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Sample records for ether copolymer maleic

  1. Oil recovery with sulfomethylated poly (lower alkyl vinyl ether/maleic anhydride)

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-05-22

    Lower alkyl vinyl ether e.g., methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, hexyl vinyl ether, is copolymerized conventionally with maleic anhydride, the resulting copolymer is treated with ammonia or ammonium hydroxide to form the partial amide-ammonium salt, and this salt is in turn treated with formaldehyde and thereafter or simultaneously with ammonium or alkali metal salt sulfite (including bisulfites, etc.) to form an at least partially sulfomethylated copolymer. Aqueous solutions of the sulfomethylated copolymer are useful in increasing the viscosity of drive fluids used in the supplemented recovery of petroleum from subterranean formations. In general, enhancing the polyionic character of mobility control agents used in supplemented recovery of petroleum provides enhanced recovery. Achieving this enhancement of polyionic character through use of sulfonate groups provides a mobility control agent with good ability to sustain viscosity in the presence of brine and lime, usually present in the connate waters of petroleum-bearing formations. (7 claims)

  2. 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

  3. 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...

  4. 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.

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

    Science.gov (United States)

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

    2014-03-01

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

  6. 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)

  7. 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.

  8. Solubilization of human cells by the styrene-maleic acid copolymer: Insights from fluorescence microscopy.

    Science.gov (United States)

    Dörr, Jonas M; van Coevorden-Hameete, Marleen H; Hoogenraad, Casper C; Killian, J Antoinette

    2017-11-01

    Extracting membrane proteins from biological membranes by styrene-maleic acid copolymers (SMAs) in the form of nanodiscs has developed into a powerful tool in membrane research. However, the mode of action of membrane (protein) solubilization in a cellular context is still poorly understood and potential specificity for cellular compartments has not been investigated. Here, we use fluorescence microscopy to visualize the process of SMA solubilization of human cells, exemplified by the immortalized human HeLa cell line. Using fluorescent protein fusion constructs that mark distinct subcellular compartments, we found that SMA solubilizes membranes in a concentration-dependent multi-stage process. While all major intracellular compartments were affected without a strong preference, plasma membrane solubilization was found to be generally slower than the solubilization of organelle membranes. Interestingly, some plasma membrane-localized proteins were more resistant against solubilization than others, which might be explained by their presence in specific membrane domains with differing properties. Our results support the general applicability of SMA for the isolation of membrane proteins from different types of (sub)cellular membranes. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Bacterial Reaction Centers Purified with Styrene Maleic Acid Copolymer Retain Native Membrane Functional Properties and Display Enhanced Stability**

    Science.gov (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R

    2014-01-01

    Integral membrane proteins often present daunting challenges for biophysical characterization, a fundamental issue being how to select a surfactant that will optimally preserve the individual structure and functional properties of a given membrane protein. Bacterial reaction centers offer a rare opportunity to compare the properties of an integral membrane protein in different artificial lipid/surfactant environments with those in the native bilayer. Here, we demonstrate that reaction centers purified using a styrene maleic acid copolymer remain associated with a complement of native lipids and do not display the modified functional properties that typically result from detergent solubilization. Direct comparisons show that reaction centers are more stable in this copolymer/lipid environment than in a detergent micelle or even in the native membrane, suggesting a promising new route to exploitation of such photovoltaic integral membrane proteins in device applications. PMID:25212490

  15. Interpolymer complexses of vinyl ether copolymer with polyacrylic and polymethacrylic acids

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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)

  1. STUDIES ON POLY (ETHYLENE TEREPHTHALATE)- POLY ( TETRAMETHYLENE ETHER ) MULTIBLOCK COPOLYMER.Ⅰ. COM POSITIONAL HOMOGENEITY

    Institute of Scientific and Technical Information of China (English)

    ZHAN Yongjian; YING Qicong; WU Meiyan; QIAN Renyuan

    1991-01-01

    The compositional homogeneity of a poly (ethylene terephthalate )-poly (tetramethylene ether)multiblock copolymer sample with low content of hard segment was examined by GPC, TLC, and solubility method. The copolymer sample was found to have a uniform composition as a function of elution volume over the major portion of sample from GPC method. However within one elution fraction, the copolymer chains, although having the same hydrodynamic volume, may have some difference in composition. Two fractions with different composition were obtained by precipitation in ethanol. Some low molar mass copolymers were also separated by a TLC technique from the copolymer sample.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Charu Vashisth Rohatgi

    2015-03-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

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    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.

  6. Styrene-maleic acid-copolymer conjugated zinc protoporphyrin as a candidate drug for tumor-targeted therapy and imaging.

    Science.gov (United States)

    Fang, Jun; Tsukigawa, Kenji; Liao, Long; Yin, Hongzhuan; Eguchi, Kanami; Maeda, Hiroshi

    2016-01-01

    Previous studies indicated the potential of zinc protoporphyrin (ZnPP) as an antitumor agent targeting to the tumor survival factor heme oxygenase-1, and/or for photodynamic therapy (PDT). In this study, to achieve tumor-targeted delivery, styrene-maleic acid-copolymer conjugated ZnPP (SMA-ZnPP) was synthesized via amide bond, which showed good water solubility, having ZnPP loading of 15%. More importantly, it forms micelles in aqueous solution with a mean particle size of 111.6 nm, whereas it has an apparent Mw of 65 kDa. This micelle formation was not detracted by serum albumin, suggesting it is stable in circulation. Further SMA-ZnPP conjugate will behave as an albumin complex in blood with much larger size (235 kDa) by virtue of the albumin binding property of SMA. Consequently, SMA-ZnPP conjugate exhibited prolonged circulating retention and preferential tumor accumulation by taking advantage of enhanced permeability and retention (EPR) effect. Clear tumor imaging was thus achieved by detecting the fluorescence of ZnPP. In addition, the cytotoxicity and PDT effect of SMA-ZnPP conjugate was confirmed in human cervical cancer HeLa cells. Light irradiation remarkably increased the cytotoxicity (IC50, from 33 to 5 μM). These findings may provide new options and knowledge for developing ZnPP based anticancer theranostic drugs.

