fabrication horizontal of electrospinning set up was developed to facilitate with double drum conveyor belt system to make ease in harvesting nanofibers rapidly. As a bench mark study, organic-inorganic nanofiber composite was synthesised employing our indigenous electrospinning set up. The aqueous solution of poly (vinyl alcohol and poly (vinyl alcohol/silica sol were employed to produce nanofiber mats in order to vary the experimental parameters such as voltage, solvent effect and the effect of catalyst. The synthesised pure electro spun poly (vinyl alcohol and poly (vinyl alcohol/silica sol fibers were characterized by Scanning electron microscopy (SEM, Atomic force microscopy (AFM and Fourier transform infra red spectroscopy (FTIR. According to the results, the fine polymeric nanofibers were achieved in the size range of 100-500 nm for pure poly (vinyl alcohol fiber and 100-700 nm for polyvinyl alcohol/silica and the constitution of silica in rendering better fiber mats with this double drum set up.

Synthesized cellulose/succinic anhydride as an ion exchanger. Calorimetry of divalent cations in aqueous suspension

Energy Technology Data Exchange (ETDEWEB)

Melo, Julio C.P. [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil); Silva Filho, Edson C. [LIMAV, Federal University of Piaui, 64049-550 Teresina, Piaui (Brazil); Santana, Sirlane A.A. [Departamento de Quimica/CCET, Universidade Federal do Maranhao, Av. dos Portugueses S/N, Campus do Bacanga, 65080-540 Sao Luiz, MA (Brazil); Airoldi, Claudio, E-mail: airoldi@iqm.unicamp.br [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

2011-09-20

Highlights: {yields} Synthetic route based on anhydride melting point. {yields} Cellulosic biopolymer/anhydride as ion exchanger. {yields} Calorimetry of cation exchange at solid/liquid interface. {yields} Favorable thermodynamic data of exchanging process. - Abstract: A synthetic route to a biopolymer/anhydride ion exchanger adds cellulose directly to molten succinic anhydride in a quasi solvent-free procedure. An amount of 3.07 {+-} 0.05 mmol of pendant groups incorporated onto the polymeric structure, which was characterized by elemental analysis, solid state carbon NMR, infrared, X-ray and thermogravimetry. The new polysaccharide is able to exchange cations from aqueous solution through a batchwise methodology, to obtain 2.46 {+-} 0.09 mmol g{sup -1} for divalent cobalt and nickel cations. The net thermal effects obtained from calorimetric titrations gave endothermic values of 3.81 {+-} 0.02 and 2.35 {+-} 0.01 kJ mol{sup -1}. The spontaneity of this ion-exchange process reflected in negative Gibbs energies and also a positive entropic contribution. These thermodynamic data at the solid/liquid interface suggests a favorable ion exchange process for this anchored biopolymer, for cation removal from the environment.

Modified Method for Detection of Benzoylecgonine in Human Urine by GC-MS: Derivatization Using Pentafluoropropanol/Acetic Anhydride.

Science.gov (United States)

Serafin, Michelle C; Paulemon, Kasandra M; Fuller, Zachary J; Bronner, William E

2017-05-01

An existing GC-MS method for detecting benzoylecgonine (BZE) in urine was modified by changing derivatizing reagents. This method modification presents a cost-effective alternative derivatization procedure for the detection of BZE in urine by GC-MS. The combination of pentafluoropropanol and acetic anhydride was found to produce the same reaction product for BZE as pentafluoropropanol with pentafluoropropionic anhydride, while reducing reagent cost. With no anhydride present, derivatization of BZE by pentafluoropropanol did not occur. Published by Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Thermal stability of homo- and copolymers of vinyl fluoride

International Nuclear Information System (INIS)

Raucher, D.; Levy, M.

1979-01-01

The thermal stability of poly(vinyl fluoride)(PVF) was studied by thermal gravimetry and mass spectrometry (TGA and TGA-MS). In low-molecular-weight polymers a two-step decomposition pattern was observed. It consisted of the dehydrofluorination to a polyene chain followed by decomposition of the resulting polyene at higher temperatures. Copolymers of vinyl fluoride-vinyl acetate (VF-VAc) and vinyl fluoride-vinyl chloride (VF-VCl) showed a simultaneous evolution of hydrofluoric acid and acetic acid and hydrofluoric acid and hydrochloric acid, respectively. This suggests that after the elimination of the weakest link a spontaneous elimination of neighboring HF molecules takes place

29 CFR 1915.1017 - Vinyl chloride.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Vinyl chloride. 1915.1017 Section 1915.1017 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1017 Vinyl chloride. Note: The requirements applicable to shipyard employment under this section...

Method of solidifying radioactive laundry wastes

International Nuclear Information System (INIS)

Yasumura, Keijiro

1984-01-01

Purpose: To enable to solidify radioactive laundry wastes containing non-ionic liquid detergents less solidifiable by plastic solidification process in liquid laundry wastes for cloths or the likes discharged from a nuclear power plant. Method: Radioactive laundry wastes are solidified by using plastic solidifying agent comprising, as a main ingredient, unsaturated polyester resins and methylmethacrylate monomers. The plastic solidifying agents usable herein include, for example, unsaturated polyester resins prepared by condensating maleic anhydride and phthalic anhydride with propylene glycol and incorporated with methylmethacrylate monomers. The mixing ratio of the methylmethacrylate monomers is preferably 30 % by weight based on the unsaturated polyester resins. (Aizawa, K.)

Reproductive toxicity of the glycol ethers.

Science.gov (United States)

Hardin, B D

1983-06-01

The glycol ethers are an important and widely used class of solvents. Recent studies have demonstrated that ethylene glycol monomethyl ether (EGME), ethylene glycol dimethyl ether (EGdiME), ethylene glycol monoethyl ether (EGEE), and ethylene glycol monoethyl ether acetate (EGEEA) are teratogenic. Other studies have demonstrated that testicular atrophy or infertility follow treatment of males with EGME, ethylene glycol monomethyl ether acetate (EGMEA), EGEE, EGEEA, diethylene glycol dimethyl ether (diEGdiME), and diethylene glycol monoethyl ether (diEGEE). Experimental data are reviewed and structure-activity relationships are speculated upon.

Thermal degradation and plasticizing mechanism of poly(vinyl chloride) plasticized with a novel cardanol derived plasticizer

Science.gov (United States)

Chen, J.; Nie, X. A.; Jiang, J. C.; Zhou, Y. H.

2018-01-01

A natural plasticizer cardanol derivatives glycidyl ether (CGE) was synthesized and employed as a plasticizer for the poly(vinyl chloride). The effect of CGE on thermal degradation of PVC films and its plasticizing mechanism were firstly reported. The molecular structure of CGE was characterized with Fourier transform infrared spectroscopy (FTIR). Thermal properties, degradation properties and compatibility of the PVC films were investigated by Differential scanning calorimeter analysis (DSC), Thermogravimetric analysis (TGA) and FTIR, respectively. Compared with the commercial plasticizers dioctylphthalate (DOP), CGE can endow PVC film with a decrease of 4.31 °C in glass transition temperature (Tg), an increase of 24.01 °C and 25.53 °C in 10% weight loss (T 10) and 50% weight loss (T 50) respectively, and a higher activetion energy of thermal degradation (Ea ).

Controlled release from aspirin based linear biodegradable poly(anhydride esters) for anti-inflammatory activity.

Science.gov (United States)

Dasgupta, Queeny; Movva, Sahitya; Chatterjee, Kaushik; Madras, Giridhar

2017-08-07

This work reports the synthesis of a novel, aspirin-loaded, linear poly (anhydride ester) and provides mechanistic insights into the release of aspirin from this polymer for anti-inflammatory activity. As compared to conventional drug delivery systems that rely on diffusion based release, incorporation of bioactives in the polymer backbone is challenging and high loading is difficult to achieve. In the present study, we exploit the pentafunctional sugar alcohol (xylitol) to provide sites for drug (aspirin) attachment at its non-terminal OH groups. The terminal OH groups are polymerized with a diacid anhydride. The hydrolysis of the anhydride and ester bonds under physiological conditions release aspirin from the matrix. The resulting poly(anhydride ester) has high drug loading (53%) and displays controlled release kinetics of aspirin. The polymer releases 8.5 % and 20%, of the loaded drug in one and four weeks, respectively and has a release rate constant of 0.0035h -0.61 . The release rate is suitable for its use as an anti-inflammatory agent without being cytotoxic. The polymer exhibits good cytocompatibility and anti-inflammatory properties and may find applications as injectable or as an implantable bioactive material. The physical insights into the release mechanism can provide development of other drug loaded polymers. Copyright © 2017 Elsevier B.V. All rights reserved.

Compatibility of anhydride cured epoxies with hexanitroazobenzene (HNAB) and hexanitrostilbene (HNS)

International Nuclear Information System (INIS)

Massis, T.M.; Wischmann, K.B.

1985-01-01

The explosives HNAB (hexanitroazobenzene) and HNS (hexanitrostilbene) have compatibility problems with amine-cured epoxy systems. A program was instituted to find compatible polymeric substitutes for use with these explosives. These polymeric materials must have rigid structures after curing for both adhesive and encapsulant applications. A promising class of epoxy materials using anhydride curing agents with various catalysts to trigger the cure reaction were developed. These polymeric systems have very good compatibility with HNS. Of those tested with HNAB, the anhydride epoxy system that used uranyl nitrate as the catalyst was found to be marginally compatible while the others were incompatible. These results indicated further studies are needed. The CRT (chemical reactivity test) was used to evaluate the compatibility of these materials. 6 references, 2 figures, 5 tables

Fundamental Studies of Butane Oxidation over Model-Supported Vanadium Oxide Catalysts: Molecular Structure-Reactivity Relationships

NARCIS (Netherlands)

Wachs, I.E.; Jehng, J.M.; Deo, G.; Weckhuysen, B.M.; Guliants, V.V.; Benziger, J.B.; Sundaresan, S.

1997-01-01

The oxidation of n-butane to maleic anhydride was investigated over a series of model-supported vanadia catalysts where the vanadia phase was present as a two-dimensional metal oxide overlayer on the different oxide supports (TiO2, ZrO2, CeO2, Nb2O5, Al2O3, and SiO2). No correlation was found

Effect of boron compounds on physical, mechanical, and fire properties of injection molded wood plastic composites

Science.gov (United States)

Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Zeki Candan; Umit Buyuksari; Erkan Avci

2011-01-01

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites (WPCs) incorporated with different levels of boron compounds, borax/boric acid (BX/BA) (0.5:0.5 wt %) and zinc borate (ZB) (4, 8, or 12 wt %) were investigated. The effect of the coupling agent loading (2, 4, or 6 wt %), maleic anhydride-grafted PP (MAPP), on the...

Properties of flat-pressed wood plastic composites containing fire retardants

Science.gov (United States)

Nadir Ayrilmis; Jan. T. Benthien; Heiko Thoemen; Robert H. White

2011-01-01

This study investigated physical, mechanical, and fire properties of the flat-pressed wood plastic composites (WPCs) incorporated with various fire retardants (FRs) [5 or 15% by weight (wt)] at 50 wt % of the wood flour (WF). The WPC panels were made from dry-blended WF, polypropylene (PP) with maleic anhydride grafted PP (2 wt %), and FR powder formulations using a...

Preparation of polymer microspheres by radiation-induced polymerization

International Nuclear Information System (INIS)

Naka, Y.; Yamamoto, Y.; Yoshida, Y.; Tagawa, S.

1995-01-01

Cross-liking monomer, diethylene glycol dimethacrylate gives microspheres from organic solution by radiation-induced polymerization. /One of the remarkable result is that the number of the microspheres is not changing during the polymerization. Ethyl methacrylate, maleic anhydride, styrene and acrylamide are used as comonomers. These comonomers give the microspheres in the range of 0 to 0.4 as mol fractions. (author)

Statistical analysis of nitrogen-containing vinyl copolymers: radiation-induced copolymerization of vinyl acetate and N-vinyl-2-pyrrolidone

International Nuclear Information System (INIS)

Peppas, N.A.; Gehr, T.W.B.

1979-01-01

Radiation-induced copolymerization of vinyl acetate and N-vinyl-2-pyrrolidone was carried out at 5 0 C using γ-irradiation of 1450 rads/min. Copolymers prepared at conversions lower than 5% were analyzed by a saponification technique. Various linear and nonlinear statistical analysis techniques were used to determine the reactivity ratios of this system as r 1 = 0.348 and r 2 = 3.108. These data were examined and analyzed in relation to problems of elemental analysis involving nitrogen-containing copolymers and to discrepancies in the reactivity ratios obtained by previous investigators. The presence of oxygen and a higher dose rate did not affect the copolymer composition within statistical error. Hydrolyzed copolymers prepared by this method have potential applications as biocompatible materials

Radiation fixation of vinyl chloride in an insecticide aerosol container

International Nuclear Information System (INIS)

Kagiya, V.T.; Takemoto, K.

1975-01-01

Recently, a large quantity of vinyl chloride has been used as spraying additive for insecticide aerosols. Since January 1974 when the Food and Drug Administration of the United States of America announced that vinyl chloride causes liver cancer, it has been forbidden in Japan and the United States of America to market insecticide aerosol containers containing vinyl chloride. In Japan, following a government order, about 20 million insecticide aerosol containers have been collected and put into storage. A report is given on the radiation fixation of vinyl chloride as polyvinylchloride powder by gamma-ray-induced polymerization in the aerosol container. Insecticide aerosol containers containing vinyl chloride were irradiated by gamma rays from 60 Co at room temperature. Vinyl chloride polymerized to form powdered polymer in the container. Polymerization conversion increased with the irradiation dose, and after 10 Mrad irradiation, vinyl chloride was not found in the sprayed gas. This establishes that vinyl chloride can be fixed by gamma-ray irradiation in the aerosol container. To accelerate the reaction rate, the effect of various additives on the reaction was investigated. It was found that halogenated hydrocarbons, such as chloroform and carbon tetrachloride, accelerated the initiation of the polymerization, and that a vinyl monomer such as vinyl acetate accelerated the reaction rate due to the promotion of the initiation and the high reactivity of the polyvinylacetate radical to vinyl chloride. Consequently, the required irradiation dose for the fixation of vinyl chloride was decreased to less than 5 Mrad by the addition of various kinds of additives. Following the request of the Ministry of Public Welfare, various technical problems for large-scale treatment are being studied with the co-operation of the Federation of Insecticide Aerosols. (author)

Radiation induced copolymerization of N-vinyl-2-pyrrolidone with vinyl acetate [Paper No. RD-3

International Nuclear Information System (INIS)

Ramakrishna, M.S.; Dhal, P.K.; Deshpande, D.D.; Babu, G.N.

1982-01-01

Copolymerization of N-vinyl-2-pyrrolidone (NVP) with vinyl acetate (VAC) was carried out using gamma-ray radiation. The compositions of the copolymers were determined from elemental analysis and the monomer reactivity ratios have been calculated using YBR method. The glass transition temperature and the intrinsic viscosities of the copolymers have been determined. All the experimental results were discussed in terms of the nature of the monomers. (author)

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

Science.gov (United States)

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

2016-07-01

Phytosterols are important bioactive compounds which have several health benefits including reduction of serum cholesterol and preventing cardiovascular diseases. The most widely used method in the synthesis of its ester analogous form is the use of catalysts and solvents. These methods have been found to present some safety and health concern. In this paper, an alternative method of synthesizing phytosterol ester from soybean sterol and acetic anhydride was investigated. Process parameters such as mole ratio, temperature and time were optimized. The structure and physicochemical properties of phytosterol acetic ester were analyzed. By the use of gas chromatography, the mole ratio of soybean sterol and acetic anhydride needed for optimum esterification rate of 99.4% was 1:1 at 135 °C for 1.5 h. FTIR spectra confirmed the formation of phytosterol ester with strong absorption peaks at 1732 and 1250 cm(-1) , which corresponds to the stretching vibration of C=O and C-O-C, respectively. These peaks could be attributed to the formation of ester links which resulted from the reaction between the hydroxyl group of soybean sterol and the carbonyl group of acetic anhydride. This paper provides a better alternative to the synthesis of phytosterol ester without catalyst and solvent residues, which may have potential application in the food, health-care food, and pharmaceutical industries. © 2016 Institute of Food Technologists®

MILLIMETER WAVE SPECTRUM AND ASTRONOMICAL SEARCH FOR VINYL FORMATE

Energy Technology Data Exchange (ETDEWEB)

Alonso, E. R.; Kolesniková, L.; Cabezas, C.; Alonso, J. L. [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, E-47011 Valladolid (Spain); Tercero, B.; Cernicharo, J. [Grupo de Astrofísica Molecular, ICMM-CSIC, C/Sor Juana Inés de la Cruz 3, E-28049 Cantoblanco (Spain); Guillemin, J.-C. [Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, F-35708 Rennes Cedex 7 (France)

2016-11-20

Previous detections of methyl and ethyl formate make other small substituted formates potential candidates for observation in the interstellar medium. Among them, vinyl formate is one of the simplest unsaturated carboxylic ester. The aim of this work is to provide direct experimental frequencies of the ground vibrational state of vinyl formate in a large spectral range for astrophysical use. The room-temperature rotational spectrum of vinyl formate has been measured from 80 to 360 GHz and analyzed in terms of Watson’s semirigid rotor Hamiltonian. Two thousand six hundred transitions within J = 3–88 and K {sub a} = 0–28 were assigned to the most stable conformer of vinyl formate and a new set of spectroscopic constants was accurately determined. Spectral features of vinyl formate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of vinyl formate are provided.

Sorption of water vapor in partially hydrolyzed poly(vinyl acetate)

International Nuclear Information System (INIS)

Spencer, H.G.; Honeycutt, S.C.

1973-01-01

The sorption kinetics of H 2 O and D 2 O in copolymers of partially hydrolyzed poly(vinyl acetate) were studied and compared with the sorption kinetics of vinyl acetate--vinyl alcohol copolymers, and poly(vinyl alcohol). The special measurement problems presented by transient-state sorption studies in water vapor--polymer systems and their effects on the results are discussed

Vinyl acetate polymerization by ionizing radiation

International Nuclear Information System (INIS)

Mesquita, Andrea Cercan

2002-01-01

The aim of this work is the synthesis and characterization of the poly(vinyl acetate) using the ionizing radiation. Six polymerizations of vinyl acetate were carried out using three techniques of polymerization: in bulk, emulsion and solution. In the technique of solution polymerization were used two solvents, the alcohol ethyl and the methylethylketone, in two proportions 1:0.5 and 1:1 related to the monomer. The solutions were irradiated with gamma rays from a 60 Co source, with dose rate between 5.25 kGy/h and 6.26 kGy/h. The polymers obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR). The glass transition temperature (Tg) was investigated by Differential Scanning Calorimeter (DSC). The molecular weight was analyzed by the technique of Gel Permeation Chromatography (GPC). Tests of density, hardness and Vicat softening temperature were carried out. The infrared spectroscopy and others results confirmed that the polymers obtained by polymerization of vinyl acetate in bulk, emulsion and solution, using ionizing radiation, really correspond at poly(vinyl acetate). (author)

Reaction of the oximes of aliphatic aldehydes and ketones with alkoxyethenes

International Nuclear Information System (INIS)

Voronkov, M.G.; Keiko, N.A.; Shuvashev, Yu.A.; Kalikhman, I.D.; Keiko, V.V.

1987-01-01

In the reaction of acetone oxime with alkyl vinyl ethers in the presence of zinc chloride variable amounts of acetone 0,0'-(2-propylidene)dioxime, acetaldehyde dialkyl acetal, acetaldehyde 0-(1-alkoxyethyl)oxide, and acetone 0-(1-alkoxy-1-methylethyl)oxime, depending on the reaction conditions, are formed in addition to acetone 0-(1-alkoxyethyl)oxime (the initial addition product). In the reaction of acetaldehyde oxime with alkyl vinyl ethers in the presence of zinc chloride acetaldehyde oxime with alkyl vinyl ethers in the presence of zinc chloride acetaldehyde dialkyl acetal was isolated in addition to acetaldehyde 0-(1-alkoxyethyl)oxime. A mechanism for the formation of the obtained compounds is proposed

Hydrotelluration of alkynes: a unique route to Z-vinyl organometallics

Directory of Open Access Journals (Sweden)

Vieira Maurício L.

2001-01-01

Full Text Available The hydrotelluration reaction of alkynes is reviewed. The transformation of vinylic tellurides into reactive vinyl organometallics and the coupling reactions of vinylic tellurides with alkynes and organometallics are presented.

Coal and biomass-based chemicals via carbonylation, hydroformylation and homologation reactions

Energy Technology Data Exchange (ETDEWEB)

Sunavala, P.D.; Raghunath, B.

The paper emphasizes the importance of carbonylation, hydroformylation and homologation reactions in the manufacture of organic chemicals (such as acetic acid, acetic anhydride, cellulose acetate, vinyl acetate monomer, aliphatic amines, isocyanates, methanol, ethanol, n-butanol, ethylene glycol, acrylic acid, etc.) from coal and biomass feedstocks. Topics covered are: synthesis of acetic acid; manufacture of acetic anhydride; synthesis of vinyl acetate monomer by carbonylation; synthesis of aliphatic amines by hydroformylation; synthesis of organic diisocyanates; ethanol synthesis by homologation of methanol; synthesis of ethylene glycol via hydroformylation of formaldehyde; synthesis of n- butanol and n-butyraldehyde by propylene formylation; synthesis of acrylic acid; homologation reaction of carboxylic acid esters with ruthenium catalysts; and synthesis of phenyl isocyanate from nitrobenzene by reductive carbonylation. 26 refs.