  7. Controlled disulfonated poly(arylene ether sulfone) multiblock copolymers for direct methanol fuel cells.

    Science.gov (United States)

    Li, Qing; Chen, Yu; Rowlett, Jarrett R; McGrath, James E; Mack, Nathan H; Kim, Yu Seung

    2014-04-23

    Structure-property-performance relationships of disulfonated poly(arylene ether sulfone) multiblock copolymer membranes were investigated for their use in direct methanol fuel cell (DMFC) applications. Multiple series of reactive polysulfone, polyketone, and polynitrile hydrophobic block segments having different block lengths and molecular composition were synthesized and reacted with a disulfonated poly(arylene ether sulfone) hydrophilic block segment by a coupling reaction. Large-scale morphological order of the multiblock copolymers evolved with the increase of block size that gave notable influence on mechanical toughness, water uptake, and proton/methanol transport. Chemical structural changes of the hydrophobic blocks through polar group, fluorination, and bisphenol type allowed further control of the specific properties. DMFC performance was analyzed to elicit the impact of structural variations of the multiblock copolymers. Finally, DMFC performances of selected multiblock copolymers were compared against that of the industrial standard Nafion in the DMFC system.

  8. Poly(ether amide) segmented block copolymers with adipicacid based tetra amide segments

    NARCIS (Netherlands)

    Biemond, G.J.E.; Feijen, Jan; Gaymans, R.J.

    2007-01-01

    Poly(tetramethylene oxide)-based poly(ether ester amide)s with monodisperse tetraamide segments were synthesized. The tetraamide segment was based on adipic acid, terephthalic acid, and hexamethylenediamine. The synthesis method of the copolymers and the influence of the tetraamide concentration,

  9. 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...

  10. 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)

  11. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes.

    Science.gov (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; Foster, Nicholas; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R

    2017-10-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such as styrene maleic acid (SMA) for the solubilisation, purification and characterisation of integral membrane proteins in the form of protein/lipid nanodiscs. Here we survey the effectiveness of various commercially-available formulations of the SMA copolymer in solubilising Rhodobacter sphaeroides reaction centres (RCs) from photosynthetic membranes. We find that formulations of SMA with a 2:1 or 3:1 ratio of styrene to maleic acid are almost as effective as detergent in solubilising RCs, with the best solubilisation by short chain variants (membranes was uniformly low, but could be increased through a variety of treatments to increase the lipid:protein ratio. However, proteins isolated from such membranes comprised clusters of complexes in small membrane patches rather than individual proteins. We conclude that short-chain 2:1 and 3:1 formulations of SMA are the most effective in solubilising integral membrane proteins, but that solubilisation efficiencies are strongly influenced by the size of the target protein and the density of packing of proteins in the membrane. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. The Formation of Polycomplexes of Poly(Methyl Vinyl Ether-Co-Maleic Anhydride and Bovine Serum Albumin in the Presence of Copper Ions

    Directory of Open Access Journals (Sweden)

    Karahan Mesut

    2014-09-01

    Full Text Available The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride (PMVEMA with copper ions and with bovine serum albumin (BSA in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II, the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.

  13. 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

  14. 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

  15. 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...

  16. Tissue engineering of bovine articular cartilage within porous poly(ether ester) copolymer scaffolds with different structures

    NARCIS (Netherlands)

    Mahmood, Tahir A.; Shastri, V. Prasad; van Blitterswijk, Clemens; Langer, Robert; Riesle, J.U.

    2005-01-01

    The potential of porous poly(ether ester) scaffolds made from poly(ethylene glycol) terephthalate: poly(butylene terephthalate) (PEGT:PBT) block copolymers produced by various methods to enable cartilaginous tissue formation in vitro was studied. Scaffolds were fabricated by two different processes:

  17. Amphiphilic poly(ether ester amide) multiblock copolymers as biodegradable matrices for the controlled release of proteins

    NARCIS (Netherlands)

    Bezemer, J.M.; Oude Weme, P.; Grijpma, Dirk W.; Dijkstra, Pieter J.; van Blitterswijk, Clemens; Feijen, Jan

    2000-01-01

    Amphiphilic poly(ether ester amide) (PEEA) multiblock copolymers were synthesized by polycondensation in the melt from hydrophilic poly(ethylene glycol) (PEG), 1,4-dihydroxybutane and short bisester-bisamide blocks. These amide blocks were prepared by reaction of 1,4-diaminobutane with dimethyl

  18. 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

  19. 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

  20. Influence of the composition of hydroxypropyl cellulose/maleic acid-alt-styrene copolymer blends on their properties as matrix for drug release

    Directory of Open Access Journals (Sweden)

    2009-05-01

    Full Text Available Poly(carboxylic acid-polysaccharide compositions have been found suitable for obtaining drug formulations with controlled release, most formulations being therapeutically efficacious, stable, and non-irritant. The influence of the characteristics of the aqueous solutions from which the polymer matrix is prepared (i.e. the total concentration of polymer in solutions and the mixing ratio between the partners, hydroxypropyl cellulose, HPC and maleic acid-alternating-styrene copolymer, MAc-alt-S on the kinetics of some drugs release in acidic environment (pH = 2 has been followed by ‘in vitro’ dissolution tests. It has been established that the kinetics of procaine hydrochloride release from HPC/MAc-alt-S matrix depends on its composition; the diffusion exponent, n is close to 0.5 for matrices where one of the components is in large excess and n~0.02 for middle composition range. The lower value of diffusion exponent for middle composition range could be caused by the so called ‘burst effect’, therefore the kinetic evaluation is difficult.