Chemical functionalization of hyaluronic acid for drug delivery applications

Energy Technology Data Exchange (ETDEWEB)

Vasi, Ana-Maria [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, 73 Prof. dr. docent Dimitrie Mangeron Street, 700050 Iasi (Romania); Popa, Marcel Ionel, E-mail: mipopa@ch.tuiasi.ro [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, 73 Prof. dr. docent Dimitrie Mangeron Street, 700050 Iasi (Romania); Butnaru, Maria [“Grigore T. Popa” University of Medicine Pharmacy, Faculty of Medical Bioengineering, 9-13 Kogalniceanu Street, 700454 Iasi (Romania); Dodi, Gianina [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, 73 Prof. dr. docent Dimitrie Mangeron Street, 700050 Iasi (Romania); SCIENT — Research Center for Instrumental Analysis, S.C. CROMATEC PLUS, 18 Sos. Cotroceni, 060114 Bucharest (Romania); Verestiuc, Liliana [“Grigore T. Popa” University of Medicine Pharmacy, Faculty of Medical Bioengineering, 9-13 Kogalniceanu Street, 700454 Iasi (Romania)

2014-05-01

Functionalized hyaluronic acid (HA) derivatives were obtained by ring opening mechanism of maleic anhydride (MA). FTIR and H{sup 1} NMR spectroscopy were used to confirm the chemical linkage of MA on the hyaluronic acid chains. Thermal analysis (TG-DTG and DSC) and GPC data for the new products revealed the formation of new functional groups, without significant changes in molecular weight and thermal stability. New gels based on hyaluronic acid modified derivatives were obtained by acrylic acid copolymerization in the presence of a redox initiation system. The resulted circular and interconnected pores of the gels were visualized by SEM. The release profiles of an ophthalmic model drug, pilocarpine from tested gels were studied in simulated media. Evaluation of the cytotoxicity and cell proliferation properties indicates the potential of the new systems to be used in contact with biological media in drug delivery applications. - Highlights: • New functionalized hyaluronic acid was prepared by ring opening of maleic anhydride. • Gels with circular pores based on acrylic acid copolymerization were formulated. • In vitro drug loading/release profile was evaluated in simulated ophthalmic media. • The cytotoxicity indicates the potential of derivatives to be used in vivo.

Indirect rapid prototyping of antibacterial acid anhydride copolymer microneedles

International Nuclear Information System (INIS)

Boehm, Ryan D; Miller, Philip R; Singh, Ritika; Narayan, Roger J; Shah, Akash; Stafslien, Shane; Daniels, Justin

2012-01-01

Microneedles are needle-like projections with microscale features that may be used for transdermal delivery of a variety of pharmacologic agents, including antibacterial agents. In the study described in this paper, an indirect rapid prototyping approach involving a combination of visible light dynamic mask micro-stereolithography and micromolding was used to prepare microneedle arrays out of a biodegradable acid anhydride copolymer, Gantrez® AN 169 BF. Fourier transform infrared spectroscopy, energy dispersive x-ray spectrometry and nanoindentation studies were performed to evaluate the chemical and mechanical properties of the Gantrez® AN 169 BF material. Agar plating studies were used to evaluate the in vitro antimicrobial performance of these arrays against Bacillus subtilis, Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Large zones of growth inhibition were noted for Escherichia coli, S. aureus, Enterococcus faecalis and B. subtilis. The performance of Gantrez® AN 169 BF against several bacteria suggests that biodegradable acid anhydride copolymer microneedle arrays prepared using visible light dynamic mask micro-stereolithography micromolding may be useful for treating a variety of skin infections. (communication)

Copolymers of Vinyl-Containing Benzoxazine with Vinyl Monomers as Precursors for High Performance Thermosets

Directory of Open Access Journals (Sweden)

Tsutomu Takeichi

2015-04-01

Full Text Available A benzoxazine containing a vinyl group (P-4va was prepared by the reaction of phenol, 4-vinylaniline, and paraformaldehyde. A differential scanning calorimetry (DSC study revealed that ring-opening polymerization of the benzoxazine and chain polymerization of the vinyl group occurred in the same temperature range. When 2,2'-azobisisobutyronitrile was added as a radical initiator to P-4va, however, only the vinyl groups were polymerized at lower temperature, giving oligo(P-4va that contains pendent benzoxazine units. Radical copolymerization of P-4va with various vinyl monomers such as styrene, methyl methacrylate (MMA, and n-butyl acrylate (BuA was examined. The chemical structure of the copolymers was confirmed by FT-IR and 1H-NMR to be one of polyolefins bearing benzoxazine units as the pendant groups. The weight-average molecular weights of the copolymers determined by size exclusion chromatography were to be in the range of 1900–51,500 depending on the comonomers. DSC of the copolymers showed that the maxima of the exothermic peaks corresponding to the ring-opening polymerization of the pendent benzoxazine units were observed in the temperature range of 229–250 °C. Thermal cure up to 240 °C of the copolymer films afforded homogenous transparent films with improved thermal properties. Tough cured film was obtained by the copolymerization with MMA, while a tough and flexible film was obtained by the copolymerization with BuA.

Exogenous ether lipids predominantly target mitochondria.

Directory of Open Access Journals (Sweden)

Lars Kuerschner

Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

Tissue distribution of 1,2-14C-vinyl chloride in rats

International Nuclear Information System (INIS)

Buchter, A.; Bolt, H.M.; Kappus, H.; Bolt, W.

1977-01-01

Rats have been pretreatet with 6-nitro-1.2.3-benzothiadiazole which completely blocks the metabolism of vinyl chloride. If the animals are exposed to atmospheric vinyl chloride, the formation of an equilibrium between the compound in the gas phase and in the animal's organism is observed. Unmetabolized vinyl chloride is accumulated in the adipose tissue. The distribution pattern of vinyl in different organs of the rat is constant over the concentration range of 25-10,000 ppm of vinyl chloride in the exposure atmosphere. The distribution of metabolites of vinyl chloride contrasts to that of the original compound; metabolites primarily are concentrated in liver and in kidneys. (orig.) [de

Ether formulations of relativity

International Nuclear Information System (INIS)

Duffy, M.C.

1980-01-01

Contemporary ether theories are surveyed and criticised, especially those formally identical to orthodox Relativity. The historical development of Relativity, Special and General, in terms of an ether, is briefly indicated. Classical interpretations of Generalized Relativity using ether are compared to Euclidean formulations using a background space. The history of a sub-group of theories, formulating a 'new' Relativity involving modified transforms, is outlined. According to the theory with which they agree, recent supposed detections of drift are classified and criticised. Cosmological evidence suggesting an ether is mentioned. Only ether theories formally identical to Relativity have been published in depth. They stand criticised as being contrary to the positivist spirit. The history of mechanical analogues is traced, from Hartley's representing gravitating matter as spherical standing waves, to recent suggestions that vortex-sponge might model electromagnetic, quantum, uncertainty and faster-than-light phenomena. Contemporary theories are particular physical theories, themselves 'second interpretations' of a primary mathematical model. Mechanical analogues are auxiliary, not necessary, to other theory, disclosing relationships between classical and non-classical descriptions of assemblies charging state. The ether-relativity polemic, part of a broader dispute about relativity, is founded on mistaken conceptions of the roles of mathematical and physical models, mechanical analogues; and a distored view of history, which indicates that ether theories have become relativistic. (author)

Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

Energy Technology Data Exchange (ETDEWEB)

Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

1999-01-01

There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

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

Science.gov (United States)

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

2003-06-01

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

Preparation of poly(vinyl alcohol) membranes grafted with N-vinyl imidazole/acrylic acid binary monomers

International Nuclear Information System (INIS)

Ajji, Zaki; Ali, Ali

2006-01-01

Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl imidazole. The influence of different parameters on the grafting yield was investigated as: type of solvent and solvent composition, comonomer concentration and composition, addition of mineral acids, and irradiation dose. Water uptake in respect to the grafting yield was also evaluated. The ability of the grafted films to adsorb copper ions was elaborated and discussed for different grafting yields and ph values of the solution. (authors)

Novel Alkyd-Type Coating Resins Produced Using Cationic Polymerization [PowerPoint

Energy Technology Data Exchange (ETDEWEB)

Chisholm, Bret; Kalita, Harjyoti; Alam, Samim; Jayasooriyamu, Anurad; Fernando, Shashi; Samanata, Satyabrata; Bahr, James; Selvakumar, Sermadurai; Sibi, Mukund; Vold, Jessica; Ulven, Chad

2014-04-07

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(vinyl ether)s provide several advantages. These advantages include miler, 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, trimmers, etc. The results of the studied showed that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerable 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.

Direct Vinylation of Alcohols or Aldehydes Employing Alkynes as Vinyl Donors: A Ruthenium Catalyzed C-C Bond Forming Transfer Hydrogenation

Science.gov (United States)

Patman, Ryan L.; Chaulagain, Mani Raj; Williams, Vanessa M.; Krische, Michael J.

2011-01-01

Under the conditions of ruthenium catalyzed transfer hydrogenation, 2-butyne couples to benzylic and aliphatic alcohols 1a–1i to furnish allylic alcohols 2a–2i, constituting a direct C-H vinylation of alcohols employing alkynes as vinyl donors. Under related transfer hydrogenation conditions employing formic acid as terminal reductant, 2-butyne couples to aldehydes 4a, 4b, and 4e to furnish identical products of carbonyl vinylation 2a, 2b, and 2e. Thus, carbonyl vinylation is achieved from the alcohol or the aldehyde oxidation level in the absence of any stoichiometric metallic reagents. Nonsymmetric alkynes 6a–6c couple efficiently to aldehyde 4b to provide allylic alcohols 2m–2o as single regioisomers. Acetylenic aldehyde 7a engages in efficient intramolecular coupling to deliver cyclic allylic alcohol 8a. PMID:19173651

XRD study of intercalation in statically annealed composites of ethylene copolymers and organically modified montmorillonites. 2. One-tailed organoclays

Directory of Open Access Journals (Sweden)

Sara Filippi

2014-01-01

Full Text Available Ethylene copolymers with different polar comonomers, such as vinyl acetate, methyl acrylate, glycidyl methacrylate, and maleic anhydride, were used for the preparation of polymer/clay nanocomposites by statically annealing their mechanical mixtures with different commercial or home-made organically modified montmorillonites containing only one long alkyl tail. The nanostructure of the products was monitored by X-ray diffraction, and the dispersion of the silicate particles within the polymer matrix was qualitatively evaluated through microscopic analyses. The effect of the preparation conditions on the structure and the morphology of the composites was also addressed through the characterization of selected samples with similar composition prepared by melt compounding. In agreement with the findings reported in a previous paper for the composites filled with two-tailed organoclays, intercalation of the copolymer chains within the tighter galleries of the one-tailed clays occurs easily, independent of the application of a mechanical stress. However, the shear-driven break-up of the intercalated clay particles into smaller platelets (exfoliation seems more hindered. A collapse of the organoclay interlayer spacing was only observed clearly for a commercial one-tailed organoclay – Cloisite® 30B – whereas the same effect was almost negligible for a home-made organoclay with similar structure.

Multifunctional e-spun colloidal nanofiber structures from various dispersed blends of PVA/ODA-MMT with PVP/ODA-MMT, poly(VP-alt-MA and AgNPs incorporated polymer complexes as electro-active platforms

Directory of Open Access Journals (Sweden)

U. Bunyatova

2016-07-01

Full Text Available This work presented a new approach to fabricate polymer nanocomposites films with nanofiber structures from solution blends of poly(vinyl alcohol + octadecyl amine-montmorillonite (ODA-MMT (matrix with poly(N-vinylpyrrolidone + ODA-MMT (partner-1, poly(N-vinylpyrrolidone-alt-maleic anhydride ((poly(VP-alt-MA + (ODA-MMT (partner-2 and their silver (Ag-carrying polymer complexes by electrospinning. Chemical and physical structures, surface morphologies, thermal behaviors, electrical conductivity and thermal resistance parameters of nanofiber structures were investigated. Poly(VP-alt-MA was used both as a crosslinker and a donor of the hydrophilic groups such as ‒COOH and ‒NH–C=O amide from pyrrolidone ring. Reactive poly(VP-alt-MA, in situ generated Ag nanoparticles (AgNPs and original partner polymer had an significant effect on the morphology and diameter distribution of nanofibers. High and excellent conductive behaviors were observed for the homopolymer and copolymer of VP based fiber structures, respectively. Upon successive chemical cross-linking of the nanofiber structures by reactive partner copolymer, the conductivity of nanofiber films as electro-active platforms dramatically increased to 3.90·10–2 S·cm–1 at room temperature. Comparative analysis results also indicated that electrical properties strongly depended on the loaded reactive organoclay and in situ generated AgNPs.

A novel approach in acidic disinfection through inhibition of acid resistance mechanisms; Maleic acid-mediated inhibition of glutamate decarboxylase activity enhances acid sensitivity of Listeria monocytogenes.

Science.gov (United States)

Paudyal, Ranju; Barnes, Ruth H; Karatzas, Kimon Andreas G

2018-02-01

Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L. monocytogenes were investigated and found that it has a higher antimicrobial activity under acidic conditions than other organic acids, while this could not be explained by its pKa or Ka values. The effects were found to be more pronounced on strains with higher GAD activity. Maleic acid affected the extracellular GABA levels while it did not affect the intracellular ones. Maleic acid had a major impact mainly on GadD2 activity as also shown in cell lysates. Furthermore, it was demonstrated that maleic acid is able to partly remove biofilms of L. monocytogenes. Maleic acid is able to inhibit the GAD of L. monocytogenes significantly enhancing its sensitivity to acidic conditions and together with its ability to remove biofilms, make a good candidate for disinfection regimes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Swelling and mechanical properties of physically crosslinked poly(vinyl alcohol) hydrogels.

Science.gov (United States)

Suzuki, Atsushi; Sasaki, Saori

2015-12-01

Physically crosslinked poly(vinyl alcohol) gels are versatile biomaterials due to their excellent biocompatibility. In the past decades, physically crosslinked poly(vinyl alcohol) and poly(vinyl alcohol)-based hydrogels have been extensively studied for biomedical applications. However, these materials have not yet been implemented due to their mechanical strength. Physically crosslinked poly(vinyl alcohol) gels consist of a swollen amorphous network of poly(vinyl alcohol) physically crosslinked by microcrystallites. Although the mechanical properties can be improved to some extent by controlling the distribution of microcrystallites on the nano- and micro-scales, enhancing the mechanical properties while maintaining high water content remains very difficult. It may be technologically impossible to significantly improve the mechanical properties while keeping the gel's high water absorbance ability using conventional fabrication methods. Physical and chemical understandings of the swelling and mechanical properties of physically crosslinked poly(vinyl alcohol) gels are considered here; some promising strategies for their practical applications are presented. This review focuses more on the recent studies on swelling and mechanical properties of poly(vinyl alcohol) hydrogels, prepared using only poly(vinyl alcohol) and pure water with no other chemicals, as potential biomedical materials. © IMechE 2015.

Respiratory irritation by trimellitic anhydride in Brown Norway and Wistar rats

NARCIS (Netherlands)

Arts, J.H.E.; Koning, M.W.de; Bloksma, N.; Kuper, C.F.

2001-01-01

Several acid anhydrides are known for their sensitizing and irritative properties. Since both irritation and respiratory allergy can cause changes of lung function, proper testing of allergen-dependent effects on the respiratory tract requires knowledge of the respiratory irritant effects. To study

Muonium-containing vinyl radicals

International Nuclear Information System (INIS)

Rhodes, C.J.; Symons, M.C.R.; Roduner, E.; Heming, M.

1987-01-01

Exposure of trimethylsilylacetylene and bis(trimethylsilyl)acetylene to positive muons gave radicals whose muon-electron hyperfine coupling constants establish that the corresponding vinyl radicals were formed. (author)

Synthesis and characterization of Cis-5-Norbornene-2, 3-dicarboxylic anhydride-chitosan

International Nuclear Information System (INIS)

Ku Marshilla Ku Ishak; Zulkifli Ahmad; Hazizan Mohd Akil

2009-01-01

Chitosan was chemically modified with bulky structure, cis-5-norbornene-2, 3-dicarboxylic anhydride and the characteristic of this modified chitosan was studied. The resulting material was analyzed by FTIR, TGA, DSC, XRD and SEM to study the effect of N-acylation to the polysaccharide structure. FTIR results show that the anhydride monomer was successfully bound to amine group of chitosan. Thermal analysis of the modified structure provides the chitosan fibers with thermal stability while XRD and SEM show the lost of crystallinity of modified chitosan. XRD of modified chitosan shows broader peak pattern and a considerable increase in a dimension while SEM of chitosan presented the single particle morphology while norbornene-chitosan shows aggromolarate behaviour due to the hydrophobic nature of norbornene pendant group which induced aggromolaration of the particles in modified structure.(author)

Mutagenicity of vinyl chloride after metabolic activation

Energy Technology Data Exchange (ETDEWEB)

Rannug, U; Johansson, A; Ramel, C; Wachtmeister, C A

1974-01-01

Vinyl chloride has recently been shown to cause a malignant liver tumor disease in man after occupational exposure in PVC plants. This actualizes the problem of whether such hazards could be avoided or at least diminished in the future by a screening for mutagenicity of chemicals used in industries. The basis for such a screening procedure is the close correlation between carcinogenic and mutagenic effects of chemicals. Experiments with Salmonella bacteria showed that the carcinogenic hazard of vinyl chloride could have been traced by means of mutagenicity tests. The data indicate that vinyl chloride is not mutagenic per se but becomes mutagenic after a metabolic activation in the liver. 24 references, 1 figure, 4 tables.

Complex Macromolecular Architectures by Living Cationic Polymerization

KAUST Repository

Alghamdi, Reem D.

2015-05-01

Poly (vinyl ether)-based graft polymers have been synthesized by the combination of living cationic polymerization of vinyl ethers with other living or controlled/ living polymerization techniques (anionic and ATRP). The process involves the synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy) ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic polymerizations of those monomers were conducted in hexane at -20 0C using Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base.[1] The PCEVE segments of the synthesized block terpolymers were then used to react with living macroanions (PS-DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The quantitative desilylation of PSiDEGVE segments by n-Bu4N+F- in THF at 0 °C led to graft co- and terpolymers in which the polyalcohol is the outer block. These co-/terpolymers were subsequently subjected to “grafting-from” reactions by atom transfer radical polymerization (ATRP) of styrene to afford more complex macromolecular architectures. The base assisted living cationic polymerization of vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether (PnBVE-OH). The resulting polymers were then modified into an ATRP macro-initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS). Bifunctional PnBVE with terminal malonate groups was also synthesized and used as a precursor for more complex architectures such as H-shaped block copolymer by “grafting-from” or �

Artemisia vulgaris pollen allergoids digestibility in the simulated conditions of the gastrointestinal tract

OpenAIRE

RATKO M. JANKOV; NATALIJA DJ. POLOVIC; MARIJA DJ. GAVROVIC-JANKULOVIC; LIDIJA BURAZER; DANICA DJERGOVIC-PETROVIC; OLGA VUCKOVIC; OLIKA DROBNJAK; ZORICA SPORCIC; MARINA ATANASKOVIC-MARKOVIC; RATKO M. JANKOV

2006-01-01

Chemically modified allergens (allergoids) have found use in both traditional and novel forms of immunotherapy of allergic disorders. Novel forms of immunotherapy include local allergen delivery, via the gastrointestinal tract. This study conveys the gastrointestinal stability of three types ofmugwort pollen allergoids under simulated conditions of the gut. Allergoids of the pollen extract of Artemisia vulgaris were obtained by means of potassium cyanate, succinic and maleic anhydride. Gastro...

Direct 13C-1H coupling constants in the vinyl group of 1-vinylpyrazoles

International Nuclear Information System (INIS)

Afonin, A.V.; Voronov, V.K.; Es'kova, L.A.; Domnina, E.S.; Petrova, E.V.; Zasyad'ko, O.V.

1987-01-01

In a continuation of a study of the rotational isomerism of 1-vinylpyrazoles, they studied the direct 13 C- 1 H coupling constants in the vinyl group of 1-vinylpyrazole, 1-vinyl-4-bromopyrazole, 1-vinyl-3-methylpyrazole, 1-vinyl-5-methylpyrazole, 1-vinyl-3,5-dimethylpyrazole, and 1-vinyl-4-nitro-3,5-dimethylpyrazole. The 13 C- 1 H direct coupling constants in the vinyl group of 1-vinylpyrazoles are stereo-specific and vary with change in the conformer ratio

Ether the nothing that connects everything

CERN Document Server

Milutis, Joe

2006-01-01

In Ether, the histories of the unseen merge with discussions of the technology of electromagnetism. Navigating more than three hundred years of the ether''s cultural and artistic history, Joe Milutis reveals its continuous reinvention and tangible impact without ever losing sight of its ephemeral, elusive nature. The true meaning of ether, Milutis suggests, may be that it can never be fully grasped.

Absolute and relative-rate measurement of the rate coefficient for reaction of perfluoro ethyl vinyl ether (C2F5OCF[double bond, length as m-dash]CF2) with OH.

Science.gov (United States)

Srinivasulu, G; Bunkan, A J C; Amedro, D; Crowley, J N

2018-01-31

The rate coefficient (k 1 ) for the reaction of OH radicals with perfluoro ethyl vinyl ether (PEVE, C 2 F 5 OCF[double bond, length as m-dash]CF 2 ) has been measured as a function of temperature (T = 207-300 K) using the technique of pulsed laser photolysis with detection of OH by laser-induced fluorescence (PLP-LIF) at pressures of 50 or 100 Torr N 2 bath gas. In addition, the rate coefficient was measured at 298 K and in one atmosphere of air by the relative-rate technique with loss of PEVE and reference reactant monitored in situ by IR absorption spectroscopy. The rate coefficient has a negative temperature dependence which can be parameterized as: k 1 (T) = 6.0 × 10 -13  exp[(480 ± 38/T)] cm 3 molecule -1 s -1 and a room temperature value of k 1 (298 K) = (3.0 ± 0.3) × 10 -12 cm 3 molecule -1 s -1 . Highly accurate rate coefficients from the PLP-LIF experiments were achieved by optical on-line measurements of PEVE and by performing the measurements at two different apparatuses. The large rate coefficient and the temperature dependence indicate that the reaction proceeds via OH addition to the C[double bond, length as m-dash]C double bond, the high pressure limit already being reached at 50 Torr N 2 . Based on the rate coefficient and average OH levels, the atmospheric lifetime of PEVE was estimated to be a few days.

Usage of the word 'ether'

International Nuclear Information System (INIS)

Duffy, M.C.

1980-01-01

Confusion has been caused by scientists using the one word 'ether' to classify models differing from each other in important respects. Major roles assigned to the word are examined, and the nature of modern ether theories surveyed. The part played by the several meanings attached to the word, in the ether concept, is outlined. (author)

Nickel/zinc-catalyzed decarbonylative addition of anhydrides to alkynes: a DFT study.

Science.gov (United States)

Meng, Qingxi; Li, Ming

2013-10-01

Density functional theory (DFT) was used to investigate the nickel- or nickel(0)/zinc- catalyzed decarbonylative addition of phthalic anhydrides to alkynes. All intermediates and transition states were optimized completely at the B3LYP/6-31+G(d,p) level. Calculated results indicated that the decarbonylative addition of phthalic anhydrides to alkynes was exergonic, and the total free energy released was -87.6 kJ mol(-1). In the five-coordinated complexes M4a and M4b, the insertion reaction of alkynes into the Ni-C bond occurred prior to that into the Ni-O bond. The nickel(0)/zinc-catalyzed decarbonylative addition was much more dominant than the nickel-catalyzed one in whole catalytic decarbonylative addition. The reaction channel CA→M1'→T1'→M2'→T2'→M3a'→M4a'→T3a1'→M5a1' →T4a1'→M6a'→P was the most favorable among all reaction pathways of the nickel- or nickel(0)/zinc- catalyzed decarbonylative addition of phthalic anhydrides to alkynes. And the alkyne insertion reaction was the rate-determining step for this channel. The additive ZnCl2 had a significant effect, and it might change greatly the electron and geometry structures of those intermediates and transition states. On the whole, the solvent effect decreased the free energy barriers.

The failure of poly (ether ether ketone) in high speed contacts

Science.gov (United States)

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.

Production of methyl-vinyl ketone from levulinic acid

Energy Technology Data Exchange (ETDEWEB)

Dumesic, James A [Verona, WI; West,; Ryan, M [Madison, WI

2011-06-14

A method for converting levulinic acid to methyl vinyl ketone is described. The method includes the steps of reacting an aqueous solution of levulinic acid, over an acid catalyst, at a temperature of from room temperature to about 1100 K. Methyl vinyl ketone is thereby formed.

Design of a multi-dopamine-modified polymer ligand optimally suited for interfacing magnetic nanoparticles with biological systems.

Science.gov (United States)

Wang, Wentao; Ji, Xin; Na, Hyon Bin; Safi, Malak; Smith, Alexandra; Palui, Goutam; Perez, J Manuel; Mattoussi, Hedi

2014-06-03

We have designed a set of multifunctional and multicoordinating polymer ligands that are optimally suited for surface functionalizing iron oxide and potentially other magnetic nanoparticles (NPs) and promoting their integration into biological systems. The amphiphilic polymers are prepared by coupling (via nucleophilic addition) several amine-terminated dopamine anchoring groups, poly(ethylene glycol) moieties, and reactive groups onto a poly(isobutylene-alt-maleic anhydride) (PIMA) chain. This design greatly benefits from the highly efficient and reagent-free one-step reaction of maleic anhydride groups with amine-containing molecules. The availability of several dopamine groups in the same ligand greatly enhances the ligand affinity, via multiple coordination, to the magnetic NPs, while the hydrophilic and reactive groups promote colloidal stability in buffer media and allow subsequent conjugation with target biomolecules. Iron oxide nanoparticles ligand exchanged with these polymer ligands have a compact hydrodynamic size and exhibit enhanced long-term colloidal stability over the pH range of 4-12 and in the presence of excess electrolytes. Nanoparticles ligated with terminally reactive polymers have been easily coupled to target dyes and tested in live cell imaging with no measurable cytotoxicity. Finally, the resulting hydrophilic nanoparticles exhibit large and size-dependent r2 relaxivity values.

Bio-composites based on polypropylene reinforced with Almond Shells particles: Mechanical and thermal properties

International Nuclear Information System (INIS)

Essabir, H.; Nekhlaoui, S.; Malha, M.; Bensalah, M.O.; Arrakhiz, F.Z.; Qaiss, A.; Bouhfid, R.

2013-01-01

Highlights: • Almond Shells (ASs) particles have been used as reinforcement in polypropylene matrix. • The SEBS-g-MA has been used to improve the adhesion between matrix and particles. • The mechanical and thermal properties of the composite have been improved by the AS. - Abstract: In this work, Almond Shells (ASs) particles are used as reinforcement in a thermoplastic matrix as polypropylene (PP). Composites containing Almond Shells (ASs) particles with and without compatibilizer (maleic anhydride grafted polypropylene; SEBS-g-MA) for various particle content (5, 10, 15, 20, 25, 30 wt.%) was investigated by means of studying their mechanical, thermal and rheological properties. The composites were prepared in a twin-screw extruder and assessed by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), tensile testing and Dynamic Mechanical Analysis (DMA). Results show a clear improvement in mechanical and rheological properties from the use of Almond Shells particles in the matrix without and with maleic anhydride compatibilizer, corresponding to a gain in Young’s modulus of 56.2% and 35% respectively, at 30 wt.% particle loading. Thermal analysis revealed that incorporation of particle in the composites resulted in increase in the initial thermal decomposition temperatures

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

Science.gov (United States)

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

2016-12-01

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

Coating material composition

International Nuclear Information System (INIS)

Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Maeda, Yutaka.

1969-01-01

A coating material composition is provided which can easily be cross-linked by irradiation with active energy, particularly electron beams and ultraviolet light, using a mixture of a prepolymer (a) with an addition reaction product (b). Such compositions have coating properties as good as thermosetting acrylic or amino alkyd resins. The prepolymer (a) is produced by primarily reacting at least 0.1 mol of saturated cyclocarboxylic acid anhydrides and/or alpha-, beta-ethylene unsaturated carboxylic acid anhydrides by addition reaction with one mol of hydroxyl radicals of a basic polymer having a molecular weight of 1,000 to 100,000, the basic polymer being obtained from 1%-40% of a hydroxyl radical containing vinyl monomer and at least 30% of (meth)acrylate monomer. One mol of the sum of hydroxyl radicals and carboxyl radicals of the primary reaction product undergoes a secondary addition reaction with at least 0.1 mol of an epoxy radical-containing vinyl monomer to form the prepolymer(a). The addition reaction product(b) is produced by reacting an epoxy radical-containing vinyl monomer with alpha-, beta-ethylene unsaturated carboxylic acids or their anhydrides. The coating material composition contains a majority of a mixture consisting of 10%-90% of (a) and 90%-10% of (b) above by weight. Four examples of the production of basic polymers, seven examples of the production of prepolymers, seven examples of the production of oligomers, and five examples of applications are given. (Iwakiri, K.)

Synthesis and Verification of Biobased Terephthalic Acid from Furfural

Science.gov (United States)

Tachibana, Yuya; Kimura, Saori; Kasuya, Ken-Ichi

2015-02-01

Exploiting biomass as an alternative to petrochemicals for the production of commodity plastics is vitally important if we are to become a more sustainable society. Here, we report a synthetic route for the production of terephthalic acid (TPA), the monomer of the widely used thermoplastic polymer poly(ethylene terephthalate) (PET), from the biomass-derived starting material furfural. Biobased furfural was oxidised and dehydrated to give maleic anhydride, which was further reacted with biobased furan to give its Diels-Alder (DA) adduct. The dehydration of the DA adduct gave phthalic anhydride, which was converted via phthalic acid and dipotassium phthalate to TPA. The biobased carbon content of the TPA was measured by accelerator mass spectroscopy and the TPA was found to be made of 100% biobased carbon.

Radiation-curable coatings containing reactive pigment dispersants

International Nuclear Information System (INIS)

Ansel, R.E.

1985-01-01

Liquid coating compositions adapted to be cured by exposure to penetrating radiation are disclosed in which a liquid vehicle of coating viscosity having an ethylenically unsaturated portion comprising one or more polyethylenically unsaturated materials adapted to cure on radiation exposure, pigment dispersed in the vehicle, and an ethylenically unsaturated radiation-curable dispersant containing a carboxyl group for wetting the pigment and assisting in the stable dipsersion of the pigment in the vehicle. This dispersant is a half amide or half ester of an ethylenically unsaturated polycarboxylic acid anhydride, such as maleic anhydride, with an organic compound having a molecular weight of from 100 to 4000 and which contains a single hydroxy group or a single amino group as the sole reactive group thereof

Effect of maleic hydrazide and waxing on quality and shelf life of papaya (carica papaya L.) fruits

International Nuclear Information System (INIS)

Abu-Goukh, A. A.; Shattir, A. E.

2012-01-01

The effect of post harvest treatment of maleic hydrazide (MH) with and with out waxing on the quality and shelf-life of Baladi and Ekostika I papaya fruits at 18 ±1°C and 85%-90% relative humidity was evaluated. Maleic hydrazide at 250 and 500 ppm significantly delayed fruit ripening by two and three days in both papaya cultivars, respectively, compared with untreated fruits. The higher the concentration, the more was the delay in fruit ripening. The results also showed that waxing addition to MH resulted in a delay of two more days in fruit ripening that treatment with MH alone. The effect of MH and waxing treatments in delaying papaya fruits ripening was manifested in retarded respiratory climacteric, reduced weight loss and delayed fruit softening and increase in total soluble solids and ascorbic acid content.(Author)

Aerobic biodegradation of vinyl chloride in groundwater samples

International Nuclear Information System (INIS)

Davis, J.W.; Carpenter, C.L.

1990-01-01

Studies were conducted to examine the biodegradation of 14 C-labeled vinyl chloride in samples taken from a shallow aquifer. Under aerobic conditions, vinyl chloride was readily degraded, with greater than 99% of the labeled material being degraded after 108 days and approximately 65% being mineralized to 14 CO 2

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

NARCIS (Netherlands)

Thiyagarajan, Shanmugam; Genuino, Homer C.|info:eu-repo/dai/nl/371571685; Sliwa, Michal; van der Waal, Jan C.; de Jong, Ed; van Haveren, Jacco; Weckhuysen, Bert M.|info:eu-repo/dai/nl/285484397; Bruijnincx, Pieter C. A.|info:eu-repo/dai/nl/33799529X; van Es, Daan S.

2015-01-01

A novel route for the production of renewable aromatic chemicals, particularly substituted phthalic acid anhydrides, is presented. The classical two-step approach to furanics-derived aromatics via Diels-Alder (DA) aromatization has been modified into a three-step procedure to address the general

Wearing ambidextrous vinyl gloves does not impair manual dexterity.

Science.gov (United States)

Drabek, Tomas; Boucek, Charles D; Buffington, Charles W

2013-01-01

Universal precautions mandate that health care workers wear gloves to prevent the unintended spread of bloodborne pathogens. Gloves may affect manual dexterity, generally delaying task completion. Our previous study showed that wearing the wrong size latex surgical glove degraded manual dexterity. The use of non-sterile and non-latex gloves may limit certain risks and be more cost-effective. However, such gloves may produce different results. We hypothesized that ambidextrous vinyl examination gloves would degrade manual dexterity compared with bare hands. We studied 20 random subjects from a medical environment. Subjects performed a standard battery of Grooved Pegboard tasks while bare-handed, wearing ambidextrous non-sterile vinyl gloves that were their preferred size, a size too small, and a size too large. The order was randomized with a Latin Square design to minimize the effects of time, boredom, and fatigue on the subjects. Subjects were also invited to comment on the fit of different size gloves. Wearing vinyl gloves of both the preferred size and a size up or down failed to affect manual dexterity vs. bare hands on time to insert pegs, and pegs dropped during insertion or removal. In contrast, the time to remove pegs was reduced by wearing preferred size vinyl gloves compared with performing the task with bare hands (Pgloves that were too small caused significant hand discomfort. Vinyl gloves surprisingly do not degrade manual dexterity even when worn in ill-fitting sizes. Wearing a preferred size vinyl glove vs. bare hands may improve dexterity in selected tasks. Choosing a comfortable, large size seems the best strategy when the preferred size is unavailable. Thinner vinyl gloves may improve grip and may not degrade touch as much as latex surgical gloves and may thus represent a reasonable choice for selected tasks.

Characterization of TPS/PHBV blends prepared in the presence of maleated PHBV

International Nuclear Information System (INIS)

Magalhaes, Natalia F.; Andrade, Cristina T.

2011-01-01

Maleated derivatives of poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) were obtained in an internal mixer in the presence of maleic anhydride and benzoyl peroxide, and characterized by infrared spectroscopy. Extruded blends of cornstarch and PHBV were prepared with and without the addition of maleated PHBV. Although the X-ray diffractograms had revealed decreased crystallinity, the micrographs obtained by scanning electron microscopy indicated that the addition of the maleated derivatives led to a partial compatibilization. (author)

Method of modifying a vinyl chloride resin by utilizing radiation cross-linking polymerization

Energy Technology Data Exchange (ETDEWEB)

Kagiya, T; Fujimoto, T; Hosoi, F; Tsuneta, K; Atogawa, M

1970-08-26

The polyvinyl chloride is improved in its mechanical, thermal and chemical properties, with particular advantages gained in dimensional stability at temperatures higher than the plasticizing temperature. The process comprises irradiating a vinyl chloride resin with ionizing radiations in the presence of a vinyl acetate monomer. In this process, the irradiation of vinyl acetate effects cross-linking and the polymerization of the monomer simultaneously. The vinyl chloride resin may be a copolymer along with another monomer, a polyvinyl chloride derivative, a graft polymer of polyvinyl chloride, a mixture of vinyl chloride with another resin and a graft copolymer of vinyl chloride on another resin in any form. The addition of the vinyl acetate monomer to the vinyl chloride is not limited to any particular procedure. The vinyl acetate monomer may be added to the polyvinyl chloride in a quantity ranging from a trace to 200% by weight. The radiation dose may be 10/sup 2/ to 10/sup 9/, but preferably 10/sup 3/ roentgen. In one example, 36 parts by weight of market available vinyl acetate monomer immersed in 100 parts by weight of hard vinyl tube were placed in a stainless reacting vessel. After the replacement of inner air with nitrogen, the vessel was exposed to ..gamma.. beams of 4.8 x 10 roentgen from a Co-60 source. After dipping the exposed samples in boiled tetrahydrofuran for 48 hours, the insoluble substance in the samjle was 78.9% by weight. In addition, after heating at 180/sup 0/C for 30 minutes, the sample did not show any deformation.

Ethyl (1R*,10S*,12R*,15S*-4-Hydroxy-2-oxo-15- (2-oxo-1-pyrrolidinyl-9-oxatetracyclo[10.2.2.01,10.03,8]hexadeca-3,5,7,13-tetraene-13-carboxylate

Directory of Open Access Journals (Sweden)

Jorge Heredia-Moya

2017-01-01

Full Text Available N-Vinylpirrolidinone reacts with (E-ethyl 5-hydroxy-3-(4-oxo-4H-chromen-3-yl acrylate (1 through a domino reaction similar to that reported reaction for ethyl vinyl ether. Inverse electron demand Diels–Alder (IEDDA–elimination-IEDDA generates isomeric tetracycles 5 and 6. The assignment of the relative stereochemistry of the products was made by comparing the proton couplings with those obtained by reaction with ethyl vinyl ether.

IRIS Toxicological Review of Vinyl Chloride (Final Report, 2000)

Science.gov (United States)

EPA is announcing the release of the final report, Toxicological Review of Vinyl Chloride: in support of the Integrated Risk Information System (IRIS). The updated Summary for Vinyl Chloride and accompanying Quickview have also been added to the IRIS Database.

A Novel Voltammetric Method for the Determination of Maleic Acid Using Silver Amalgam Paste Electrode

Czech Academy of Sciences Publication Activity Database

Niaz, A.; Fischer, J.; Barek, J.; Josypčuk, Bohdan; Sirajuddin, C.; Bhanger, M. I.

2009-01-01

Roč. 21, č. 15 (2009), s. 1719-1722 ISSN 1040-0397 R&D Projects: GA MŠk(CZ) LC06035; GA ČR GA203/07/1195 Institutional research plan: CEZ:AV0Z40400503 Keywords : voltammetry * maleic acid * silver amalgam paste electrode Subject RIV: CG - Electrochemistry Impact factor: 2.630, year: 2009

Meiotic changes in Vicia faba L. subsequent to treatments of hydrazine hydrate and maleic hydrazide

Directory of Open Access Journals (Sweden)

Shaheen Husain

2013-01-01

Full Text Available Assessing the impact of mutagens for creating variations in crops like faba bean (Vicia faba L. is an important criterion in the contemporary world where food insecurity and malnutrition is alarming at the doors of various nations. Impact of two chemical mutagens viz. hydrazine hydrate (HZ and maleic hydrazide (MH on the two varieties (NDF-1 and HB-405 of Vicia faba were analysed in terms of meiotic behavior and pollen sterility. Since there are not enough data about the effect of these mutagens on the chromosomal behaviors of Vicia faba, this study presents the role of hydrazine hydrate and maleic hydrazide as well as various types of chromosomal aberrations in crop improvement. The lower concentration of mutagens showed less pollen sterility compared to the higher concentrations. Manipulation of plant structural component to induce desirable alternations provides valuable material for the breeders and could be used favorably for increasing mutation rate and obtaining a desirable spectrum of mutation in faba beans based on preliminary studies of cell division.

Graft copolymerization of styrene onto poly(vinyl alcohol) initiated by potassium diperiodatocuprate (III)

International Nuclear Information System (INIS)

Bai, L.; Wang, Ch.; Jin, J.; Liu, Y.

2009-01-01

The graft copolymerization of styrene onto poly(vinyl alcohol) is studied by using a novel redox system of potassium diperiodatocuprate-poly(vinyl alcohol) (Cu(III)poly(vinyl alcohol) in alkaline medium. Cu(III)-poly(vinyl alcohol) redox pair is an efficient initiator for this graft copolymerization which is proved by high graft efficiency (>97%) and high percentage of graft (>300%). Reaction conditions (monomer-to-poly(vinyl alcohol) weight ratio, initiator concentration, p H, time and temperature) affect the graft parameters which have been investigated systematically. The optimum reaction conditions are found as St/poly(vinyl alcohol) = 5.4; [Cu(III)] = 1*10 -2 M; p H = 12.7; temperature = 50 d eg C ; time = 3.5 h. Further, the equation of the overall polymerization rate can be written as follows: R p = k C 1.9 (St) C 1.7 (Cu(III)). The overall activation energy was calculated to be 42.0 kJ/mol based on the experimental data of the relations between R p and C(St); R p and C(Cu(III)); and R p and temperature. A mechanism is proposed to explain the formation of radicals and the initiation. The structure of the graft copolymers is confirmed by Fourier transfer infrared spectroscopy. Some peaks were compared with poly(vinyl alcohol) at 3080.34-3001.79 cm -1 (=C-H stretching in the phenyl ring), 1600.34-1450.95 cm -1 (C=C stretching in the phenyl ring), 755.17 cm -1 and 698.64 cm -1 (=C-H out-off-plane bending in phenyl ring) which are considered to belong to the characteristic absorption bands of phenyl group of polystyrene. Therefore it proves that the graft copolymer is composed of poly(vinyl alcohol) and polystyrene. thermal gravimetric analysis thermo grams of poly(vinyl alcohol) and poly(vinyl alcohol)-graft-polystyrene are investigated as well. As it is shown the initial decomposition temperature of poly(vinyl alcohol)-g-polystyrene(377.3 d eg C ) is much higher than that of poly(vinyl alcohol) (241.8 d eg C ), which indicates that the thermal stability of the

Vapor phase carbonylation of dimethyl ether and methyl acetate with supported transition metal catalysts

International Nuclear Information System (INIS)

Shikada, T.; Fujimoto, K.; Tominaga, H.O.

1986-01-01

The synthesis of acetic acid (AcOH) from methanol (MeOH) and carbon monoxide has been performed industrially in the liquid phase using a rhodium complex catalyst and an iodide promoter. The selectivity to AcOH is more than 99% under mild conditions (175 0 C, 28 atm). The homogeneous rhodium catalyst has been also effective for the synthesis of acetic anhydride (Ac 2 O) by carbonylation of dimethyl ether (DME) or methyl acetate (AcOMe). However, rhodium is one of the most expensive metals and its proved reserves are quite limited. It is highly desired, therefore, to develop a new catalyst as a substitute for rhodium. The authors have already reported that nickel supported on active carbon exhibits an excellent activity for the vapor phase carbonylation of MeOh in the presence of iodide promoter and under moderately pressurized conditions. In addition, corrosive attack on reactors by iodide compounds is expected to be negligible in the vapor phase system. In the present work, vapor phase carbonylation of DME and AcOMe on nickel-active carbon (Ni/A.C.) and molybdenum-active carbon (Mo/A.C.) catalysts was studied

Syntheses of protoporphyrin-IX regioselectivity carbon-13 labelled at the alpha-vinyl carbons

International Nuclear Information System (INIS)

Smith, K.M.; Fujinari, E.M.

1986-01-01

A method for transformation of readily available beta-vinyl 99% carbon-13 enriched derivatives of protoporphyrin-IX dimethyl ester into the less accessible alpha-vinyl labelled isomers is described. The procedure involves thallium(III) promoted vinyl carbon rearrangement, and proceeds through 2,2-dimethoxyethyl, formylmethyl, 2-hydroxyethyl and 2-chloroethyl porphyrins; the rearranged vinyl groups are regenerated from 2-chloroethyl in the last step by treatment with base. No evidence of vinyl carbon scrambling in the sequence is observed, and spectroscopic data of the products are given. (author)

Silane Cross-Linked Sulfonted Poly(Ether Ketone/Ether Benzimidazoles for Fuel Cell Applications

Directory of Open Access Journals (Sweden)

Zilu Yao

2017-11-01

Full Text Available γ-(2,3-epoxypropoxy propyltrimethoxysilane (KH-560 was incorporated in various proportions into side-chain-type sulfonated poly(ether ketone/ether benzimidazole (SPEKEBI as a crosslinker, to make membranes with high ion exchange capacities and excellent performance for direct methanol fuel cells (DMFCs. Systematical measurements including Fourier transform infrared (FT-IR, scanning electron microscopy-energy-dispersive and X-ray photoelectron spectroscopy (XPS proved the complete disappearance of epoxy groups in KH-560 and the existence of Si in the membranes. The resulting membranes showed increased mechanical strength and thermal stability compared to the unmodified sulfonated poly(ether ketone/ether benzimidazole membrane in appropriate doping amount. Meanwhile, the methanol permeability has decreased, leading to the increase of relative selectivities of SPEKEBI-x-SiO2 membranes. Furthermore, the H2/O2 cell performance of SPEKEBI-2.5-SiO2 membrane showed a much higher peak power density compared with the pure SPEKEBI memrbrane.