  1. Probing molecular interactions of poly(styrene-co-maleic acid) with lipid matrix models to interpret the therapeutic potential of the co-polymer.

    Science.gov (United States)

    Banerjee, Shubhadeep; Pal, Tapan K; Guha, Sujoy K

    2012-03-01

    To understand and maximize the therapeutic potential of poly(styrene-co-maleic acid) (SMA), a synthetic, pharmacologically-active co-polymer, its effect on conformation, phase behavior and stability of lipid matrix models of cell membranes were investigated. The modes of interaction between SMA and lipid molecules were also studied. While, attenuated total reflection-Fourier-transform infrared (ATR-FTIR) and static (31)P nuclear magnetic resonance (NMR) experiments detected SMA-induced conformational changes in the headgroup region, differential scanning calorimetry (DSC) studies revealed thermotropic phase behavior changes of the membranes. (1)H NMR results indicated weak immobilization of SMA within the bilayers. Molecular interpretation of the results indicated the role of hydrogen-bond formation and hydrophobic forces between SMA and zwitterionic phospholipid bilayers. The extent of membrane fluidization and generation of isotropic phases were affected by the surface charge of the liposomes, and hence suggested the role of electrostatic interactions between SMA and charged lipid headgroups. SMA was thus found to directly affect the structural integrity of model membranes. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. A Styrene-alt-Maleic Acid Copolymer Is an Effective Inhibitor of R5 and X4 Human Immunodeficiency Virus Type 1 Infection

    Directory of Open Access Journals (Sweden)

    Vanessa Pirrone

    2010-01-01

    Full Text Available An alternating copolymer of styrene and maleic acid (alt-PSMA differs from other polyanionic antiviral agents in that the negative charges of alt-PSMA are provided by carboxylic acid groups instead of sulfate or sulfonate moieties. We hypothesized that alt-PSMA would have activity against human immunodeficiency virus type 1 (HIV-1 comparable to other polyanions, such as the related compound, poly(sodium 4-styrene sulfonate (PSS. In assays using cell lines and primary immune cells, alt-PSMA was characterized by low cytotoxicity and effective inhibition of infection by HIV-1 BaL and IIIB as well as clinical isolates of subtypes A, B, and C. In mechanism of action assays, in which each compound was added to cells and subsequently removed prior to HIV-1 infection (“washout” assay, alt-PSMA caused no enhancement of infection, while PSS washout increased infection 70% above control levels. These studies demonstrate that alt-PSMA is an effective HIV-1 inhibitor with properties that warrant further investigation.

  3. Poly(vinyl methyl ether/maleic anhydride)-Doped PEG-PLA Nanoparticles for Oral Paclitaxel Delivery To Improve Bioadhesive Efficiency.

    Science.gov (United States)

    Wang, Qian; Li, Chan; Ren, Tianyang; Chen, Shizhu; Ye, Xiaoxia; Guo, Hongbo; He, Haibing; Zhang, Yu; Yin, Tian; Liang, Xing-Jie; Tang, Xing

    2017-10-02

    Bioadhesive nanoparticles based on poly(vinyl methyl ether/maleic anhydride) (PVMMA) and poly(ethylene glycol) methyl ether-b-poly(d,l-lactic acid) (mPEG-b-PLA) were produced by the emulsification solvent evaporation method. Paclitaxel was utilized as the model drug, with an encapsulation efficiency of up to 90.2 ± 4.0%. The nanoparticles were uniform and spherical in shape and exhibited a sustained drug release compared with Taxol. m-NPs also exhibited favorable bioadhesive efficiency at the same time. Coumarin 6 or DiR-loaded nanoparticles with/without PVMMA (C6-m-NPs/DiR-m-NPs or C6-p-NPs/DiR-p-NPs) were used for cellular uptake and intestinal adhesion experiments, respectively. C6-m-NPs were shown to enhance cellular uptake, and caveolae/lipid raft mediated endocytosis was the primary route for the uptake of the nanoparticles. Favorable bioadhesive efficiency led to prolonged retention in the intestine reflected by the fluorescence in isolated intestines ex vivo. In a ligated intestinal loops model, C6-m-NPs showed a clear advantage for transporting NPs across the mucus layer over C6-p-NPs and free C6. The apparent permeability coefficient (Papp) of PTX-m-NPs through Caco-2/HT29 monolayers was 1.3- and 1.6-fold higher than PTX-p-NPs and Taxol, respectively, which was consistent with the AUC 0-t of different PTX formulations after oral administration in rats. PTX-m-NPs also exhibited a more effective anticancer efficacy, with an IC 50 of 0.2 ± 1.4 μg/mL for A549 cell lines, further demonstrating the advantage of bioadhesive nanoparticles. The bioadhesive nanoparticles m-NPs demonstrated both mucus permeation and epithelial absorption, and thus, this bioadhesive drug delivery system has the potential to improve the bioavailability of drugs that are insoluble in the gastrointestinal environment.