Critical properties of some aliphatic symmetrical ethers

International Nuclear Information System (INIS)

Nikitin, Eugene D.; Popov, Alexander P.; Bogatishcheva, Nataliya S.

2014-01-01

Highlights: • Critical properties of simple aliphatic ethers were measured. • The ethers decompose at near-critical temperatures. • Pulse-heating method with short residence times was used. -- Abstract: The critical temperatures T c and the critical pressures p c of dihexyl, dioctyl, and didecyl ethers have been measured. According to the measurements, the coordinates of the critical points are T c = (665 ± 7) K, p c = (1.44 ± 0.04) MPa for dihexyl ether, T c = (723 ± 7) K, p c = (1.19 ± 0.04) MPa for dioctyl ether, and T c = (768 ± 8) K, p c = (1.03 ± 0.03) MPa for didecyl ether. All the ethers studied degrade chemically at near-critical temperatures. A pulse-heating method applicable to measuring the critical properties of thermally unstable compounds has been used. The times from the beginning of a heating pulse to the moment of reaching the critical temperature were from 0.06 to 0.46 ms. The short residence times provide little decomposition of the substances in the course of the experiments. The critical properties of the ethers investigated in this work have been discussed together with those of methyl to butyl ethers. The experimental critical constants of the ethers have been compared with those estimated by the group-contribution methods of Wilson and Jasperson and Marrero and Gani. The Wilson/Jasperson method provides a better estimation of the critical temperatures and pressures of simple aliphatic ethers in comparison with the Marrero/Gani method if reliable normal boiling temperatures are used in the method of Wilson and Jasperson

Effect of gamma ray on poly(lactic acid)/poly(vinyl acetate-co-vinyl alcohol) blends as biodegradable food packaging films

International Nuclear Information System (INIS)

Razavi, Seyed Mohammad; Dadbin, Susan; Frounchi, Masoud

2014-01-01

Poly(lactic acid) (PLA)/poly(vinyl acetate-co-vinyl alcohol) [P(VAc-co-VA)] blends as new transparent film packaging materials were prepared at various blend compositions and different vinyl alcohol contents. The blends and pure PLA were irradiated by gamma rays to investigate the extent of changes in the packaging material during gamma ray sterilization process. The miscibility of the blends was dependent on the blend composition and vinyl alcohol content; gamma irradiation had little effect on the extent of miscibility. The glass transition temperature of pure PLA and PLA/P(VAc-co-VA) miscible blends reduced after irradiation. On the other hand in PLA/P(VAc-co-VA) immiscible blends, while the glass transition temperature of the PLA phase decreased; that of the copolymer phase slightly increased. The reduction in the glass transition was about 10 percent for samples irradiated with 50 kGy indicating dominance of chain scission of PLA molecules at high irradiation dose. The latter was verified by drop in mechanical properties of pure PLA after exposing to gamma irradiation at 50 kGy. Blending of PLA with the copolymer P(VAc-co-VA) compensated greatly the adverse effects of irradiation on PLA. The oxygen-barrier property of the blend was superior to the neat PLA and remained almost intact with irradiation. The un-irradiated and irradiated blends had excellent transparency. Gamma ray doses used for sterilization purposes are usually less than 20 kGy. It was shown that gamma irradiation at 20 kGy had no or little adverse effects on PLA/P(VAc-co-VA) blends mechanical and gas barrier properties. - Highlights: • Poly(lactic acid)/poly(vinyl acetate-co-vinyl alcohol) blends were prepared as new packaging film. • The blends are superior to PLA in oxygen gas barrier property. • The blends are suitable for gamma ray sterilization and maintain useful mechanical properties. • The blends are perfectly transparent

In situ polymerization of vinyl monomers in polyester yarns

International Nuclear Information System (INIS)

Avny, Y.; Rebenfeld, L.; Weigmann, H.D.

1978-01-01

The effects of a pretreatment of polyester (PET) yarns with a strongly interacting solvent such as dimethylformamide (DMF) on vinyl monomer incorporation were investigated. When the DMF pretreatment is carried out at high temperatures (above 120 0 C), the swollen PET structure is stabilized by solvent-induced secondary crystallization. This substrate is highly suitable for the incorporation of vinyl monomers. In situ polymerization of vinyl monomers in DMF-treated PET was investigated using chemical and γ-irradiation polymerization techniques, both in the presence and in the absence of excess monomer outside the PET fibers. When polymerization was carried out in a system in which a constant supply of free radicals was available from the outside of the PET fibers, lower initiator concentrations and smaller γ-irradiation doses were necessary. These results are attributed to a low efficiency of the initiator inside the PET fiber due to mobility restrictions. Water uptake and moisture regain of PET yarns containing poly(hydroxyethyl methacrylate) and poly(acrylic acid) were also investigated. When most of the vinyl polymer was inside the PET fiber, water absorption was limited. The changes in mechanical properties of the PET yarns resulting from the DMF pretreatment were partially reversed by in situ polymerization of vinyl monomers

Poly (ether ether ketone) membranes for fuel cells

International Nuclear Information System (INIS)

Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D.; Hui, Wang S.; Oliveira, Vivianna S. de

2015-01-01

Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

Ion-Selective Ionic Polymer Metal Composite (IPMC) actuator based on crown ether containing sulfonated Poly(Arylene Ether Ketone)

NARCIS (Netherlands)

Tas, S.; Zoetebier, B.; Sukas, O.S.; Bayraktar, M.; Hempenius, M.; Vancso, G.J.; Nijmeijer, K.

2017-01-01

This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

Research Needs: Glass Solar Reflectance and Vinyl Siding

Energy Technology Data Exchange (ETDEWEB)

Hart, Robert; Curcija, Charlie; Arasteh, Dariush; Goudey, Howdy; Kohler, Christian; Selkowitz, Stephen

2011-07-07

The subject of glass solar reflectance and its contribution to permanent vinyl siding distortion has not been extensively studied, and some phenomena are not yet well understood. This white paper presents what is known regarding the issue and identifies where more research is needed. Three primary topics are discussed: environmental factors that control the transfer of heat to and from the siding surface; vinyl siding properties that may affect heat build-up and permanent distortion; and factors that determine the properties of reflected solar radiation from glass surfaces, including insulating window glass. Further research is needed to fully characterize the conditions associated with siding distortion, the scope of the problem, physical properties of vinyl siding, insulating window glass reflection characteristics, and possible mitigation or prevention strategies.

Respiratory Allergy to Trimellitic Anhydride in Rats: Concentration-Response Relationships during Elicitation

NARCIS (Netherlands)

Arts, J.H.E.; Koning, M.W. de; Bloksma, N.; Kuper, C.F.

2004-01-01

The present study investigated whether airway responses of sensitized rats to trimellitic anhydride (TMA) were concentration dependent and whether these were related to irritation by TMA. Groups of BN and Wistar rats were sensitized by two dermal applications of TMA (50% w/v, followed by 25% w/v in

Improving the Conductivity of Sulfonated Polyimides as Proton Exchange Membranes by Doping of a Protic Ionic Liquid

Directory of Open Access Journals (Sweden)

Bor-Kuan Chen

2014-10-01

Full Text Available Proton exchange membranes (PEMs are a key component of a proton exchange membrane fuel cell. Sulfonated polyimides (SPIs were doped by protic ionic liquid (PIL to prepare composite PEMs with substantially improved conductivity. SPIs were synthesized from diamine, 2,2-bis[4-(4-amino-phenoxyphenyl]propane (BAPP, sulfonated diamine, 4,4'-diamino diphenyl ether-2,2'-disulfonic acid (ODADS and aromatic anhydride. BAPP improved the mechanical and thermal properties of SPIs, while ODADS enhanced conductivity. A PIL, 1-vinylimidazolium trifluoromethane-sulfonate ([VIm][OTf], was utilized. [VIm][OTf] offered better conductivity, which can be attributed to its vinyl chemical structure attached to an imidazolium ring that contributed to ionomer-PIL interactions. We prepared sulfonated polyimide/ionic liquid (SPI/IL composite PEMs using 50 wt% [VIm][OTf] with a conductivity of 7.17 mS/cm at 100 °C, and in an anhydrous condition, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride (DSDA was used in the synthesis of SPIs, leading to several hundred-times improvement in conductivity compared to pristine SPIs.

Radiation-chemical preparation of poly(vinyl alcohol) hydrogels

International Nuclear Information System (INIS)

Duflot, Anastasia V.; Kitaeva, Natalia K.; Duflot, Vladimir R.

2015-01-01

This work reports the usage of method of radiation-chemical synthesis to prepare cross-linked hydrogels from poly(vinyl alcohol) modified with glycidyl methacrylate. Synthesis kinetics of modified poly(vinyl alcohol) and properties of hydrogels were studied. The gel fraction, swelling, mechanical properties, and water content of the hydrogels were measured. It was found that gel fraction increases with increasing radiation dose, concentration of modified poly(vinyl alcohol), and reaches 60%. It was established by differential scanning calorimetry that a fraction of the “bound” water in hydrogels is 50–70% and independent of gel fraction content. In addition to “bound” and “free” states, water in hydrogels is also present in the intermediate state. - Highlights: • The synthesis and the properties of poly(vinyl alcohol) hydrogels were studied. • PVA was modified by glycidyl methacrylate before gamma cross-linking. • The modification results in decreasing of PVA cross-linking dose by 3 orders lower. • The gel fraction and water content of the hydrogels were measured. • A fraction of the “bound” water in hydrogels is independent of gel fraction content

Mass spectrometric investigation of vinyl-substituted organic boron compounds

International Nuclear Information System (INIS)

Tarielashvili, V.O.; Ordzhonikidze, K.G.; Parulava, L.P.; Vakhaniya, G.V.

1992-01-01

Mass spectrometric investigation of vinyl-substituted organic compounds was conducted. Ionization was performed by electron shock. Possibility of determining boron isotope content is all analyzed organic boron vinyl-substituted compounds by direct method is shown. This simplifies sufficiently and lowers the price of analysis, improves its accuracy and rapidity

Antimicrobial residual effects of irrigation regimens with maleic acid in infected root canals

OpenAIRE

Ferrer-Luque, Carmen Mar?a; Gonz?lez-Castillo, Silvia; Ruiz-Linares, Matilde; Arias-Moliz, Mar?a Teresa; Rodr?guez-Archilla, Alberto; Baca, Pilar

2015-01-01

Background The success of endodontic treatment depends largely on the control of microorganisms present in infected root canals. The aim of this study was to determine the residual antimicrobial activity of several final irrigation protocols with 7% maleic acid (MA) alone and combined with chlorhexidine (CHX), cetrimide (CTR) or both, in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown in uniradicular roots for 4 weeks. A total of 72 specimens were divided i...

High performance maleated lignocellulose epicarp fibers for copper ion removal

OpenAIRE

Vieira,A. P.; Santana,S. A. A.; Bezerra,C. W. B.; Silva,H. A. S.; Santos,K. C. A.; Melo,J. C. P.; Silva Filho,E. C.; Airoldi,C.

2014-01-01

Natural lignocellulosic fiber epicarp extracted from the babassu coconut (Orbignya speciosa) was chemically modified through reaction with molten maleic anhydride without solvent, with incorporation of 189.34 mg g(-1) of carboxylic acid groups into the biopolymer structure. The success of this reaction was also confirmed by the presence of carboxylic acid bands at 1741 and 1164 cm(-1) in the infrared spectrum. Identically, the same group is observed through C-13 NMR CP/MAS in the solid state,...

IgG binding of mugwort pollen allergens and allergoids exposed to simulated gastrointestinal conditions measured by a self-developed ELISA test

OpenAIRE

RATKO M. JANKOV; OLGA VUCKOVIC; DANICA DJERGOVIC-PETROVIC; LIDIJA BURAZER; TANJA D. CIRKOVICVELICKOVIC; MARIJA DJ. GAVROVIC-JANKULOVIC; NATALIJA DJ. POLOVIC

2004-01-01

This study considers the influence of exposure to simulated gastrointestinal conditions (saliva, gut, intestine and acidic conditions of the gut) on IgG binding of unmodified allergens and three types of LMW allergoids of Artemisia vulgaris pollen extract obtained by means of potassium cyanate, succinic and maleic anhydride. It also concerns the optimization of a self-developed ELISA assay for comparison of the specific IgG binding of mugwort pollen extract and modified mugwort pollen derivat...

Morphology Development and Mechanical Properties Variation during Cold-Drawing of Polyethylene-Clay Nanocomposite Fibers

OpenAIRE

Bartolomeo Coppola; Paola Scarfato; Loredana Incarnato; Luciano Di Maio

2017-01-01

In this work, the influence of composition and cold-drawing on nano- and micro-scale morphology and tensile mechanical properties of PE/organoclay nanocomposite fibers was investigated. Nanocomposites were prepared by melt compounding in a twin-screw extruder, using a maleic anhydride grafted linear low density polyethylene (LLDPE–g–MA) and an organomodified montmorillonite (Dellite 67G) at three different loadings (3, 5 and 10 wt %). Fibers were produced by a single-screw extruder and drawn ...

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-08-19

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

All solid supercapacitor based on polyaniline and crosslinked sulfonated poly[ether ether ketone

International Nuclear Information System (INIS)

Sivaraman, P.; Kushwaha, R.K.; Shashidhara, K.; Hande, V.R.; Thakur, A.P.; Samui, A.B.; Khandpekar, M.M.

2010-01-01

All solid supercapacitor based on polyaniline (PANI) and crosslinked sulfonated poly[ether ether ketone] (XSPEEK,) is reported in this paper. The crosslinker used for sulfonated poly[ether ether ketone] (SPEEK) is 1,4-bis(hydroxymethyl) benzene. The XSPEEK is used as both solid electrolyte and separator membrane. Supercapacitors are fabricated using various PANI/XSPEEK weight ratios. These are characterized by cyclic voltammetry and galvanostatic charge-discharge studies. The supercapacitor with PANI/XSPEEK weight ratio 1:0.5, exhibit a specific capacitance of 480 F g -1 of PANI. To the best of authors' knowledge, the value reported here is the highest for a supercapacitor based on a proton conducting solid polymer electrolyte and PANI. Detailed electrochemical impedance spectroscopy analysis is carried out. The analysis shows that the complex capacitance of the supercapacitor depends on the XSPEEK content. The time constant (t 0 ), derived from the imaginary part of complex capacitance decreases with increase in the XSPEEK content in the supercapacitor. Cycle life characteristics of the supercapacitor show a decrease in specific capacitance during initial cycles and get stabilized during later cycles.

Production of polymer composites by radiation and chemical treatments from recycled plastic wastes and their applications

International Nuclear Information System (INIS)

Khaffaga, M.R.A.

2009-01-01

Different applied methods have been proposed for the recycling of poly (ethylene terephthalate)(PET) and its blends with other polymers to obtain useful products. These methods are based on blending with different polymers or compounding with radiation synthesized copolymers based on maleic anhydride with methyl methacrylate, styrene and vinyl acetate. On the other hand, the methods proposed to improve the miscibility of mixed polymers are based on different methods of gamma and electron beam irradiation at various doses (30-50 kGy). Also , the addition of compatibilizers based on LDPE graft copolymer with comonomer composed of ethylene glycol (EG) and acrylic acid (AAc) as well as radiation synthesized copolymer based on acrylic acid and styrene (Sty) monomers during mixing. The modified properties were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), mechanical testing and studying the affinity for acid, based and disperse dyes. Based on the results obtained throughout this work, few conclusions may made:(1) The composites of PET with copolymers is effective than the blending with other polymers. (2) The pre method of gamma or electron beam irradiation is effectively improved the miscibility of PET/LDPE or PET/PS blends than the direct method of irradiation.(3) The addition of EG/AAc or AAc/Sty copolymers during mixing improved the miscibility than the use of graft copolymer.

Synthesis and characterization of functional copolymer/organo-silicate nanoarchitectures through interlamellar complex-radical (coterpolymerization

Directory of Open Access Journals (Sweden)

2008-09-01

Full Text Available The functional copolymers, having a combination of rigid/flexible linkages and an ability of complex-formation with interlayered surface of organo-silicate, and their nanocomposites have been synthesized by interlamellar complex-radical (coterpolymerization of intercalated monomer complexes of maleic anhydride (MA and itaconic acid (IA with dimethyl dodecylamine surface modified montmorillonite (organo-MMT (MA…DMDA-MMT and IA…DMDA-MMT n-butyl methacrylate (BMA and/or BMA/styrene monomer mixtures. The results of nanocomposite structure–composition– property relationship studies indicate that interlamellar complex-formation between anhydride/acid units and surface alkyl amine and rigid/flexible linkage balance in polymer chains are important factors providing the effective intercalation/ exfoliation of the polymer chains into the silicate galleries, the formation of nanostructural hybrids with higher thermal stability, dynamic mechanical behaviour and well dispersed morphology.

Langmuir-Blodgett films prepared from pre-formed cholestanic liquid-crystalline polymers

Energy Technology Data Exchange (ETDEWEB)

Tundo, P.; Hodge, P.; Valli, L.; Davis, F. (Venice Univ. (Italy). Dip. di Scienze Ambientali Lecce Univ. (Italy). Dip. di Scienza dei Materiali Manchester Univ. (United Kingdom). Dep. of Chemistry)

1992-01-01

A series of alternating copolymers of maleic anhydride and a-olefins functionalized through different alkyl chains with cholestanic groups were synthetised and derivatives prepared by reactions of the anhydride residues with methanol, water, dimethylamine and morpholine, respectively. The same starting functionalized a-olefins were used to prepare other suitable compounds in order to correlate the features of the liquid-crystalline behaviour of the mesogenic cholestanic group with the stability of the forthcoming polymeric or not polymeric Langmuir-Blodgett (LB) films. For some copolymers surface pressure against area per molecule isotherms are reported. In some multilayer (LB) films, the spacings between the layers were determined by the detection of BRAGG peaks by X-ray diffraction. The (LB) films of these polymers are closed packed, owing to either the polymeric skeleton or liquid-crystalline interaction.

Hydrogen storage by functionalised Poly(ether ether ketone)

Energy Technology Data Exchange (ETDEWEB)

Pedicini, R.; Giacoppo, G.; Carbone, A.; Passalacqua, E. [CNR-ITAE, Messina (Italy). Inst. for Advanced Energy Technologies

2010-07-01

In this work a functionalised polymer was studied as potential material for hydrogen storage in solid state. A Poly(ether ether ketone) (PEEK) matrix was modified by a manganese oxide in situ formation. Here we report the functionalisation process and the preliminary results on hydrogen storage capability of the synthesised polymer. The polymer was characterized by Scanning Electron Microscopy, X-ray diffraction, Transmission Electron Microscopy and Gravimetric Hydrogen Adsorption measurements. In the functionalised PEEK, morphological changes occur as a function of oxide precursor concentration and reaction time. Promising results by gravimetric measurements were obtained with a hydrogen sorption of 0.24%wt/wt at 50 C and 60 bar, moreover, reversibility hydrogen adsorption and desorption in a wide range of both temperature and pressure was confirmed. (orig.)

40 CFR 116.4 - Designation of hazardous substances.

Science.gov (United States)

2010-07-01

... acetic acid, vinegar acid Acetic anhydride 108247 Acetic oxide, acetyl oxide Acetone cyanohydrin 75865 2... Allyl alcohol 107186 2-propen-1-ol, 1-propenol-3, vinyl carbinol Allyl chloride 107051 3-chloropropene..., mercaptomethane, methyl sulfhydrate, thiomethyl alcohol Methyl methacrylate 80626 Methacrylic acid methyl ester...

Surface Properties of a Novel Poly(vinyl alcohol Film Prepared by Heterogeneous Saponification of Poly(vinyl acetate Film

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Seong Baek Yang

2017-10-01

Full Text Available Almost general poly(vinyl alcohol (PVA films were prepared by the processing of a PVA solution. For the first time, a novel poly(vinyl alcohol (PVA film was prepared by the saponification of a poly(vinyl acetate (PVAc film in a heterogenous medium. Under the same saponification conditions, the influence of saponification time on the degree of saponification (DS was studied for the preparation of the saponified PVA film, and it was found that the DS varied with time. Optical microscopy was used to confirm the characteristics and surface morphology of the saponified PVA film, revealing unusual black globules in the film structure. The contact angle of the films was measured to study the surface properties, and the results showed that the saponified PVA film had a higher contact angle than the general PVA film. To confirm the transformation of the PVAc film to the PVA film, 1H nuclear magnetic resonance spectroscopy, X-ray diffraction measurements, differential scanning calorimetry, and Fourier-transform infrared spectroscopy were employed.

Synthesis and Characterization of Polyaniline/Graphene Composite Nanofiber and Its Application as an Electrochemical DNA Biosensor for the Detection of Mycobacterium tuberculosis

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Fatimah Syahidah Mohamad

2017-12-01

Full Text Available This article describes chemically modified polyaniline and graphene (PANI/GP composite nanofibers prepared by self-assembly process using oxidative polymerization of aniline monomer and graphene in the presence of a solution containing poly(methyl vinyl ether-alt-maleic acid (PMVEA. Characterization of the composite nanofibers was carried out by Fourier transform infrared (FTIR and Raman spectroscopy, transmission electron microscopy (TEM and scanning electron microscopy (SEM. SEM images revealed the size of the PANI nanofibers ranged from 90 to 360 nm in diameter and was greatly influenced by the proportion of PMVEA and graphene. The composite nanofibers with an immobilized DNA probe were used for the detection of Mycobacterium tuberculosis by using an electrochemical technique. A photochemical indicator, methylene blue (MB was used to monitor the hybridization of target DNA by using differential pulse voltammetry (DPV method. The detection range of DNA biosensor was obtained from of 10−6–10−9 M with the detection limit of 7.853 × 10−7 M under optimum conditions. The results show that the composite nanofibers have a great potential in a range of applications for DNA sensors.

Proton-conducting membrane based on epoxy resin-poly(vinyl alcohol)-sulfosuccinic acid blend and its nanocomposite with sulfonated multiwall carbon nanotubes for fuel-cell application

Science.gov (United States)

Kakati, Nitul; Das, Gautam; Yoon, Young Soo

2016-01-01

A blend of poly(vinyl alcohol) (PVA) with diglycidyl ether of bisphenol-A (DGB) in the presence of sulfosuccinic acid (SSA) was investigated as hydrolytically-stable proton-conducting membrane. The PVA modification was carried out by varying the DGB:SSA ratio (20:20, 10:20, and 5:20). A nanocomposite of the blend (20:20) was prepared with sulfonated multiwall carbon nanotubes (viz., 1, 3 and 5 wt%). The water uptake behavior and the proton conductivity of the prepared membranes were evaluated. The ionic conductivity of the membranes and the water uptake behavior depended on the s-MWCNT and the DGB contents. The ionic conductivity showed an enhancement for the blend and for the nanocomposite membrane as compared to the pristine polymer.

Tailor-made starch-based conjugates containing well-defined poly(vinyl acetate and its derivative poly(vinyl alcohol

Directory of Open Access Journals (Sweden)

2011-06-01

Full Text Available Reversible addition-fragmentation chain transfer (RAFT polymerization was adopted to synthesize starch-based conjugates that possessed controllable architecture and properties. Starch-based xanthate agent was prepared and applied as chain transfer agent to conduct the living/controlled polymerization (LCP of vinyl acetate, which generated tailor-made conjugates of starch and well-defined poly(vinyl acetate (SVAc. The relevant derivatives, conjugates of starch and chain length-controlled poly(vinyl alcohol (SVA, were obtained subsequently. Various characterizations such as Fourier transform infrared spectra (FTIR, ultraviolet-visible spectroscopy (UV, proton nuclear magnetic resonance (1H NMR, gel permeation chromatography (GPC, X-ray diffraction (XRD, Thermogravimetric analysis (TGA, and dynamic mechanical thermal analysis (DMTA were performed to examine the structure of intermediates and the starch-based conjugates. Static contact angle measurements revealed that the hydrophilic character of starch-based conjugates was tunable. Well-defined SVAc was amphiphilic and it was able to self-assemble into size controllable micelles, which was verified by contact angles, transmission electron microscopy (TEM and dynamic light scattering (DLS tests. SVA exhibited much higher capability to form physically cross-linked hydrogel than starch did. Both the characteristic of SVAc and SVA were chain length-dependent.

Maleic acid and aluminum chloride catalyzed conversion of glucose to 5-(hydroxymethyl) furfural and levulinic acid in aqueous media

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ximing [Laboratory of Renewable Resources Engineering and Department of Agricultural and Biological Engineering; Purdue University; West Lafayette; USA; The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Murria, Priya [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Jiang, Yuan [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Xiao, Weihua [Laboratory of Renewable Resources Engineering and Department of Agricultural and Biological Engineering; Purdue University; West Lafayette; USA; College of Engineering; Kenttämaa, Hilkka I. [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Abu-Omar, Mahdi M. [The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio); Discovery Park; Purdue University; West Lafayette; USA; Mosier, Nathan S. [Laboratory of Renewable Resources Engineering and Department of Agricultural and Biological Engineering; Purdue University; West Lafayette; USA; The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio)

2016-01-01

Maleic acid (MA) and AlCl₃self-assemble into catalytic complexes (Al–(MA)₂–(OH)₂(aq)) with improved selectivity for converting glucose to HMF, and levulinic acid.

Novel coating compositions

International Nuclear Information System (INIS)

Kimura, Tadashi; Kobayashi, Juichi; Nakamoto, Hideo.

1969-01-01

An acrylic coating composition rapidly hardenable by irradiating with ionizing radiations or light beams is given using hydroxyl group-containing vinyl monomers, polycarboxylic acid anhydrides, epoxy group-containing vinyl monomers and an organic solvent having a boiling point of at least 120 0 C. The process comprises the steps of first and second reactions. The first reaction takes place between one mol of a hydroxyl group of a basic polymer and at least 0.1 mol of polycarboxylic acid anhydride, wherein the basic polymer has a molecular weight ranging from 5,000 to 100,000 and consists of 1-40% by weight of vinyl monomer containing hydroxyl group, at least 30% of (meth)acrylic monomer and other vinyl monomers if required. The second reaction takes place between one mol of hydroxyl plus a carboxyl group of the thus obtained basic polymer and at least 0.1 mol of an epoxy group-containing vinyl monomer to produce a prepolymer. The prepolymer is mixed with a solvent such as ethyl benzene to produce the coating material. The electron beam accelerator energy level may be 0.1-2.0 MeV. In light beam polymerization, benzoin is particularly utilized as an intensifying substance. In one example, a basic polymer is produced by reacting 39 parts of styrene, 37 parts of ethyl acrylate, 24 parts of 2-hydroxyl ethyl acrylate, 4 parts of dimethyl amino ethyl methacrylate and others. A prepolymer is produced by reacting this basic polymer with 30 parts of glycidyl acrylate and others. (Iwakiri, K.)

Activity relationships for aromatic crown ethers

International Nuclear Information System (INIS)

Wilson, Mark James

1998-01-01

This thesis involves an investigation of aromatic crown ethers and a study of their binding constants for alkali metals. The study was motivated by the current needs of the semiconductor industry to improve the scavenging of mobile ions from fabricated circuits. A number of aromatic crown ethers have been sulphonated in an attempt to improve their water solubility and cation binding activity. These materials have been extensively studied and their binding activity determined. In collaboration with a molecular modelling study, the effect of ionisable sulphonate groups on the macrocycles' behaviour has been investigated. The broader issue of the effect of substituents in aromatic crown ethers has also been studied with the preparation of a wide range of substituted crown ethers. The cation binding activity of these materials has been found to bear a simple relationship to the electron withdrawing nature of the aromatic substituents. This relationship can be accurately monitored using electronic charge densities from molecular modelling and this rational has been applied to the study of proton ionisable and lariating crown ethers. The incorporation of crown ethers into polyamic acid and polyimide frameworks has also been investigated, where the resulting materials have been found to exhibit unusual cation binding and uptake properties. These results imply that the combination of the crown ethers' macrocycle and adjacent carboxylic acid residues, from the polyamic acids, are conducive to effective cationic binding. NMR measurements, in conjunction with molecular modelling, have been used to explore the geometry changes encountered as the crown ether goes from it's uncomplexed to its complexed state. The energy requirement for these geometry changes has subsequently been used to examine the cation selectivity of these materials. The electronic charge changes associated with the complexation have also been investigated and correlated with the theoretical results. (author)

Importance of relative humidity in the oxidative ageing of organic aerosols: case study of the ozonolysis of maleic acid aerosol

Directory of Open Access Journals (Sweden)

P. J. Gallimore

2011-12-01

Full Text Available Many important atmospheric aerosol processes depend on the chemical composition of the aerosol, e.g. water uptake and particle cloud interactions. Atmospheric ageing processes, such as oxidation reactions, significantly and continuously change the chemical composition of aerosol particles throughout their lifetime. These ageing processes are often poorly understood. In this study we utilize an aerosol flow tube set up and an ultra-high resolution mass spectrometer to explore the effect of relative humidity (RH in the range of <5–90% on the ozonolysis of maleic acid aerosol which is employed as model organic aerosol system. Due to the slow reaction kinetics relatively high ozone concentrations of 160–200 ppm were used to achieve an appreciable degree of oxidation of maleic acid. The effect of oxidative ageing on the hygroscopicity of maleic acid particles is also investigated using an electrodynamic balance and thermodynamic modelling. RH has a profound effect on the oxidation of maleic acid particles. Very little oxidation is observed at RH < 50% and the only observed reaction products are glyoxylic acid and formic acid. In comparison, when RH > 50% there are about 15 oxidation products identified. This increased oxidation was observed even when the particles were exposed to high humidities long after a low RH ozonolysis reaction. This result might have negative implications for the use of water as an extraction solvent for the analysis of oxidized organic aerosols. These humidity-dependent differences in the composition of the ozonolyzed aerosol demonstrate that water is both a key reactant in the oxidation scheme and a determinant of particle phase and hence diffusivity. The measured chemical composition of the processed aerosol is used to model the hygroscopic growth, which compares favourably with water uptake results from the electrodynamic balance measurements. A reaction mechanism is presented which takes into account the RH dependent

Preparation and characterization of poly(methyl methacrylate)-clay nanocomposites via melt intercalation: Effect of organoclay on thermal, mechanical and flammability properties

Energy Technology Data Exchange (ETDEWEB)

Unnikrishnan, Lakshmi; Mohanty, Smita [Laboratory for Advanced Research in Polymeric Materials (LARPM), Central Institute of Plastics Engineering and Technology, Bhubaneswar 751024 (India); Nayak, Sanjay K., E-mail: drsknayak@gmail.com [Laboratory for Advanced Research in Polymeric Materials (LARPM), Central Institute of Plastics Engineering and Technology, Bhubaneswar 751024 (India); Ali, Anwar [Laboratory for Advanced Research in Polymeric Materials (LARPM), Central Institute of Plastics Engineering and Technology, Bhubaneswar 751024 (India)

2011-05-15

Research highlights: {yields} The present work deals with preparation and characterization of poly(methyl methacrylate) nanocomposites via melt intercalation technique. {yields} The effect of various modified nanoclays on the properties of base matrix has been investigated. {yields} It was observed that compatibilization using maleic anhydride improved the performance characteristics of PMMA/layered silicate nanocomposites. - Abstract: The PMMA nanocomposites were prepared by melt processing method. The influence of organoclay loading on extent of intercalation, thermal, mechanical and flammability properties of poly(methyl methacrylate) (PMMA)-clay nanocomposites were studied. Three different organoclay modifiers with varying hydrophobicity (single tallow vs. ditallow) were investigated. The nanocomposites were characterized by using wide angle X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and tensile tests. The intercalation of polymer chain within the silicate galleries was confirmed by WAXD and TEM. Mechanical properties such as tensile modulus (E), tensile strength, percentage elongation at break and impact strength were determined for nanocomposites at various clay loadings. Overall thermal stability of nanocomposites increased by 16-17 deg. C. The enhancement in T{sub g} of nanocomposite is merely by 2-4 deg. C. The incorporation of maleic anhydride as compatibilizer further enhanced all the properties indicating improved interface between PMMA and clay. The flammability characteristics were studied by determining the rate of burning and LOI.

Preparation and characterization of poly(methyl methacrylate)-clay nanocomposites via melt intercalation: Effect of organoclay on thermal, mechanical and flammability properties

International Nuclear Information System (INIS)

Unnikrishnan, Lakshmi; Mohanty, Smita; Nayak, Sanjay K.; Ali, Anwar

2011-01-01

Research highlights: → The present work deals with preparation and characterization of poly(methyl methacrylate) nanocomposites via melt intercalation technique. → The effect of various modified nanoclays on the properties of base matrix has been investigated. → It was observed that compatibilization using maleic anhydride improved the performance characteristics of PMMA/layered silicate nanocomposites. - Abstract: The PMMA nanocomposites were prepared by melt processing method. The influence of organoclay loading on extent of intercalation, thermal, mechanical and flammability properties of poly(methyl methacrylate) (PMMA)-clay nanocomposites were studied. Three different organoclay modifiers with varying hydrophobicity (single tallow vs. ditallow) were investigated. The nanocomposites were characterized by using wide angle X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and tensile tests. The intercalation of polymer chain within the silicate galleries was confirmed by WAXD and TEM. Mechanical properties such as tensile modulus (E), tensile strength, percentage elongation at break and impact strength were determined for nanocomposites at various clay loadings. Overall thermal stability of nanocomposites increased by 16-17 deg. C. The enhancement in T g of nanocomposite is merely by 2-4 deg. C. The incorporation of maleic anhydride as compatibilizer further enhanced all the properties indicating improved interface between PMMA and clay. The flammability characteristics were studied by determining the rate of burning and LOI.

Mechanical and thermal properties of polymer composite based on natural fibers: Moroccan hemp fibers/polypropylene

International Nuclear Information System (INIS)

Elkhaoulani, A.; Arrakhiz, F.Z.; Benmoussa, K.; Bouhfid, R.; Qaiss, A.

2013-01-01

Highlights: ► Moroccan hemp fibers are used as reinforcement in thermoplastic matrix. ► Moroccan hemp fiber was alkali treated to remove waxes and noncellulosic component. ► Fiber–matrix adhesion was assured by the use of a SEBS-g-MA as a compatibilizer. - Abstract: Moroccan hemp is a cellulosic fiber obtained from the north of Morocco. Their use as reinforcement in thermoplastic matrix composite requires a knowledge of their morphology and structure. In this paper the Moroccan hemp fiber was alkali treated to remove waxes and noncellulosic surface components. Fiber/matrix adhesion was assured by the use of a styrene-(ethylene-butene)-styrene three-block copolymer grafted with maleic anhydride (SEBS-g-MA) as a compatibilizer. Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), tensile and torsional tests were carried out for hemp fibers polypropylene composite and the compatibilized composite at different fiber content. Thus, the binary composite PP/hemp fibers (Alk) and ternary system with maleic anhydride indicate clearly an improved adhesion of the fiber to the matrix as results of the good interaction at the interface. A gain of 50% on the Young’s modulus of PP/hemp 25 wt.% without coupling agent and 74% on the PP/hemp 20 wt.% composite with the coupling agent were found. Tensile strength curve shows a remarkable stabilization when the coupling agent was used

Evaluation of mechanical and thermal properties of Pine cone fibers reinforced compatibilized polypropylene

International Nuclear Information System (INIS)

Arrakhiz, F.Z.; El Achaby, M.; Benmoussa, K.; Bouhfid, R.; Essassi, E.M.; Qaiss, A.

2012-01-01

Highlights: ► Pine cone fibers are used as reinforcement in thermoplastic matrix. ► Pine cone fiber was alkali treated to remove waxes and non cellulosic component. ► Fiber–matrix adhesion was assured by the use of a SEBS-g-MA as a compatibilizer. -- Abstract: Pine cone fibers are a cellulosic material readily available and can be used as reinforcement in a thermoplastic-based composite. A solid knowledge of their fibrillar morphology and structure is required to evaluate their usefulness as a substitute to other abundant natural fibers. Pine cone fibers were alkali treated prior usage to remove waxes and non cellulosic surface component. Fiber–matrix adhesion was assured by both a styrene–(ethylene–butene)–styrene triblock copolymer grafted with maleic anhydride (SEBS-g-MA) and a linear block copolymer based on styrene and butadiene compatibilizer. Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, Thermogravimetric analysis (TGA), tensile and torsional tests were employed for Pine cone polypropylene composite and compatibilized composite at different fiber content. Results show a clear improvement in mechanical properties from the use of both alkali treated Pine cone and Pine cone compatibilized with maleic anhydride, a gain of 43% and 49% respectively in the Young’s modulus, as a results of improved adhesion between fibers and matrix at the interface.

nanohybrid composites as antimicrobial, antifungal and anticancer platforms

Directory of Open Access Journals (Sweden)

D. Demircan

2018-08-01

Full Text Available This work presents a new approach to synthesize the colloidal ODA-MMT-poly(maleic anhydride-alt-1-dodecene-g-α,ω-methoxyhydroxyl-PEO/silver nanoparticles (AgNPs nanohybrid composites (NHC using the following synthetic pathways: (1 complex-radical alternating copolymerization of maleic anhydride with 1-dodecene α-olefin comonomer, (2 grafting of PEO onto alternating copolymer through esterification, (3 intercalating a copolymer-g-PEO between organoclay layers via complex formation of maleate carboxyl with octadecyl amine, and (4 in situ generation of AgNPs in polymer nanocomposite by annealing method under vacuum. The obtained multifunctional NHCs with different contents of AgNPs were characterized by UV spectroscopy, ζ-potential and size analysis methods. It was demonstrated that annealing of the colloidal NHC is accompanied with in situ generation of stable and partially protonated AgNPs due to specific reducing and stabilizing effects of multifunctional matrix polymer contained positively charged reactive and bioactive sites. Antibacterial and antifungal activities against Gram-negative and Gram-positive bacteria and fungal microorganism were investigated. The cytotoxic, apoptotic and necrotic effects in NHC/L929 fibroblast cells systems were evaluated. The synthesized watersoluble, biocompatible, and bioactive colloidal NHCs are promising candidate for a wide-range of applications in air filtration, food packaging systems, bioengineering, especially in tissue regeneration and nanomedicine.

Effect of modified polypropylene on the interfacial bonding of polymer–aluminum laminated films

International Nuclear Information System (INIS)

Liang, Chang-Sheng; Lv, Zhong-Fei; Bo, Yang; Cui, Jia-Yang; Xu, Shi-Ai

2015-01-01

Highlights: • Aluminium-polymer composite packing material with high T-peel strength was prepared. • Polypropylene was grafted by acrylic acid, glycidyl methacrylate, maleic anhydride. • Grafted polypropylene greatly improved the T-peel strength. • Chemical bonding plays an important role in improving the adhesion strength. - Abstract: The interfacial bonding between functionalized polymers and chromate–phosphate treated aluminum (Al) foil were investigated in this study. Glycidyl methacrylate (GMA), acrylic acid (AA) and maleic anhydride (MAH) were grafted onto polypropylene (PP) to improve its adhesion strength with the treated Al foil. The interfacial peel strength was evaluated by the T-peel test, and the results showed that modification of PP resulted in a significant improvement in the interfacial peel strength from 1 N/15 mm for pure PP to 10–14 N/15 mm for the modified PP. The surface chemistry, topography and surface energy of the modified PP and Al foil after peeling were characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and contact angle measurement. The treated Al foil could react with the functional groups of PP, resulting in the formation of new carboxylates. The new chemical bonding rather than the mechanical interlocking contributed to the improvement of adhesion strength

Thermotropic properties of phosphatidylcholine nanodiscs bounded by styrene-maleic acid copolymers.

Science.gov (United States)

Dominguez Pardo, J J; Dörr, J M; Renne, M F; Ould-Braham, T; Koorengevel, M C; van Steenbergen, M J; Killian, J A

2017-11-01

Styrene-maleic acid copolymers (SMA) have been gaining interest in the field of membrane research due to their ability to solubilize membranes into nanodics. The SMA molecules act as an amphipathic belt that surrounds the nanodiscs, whereby the hydrophobic styrene moieties can insert in between the lipid acyl chains. Here we used SMA variants with different styrene-to-maleic acid ratio (i.e. 2:1, 3:1 and 4:1) to investigate how lipid packing in the nanodiscs is affected by the presence of the polymers and how it depends on polymer composition. This was done by analyzing the thermotropic properties of a series of saturated phosphatidylcholines in nanodiscs using laurdan fluorescence and differential scanning calorimetry. In all cases it was found that the temperature of the main phase transition (T m ) of the lipids in the nanodiscs is downshifted and that its cooperativity is strongly reduced as compared to the situation in vesicles. These effects were least pronounced for lipids in nanodiscs bounded by SMA 2:1. Unexpected trends were observed for the calorimetric enthalpy of the transition, suggesting that the polymer itself contributes, possibly by rearranging around the nanodiscs when the lipids adopt the fluid phase. Finally, distinct differences in morphology were observed for nanodiscs at relatively high polymer concentrations, depending on the SMA variant used. Overall, the results suggest that the extent of preservation of native thermodynamic properties of the lipids as well as the stability of the nanodiscs at high polymer concentrations is better for SMA 2:1 than for the other SMA variants. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Biaxial deformation behaviour of poly-ether-ether-ketone

Science.gov (United States)

Turner, Josh; Menary, Gary; Martin, Peter

2018-05-01

The biaxial tensile properties of thin poly-ether-ether-ketone (PEEK) films are presented. Investigation into the biaxial mechanical behaviour of PEEK films will provide a preliminary insight into the anticipated stress/strain response, and potential suitability, to the possible fabrication of thin walled parts through stretch blow moulding and thermoforming processes - with the multi-axial state of strain imposed onto the heated thermoplastic sheet representative of the expected strain history experienced during these material forming processes. Following identification of the prospective forming temperature window, the biaxial mechanical behaviour of the material is characterized under differing modes of deformation, at a nominal strain rate of 1 s-1. The temperature dependence is outlined within - with an appreciable increase in flow behaviour correlated with specimen temperature exceeding its glass transition temperature (Tg).

Novel crosslinked membranes based on sulfonated poly(ether ether ketone) for direct methanol fuel cells.

Science.gov (United States)

Zhu, Yuanqin; Zieren, Shelley; Manthiram, Arumugam

2011-07-14

Novel covalently crosslinked membranes based on sulfonated poly(ether ether ketone) and carboxylated polysulfone exhibit much lower methanol crossover and better performance in direct methanol fuel cells at 65 °C in 1 and 2 M methanol solutions compared to Nafion 115 membranes.

Preparation and Characterization of Sulfonated Poly (ether ether ...

African Journals Online (AJOL)

NJD

2007-08-10

Aug 10, 2007 ... Preparation and Characterization of Sulfonated Poly (ether ... Currently perfluori- ... with phosphoric acid solution according to the method described earlier.11,12 ... where A is the membrane area available for diffusion; CA is.

46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

Science.gov (United States)

2010-10-01

... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154.1750 Section 154.1750 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK...

Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Chiu, K.-F.; Su, S.-H., E-mail: minimono42@gmail.com

2013-10-01

Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO{sub 4} were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO{sub 4}, the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance.

Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

International Nuclear Information System (INIS)

Chiu, K.-F.; Su, S.-H.

2013-01-01

Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO 4 were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO 4 , the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance

Chemical radiolabeling of carboxyatractyloside by [14C]acetic anhydride

International Nuclear Information System (INIS)

Block, M.R.; Pougeois, R.; Vignais, P.V.

1980-01-01

The authors report the synthesis and biological properties of a radiolabeled derivative of CAT obtained with acetylation of the primary alcohol of CAT with radiolabeled acetic anhydride. They also investigate the question of mutual exclusion of CAT and BA for binding to the mitochondrial ADP/ATP carrier in double labeling experiments based on the use of [ 3 H]BA and [ 14 C]Ac-CAT. The results are consistent with the view that the ADP/ATP carrier possesses two separate interacting binding sites for AT (or CAT) and for BA. (Auth.)

Hardness and wear properties of boron-implanted poly(ether-ether-ketone) and poly-ether-imide

International Nuclear Information System (INIS)

Lee Youngchul; Lee, E.H.; Mansur, L.K.