  4. 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

  5. Moessbauer spectroscopic study of Fe{sup II}-doped sulphonated poly(ether-urethane)-styrene-acrylate copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, A. A. [Russian Academy of Sciences, Institute of Biochemistry and Physiology of Plants and Microorganisms (Russian Federation); Grigoryeva, O. P.; Fainleib, A. M. [National Academy of Sciences of Ukraine, Institute of Macromolecular Chemistry (Ukraine); Kuzmann, E., E-mail: kuzmann@ludens.elte.hu [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

    2013-04-15

    Thermoplastic linear ionomer based on sulphonated poly(ether-urethane)-styrene-acrylate copolymer, doped with natural Fe{sup 2 + }, was studied by Moessbauer spectroscopy at T = 78 and 290 K to monitor the chemical state of Fe species. The Fe{sup 2 + } added to aqueous suspension of the system was only partly oxidised in the course of polymer film preparation and drying in air. The oxidised part comprised a magnetic phase ({approx}19 % of total Fe both at T = 78 and 298 K) and a quadrupole doublet ({approx}40 %), while Fe{sup II} (over 40 %) stabilised in two types of microenvironments.

  6. A poly(ether-ester) copolymer for the preparation of nanocarriers with improved degradation and drug delivery kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Gagliardi, M., E-mail: mariacristina.gagliardi@iit.it [Center for Micro Bio-Robotics @SSSA, Istituto Italiano di Tecnologia, Viale Rinaldo Piaggio 34, 56025 Pontedera (Italy); Bertero, A. [Department of Biology, Unit of Cellular and Developmental Biology, University of Pisa, S.S.12 Abetone e Brennero 4, 56127 Pisa (Italy); Center for Neuroscience and Cognitive Systems @UNITN, Istituto Italiano di Tecnologia, Corso Bettini 31, 38068 Rovereto (Italy); Bardi, G. [Center for Bio-Molecular Nanotechnologies @UniLe, Istituto Italiano di Tecnologia, Via Barsanti, 73010 Arnesano (Italy); Bifone, A. [Center for Neuroscience and Cognitive Systems @UNITN, Istituto Italiano di Tecnologia, Corso Bettini 31, 38068 Rovereto (Italy)

    2016-02-01

    This paper reports the synthesis and the physicochemical, functional and biological characterisations of nanocarriers made of a novel di-block biodegradable poly(ether-ester) copolymer. This material presents tunable, fast biodegradation rates, but its products are less acidic than those of other biosorbable polymers like PLGA, thus presenting a better biocompatibility profile and the possibility to carry pH-sensitive payloads. A method for the production of monodisperse and spherical nanoparticles is proposed; drug delivery kinetics and blood protein adsorption were measured to evaluate the functional properties of these nanoparticles as drug carriers. The copolymer was labelled with a fluorescent dye for internalisation tests, and rhodamine B was used as a model cargo to study transport and release inside cultured cells. Biological tests demonstrated good cytocompatibility, significant cell internalisation and the possibility to vehiculate non-cell penetrating moieties into endothelial cells. Taken together, these results support the potential use of this nanoparticulate system for systemic administration of drugs. - Highlights: • We propose a novel biodegradable nanocarrier for intracellular drug delivery. • Biodegradation rates can be finely tuned by controlling copolymer composition. • Degradation products are less acidic, thus enabling delivery of pH-sensitive cargoes. • We demonstrate intracellular delivery of a non-cell-penetrating model drug. • No significant membrane damage by the polymer nanocarriers is observed.

  7. A poly(ether-ester) copolymer for the preparation of nanocarriers with improved degradation and drug delivery kinetics

    International Nuclear Information System (INIS)

    Gagliardi, M.; Bertero, A.; Bardi, G.; Bifone, A.

    2016-01-01

    This paper reports the synthesis and the physicochemical, functional and biological characterisations of nanocarriers made of a novel di-block biodegradable poly(ether-ester) copolymer. This material presents tunable, fast biodegradation rates, but its products are less acidic than those of other biosorbable polymers like PLGA, thus presenting a better biocompatibility profile and the possibility to carry pH-sensitive payloads. A method for the production of monodisperse and spherical nanoparticles is proposed; drug delivery kinetics and blood protein adsorption were measured to evaluate the functional properties of these nanoparticles as drug carriers. The copolymer was labelled with a fluorescent dye for internalisation tests, and rhodamine B was used as a model cargo to study transport and release inside cultured cells. Biological tests demonstrated good cytocompatibility, significant cell internalisation and the possibility to vehiculate non-cell penetrating moieties into endothelial cells. Taken together, these results support the potential use of this nanoparticulate system for systemic administration of drugs. - Highlights: • We propose a novel biodegradable nanocarrier for intracellular drug delivery. • Biodegradation rates can be finely tuned by controlling copolymer composition. • Degradation products are less acidic, thus enabling delivery of pH-sensitive cargoes. • We demonstrate intracellular delivery of a non-cell-penetrating model drug. • No significant membrane damage by the polymer nanocarriers is observed.

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

    Science.gov (United States)

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

    1990-01-01

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

  9. In vivo and in vitro degradation of poly(ether ester) block copolymers based on poly(ethylene glycol) and poly(butylene terephthalate

    NARCIS (Netherlands)

    Deschamps, A.A.; van Apeldoorn, Aart A.; Hayen, H.; de Bruijn, Joost Dick; Karst, U.; Grijpma, Dirk W.; Feijen, Jan

    2004-01-01

    Two in vivo degradation studies were performed on segmented poly(ether ester)s based on polyethylene glycol (PEG) and poly(butylene terephthalate) (PBT) (PEOT/PBT). In a first series of experiments, the in vivo degradation of melt-pressed discs of different copolymer compositions were followed up

  10. Decoration of a Poly(methyl vinyl ether-co-maleic anhydride)-Shelled Selol Nanocapsule with Folic Acid Increases Its Activity Against Different Cancer Cell Lines In Vitro.

    Science.gov (United States)

    Ganassin, Rayane; Souza, Ludmilla Regina de; Py-Daniel, Karen Rapp; Longo, João Paulo Figueiró; Coelho, Janaína Moreira; Rodrigues, Mosar Correa; Jiang, Cheng-Shi; Gu, Jinsong; Morais, Paulo César de; Mosiniewicz-Szablewska, Ewa; Suchocki, Piotr; Báo, Sônia Nair; Azevedo, Ricardo Bentes; Muehlmann, Luis Alexandre

    2018-01-01

    Due to the low therapeutic index of different chemotherapeutic drugs used for cancer treatment, the development of new anticancer drugs remains an intense field of research. A recently developed mixture of selenitetriacylglycerides, selol, was shown to be active against different cancer cells in vitro. As this compound is highly hydrophobic, it was encapsulated, in a previous study, into poly(methyl vinyl ether-co-maleic anhydride)-shelled nanocapsules in order to improve its dispersibility in aqueous media. Following this line of research, the present report aimed at enhancing the In Vitro activity of the selol nanocapsules against cancerous cells by decorating their surface with folic acid. It is known that several cancer cells overexpress folate receptors. Stable folic acid-decorated selol nanocapsules (SNP-FA) were obtained, which showed to be spherical, with a hydro-dynamic diameter of 364 nm, and zeta potential of -24 mV. In comparison to non-decorated selol nanocapsules, SNP-FA presented higher activity against 4T1, MCF-7 and HeLa cells. Moreover, the decoration of the nanocapsules did not alter their toxicity towards fibroblasts, NIH-3T3 cells. These results show that the decoration with folic acid increased the toxicity of selol nanocapsules to cancer cells. These nanocapsules, besides enabling to disperse selol in an aqueous medium, increased the toxicity of this drug In Vitro, and may be useful to treat cancer in vivo, potentially increasing the specificity of selol towards cancer cells.

  11. 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.

  12. Surface-Initiated Atom Transfer Radical Polymerization of Magnetite Nanoparticles with Statistical Poly(tert-butyl acrylate-poly(poly(ethylene glycol methyl ether methacrylate Copolymers

    Directory of Open Access Journals (Sweden)

    Patcharin Kanhakeaw

    2015-01-01

    Full Text Available This work presented the surface modification of magnetite nanoparticle (MNP with poly[(t-butyl acrylate-stat-(poly(ethylene glycol methyl ether methacrylate] copolymers (P[(t-BA-stat-PEGMA] via a surface-initiated “grafting from” atom transfer radical polymerization (ATRP. Loading molar ratio of t-BA to PEGMA was systematically varied (100 : 0, 75 : 25, 50 : 50, and 25 : 75, resp. such that the degree of hydrophilicity of the copolymers, affecting the particle dispersibility in water, can be fine-tuned. The reaction progress in each step of the synthesis was monitored via Fourier transform infrared spectroscopy (FTIR. The studies in the reaction kinetics indicated that PEGMA had higher reactivity than that of t-BA in the copolymerizations. Gel permeation chromatography (GPC indicated that the molecular weights of the copolymers increased with the increase of the monomer conversion. Transmission electron microscopy (TEM revealed that the particles were spherical with averaged size of 8.1 nm in diameter. Dispersibility of the particles in water was apparently improved when the copolymers were coated as compared to P(t-BA homopolymer coating. The percentages of MNP and the copolymer in the composites were determined via thermogravimetric analysis (TGA and their magnetic properties were investigated via vibrating sample magnetometry (VSM.

  13. Dynamic mechanical analysis of binary and ternary polymer blends based on nylon copolymer/EPDM rubber and EPM grafted maleic anhydride compatibilizer

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available The dynamic mechanical properties such as storage modulus, loss modulus and damping properties of blends of nylon copolymer (PA6,66 with ethylene propylene diene (EPDM rubber was investigated with special reference to the effect of blend ratio and compatibilisation over a temperature range –100°C to 150°C at different frequencies. The effect of change in the composition of the polymer blends on tanδ was studied to understand the extent of polymer miscibility and damping characteristics. The loss tangent curve of the blends exhibited two transition peaks, corresponding to the glass transition temperature (Tg of individual components indicating incompatibility of the blend systems. The morphology of the blends has been examined by using scanning electron microscopy. The Arrhenius relationship was used to calculate the activation energy for the glass transition of the blends. Finally, attempts have been made to compare the experimental data with theoretical models.

  14. 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

  15. pH-sensitive polymeric cisplatin-ion complex with styrene-maleic acid copolymer exhibits tumor-selective drug delivery and antitumor activity as a result of the enhanced permeability and retention effect.