1992-01-01

The effects of boron beam irradiation on the hardness, friction, and wear of polymer surfaces were investigated. Typical high-performance thermoplastics, poly(ether-ether-ketone) (PEEK) and a poly-ether-imide (Ultem) were studied after 200 keV boron ion beam treatment at ambient temperature to doses of 2.3x10 14 , 6.8x10 14 , and 2.2x10 15 ions cm -2 . The hardnesses of pristine and boron-implanted materials were characterized by a conventional Knoop method and a load-depth sensing nanoindentation technique. Both measurements showed a significant increase in hardness with increasing dose. The increase in hardness was also found to depend on the penetration depth of the diamond indenter. Wear and friction properties were characterized by a reciprocating sliding friction tester with an SAE 52100 high-carbon, chrome steel ball at 0.5 and 1 N normal loads. Wear and frictional properties varied in a complex fashion with polymer type and dose, but not much with normal load. A substantial reduction in friction coefficient was observed for PEEK at the highest dose but no reduction was observed for Ultem. The wear damage was substantially reduced at the highest dose for both Ultem and PEEK. For the system studied, the highest dose, 2.2x10 15 ions cm -2 , appears to be optimum in improving wear resistance for both PEEK and Ultem. (orig.)

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

NARCIS (Netherlands)

Koziara, B.T.; Nijmeijer, K.; Benes, N.E.

2015-01-01

The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (≤5 wt%) and not too low spin speeds

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

NARCIS (Netherlands)

Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

2015-01-01

The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

Resonance Raman assignment and evidence for noncoupling of individual 2- and 4-vinyl vibrational modes in a monomeric cyanomethemoglobin

International Nuclear Information System (INIS)

Gersonde, K.; Yu, N.T.; Lin, S.H.; Smith, K.M.; Parish, D.W.

1989-01-01

We have investigated the resonance Raman spectra of monomeric insect cyanomethemoglobins (CTT III and CTT IV) reconstituted with (1) protohemes IX selectively deuterated at the 4-vinyl as well as the 2,4-divinyls, (2) monovinyl-truncated hemes such as pemptoheme (2-hydrogen, 4-vinyl) and isopemptoheme (2-vinyl, 4-hydrogen), (3) symmetric hemes such as protoheme III (with 2- and 3-vinyls) and protoheme XIII (with 1- and 4-vinyls), and (4) hemes without 2- and 4-vinyls such as mesoheme IX, deuteroheme IX, 2,4-dimethyldeuteroheme IX, and 2,4-dibromodeuteroheme IX. Evidence is presented that the highly localized vinyl C = C stretching vibrations at the 2- and 4-positions of the heme in these cyanomet CTT hemoglobins are noncoupled and inequivalent; i.e., the 1631- and 1624-cm-1 lines have been assigned to 2-vinyl and 4-vinyl, respectively. The elimination of the 2-vinyl (in pemptoheme) or the 4-vinyl (in isopemptoheme) does not affect the C = C stretching frequency of the remaining vinyl. Furthermore, two low-frequency vinyl bending modes at 412 and 591 cm-1 exhibit greatly different resonance Raman intensities between 2-vinyl and 4-vinyl. The observed intensity at 412 cm-1 is primarily derived from 4-vinyl, whereas the 591-cm-1 line results exclusively from the 2-vinyl. Again, there is no significant coupling between 2-vinyl and 4-vinyl for these two bending modes

Poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) membranes

Energy Technology Data Exchange (ETDEWEB)

Hwang, Mi-Lim; Choi, Jisun; Woo, Hyun-Su; Kumar, Vinod; Sohn, Joon-Yong; Shin, Junhwa, E-mail: shinj@kaeri.re.kr

2014-02-15

Highlights: • PEEK-g-PVBSA, a polymer electrolyte membrane was prepared by a radiation grafting technique. • Poly(ether ether ketone) (PEEK), an aromatic hydrocarbon polymer was used as a grafting backbone film. • The water uptake, proton conductivity, and methanol permeability of the membranes were evaluated. • PEEK-g-PVBSA membranes show considerably lower methanol permeability compared to a Nafion membrane. -- Abstract: In this study, an aromatic hydrocarbon based polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) (PEEK-g-PVBSA), has been prepared by the simultaneous irradiation grafting of vinylbenzyl chloride (VBC) monomer onto a PEEK film and subsequent sulfonation. Each chemical conversion was monitored by FT-IR and SEM–EDX instruments. The physicochemical properties including IEC, water uptake, proton conductivity, and methanol permeability of the prepared membranes were also investigated and found that the values of these properties increase with the increase of degree of grafting. It was observed that the IEC values of the prepared PEEK-g-PVBSA membranes with 32%, 58%, and 80% DOG values were 0.50, 1.05, and 1.22 meq/g while the water uptakes were 14%, 20%, and 21%, respectively. The proton conductivities (0.0272–0.0721 S/cm at 70 °C) were found to be somewhat lower than Nafion 212 (0.126 S/cm at 70 °C) at a relative humidity of 90%. However, the prepared membranes showed a considerably lower methanol permeability (0.61–1.92 × 10{sup −7} cm{sup 2}/s) compared to a Nafion 212 membrane (5.37 × 10{sup −7} cm{sup 2}/s)

Application of the photo-fenton process to the mineralization of phthalic anhydride in aqueous medium

International Nuclear Information System (INIS)

Trabelsi Souissi, Souhaila; Oturan, N.; Oturan, M. A; Bellakhal, N.

2009-01-01

A photochemical method for the oxidation of persistent organic pollutants (POPs) present in liquid effluents of plastic industry is described. This method, called p hoto-Fenton , involves the generation of hydroxyl radicals by coupling the Fenton reaction and photochemistry, .OH radicals thus formed react rapidly with organic pollutants leading to their oxidation until their total mineralization. In this study, we applied the photo-Fenton process for the removal of phthalic anhydride (plasticizer). In this way, an optimization of experimental parameters (namely the ratio R = [H 2 O 2 ]/[Fe 3+ ] and Fe 3+ initial concentration) was performed. Under optimal conditions, the kinetic of mineralization of phthalic anhydride by .OH has been studied. All results confirm the efficiency of photo-Fenton process for the decontamination of liquid effluents loaded with plasticizers.

Thermal stability of sulfonated Poly(Ether Ether Ketone) films : on the role of Protodesulfonation

NARCIS (Netherlands)

Koziara, B.T.; Kappert, E.J.; Ogieglo, W.; Nijmeijer, Kitty; Hempenius, M.A.; Benes, N.E.

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160–250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material,

Preparation of robust braid-reinforced poly(vinyl chloride) ultrafiltration hollow fiber membrane with antifouling surface and application to filtration of activated sludge solution.

Science.gov (United States)

Zhou, Zhuang; Rajabzadeh, Saeid; Fang, Lifeng; Miyoshi, Taro; Kakihana, Yuriko; Matsuyama, Hideto

2017-08-01

Braid-reinforced hollow fiber membranes with high mechanical properties and considerable antifouling surface were prepared by blending poly(vinyl chloride) (PVC) with poly(vinyl chloride-co-poly(ethylene glycol) methyl ether methacrylate) (poly(VC-co-PEGMA)) copolymer via non-solvent induced phase separation (NIPS). The tensile strength of the braid-reinforced PVC hollow fiber membranes were significantly larger than those of previously reported various types of PVC hollow fiber membranes. The high interfacial bonding strength indicated the good compatibility between the coating materials and the surface of polyethylene terephthalate (PET)-braid. Owing to the surface segregation phenomena, the membrane surface PEGMA coverage increased upon increasing the poly(VC-co-PEGMA)/PVC blending ratio, resulting in higher hydrophilicities and bovine serum albumin (BSA) repulsion. To compare the fouling properties, membranes with similar PWPs were prepared by adjusting the dope solution composition to eliminate the effect of hydrodynamic conditions on the membrane fouling performance. The blend membranes surface exhibited considerable fouling resistance to the molecular adsorption from both BSA solution and activated sludge solution. In both cases, the flux recovered to almost 80% of the initial flux using only water backflush. Considering their great mechanical properties and antifouling resistance to activated sludge solution, these novel membranes show good potential for application in wastewater treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Vintage Vinyl Record Design

Science.gov (United States)

Sacco, Michael

2008-01-01

In this article, the author describes a project in which his ninth-grade art students utilized a vinyl record as an unusual medium to create a work that exhibited solid design, great creativity, and strong craftsmanship. Students presented their pieces to the class for critique, explained the process, the media, and their feelings about their…

Continuous Preparation of 1:1 Haloperidol-Maleic Acid Salt by a Novel Solvent-Free Method Using a Twin Screw Melt Extruder.

Science.gov (United States)

Lee, Hung Lin; Vasoya, Jaydip M; Cirqueira, Marilia de Lima; Yeh, Kuan Lin; Lee, Tu; Serajuddin, Abu T M

2017-04-03

Salts are generally prepared by acid-base reaction in relatively large volumes of organic solvents, followed by crystallization. In this study, the potential for preparing a pharmaceutical salt between haloperidol and maleic acid by a novel solvent-free method using a twin-screw melt extruder was investigated. The pH-solubility relationship between haloperidol and maleic acid in aqueous medium was first determined, which demonstrated that 1:1 salt formation between them was feasible (pH max 4.8; salt solubility 4.7 mg/mL). Extrusion of a 1:1 mixture of haloperidol and maleic acid at the extruder barrel temperature of 60 °C resulted in the formation of a highly crystalline salt. The effects of operating temperature and screw configuration on salt formation were also investigated, and those two were identified as key processing parameters. Salts were also prepared by solution crystallization from ethyl acetate, liquid-assisted grinding, and heat-assisted grinding and compared with those obtained by melt extrusion by using DSC, PXRD, TGA, and optical microscopy. While similar salts were obtained by all methods, both melt extrusion and solution crystallization yielded highly crystalline materials with identical enthalpies of melting. During the pH-solubility study, a salt hydrate form was also identified, which, upon heating, converted to anhydrate similar to that obtained by other methods. There were previous reports of the formation of cocrystals, but not salts, by melt extrusion. 1 H NMR and single-crystal X-ray diffraction confirmed that a salt was indeed formed in the present study. The haloperidol-maleic acid salt obtained was nonhygroscopic in the moisture sorption study and converted to the hydrate form only upon mixing with water. Thus, we are reporting for the first time a relatively simple and solvent-free twin-screw melt extrusion method for the preparation of a pharmaceutical salt that provides material comparable to that obtained by solution

On new physical reality (on ψ-ether)

International Nuclear Information System (INIS)

Isaev, P.S.

2002-01-01

It is shown that there exists a new physical reality - the ψ-ether. All the achievements of quantum mechanics and quantum field theory are due to the fact that both the theories include the influence of ψ-ether on the physical processes occurring in the Universe. Physics of the XX century was first of all the physics of ψ-ether

Separation of gases through gas enrichment membrane composites

Science.gov (United States)

Swedo, Raymond J.; Kurek, Paul R.

1988-01-01

Thin film composite membranes having as a permselective layer a film of a homopolymer of certain vinyl alkyl ethers are useful in the separation of various gases. Such homopolymers have a molecular weight of greater than 30,000 and the alkyl group of the vinyl alkyl monomer has from 4 to 20 carbon atoms with branching within the alkyl moiety at least at the carbon atom bonded to the ether oxygen or at the next adjacent carbon atom. These membranes show excellent hydrolytic stability, especially in the presence of acidic or basic gaseous components.

Polimerni aditivi za poboljšanje tecivosti nafte i plinskog kondenzata

Directory of Open Access Journals (Sweden)

Jelić-Balta, J.

2007-10-01

Full Text Available This paper describes the problem of paraffin deposition during production, transportation and processing of crude oil and gas condensate. The troublesome paraffin stands for normal hydrocarbons ranging from approximately C18-C38, mixed with small amounts of branched paraffin, monocyclic paraffin, polycyclic paraffin, and aromatics. The amount of paraffin found in crude oils as described in the literature, varies from less than 1 to more than 50 percent. The solubility of paraffin depends on chemical composition, temperature and pressure. Paraffin precipitates at an equilibrium temperature and pressure defined as the cloud point. The paraffin deposits often begin on surfaces cooler than the liquid. The viscosity is increased by the presence of paraffin crystals and if the temperature is reduced sufficiently, the crude oil/gas condensate will become very viscous(pour point. The crude oil/gas condensate viscosity behaves in a Newtonian manner until wax crystals begin to form and, after lowering the temperature, behaves in a non-Newtonian manner.Many options are available to counter the problems caused by paraffin wax deposition. These include various mechanical, thermal and chemical means (for example, steam heating, blending with lighter cutter stocks and treating with chemical additives. A preferred option would be to use wax modifier additives, commonly known as pour point depressants. Crystal modifiers are copolymers from these groups: copolymers of ethylene vinyl acetate, poly alpha-olefins, alkyl fumarate- vinyl acetate copolymers of C18-through C22 methacrylates and copolymers of maleic anhydride esters. The mechanism of paraffin deposition and prevention is described. The additives modify the size and shape of the crystal and inhibit the formation of large wax crystal lattices. With efficient additives, crude oil/gas condensate behaves in a Newtonian manner at low temperature.A section of the paper describes the influence of chemical

Radicals derived from acetaldehyde and vinyl alcohol.

Science.gov (United States)

Estep, Marissa L; Morgan, W James; Winkles, Alexander T; Abbott, Adam S; Villegas-Escobar, Nery; Mullinax, J Wayne; Turner, Walter E; Wang, Xiao; Turney, Justin M; Schaefer, Henry F

2017-10-18

Vinyl alcohol and acetaldehyde are isoelectronic products of incomplete butanol combustion. Along with the radicals resulting from the removal of atomic hydrogen or the hydroxyl radical, these species are studied here using ab initio methods as complete as coupled cluster theory with single, double, triple, and perturbative quadruple excitations [CCSDT(Q)], with basis sets as large as cc-pV5Z. The relative energies provided herein are further refined by including corrections for relativistic effects, the frozen core approximation, and the Born-Oppenheimer approximation. The effects of anharmonic zero-point vibrational energies are also treated. The syn conformer of vinyl alcohol is predicted to be lower in energy than the anti conformer by 1.1 kcal mol -1 . The alcoholic hydrogen of syn-vinyl alcohol is found to be the easiest to remove, requiring 84.4 kcal mol -1 . Five other radicals are also carefully considered, with four conformers investigated for the 1-hydroxyvinyl radical. Beyond energetics, we have conducted an overhaul of the spectroscopic literature for these species. Our results also provide predictions for fundamental modes yet to be reported experimentally. To our knowledge, the ν 3 (3076 cm -1 ) and ν 4 (2999 cm -1 ) C-H stretches for syn-vinyl alcohol and all but one of the vibrational modes for anti-vinyl alcohol (ν 1 -ν 14 ) are yet to be observed experimentally. For the acetyl radical, ν 6 (1035 cm -1 ), ν 11 (944 cm -1 ), ν 12 (97 cm -1 ), and accounting for our changes to the assignment of the 1419.9 cm -1 experimental mode, ν 10 (1441 cm -1 ), are yet to be observed. We have predicted these unobserved fundamentals and reassigned the experimental 1419.9 cm -1 frequency in the acetyl radical to ν 4 rather than to ν 10 . Our work also strongly supports reassignment of the ν 10 and ν 11 fundamentals of the vinoxy radical. We suggest that the bands assigned to the overtones of these fundamentals were in fact combination bands. Our

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

Science.gov (United States)

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

2015-07-01

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

Radiation-induced emulsion copolymerization of vinyl chloride with vinyl acetate in an engineering flow system

International Nuclear Information System (INIS)

Tsai, J.T.; Stahel, E.P.; Stannett, V.T.

1979-01-01

A flow reactor system was used to study the radiation-induced emulsion copolymerization of vinyl chloride with vinyl acetate. The emulsion was recirculated from a stirred vessel through transfer lines to a tubular reactor located within a high-intensity Co-60 source. The effects of physical chemical variables such as soap concentration, phase ratio, reaction temperature and residence time distribution on the molecular weight properties were investigated. The rate of copolymerization was found to be proportional to the 0.17 power of the soap concentration. Variation of the monomer-water ratio produced no significant change in rate. The rate increased with an increase in temperature over the range 5 to 50 0 C, while the average molecular weights of the copolymer increased with decreasing polymerization temperature. The molecular weight distribution in this engineering system was found to be essentially similar to those produced in a batch system

Partial oxidation of n- and i-pentane over promoted vanadium-phosphorus oxide catalysts

Energy Technology Data Exchange (ETDEWEB)

Zazhigalov, V.A.; Mikhajluk, B.D.; Komashko, G.A. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Fizicheskoj Khimii

1998-12-31

It is known, that the cost of raw materials for catalytic oxidation processes is about 60% of the product price. Cheap initial compounds to produce variety of products and to replace olefins and aromatic hydrocarbons are paraffins. That is why catalytic systems which could be possibly rather efficient in selective oxidation of paraffin hydrocarbons are under very close investigation now. One of such processes in n-pentane oxidation. The obtained results on n-pentane oxidation over VPO catalysts were quite encouraging in respect of possible reach high selectivity and yield of phthalic anhydride. However, in our work it was shown that the main product of n-pentane oxidation in the presence of VPO catalytic system as well as VPMeO was maleic anhydride. Some later our results were confirmed in, where to grow the selectivity towards phthalic anhydride the Co-additive was introduced. On the basis of the proposal made before on the mechanism of paraffins conversion over the vanadyl pyrophosphate surface with their activation at the first and fourth carbon atoms, we assumed possible methylmaleic (citraconic) anhydride forming at n- and i-pentane oxidation. This assumption has been recently supported by both our and other researchers` experimental results. In it was also hypothized possible mechanistic features for phthalic anhydride forming from n-pentane. The present work deals with the results of n- and i-pentane oxidation over VPO catalysts promoted with Bi, Cs, Te, Zr. (orig.)

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

Science.gov (United States)

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

2015-09-07

Diazo anhydrides (Ar-N=N-O-N=N-Ar) have been known since 1896 but have rarely been used in synthesis. This communication describes the development of a photochemical catalyst-free C-H arylation methodology for the preparation of bi(hetero)aryls by the one-pot reaction of anilines with tert-butyl nitrite and (hetero)arenes under neutral conditions. The key step in this procedure is the in situ formation and subsequent photochemical (>300 nm) homolytic cleavage of a transient diazo anhydride intermediate. The generated aryl radical then efficiently reacts with a (hetero)arene to form the desired bi(hetero)aryls producing only nitrogen, water, and tert-butanol as byproducts. The scope of the reaction for several substituted anilines and (hetero)arenes was investigated. A continuous-flow protocol increasing selectivity and safety has been developed enabling the experimentally straightforward preparation of a variety of substituted bi(hetero)aryls within 45 min of reaction time. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

Energy Technology Data Exchange (ETDEWEB)

Fayolle-Guichard, F

2005-04-01

Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

Antimocrobial Polymer

Science.gov (United States)

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

2005-09-06

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

The polymerization of furfuryl alcohol with p-toluenesulfonic acid: photo cross-linkable feature of the polymer

International Nuclear Information System (INIS)

Principe, Martha; Martinez, Ricardo; Ortiz, Pedro; Rieumont, Jacques

2000-01-01

Poly (furfuryl alcohol) with different amounts of oxymethylenic bridges was synthesized using trifluoroacetic and p-toluenesulfonic acid. All polymers displayed a tendency to retain acids. The isolated products containing traces of acid became insoluble in a few hours; while neutral material maintains theirs solubility for at least one month. Polymers stored in solution were stable according to their HNMR spectra. Polymers cross-linked after being exposed to UV radiation. The product of the reaction of polymer with maleic anhydride is useful for preparing negative photo resists. (author)

Sulfonated poly(ether ether ketone) membranes for electric double layer capacitors

International Nuclear Information System (INIS)

Kim, Wan Ju; Kim, Dong-Won

2008-01-01

Sulfonated poly(ether ether ketone) (S-PEEK) with different degree of sulfonation (DS) has been prepared and evaluated as a proton conducting membrane for electric double layer capacitor (EDLC). The polymer electrolytes prepared with S-PEEK membrane exhibited ionic conductivities about 1.2 x 10 -3 -4.5 x 10 -3 S cm -1 at room temperature, which depended on both soaking solvent and degree of sulfonation. The quasi-solid-state EDLCs consisted of activated carbon electrodes and S-PEEK membrane were assembled, and their electrochemical characteristics were studied by cyclic voltammetry and charge-discharge cycle tests. The effect of DS on the electrochemical performances of EDLCs has been investigated

Effect of Molecular Weight on the Thermal and Spectroscopic Properties of Poly(vinyl alcohol) Films

International Nuclear Information System (INIS)

Khafagy, R.M.; Abd El-Kader, K.M.; Badr, Y.A.

2009-01-01

Thin films of Poly(vinyl alcohol) (PVA) with molecular weights 5000, 17000,72000 and 125000 g/mol were prepared by casting technique.Samples were thermally and spectroscopically investigated using TGA, DSC, FTIR and FT-Raman spectroscopy, in order to show how the thermal stability and structure of PVA might be correlated with its molecular weight. Thermal analysis showed that samples degrade in two steps mechanism. The mechanism observed for degradation in an inert atmosphere was in accordance with the accepted mechanism of elimination followed by pyrolisation. PVA 5000MW and PVA 17000Mw showed almost similar thermal behavior due to their expected similar structure. PVA 72000Mw showed lower thermal stability since it is characterized with the presence of the unstable C-O-C ether linkages, which lead to the fast melting of this sample. PVA 125000Mw showed the highest thermal stability because crosslinking of the main chains takes place due to introducing additional PVA units, which substitute each over oxygen atom. ΔH values obtained from DSC showed good accordance with TGA and Drtg analysis. Moreover, FTIR and FT-Raman results agreed well with thermal analysis, and confirmed our supposed structural changes which might take place as the molecular weight of the sample changes: since the water uptake, presence of ether linkages, and double bonds formulation due to crosslinking, were confirmed with FTIR and FT-Raman spectral analysis. The crystallinity percentage of the samples was calculated from Raman spectra and results confirmed our spectroscopic explanations. The thermal and spectroscopic behavior of the samples was explained as a result of the competitive action of at least three factors due to increasing the molecular weight: (i) diminution of the existing physical network due to changes in hydrogen bonding; (ii) formation of a chemical network; and (iii) introduction of flexible moieties due to the specific chemical structure after crosslinking

PSD Applicability for Ashland Chemical's Maleic Anhydride Plant in Neal, West Virginia

Science.gov (United States)

This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Promoting environmentally sound management of polybrominated diphenyl ethers in Asia.

Science.gov (United States)

Li, Jinhui; Zhao, Nana; Liu, Xue; Wu, Xiaoyang

2014-06-01

Polybrominated diphenyl ethers with persistent organic pollutant properties are required to be controlled by the Stockholm Convention. Recently, polybrominated diphenyl ether contamination has become widespread in Asia, mainly because of the disposal and recycling processes of polybrominated diphenyl ether-containing wastes. The management status, production, usage, import/export, treatment, and disposal, as well as implementation deficiencies for the environmentally sound management of polybrominated diphenyl ethers and polybrominated diphenyl ether-containing materials in ten Asian countries were investigated and assessed in this study. This information could help the participating countries implement the Stockholm Convention and could promote the regional environmentally sound management of polybrominated diphenyl ether-containing articles and products. The results obtained were as follows. (1) Most of the countries studied lacked environmental policies and regulations, or even standards of polybrominated diphenyl ether pollution management and emission control actions. Accurate data on the consumption and importation of polybrominated diphenyl ether-containing materials, however, were not available for all the participating countries. In addition, there were no special treatment or disposal systems for polybrominated diphenyl ether-containing materials, or emission-cutting measures for the treatment of waste in these countries, owing to the lack of sufficient funding or technologies. (2) The improper dismantling of e-waste is a major source of polybrominated diphenyl ether emissions in these countries. (3) Proper e-waste management could result in a breakthrough in the environmentally sound management of this major polybrominated diphenyl ether-containing material flow, and could significantly reduce polybrominated diphenyl ether emissions. Finally, based on the study results, this article puts forward some recommendations for improving the environmentally

Chemoselective Deprotection of Triethylsilyl Ethers

Science.gov (United States)

Chandra, Tilak; Broderick, William E.; Broderick, Joan B.

2009-01-01

An efficient and selective method was developed for the deprotection of triethylsilyl (TES) ethers using formic acid in methanol (5–10%) or in methylene chloride 2–5%) with excellent yields. TES ethers are selectively deprotected to the corresponding alcohols in high yields using formic acid in methanol under mild reaction conditions. Other hydroxyl protecting groups like t-butyldimethylsilyl (TBDMS) remain unaffected. PMID:20183570

40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

Science.gov (United States)

2010-07-01

... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride...

Controlling Styrene Maleic Acid Lipid Particles through RAFT.

Science.gov (United States)

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

2017-11-13

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

Preparation and characterization of film of poly vinyl acetate ethylene copolymer emulsion

International Nuclear Information System (INIS)

Zhang, Yanhua; Gu, Jiyou; Tan, Haiyan; Shi, Junyou; Di, Mingwei; Zuo, Yingfeng; Qiu, Si

2013-01-01

In order to improve the storage modulus and water resistance of poly (vinyl acetate), the vinyl acetate and poly (vinyl alcohol) (PVA) were respectively used as monomers and protective colloid to prepare a new kind of polyvinyl acetate emulsion adhesive by continuous emulsion polymerization. The dynamic mechanics, particle distribution, glass transition temperature, polymer emulsion structure of both polymerized and copolymerized emulsion were analyzed by SEM, DMA and XPS, respectively. The results indicated that the copolymerized emulsion has the appropriate particle size and the uniform particle distribution, the glass transition temperature increased from 50 °C to 70 °C, compared with poly (vinyl acetate). It could be seen from XPS spectra of copolymerized emulsion that key characteristic peak of C=O was still existent. X-ray photoelectron spectra revealed that the addition of EVA did not generate the new bond, whereas the maximum percentage increases in ester was determined in the composite film with the introduction of EVA of 25%, which indicated that the composite film has copolymer structure. The storage modulus and water resistance of poly (vinyl acetate) were improved due to the introduction of the EVA.

Life test of DMFC using poly(ethylene glycol)bis(carboxymethyl)ether plasticized PVA/PAMPS proton-conducting semi-IPNs

Energy Technology Data Exchange (ETDEWEB)

Qiao, Jinli [National Institute of Advanced Industrial Science and Technology, Higashi 1-1-1, Central 5, Tsukuba, Ibaraki 305-8565 (Japan); New Energy Technology Research Center, Tongji University, Shanghai 201804 (China); Ikesaka, Shinya; Saito, Morihiro; Kuwano, Jun [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigayafunagawara-machi, Shinjuku-ku, Tokyo 162-0826 (Japan); Okada, Tatsuhiro [National Institute of Advanced Industrial Science and Technology, Higashi 1-1-1, Central 5, Tsukuba, Ibaraki 305-8565 (Japan)

2007-08-15

A novel, low-cost proton-conducting semi-IPN (semi-interpenetrating polymer network) has been successfully prepared from PVA/PAMPS (poly(vinyl alcohol) and poly(2-acrylamindo-2-methyl-1-propanesulfonic acid))blends by incorporating poly(ethylene glycol)bis(carboxymethyl)ether (PEGBCME) as a novel plasticizer. Although, the polymer is based on a relatively low content of PAMPS as a component of ion conducting sites, the resulting semi-IPN exhibited high proton conductivity (0.1 S cm{sup -1}) at 25 C, which afforded a higher power density of 51 mW cm{sup -2} at 80 C. A striking feature is that a long-term initial performance is achieved with a 130 h of stable fuel cell operation in DMFC mode due to effectively suppressed methanol crossover. This is a new record for a fully hydrocarbon membrane in DMFC, seeing that the PVA-PAMPS proton-conducting semi-IPNs are made simply of aliphatic skeletons. (author)

[Early contributions from Erlangen to the theory and practice of ether and chloroform anesthesia. 1. Heyfelder's clinical trial with ether and chloroform].

Science.gov (United States)

Hintzenstern, U v; Schwarz, W

1996-02-01

The era of modern anaesthesia in Germany began on January 24th, 1847. This day, professor in ordinary Johann Ferdinand Heyfelder anaesthetized a patient with sulphuric ether in the clinic of surgery and ophthalmology of the University of Erlangen. By March 17th, 1847, Heyfelder had performed 121 surgical procedures under ether. The operations in majority were teeth-extractions, and a few more complex operations such as the treatment of a harelip or of lip cancer or the resection of the shoulder joint. Heyfelder described in detail 108 of these inhalations in a little book entitled The experiments with sulphuric ether. This monograph published in March, 1847, represents one of the first complete dissertations on sulphuric ether in the German literature. In a special chapter he analyzed the development of various physiological and psychological parameters during etherization. Heyfelder also examined blood and urine of some etherized patients and reported that he did not find any important or specific alterations. In 1847, Heyfelder was probably the first to apply salt-ether in man. After 4 administrations he concluded that salt ether acted more quickly but shorter than sulphuric ether. Advantageous were its application without problems and ease of induction. Disadvantageous were its high volatility, its price and the difficulty of getting it in a pure form. From December, 1847, on Heyfelder started to use chloroform. He was now able to perform more major operations, for example, the total resection of the hip-joint. In his book The experiments with sulphuric ether, salt ether, and chloroform he describes a great number of anaesthetic administrations using these 3 agents. In his summary Heyfelder concluded, that chloroform was undoubtly superior to sulphuric ether mainly because it was a quicker acting and longer lasting agent and leads to deeper narcosis. Moreover its application was much easier for it needed no special apparatus. However, because of its great

Radiation curing of mixtures of diallylphthalate prepolymer and vinyl monomer, 9

International Nuclear Information System (INIS)

Gotoda, Masao; Kitada, Yoshinori.

1975-01-01

Radiation curing, mainly by electron beams was studied with mixtures of low molecular weight diallylphthalate prepolymer (DAPsub(p).L) and vinyl monomers with special reference to their workability. Among the vinyl monomers, acrylonitrile gave a solution of low viscosity and methyl acrylate gave a solution of low dose curing. Radiation curing of DAPsub(p).L/vinyl monomer mixtures impregnated in wood was also tried. To obtain uniform wood-polymer composites, γ-irradiation after impregnation at 10 kg/cm 2 was found to be required for thick plate (110 mm), while electron beam irradiation after impregnation at normal pressure was sufficient for thin plate. (author)

Molecular structure impacts on secondary organic aerosol formation from glycol ethers

Science.gov (United States)

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

Palladium-Catalyzed Reductive Insertion of Alcohols into Aryl Ether Bonds

Energy Technology Data Exchange (ETDEWEB)

Wang, Meng [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Gutiérrez, Oliver Y. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Camaioni, Donald M. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Lercher, Johannes A. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Department of Chemistry and Catalysis Research Institute, TU München, Lichtenbergstrasse 4 85748 Garching Germany

2018-03-06

Pd/C catalyzes C-O bond cleavage of aryl ethers (diphenyl ether and cyclohexyl phenyl ether) by methanol in H2. The aromatic C-O bond is cleaved by reductive methanolysis, which is initiated by Pd-catalyzed partial hydrogenation of one phenyl ring to form an enol ether. The enol ether reacts rapidly with methanol to form a ketal, which generates methoxycyclohexene by eliminating phenol or an alkanol. Subsequent hydrogenation leads to methoxycyclohexane.

Modified nanocrystal cellulose/fluorene-containing sulfonated poly(ether ether ketone ketone) composites for proton exchange membranes

Science.gov (United States)

Wei, Yingcong; Shang, Yabei; Ni, Chuangjiang; Zhang, Hanyu; Li, Xiaobai; Liu, Baijun; Men, Yongfeng; Zhang, Mingyao; Hu, Wei

2017-09-01

Highly sulfonated poly(ether ether ketone ketone)s (SFPEEKKs) with sulfonation degrees of 2.34 (SFPEEKK5) and 2.48 (SFPEEKK10) were synthesized through the direct sulfonation of a fluorene-containing poly(ether ether ketone ketone) under a relatively mild reaction condition. Using the solution blending method, sulfonated nanocrystal cellulose (sNCC)-enhanced SFPEEKK composites (SFPEEKK/sNCC) were successfully prepared for investigation as proton exchange membranes. Transmission electron microscopy showed that sNCC was uniformly distributed in the composite membranes. The properties of the composite membranes, including thermal stability, mechanical properties, water uptake, swelling ratio, oxidative stability and proton conductivity were thoroughly evaluated. Results indicated that the insertion of sNCC could contribute to water management and improve the mechanical performance of the membranes. Notably, the proton conductivity of SFPEEKK5/sNCC-5 was as high as 0.242 S cm-1 at 80 °C. All data proved the potential of SFPEEKK/sNCC composites for proton exchange membranes in medium-temperature fuel cells.

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

Science.gov (United States)

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

Dynamics study of free volume properties of SMA/SMMA blends by PAL method

International Nuclear Information System (INIS)

Jiang, Z.Y.; Jiang, X.Q.; Huang, Y.J.; Lin, J.; Li, S.M.; Li, S.Z.; Hsia, Y.F.

2006-01-01

Miscibility of poly(styrene-co-maleic anhydride) (containing 7 wt% maleic anhydride)/poly(styrene-co-methyl methacrylate) (containing 40 wt% styrene) blends were previously studied. It was obtained that SMA70 (containing 70 wt% of SMA in SMA/SMMA blends) is miscible in molecular level but SMA20 is not. In this paper, the two blends selected were used to investigate the temperature dependence of free volume parameters. It showed there are different deviations of free volume parameters in SMA20 and SMA70, and it was interesting that temperature dependence of ortho-positronium lifetime τ 3 of the SMA20 mixture exhibits two breaks in the range temperature from 90 deg. C to 120 deg. C, which revealed that the mixture has two glass transition ranges. Also, ortho-positronium lifetime τ 3 of the SMA20 mixture is nearly constant in the temperature range from 130 deg. C to 160 deg. C. These indicated that SMA20 blend is phase-separated in room temperature and become miscible above 130 deg. C, which may be due to steric hindrance effect of phenyl rings of SMMA and SMA. From the deviation of o-Ps lifetimes of SMA70, the single glass transition temperature of SMA70 blend was shown. Combining the previous study, it was further concluded that PAL method seems to be a powerful method to detect in situ phase behavior of immiscible polymer blends and glass transition of miscible polymer blends

Effect of gamma ray on poly(lactic acid)/poly(vinyl acetate-co-vinyl alcohol) blends as biodegradable food packaging films

Science.gov (United States)

Razavi, Seyed Mohammad; Dadbin, Susan; Frounchi, Masoud

2014-03-01

Poly(lactic acid) (PLA)/poly(vinyl acetate-co-vinyl alcohol) [P(VAc-co-VA)] blends as new transparent film packaging materials were prepared at various blend compositions and different vinyl alcohol contents. The blends and pure PLA were irradiated by gamma rays to investigate the extent of changes in the packaging material during gamma ray sterilization process. The miscibility of the blends was dependent on the blend composition and vinyl alcohol content; gamma irradiation had little effect on the extent of miscibility. The glass transition temperature of pure PLA and PLA/P(VAc-co-VA) miscible blends reduced after irradiation. On the other hand in PLA/P(VAc-co-VA) immiscible blends, while the glass transition temperature of the PLA phase decreased; that of the copolymer phase slightly increased. The reduction in the glass transition was about 10 percent for samples irradiated with 50 kGy indicating dominance of chain scission of PLA molecules at high irradiation dose. The latter was verified by drop in mechanical properties of pure PLA after exposing to gamma irradiation at 50 kGy. Blending of PLA with the copolymer P(VAc-co-VA) compensated greatly the adverse effects of irradiation on PLA. The oxygen-barrier property of the blend was superior to the neat PLA and remained almost intact with irradiation. The un-irradiated and irradiated blends had excellent transparency. Gamma ray doses used for sterilization purposes are usually less than 20 kGy. It was shown that gamma irradiation at 20 kGy had no or little adverse effects on PLA/P(VAc-co-VA) blends mechanical and gas barrier properties.

Microwave sintering of poly-ether-ether-ketone (PEEK) based coatings deposited on metallic substrate

International Nuclear Information System (INIS)

Zhang, G.; Leparoux, S.; Liao, H.; Coddet, C.

2006-01-01

In this paper, the feasibility of microwave (MW) sintering PEEK (poly-ether-ether-ketone) based coatings was investigated. Three coatings were studied: pure PEEK, micron-SiC and nano-SiC particles filled (wt.10%) PEEK coatings. The results indicate that, for the two composite coatings, the SiC particles distributed in the polymer matrix, as a good MW susceptor, could be heated preferentially by MW radiation. Consequently, the polymer matrix was heated by these particles

Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

Energy Technology Data Exchange (ETDEWEB)

Fayolle-Guichard, F.

2005-04-01

Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

Effect of irradiation on poly(vinyl chloride)/epoxidized natural rubber blend in the presence of additives: FTIR analysis

International Nuclear Information System (INIS)

Chantara Thevy Ratnam; Khairul Zaman Dahlan; Baharin, A.; Nasir, M.

2001-01-01

The effect of irradiation on the structure of 50/50 poly(vinyl chloride)/epoxidized natural rubber blend (PVC/ENR) was studied using the Fourier Transform Spectroscopy (FTIR). The 50/50 PVC/ENR blend was irradiated by using 3.0 MeV electron beam machine at 0 and 200 kGy irradiation doses. The influence of several additives such as TMPTA, Irganox 1010, and tribasic lead sulfate on the irradiation induced changes of the blend was investigated. It was found that upon irradiation, ring opening of the epoxide groups, oxidation as well crosslinking at residual double bonds occurred, leading to decreases in the intensities of the epoxide and cis double bond bands and an increases in ether and furan bands. The addition of Irganox 1010 and tribasic lead sulfate were found to inhibit the irradiation-induced reaction in the blend to a considerable extent. The importance of TMPTA in preventing the intramolecular ring opening side chain reaction was also discussed. However, studies did not reveal the exact nature of the irradiation-induced reactions involved in the blend. (Author)

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

Science.gov (United States)

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

2015-01-01

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

Actinide/crown ether chemistry

International Nuclear Information System (INIS)

Benning, M.M.

1988-01-01

A structural survey of actinide/crown ether compounds was conducted in order to investigate the solid state chemistry of these complexes. Several parameters - the metal size, crown type, counterion, solvent systems and reaction and crystallization conditions - were varied to correlate their importance in complexation. Under atmospheric conditions, two types of complexes were isolated, those containing only hydrogen-bonded crown interactions and instances where the crown interacts directly with the metal center. In both cases, water seems to play a very important role. When coordinated to the metal, water molecules exhibit the necessary donor properties required for the formation of hydrogen-bonded contacts. The water molecules also provide fierce competition with the crown ethers for metal-binding sites and in most cases prohibit the formation of complexes in which direct metal-ligand association exists. The results of this study indicate that direct interaction between the metal atoms and the crown ethers, in the presence of water, can only occur with polyether conformations which limit the steric replusions within the metal coordination sphere

Plastics piping systems for industrial applications : acrylonitrile-butadiene- styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) : specifications for components and the system : metric series

CERN Document Server

International Organization for Standardization. Geneva

2003-01-01

Plastics piping systems for industrial applications : acrylonitrile-butadiene- styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) : specifications for components and the system : metric series

Directory of Open Access Journals (Sweden)

Kamal M. El-Gamal

2016-12-01

Full Text Available A series of 3-substituted 6-methoxy-1H-pyrazolo [3,4-b]quinoline derivatives was synthesized by treating 6-methoxy-1H-pyrazolo[3,4-b]quinolin-3-amine (6 with different acid anhydrides including succinic anhydride, maleic anhydride and phthalic anhydride. Also, a series of 3-heteroaryl-2-chloro-6-methoxyquinolines was prepared through 1,3-dipolar cycloaddition of different bi-nucleophiles including hydrazine hydrate, hydroxylamine hydrochloride, thiourea, guanidine hydrochloride, urea and metformin hydrochloride to the chalcone derivative 3-(2-chloro-6-methoxyquinolin-3-yl-1-(4-methoxyphenylprop-2-en-1-one. Structural identifications of all products were reported and the new compounds were screened for their in vitro antimicrobial activity against Streptococcus pneumonia and Bacillus subtilis as examples for Gram-positive bacteria, Pseudomonas aeruginosa and Escherichia coli as examples for Gram-negative bacteria, and Aspergillus fumigatus, Syncephalastrum racemosum, Geotriucum candidum and Candida albicans as representative examples of fungi. The majority of tested compounds showed moderate activities against a wide range of the selected organisms. Among the tested compounds, pyrimidine derivatives 16 and 17 showed the highest antimicrobial activity against gram-positive strains while the highest activity against E. coli as example for Gram-negative strains was observed in the case of 11 and 17. Compounds 14 and 17 were found to be extremely potent against three of the selected fungal strains.

Preliminary in vivo report on the osteocompatibility of poly(anhydride-co-imides) evaluated in a tibial model.

Science.gov (United States)

Ibim, S E; Uhrich, K E; Attawia, M; Shastri, V R; El-Amin, S F; Bronson, R; Langer, R; Laurencin, C T

1998-01-01

A novel class of polymers with mechanical properties similar to cancellous bone are being investigated for their ability to be used in weight-bearing areas for orthopedic applications. The poly(anhydride-co-imide) polymers based on poly[trimellitylimidoglycine-co-1,6-bis(carboxyphenoxy)hexan e] (TMA-Gly:CPH) and poly[pyromellitylimidoalanine-co-1,6-bis(carboxyphenoxy)hexa ne] (PMA-Ala:CPH) in molar ratios of 30:70 were investigated for osteocompatibility, with effects on the healing of unicortical 3-mm defects in rat tibias examined over a 30-day period. Defects were made with surgical drill bits (3-mm diameter) and sites were filled with poly(anhydride-co-imide) matrices and compared to the control poly(lactic acid-glycolic acid) (PLAGA) (50:50), a well-characterized matrix frequently used in bone regeneration studies, and defects without polymeric implants. At predetermined time intervals (3, 6, 9, 12, 20, and 30 days), animals were sacrificed and tissue histology was examined for bone formation, polymer-tissue interaction, and local tissue response by light microscopy. The studies revealed that matrices of TMA-Gly:CPH and PMA-Ala:CPH produced responses similar to the control PLAGA with tissue compatibility characterized by a mild response involving neutrophils, macrophages, and giant cells throughout the experiment for all matrices studied. Matrices of PLAGA were nearly completely degraded by 21 days in contrast to matrices of TMA-Gly:CPH and PMA-Ala:CPH that displayed slow erosion characteristics and maintenance of shape. Defects in control rats without polymer healed by day 12, defects containing PLAGA healed after 20 days, and defects containing poly(anhydride-co-imide) matrices produced endosteal bone growth as early as day 3 and formed bridges of cortical bone around matrices by 30 days. In addition, there was marrow reconstitution at the defect site for all matrices studied along with matured bone-forming cells. This study suggests that novel poly(anhydride

Preliminary characterization in the development of the nano composite low density polyethylene with attapulgite clay

International Nuclear Information System (INIS)

Domingos, Luanda G.; Rego, Jose K.M.A. do; Ito, Edson N.; Acchar, Wilson

2011-01-01

The aim of this study was a preliminary study of the physical, thermal and rheological properties of the materials to be used in the development of nano composite low density polyethylene (LDPE) with Brazilian attapulgite clay (ATP), with and without the use of a compatibilizing agent interfacial, polyethylene grafted with maleic anhydride (PE-g-MAH). The materials were characterized by X-ray diffraction (XRD), thermogravimetry (TG) and torque rheometry. The materials were characterized and potentially could be developed polymeric nano composites with technological applications using attapulgite fibers in the nanometer scale. (author)

Effect of Multiple Extrusions on the Impact Properties of Polypropylene/Clay Nanocomposites

DEFF Research Database (Denmark)

Klitkou, Rasmus; Jensen, Erik Appel; Christiansen, Jesper de Claville

2012-01-01

Polypropylene (PP)-based polymer nanocomposites containing organically modified montmorillonite (OMMT) with and without maleic anhydride grafted PP, were compounded by twin-screw extrusion. The extrusion process was repeated various numbers of times to increase the extruder residence time (TR) and......) increased monotonically with increased TR by 70% from least dispersed to best dispersed, which was still 20% below the level for neat PP. Both the fracture initiation energy and propagation energy increased with TR, but the primary effect on ri came from the fracture propagation energy, which delivered 80...

Aspects and prospects of the chemistry of organic heterocycles (review)

International Nuclear Information System (INIS)

Schroth, W.