    Science.gov (United States)

    Saisyo, Atsuyuki; Nakamura, Hideaki; Fang, Jun; Tsukigawa, Kenji; Greish, Khaled; Furukawa, Hiroyuki; Maeda, Hiroshi

    2016-02-01

    Cisplatin (CDDP) is widely used to treat various cancers. However, its distribution to normal tissues causes serious adverse effects. For this study, we synthesized a complex of styrene-maleic acid copolymer (SMA) and CDDP (SMA-CDDP), which formed polymeric micelles, to achieve tumor-selective drug delivery based on the enhanced permeability and retention (EPR) effect. SMA-CDDP is obtained by regulating the pH of the reaction solution of SMA and CDDP. The mean SMA-CDDP particle size was 102.5 nm in PBS according to electrophoretic light scattering, and the CDDP content was 20.1% (w/w). The release rate of free CDDP derivatives from the SMA-CDDP complex at physiological pH was quite slow (0.75%/day), whereas it was much faster at pH 5.5 (4.4%/day). SMA-CDDP thus had weaker in vitro toxicity at pH 7.4 but higher cytotoxicity at pH 5.5. In vivo pharmacokinetic studies showed a 5-fold higher tumor concentration of SMA-CDDP than of free CDDP. SMA-CDDP had more effective antitumor potential but lower toxicity than did free CDDP in mice after i.v. administration. Administration of parental free CDDP at 4 mg/kg×3 caused a weight loss of more than 5%; SMA-CDDP at 60 mg/kg (CDDP equivalent)×3 caused no significant weight change but markedly suppressed S-180 tumor growth. These findings together suggested using micelles of the SMA-CDDP complex as a cancer chemotherapeutic agent because of beneficial properties-tumor-selective accumulation and relatively rapid drug release at the acidic pH of the tumor-which resulted in superior antitumor effects and fewer side effects compared with free CDDP. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. 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.

  17. Graft-crosslinked copolymers based on poly(arylene ether ketone)-gc-sulfonated poly(arylene ether sulfone) for PEMFC applications.

    Science.gov (United States)

    Zhang, Xuan; Hu, Zhaoxia; Luo, Linqiang; Chen, Shanshan; Liu, Jianmei; Chen, Shouwen; Wang, Lianjun

    2011-07-15

    Novel poly(arylene ether ketone) polymers with fluorophenyl pendants and phenoxide-terminated wholly sulfonated poly(arylene ether sulfone) oligomers are prepared via Ni(0)-catalyzed and nucleophilic polymerization, respectively, and subsequently used as starting materials to obtain graft-crosslinked membranes as polymer electrolyte membranes. The phenoxide-terminated sulfonated moieties are introduced as hydrophilic parts as well as crosslinking units. The chemical structure and morphology of the obtained membranes are confirmed by (1) H NMR and tapping-mode AFM. The properties required for fuel cell applications, including water uptake and dimensional change, as well as proton conductivity, are investigated. AFM results show a clear nanoscale phase-separation microstructure of the obtained membranes. The membranes show good dimensional stability and reasonably high proton conductivities under 30-90% relative humidity. The anisotropic proton conductivity ratios (σ(formula see text) ) of the membranes in water are in the range 0.65-0.92, and increase with an increase in hydrophilic block length. The results indicate that the graft-crosslinked membranes are promising candidates for applications as polymer electrolyte membranes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A controlled release system for proteins based on poly(ether ester) block-copolymers: polymer network characterization

    NARCIS (Netherlands)

    Bezemer, J.M.; Grijpma, Dirk W.; Dijkstra, Pieter J.; van Blitterswijk, Clemens; Feijen, Jan

    1999-01-01

    The properties of a series of multiblock copolymers, based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(butylene terephthalate) (PBT) blocks were investigated with respect to their application as a matrix for controlled release of proteins. The degree of swelling, Q, of the

  19. Designing of molecular architecture, synthesis and properties of the next generation of state-of-the-art high-performance thermoplastic fluoro-poly(ether amide)s, (6F-PEA), fluoro-poly(ether amide-imide)s (6F-PEAI), and their co-polymers

    International Nuclear Information System (INIS)

    Vora, Rohitkumar H.

    2010-01-01

    Graphical abstract: Molecular architectures of next generation of high-performance advanced heat stable thermoplastic polymer compositions of fluoro-poly(ether amide) (6F-PA) and fluoro-poly(ether amide-imide) (6F-PEAI) having di-ether diamines moieties were designed based on fluoro-polyimide (6F-PI) chemistry, and polymers were synthesized using two novel state-of-the-art 2-(3,4'-carboxy anhydrophenyl-2(4-carboxyphenyl) hexafluoropropane (6FTMA) and 2,2'-bis(4-carboxyphenyl) hexafluropropane (6F-DAc) monomers. Their copolymers: fluoro-copoly(ether amide-(ether imide))s (6F-co(PEA-PEI)), fluoro-copoly(ether amide-(ether amide-imide))s (6F-co(PEA-PEAI)) and fluoro-copoly(ether amide-imide-(ether imide))s (6F-co(PEAI-PEI)) were also designed and synthesized using 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydrides (6FDA) for the advanced aerospace, defense and industrial engineering applications. -- Abstract: A new generation of high-performance polymers for the advanced industrial, aerospace and defense engineering applications are being investigated in the academic and industrial research institutions throughout the world. Fluoro-polyimides (6F-PI) are one such sub-class of high-performance polyimide polymers. In the last 25 years a number of fluoro-polyimides have been reported but only a handful of them have been commercialized. This paper describes the 6F-polyimide chemistry-based designed molecular architectures and synthesis of two series of next generation of heat stable thermoplastic polymer compositions having di-ether diamines moieties, such as fluoro-poly(ether amide) (6F-PA) and fluoro-poly(ether amide-imide) (6F-PEAI) using the novel state-of-the-art 2-(3,4'-carboxy anhydrophenyl-2(4-carboxyphenyl) hexafluoropropane (6F-TMA) and 2,2'-bis(4-carboxyphenyl) hexafluoropropane (6F-DAc) monomers. Their co-polymers: fluoro-copoly(ether amide-(ether imide))s (6F-co(PEA-PEI)), fluoro-copoly(ether amide-(ether amide-imide))s (6F-co(PEA-PEAI)) and fluoro-copoly(ether

  20. Deformation Behaviour During Cold Drawing of Nanocomposites Based on Single Wall Carbon Nanotubes and Poly(ether ester) Copolymers

    International Nuclear Information System (INIS)

    Hernandez, J.; Garcia-Gutierrez, M.; Nogales, A.; Rueda, D.; Sanz, A.; Sics, I.; Hsiao, B.; Roslaniec, Z.; Broza, G.; Ezquerra, T.