1986-01-01

The systematics of heterocycles, their place in organic chemistry, and their significance for theory and practice are discussed. Problems of the chemistry of heterocycles are discussed on the examples of systems with various types of conjugation and ring sizes. The focus is on the principles of synthesis of heterocycles, in particular, those based on acetylene, various C 3 fragments, carbon disulfide, and maleic anhydride. Individual sections of the survey are devoted to the role of heterocycles in biosynthesis, as well as certain problems common to the chemistry of heterocycles, biochemistry, and macromolecular chemistry

Synthesis and Characterization of a New Heterocyclic Azo Pigment

International Nuclear Information System (INIS)

Asniza, M.; Issam, A.M.; Khalil, H.P.S.A.

2011-01-01

A new heterocyclic coupling agent has been produced from the reaction of maleic anhydride and p-aminophenol, namely N-(4-hexahydrophenol)maleimide. The coupling agent underwent azo coupling reaction with aromatic amine, which is p-aminophenol to produce a new heterocyclic azo pigment. The pigment was then subjected to solubility, hiding power and light fastness test. Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet/ Visible (UV/Vis) Spectroscopy, and Nuclear Magnetic Resonance Spectroscopy ( 1 H-NMR, 13 C-NMR) were used to obtain the characteristics and structural features of the pigment. (author)

Effect of ionizing radiation on the properties of prepared plastic/starch blends and their applications as biodegradable materials

International Nuclear Information System (INIS)

Khalil, S.A.

2010-01-01

Blends based on different ratios of plasticised starch (PLST), low density poly-ethyleen (LDPE) were prepared by mixing in extrouder. The LDPE/PLST/POMA (poly-olefin maleic anhydride) and LDPE/PLST/TMPTA (tri-methylol propane tri-acrylate) were exposed to different doses of electron beam. The effect of mixing and E-Beam irradiation on the thermal, mechanical, water absorption, and structure morphology properties were investigated. The results showed that the addition of compatibilizers and E-Beam irradiation improve all the physical properties, which provides suitable material based on natural polymer for biodegradable plastic.

Rearrangements of Cycloalkenyl Aryl Ethers

Directory of Open Access Journals (Sweden)

Mercedesz Törincsi

2016-04-01

Full Text Available Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed.

Ether: Bitcoin's competitor or ally?

OpenAIRE

Bouoiyour, Jamal; Selmi, Refk

2017-01-01

Although Bitcoin has long been dominant in the crypto scene, it is certainly not alone. Ether is another cryptocurrency related project that has attracted an intensive attention because of its additional features. This study seeks to test whether these cryptocurrencies differ in terms of their volatile and speculative behaviors, hedge, safe haven and risk diversification properties. Using different econometric techniques, we show that a) Bitcoin and Ether are volatile and relatively more resp...

Highly Efficient Fumed Silica Nanoparticles for Peptide Bond Formation: Converting Alanine to Alanine Anhydride.

Science.gov (United States)

Guo, Chengchen; Jordan, Jacob S; Yarger, Jeffery L; Holland, Gregory P

2017-05-24

In this work, thermal condensation of alanine adsorbed on fumed silica nanoparticles is investigated using thermal analysis and multiple spectroscopic techniques, including infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectroscopies. Thermal analysis shows that adsorbed alanine can undergo thermal condensation, forming peptide bonds within a short time period and at a lower temperature (∼170 °C) on fumed silica nanoparticle surfaces than that in bulk (∼210 °C). Spectroscopic results further show that alanine is converted to alanine anhydride with a yield of 98.8% during thermal condensation. After comparing peptide formation on solution-derived colloidal silica nanoparticles, it is found that fumed silica nanoparticles show much better efficiency and selectivity than solution-derived colloidal silica nanoparticles for synthesizing alanine anhydride. Furthermore, Raman spectroscopy provides evidence that the high efficiency for fumed silica nanoparticles is likely related to their unique surface features: the intrinsic high population of strained ring structures present at the surface. This work indicates the great potential of fumed silica nanoparticles in synthesizing peptides with high efficiency and selectivity.

Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran

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Sari Fouad

2012-12-01

Full Text Available We reported in this work that the cationic copolymerization in one step takes place between carbon–carbon double-bond monomer styrene with cyclic monomer tetrahydrofuran. The comonomers studied belong to different families: vinylic and cyclic ether. The reaction is initiated with maghnite-H+ an acid exchanged montmorillonite as acid solid ecocatalyst. Maghnite-H+ is already used as catalyst for polymerization of many vinylic and heterocyclic monomers. The oxonium ion of tetrahydrofuran and carbonium ion of styrene propagated the reaction of copolymerization. The acetic anhydride is essential for the maintenance of the ring opening of tetrahydrofuran and the entry in copolymerization. The temperature was kept constant at 40°C in oil bath heating for 6 hours. A typical reaction product was analyzed by 1H-NMR, 13C-NMR and IR and the formation of the copolymer was confirmed. The reaction was proved by matched with analysis. The maghnite-H+ allowed us to obtain extremely pure copolymer in good yield by following a simples operational conditions. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 29th October 2012; Revised: 29th November 2012; Accepted: 29th November 2012[How to Cite: S. Fouad, M.I. Ferrahi, M. Belbachir. (2012. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 165-171. (doi:10.9767/bcrec.7.2.4074.165-171][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4074.165-171 ] | View in 

Highly filled biocomposites based on ethylene-vinyl acetate copolymer and wood flour

Science.gov (United States)

Shelenkov, P. G.; Pantyukhov, P. V.; Popov, A. A.

2018-05-01

Recently, there is a great interest in the world to biodegradable materials based on synthetic polymers in a composition with natural fillers. Highly filled polymer composite materials based on various grades of synthetic block copolymer of ethylene vinyl acetate with wood flour were under investigation. Five grades of ethylene-vinyl acetate copolymer differing in the content of vinyl acetate groups and a melt flow index were used in this work in order to find the best one for highly filled biocomposites. Wood flour content in biocomposites was 50, 60, 70 weight %. The rheological and physico-mechanical characteristics of the resulting biocomposites were studied.

Effect of Saponification Condition on the Morphology and Diameter of the Electrospun Poly(vinyl acetate) Nanofibers for the Fabrication of Poly(vinyl alcohol) Nanofiber Mats

OpenAIRE

Seong Baek Yang; Jong Won Kim; Jeong Hyun Yeum

2016-01-01

Novel poly(vinyl alcohol) (PVA) nanofiber mats were prepared for the first time through heterogeneous saponification of electrospun poly(vinyl acetate) (PVAc) nanofibers. The effect of varying the saponification conditions, including temperature, time, and concentration of the alkaline solution, on the morphology of the saponified PVA fibers were evaluated by field-emission scanning electron microscopy. At 25 °C, the saponified PVA fibers exhibited a broad diameter distribution. The average f...

Catalytic hydroprocessing of lignin β-O-4 ether bond model compound phenethyl phenyl ether over ruthenium catalysts

NARCIS (Netherlands)

Gomez-Monedero, B.; Faria, J.; Bimbela, F.; Ruiz, M.P.

2017-01-01

The catalytic hydroprocessing of phenethyl phenyl ether (PPE), a model compound of one of the most significant ether linkages within lignin structure, β-O-4, has been studied. Reactions were carried out using two ruthenium-based catalysts, supported on different materials: 3.8 wt.% Ru/C and 3.9 wt.%

Synthesis and structure of aromatic and heterocyclic tellurium compounds 33. Synthesis of [2-(aryltelluro)vinyl]aldehydes and ketones and stereochemistry of nucleophilic substitution under vinyl atom of carbon

International Nuclear Information System (INIS)

Sadekov, I.D.; Rivkin, B.B.; Zakharov, A.V.; Minkin, V.I.

1996-01-01

By means of interaction of (2-vinylchlorida) carbonyl compounds and (2-acylvinyl) triethylammonium chlorides and arenetellurolate-anions certain, [2-(aryltelluro)vinyl]ketones and [2-(aryltelluro)vinyl]aldehydes have been synthesized, while by means of reaction between 2-aroylvinyl chlorides and Li 2 Te some di(2-aroylvinyl)tellurides have been prepared. Interaction of (2-vinylchloride)ketones with arenetellurolate-anions always gives rise to Z-isomers of [2-(aryltelluro)vinyl]ketones as a result of stabilization of intermediate carbanion by intramolecular coordination O→Te. Nucleophilic addition of arenetellurolate-anions to α-acetylene aldehydes and ketones occurs as trans-addition. 36 refs., 2 figs., 1 tab

Perylene anhydride fused porphyrins as near-infrared sensitizers for dye-sensitized solar cells

KAUST Repository

Jiao, Chongjun

2011-07-15

Two perylene anhydride fused porphyrins 1 and 2 have been synthesized and employed successfully in dye-sensitized solar cells (DSCs). Both compounds showed broad incident monochromatic photon-to-current conversion efficiency spectra covering the entire visible spectral region and even extending into the near-infrared (NIR) region up to 1000 nm, which is impressive for ruthenium-free dyes in DSCs. © 2011 American Chemical Society.

Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use

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Denny Joseph Manual Kollareth

2018-03-01

Full Text Available Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [3H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [3H]cholesteryl oleoyl ether and [3H]cholesteryl hexadecyl ether from different suppliers, employing in vitro, in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro, in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments. Keywords: Cholesteryl ether, J774 A2 macrophages, Soy oil emulsion, Thin layer chromatography, triDHA emulsion

Simultaneous determination of furfural and its degradation products, furoic acid and maleic acid, in transformer oil by the reversed-phase vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography.

Science.gov (United States)

Wang, Yifan; Li, Haiyan; Yang, Zhen; Zhang, Weijie; Hua, Jia

2017-12-01

To explore why the use of furfural as a transformer oil-paper insulation aging characteristic is problematic in real world application, we developed a method for the simultaneous determination of furfural, furoic acid, and maleic acid in transformer oil by reversed-phase vortex-assisted liquid-liquid microextraction combined with high-performance liquid chromatography. The conditions for the proposed method were optimized, and the obtained extract can be directly analyzed by high-performance liquid chromatography. The detection limits (signal-to-noise ratio = 3) of the method ranged from 1.0 to 4.6 μg/L, the enrichment factors for furfural, furoic acid, maleic acid, and fumaric acid were 4.6, 25.1, 15.6, and 17.5, respectively, and the recovery rates for three analytes (fumaric acid was undetected) range from 82.1 to 106.2%. The contents of furfural, furoic acid, and maleic acid resulted from accelerated aging of transformer insulation oil-paper were measured using the present method for the first time, and the aging samples were analyzed by liquid chromatography with mass spectrometry for the identification of furoic acid and maleic acid in the aging transformer oil samples. Using the optimal method, the target products of samples at different aging time were tracked and measured. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use.

Science.gov (United States)

Manual Kollareth, Denny Joseph; Chang, Chuchun L; Hansen, Inge H; Deckelbaum, Richard J

2018-03-01

Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [ 3 H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [ 3 H]cholesteryl oleoyl ether and [ 3 H]cholesteryl hexadecyl ether from different suppliers, employing in vitro , in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro , in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments.

A study of the barrier properties of polyethylene coated with a nanocellulose/magnetite composite film

Directory of Open Access Journals (Sweden)

Đorđević Nenad

2016-01-01

Full Text Available The morphological, thermal and barrier properties of low-density polyethylene/polycaprolactone-modified nanocellulose hybrid materials were investigated in this paper. Nanonocelulose/magnetite (NC-Fe3O4 nanocomposite and maleic acid functionalized NC/magnetite (NCMA-Fe3O4 nanocomposite were prepared and used as filler at various concentrations (5, 10 and 15 wt. % in polycaprolactone (PCL layer. PE was coated with PCL/NC/magnetite layer. The addition of the filler did not unfavorably affect the inherent properties of the polymer, especially its barrier properties. Oxygen permeation measurements show that the oxygen barrier properties of magnetite enriched PCL film were improved due to chemical activity of added material. The highest level of barrier capacity was observed for PE samples coated with PCL based composite with NCMA-Fe3O4 micro/-nanofiller, which implies the significant contribution of nanocellulose surface modification with maleic anhydride residue to improved barrier properties. [Projekat Ministarstva nauke Republike Srbije, br. III45019 i br. OI172013

Anodic incineration of phthalic anhydride using RuO2–IrO2–SnO2–TiO2 coated on Ti anode

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S. Chellammal

2016-11-01

Full Text Available Phthalic anhydride is a toxic and non-biodegradable organic compound and is widely used for the production of dyes. This paper has investigated the electrochemical oxidation of phthalic anhydride in an undivided cell at different experimental parameters such as pH, current density and supporting electrolytes on the anode of titanium substrate coated with mixed metal oxides of RuO2, IrO2, SnO2 and TiO2 prepared by thermal decomposition method. The surface morphology and the structure of the above anode were characterized by scanning electron microscopy, electron dispersion microscopy and X-ray diffraction. The study shows that the electrode exhibits good electro catalytic activity together with chemical stability during the treatment of the phthalic anhydride. At pH 3, the maximum removal of COD of 88% with energy consumption of 30.5 kW h kg−1 was achieved by the addition of 10 g l−1 NaCl in 0.2 mol dm−3 Na2SO4 at 5 Adm−2. This electrolytic investigation offers an attractive alternative method for the destruction of industrial effluents contaminated with phthalic anhydride.

“Why is it that we can’t let go of the vinyl record?”

OpenAIRE

Julien, Olivier

2015-01-01

If one were to try to summarize Richard Osborne’s Vinyl: A History of the Analogue Record, we might describe it as an endeavour to discover what makes the vinyl disc record such a key medium in the determination of twentieth-century music by sound recording. As the author makes clear from the outset: “Although vinyl lost its status as Britain’s leading albums format as long ago as 1985 and thus looked set for a permanent decline, sales of vinyl LPs rose year on year by 43.7 per cent in 2011....

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salenCo(III complex tethering four quaternary ammonium salts

Directory of Open Access Journals (Sweden)

Jong Yeob Jeon

2014-08-01

Full Text Available The (salenCo(III complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalates were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalates because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1 and the number of chain-growing sites per 1 [anions in 1 (5 + water (present as impurity + ethanol (deliberately fed], and the molecular weight distributions were narrow (Mw/Mn, 1.05–1.5. Because of the extremely high activity of 1, high-molecular-weight polymers were generated (Mn up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively. The terpolymers bearing a substantial number of PA units (fPA, 0.23 showed a higher glass-transition temperature (48 °C than the CO2/PO alternating copolymer (40 °C.

Numerical investigation on the effect of injection pressure on the internal flow characteristics for diethyl ether, dimethyl ether and diesel fuel injectors using CFD

Directory of Open Access Journals (Sweden)

Vijayakumar Thulasi

2011-01-01

Full Text Available The spray characteristics of the diesel fuel are greatly affected by the cavitation formed inside the injector due to the high pressure differential across the nozzle. Many researchers across the globe are exploring the potential of using diethyl ether and dimethyl ether as an alternate for diesel fuel to meet the strict emission norms. Due to the variation in the fuel properties the internal flow characteristics in injectors for ether fuels are expected to be different from that of the diesel fuel. In this paper computational technique is used to study and compare the internal flow characteristics of diethyl ether, dimethyl ether and diesel fuel. The two phase flow model considering the fuel as a mixture of liquid and vapor is adopted for the simulation study. The injection pressure is varied from 100 to 400 bar and the flow characteristics of all three fuels are simulated and compared. Results indicate that all three fuels have distinct cavitating patterns owing to different property values. The dimethyl ether is found to be more cavitating than diesel and diethyl ether fuels as expected. The mass of fuel injected are found to be decreasing for the ether fuels when compared with diesel fuel at all injection pressures.

Graft copolymerization of vinyl monomers onto nylon 6 fibers by γ-ray pre-irradiation in air

International Nuclear Information System (INIS)

Iwasaki, Tatsuo; Ueda, Yoshitsugu

1992-01-01

Vinyl acetate, methyl methacrylate, alkyl acrylates, acrylonitrile, and acrylamide, were grafted onto nylon 6 fibers by the γ-ray pre-irradiation technique, and the effects of grafting on the microstructure and the mechanical properties of the graft copolymers were investigated. According to the analysis by wide-angle X-ray diffraction, the degree of crystallization decreased by increasing the percent graft of poly(vinyl acetate) in the grafted nylon 6 films. The mechanical parameters, such as the Young's modulus and the tensile strength at break, increased with increasing percent graft up to 50%. When percent grafting was smaller than 50%, rather homogeneous amorphous materials were obtained with vinyl acetate, while heterogeneous ones were obtained with other vinyl monomers. A poly(vinyl alcohol) grafted nylon 6 was obtained effectively by saponification of poly(vinyl acetate) grafted nylon 6, the former showing higher mechanical properties than the latter. Similar behavior was observed after saponification of the poly(methyl acrylate) grafted nylon 6. (author)

AIRBORNE POLYBROMINATED DIPHENYL ETHERS IN A COMPUTER CLASSROOM OF COLLEGE IN TAIWAN

Directory of Open Access Journals (Sweden)

F. H. Chang ، C. R. Yang ، C. Y. Tsai ، W. C. Lin

2009-04-01

Full Text Available This study characterized the airborne exposure of students to thirty polybrominated diphenyl ether congeners inside and outside a computer classroom in a southern Taiwan college. Arithmetic mean values of total indoor and outdoor polybrominated diphenyl ether concentrations were 125.0 pg/m3 (89.8 to 203.9 pg/m3 and 110.3 pg/m3 (83.5 to 157.0 pg/m3, respectively. Total indoor polybrominated diphenyl ether concentrations were one order of magnitude lower than those detected in homes in Birmingham, United Kingdom and in Ottawa, Canada but were several times higher than those measured in the ambient air in Ottawa, Canada and from the Bohai Sea to the Arctic. The five highest indoor concentrations of polybrominated diphenyl ether congeners were decabromodiphenyl ether (23.0 pg/m3, 4,4’-dibromodiphenyl ether (15.9 pg/m3, 2,2’,3,4,4’,5,5’,6-octabromodiphenyl ether (10.6 pg/m3, 2,4-dibromodiphenyl ether (10.3 pg/m3 and 2,2’,3,4,4’,5’,6-heptabromodiphenyl ether (10.0 pg/m3. Although indoor and outdoor total polybrominated diphenyl ether concentrations did not significantly differ, the indoor concentrations of 2,4-dibromodiphenyl ether, 2,2’,4-tribromodiphenyl ether, 2,4,4’-tribromodiphenyl ether, 2,2’,4,5’-tetrabromodiphenyl ether and 2,3’,4’,6-tetrabromodiphenyl ether were significantly higher than their outdoor concentrations. This study suggests the following measures: 1 to increase the air exchange rate and open classroom doors and windows for several minutes before classes to reduce indoor PBDE concentrations; 2 to reduce polybrominated diphenyl ether emissions from new devices, it’s better to use computer-related products that meet the Restriction of Hazardous Substances Directive adopted by the European Union.

Thermally reversible cross-linked poly(ether-urethanes

Directory of Open Access Journals (Sweden)

V. Gaina

2013-07-01

Full Text Available Cross-linked poly(ether-urethanes were prepared by Diels-Alder (DA reaction of the furan-containing poly(ether-urethane to bismaleimides and showed thermal reversibility evidenced by differential scanning calorimetry and attenuated total reflectance in conjunction with Fourier transform infrared spectroscopy (ATR-FTIR. The furan-containing poly(ether-urethanes were synthesized by the polyaddition reaction of 1,6-hexamethylene diisocyanate (HMDI or 4,4'- dibenzyl diisocyanate (DBDI to poly(tetramethylene ether glycol (PTMEG having Mn = 250, 650, 1000, 1500 and 2000 and 2-[N,N-bis(2-methyl-2-hydroxyethylamino]furfuryl as chain extender by the solution prepolymer method. The molar ratio of isocyanate: PTMEG:chain extender varied from 2:1:1 to 4:1:3, which produces a molar concentration of furyl group ranging between 3.65•10–4 and 1.25•10–3 mol/g.

Thermal Stability of Sulfonated Poly(Ether Ether Ketone) Films: on the Role of Protodesulfonation

OpenAIRE

Koziara, Beata; Kappert, Emiel; Ogieglo, Wojciech; Nijmeijer, Dorothea C.; Hempenius, Mark A.; Benes, Nieck Edwin

2016-01-01

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160–250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material, most likely via a slight cross-linking by H-substitution. It is well-known that the sulfonate proton plays a major role in the desulfonation reactions, and exchanging the protons with other cations ...

29 CFR 1926.1117 - Vinyl chloride.

Science.gov (United States)

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Vinyl chloride. 1926.1117 Section 1926.1117 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... chloride. Note: The requirements applicable to construction work under this section are identical to those...

Dimethyl ether as a drift-chamber gas

International Nuclear Information System (INIS)

Bari, G.; Basile, M.; Bonvicini, G.; Cara Romeo, G.; Casaccia, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; D'Ali, G.; Del Papa, C.; Focardi, S.; Iacobucci, G.; Maccarrone, G.; Massam, T.; Motta, F.; Nania, R.; Palmonari, F.; Prisco, G.; Sartorelli, G.; Susinno, G.; Votano, L.; Zichichi, A.; Istituto Nazionale di Fisica Nucleare, Bologna; European Organization for Nuclear Research, Geneva; Istituto Nazionale di Fisica Nucleare, Frascati; Michigan Univ., Ann Arbor; Palermo Univ.

1986-01-01

We have continued the testing of dimethyl ether as a drift-chamber gas in order to improve the understanding of its properties. In particular, we report on measurement accuracy, on systematic effects, and some preliminary data on the ageing of a detector filled with dimethyl ether. (orig.)

Evaluation of genotoxic activity of maleic hydrazide, ethyl methane sulfonate, and N-nitroso diethylamine in Tradescantia

OpenAIRE

Alvarez-Moya Carlos; Santerre-Lucas Anne; Zúñiga-González Guillermo; Torres-Bugarín Olivia; Padilla-Camberos Eduardo; Feria-Velasco Alfredo

2001-01-01

Objective. To assess the genotoxic activity of N-nitroso diethylamine (NDEA), maleic hydrazide (MH), and ethyl methane sulfonate (EMS) using two systems: the comet assay on nuclei from Tradescantia, and the pink mutation test on Tradescantia staminal hairs (clone 4430). Material and Methods. Tradescantia cups was obtained from Laboratorio de Citogenética y Mutagénesis del Centro de Ciencias de la Atmósfera de la Universidad Nacional Autónoma de México and treated with: N-nitroso diethylamine ...

Process for making propenyl ethers and photopolymerizable compositions containing them

Science.gov (United States)

Crivello, James V.

1996-01-01

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