    2007-01-01

    Relationships between the macroscopic deformation behaviour and microstructure of a pure (PBT-b-PTMO) block copolymer and a polymer nanocomposite (PBT-b-PTMO + 0.2 wt% SWCNT) were investigated by simultaneous small- and wide-angle X-ray scattering (SAXS and WAXS) during tensile deformation using synchrotron radiation. The Young's modulus was found to be 15% higher for the nanocomposite than for the pure block copolymer as well as the yield strength, while the elongation-to-break was less than a half. This different behaviour can be explained by taking into account the different structural features revealed by SAXS and WAXS and thus considering that SWCNT act as anchors in the nanocomposite, sharing the applied stress with the PBT crystals and partially preventing the flexible, non-crystallisable PTMO chains to elongate

  1. Effects of Block Length and Membrane Processing Conditions on the Morphology and Properties of Perfluorosulfonated Poly(arylene ether sulfone) Multiblock Copolymer Membranes for PEMFC.

    Science.gov (United States)

    Assumma, Luca; Nguyen, Huu-Dat; Iojoiu, Cristina; Lyonnard, Sandrine; Mercier, Régis; Espuche, Eliane

    2015-07-01

    Perfluorosulfonated poly(arylene ether sulfone) multiblock copolymers have been shown to be promising as proton exchange membranes. The commonly used approach for preparation of the membrane is solvent casting; the properties of the resulting membranes are very dependent on the membrane processing conditions. In this paper, we study the effects of block length, selectivity of the solvent, and thermal treatment on the membrane properties such as morphology, water uptake, and ionic conductivity. DiMethylSulfOxide (DMSO), and DiMethylAcetamide (DMAc) were selected as casting solvents based on the Flory-Huggins parameter calculated by inversion gas chromatography (IGC). It was found that the solvent selectivity has a mild impact on the mean size of the ionic domains and the expansion upon swelling, while it dramatically affects the supramolecular ordering of the blocks. The membranes cast from DMSO exhibit more interconnected ionic clusters yielding higher conductivities and water uptake as compared to membranes cast from DMAc. A 10-fold increase in proton conductivity was achieved after thermal annealing of membranes at 150 °C, and the ionomers with longer block lengths show conductivities similar to Nafion at 80 °C and low relative humidity (30%).

  2. Phase behavior in blends of ethylene oxide-propylene oxide copolymer and poly(ether sulfone) studied by modulated-temperature DSC and NMR relaxometry.

    Science.gov (United States)

    Van Lokeren, Luk; Gotzen, Nicolaas-Alexander; Pieters, Ronny; Van Assche, Guy; Biesemans, Monique; Willem, Rudolph; Van Mele, Bruno

    2009-01-01

    The state diagram of a blend consisting of a copolymer containing ethylene oxide and propylene oxide, P(EO-ran-PO), and poly(ether sulfone), PES, is constructed by using modulated-temperature differential scanning calorimetry (MTDSC), T(2) NMR relaxometry, and light scattering. The apparent heat capacity signal in MTDSC is used for the characterization of polymer miscibility and morphology development. T(2) NMR relaxometry is used to detect the onset of phase separation, which is in good agreement with the onset of phase separation in the apparent heat capacity from MTDSC and the cloud-point temperature as determined from light scattering. The coexistence curve can be constructed from T(2) values at various temperatures by using a few blends with well-chosen compositions. These T(2) values also allow the detection of the boundary between the demixing zones with and without interference of partial vitrification and are in good agreement with stepwise quasi-isothermal MTDSC heat capacity measurements. Important interphases are detected in the heterogeneous P(EO-ran-PO)/PES blends.

  3. 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)

  4. 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

  5. Synthesis and thermal characterization of CdS nano crystals in previously formed template of maleic anhydride-octene 1-vinyl butyl terpolymer

    International Nuclear Information System (INIS)

    Akbarov, O.H; Mammadova, R.E; Malikov, E.Y.

    2008-01-01

    Full text: Nano crystals have dimensions in the range 10100 nm. Crystals in this size range possess unique properties, which enable scientists to manufacture materials and devices capable of performing unimaginable tasks. For that reason synthesis of this semiconductor nano crystals is expedient. Many useful methods have been used for preparing sulphide semiconductor nano crystals, such as colloidal chemistry method, sol-gel method, inverse micelle method, in situ synthesis and assemble on polymer template. The most significant method is in situ synthesis and assemble of sulphide semiconductor nano crystals on polymer. Compared with other methods, the stability of nanoparticles is improved by the protection and confinement of the copolymer. Because of confinement and protection effects of template environmental risk is prevented in this method. On the base of this principles in situ synthesis of CdS nano crystals in maleic anhydride-octene 1-vinyl butyl terpolymer was realized in this scientific work. First of all in specific condition maleic anhydride, octene 1, and vinyl butyl ether were polymerized to form a terpolymer as the result of radical ter polymerization. In second step CdS nano crystals were synthesized in N,N-dimethylformamide solution of maleic anhydride-octene 1-vinyl butyl terpolymer through the reaction of thiourea with cadmium chloride. In this process CdCI 2 x 2.5H 2 O was dissolved in N,N-dimethylformamide solution of previously formed terpolymer and was heated in 90 0 C temperature for 4 hours with vigorous stirring. Then desired amount of thiourea in N,N-dimethylformamide was quickly injected into the reaction flask using a syringe. The reaction continued for another 1 hour, and a yellow clear solution was obtained, which indicated the formation of CdS nano crystals

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

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, James E.; Baird, Donald G.

    2010-06-03

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

  7. 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.

  8. Novel poly(ethylene oxide monomethyl ether)-b-poly(.epsilon.-caprolactone) diblock copolymers containing a pH-acid labile ketal group as a block linkage

    Czech Academy of Sciences Publication Activity Database

    Petrova, Svetlana; Jäger, Eliezer; Konefal, Rafal; Jäger, Alessandro; Venturini, Cristina Garcia; Spěváček, Jiří; Pavlova, Ewa; Štěpánek, Petr

    2014-01-01

    Roč. 5, č. 12 (2014), s. 3884-3893 ISSN 1759-9954 R&D Projects: GA ČR GAP208/10/1600; GA TA ČR TE01020118 Institutional support: RVO:61389013 Keywords : MPOE-b-PCL diblock copolymers * ring-opening polymerization * "click" chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.520, year: 2014

  9. 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.

  10. In vitro evaluation of poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether copolymer coating effects on cells adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Rusen, Laurentiu [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Neacsu, Patricia; Cimpean, Anisoara [University of Bucharest, Department of Biochemistry and Molecular Biology, Bucharest (Romania); Valentin, Ion; Brajnicov, Simona; Dumitrescu, L.N. [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Banita, Janina [University of Bucharest, Faculty of Chemistry, Bucharest (Romania); IBAR, Institute of Biochemistry of the Romanian Academy, 296 Splaiul Independentei, RO-060031 Bucharest (Romania); Dinca, Valentina, E-mail: valentina.dinca@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Dinescu, Maria [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania)

    2016-06-30

    Understanding and controlling natural and synthetic biointerfaces is known to be the key to a wide variety of application within cell culture and tissue engineering field. As both material characteristics and methods are important in tailoring biointerfaces characteristics, in this work we explore the feasibility of using Matrix Assisted Pulsed Laser Evaporation technique for obtaining synthetic copolymeric biocoatings (i.e. poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether) for evaluating in vitro Vero and MC3T3-E1 pre-osteoblasts cell response. Characterization and evaluation of the coated substrates were carried out using different techniques. The Fourier transform infrared spectroscopy data demonstrated that the main functional groups in the MAPLE-deposited films remained intact. Atomic Force Microscopy images showed the coatings to be continuous, with the surface roughness depending on the deposition parameters. Moreover, the behaviour of the coatings in medium mimicking the pH and temperature of the human body was studied and corelated to degradation. Spectro-ellipsometry (SE) and AFM measurements revealed the degradation trend during immersion time by the changes in coating thickness and roughness. In vitro biocompatibility was studied by indirect contact tests on Vero cells in accordance with ISO 10993-5/2009. The results obtained in terms of cell morphology (phase contrast microscopy) and cytotoxicity (LDH and MTT assays) proved biocompatibility. Furthermore, direct contact assays on MC3T3-E1 pre-osteoblasts demonstrated the capacity of all analyzed specimens to support cell adhesion, normal cellular morphology and growth.

  11. In vitro evaluation of poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether copolymer coating effects on cells adhesion and proliferation

    Science.gov (United States)

    Rusen, Laurentiu; Neacsu, Patricia; Cimpean, Anisoara; Valentin, Ion; Brajnicov, Simona; Dumitrescu, L. N.; Banita, Janina; Dinca, Valentina; Dinescu, Maria

    2016-06-01

    Understanding and controlling natural and synthetic biointerfaces is known to be the key to a wide variety of application within cell culture and tissue engineering field. As both material characteristics and methods are important in tailoring biointerfaces characteristics, in this work we explore the feasibility of using Matrix Assisted Pulsed Laser Evaporation technique for obtaining synthetic copolymeric biocoatings (i.e. poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether) for evaluating in vitro Vero and MC3T3-E1 pre-osteoblasts cell response. Characterization and evaluation of the coated substrates were carried out using different techniques. The Fourier transform infrared spectroscopy data demonstrated that the main functional groups in the MAPLE-deposited films remained intact. Atomic Force Microscopy images showed the coatings to be continuous, with the surface roughness depending on the deposition parameters. Moreover, the behaviour of the coatings in medium mimicking the pH and temperature of the human body was studied and corelated to degradation. Spectro-ellipsometry (SE) and AFM measurements revealed the degradation trend during immersion time by the changes in coating thickness and roughness. In vitro biocompatibility was studied by indirect contact tests on Vero cells in accordance with ISO 10993-5/2009. The results obtained in terms of cell morphology (phase contrast microscopy) and cytotoxicity (LDH and MTT assays) proved biocompatibility. Furthermore, direct contact assays on MC3T3-E1 pre-osteoblasts demonstrated the capacity of all analyzed specimens to support cell adhesion, normal cellular morphology and growth.

  12. 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)

  13. Poly(ether ester amide)s for tissue engineering

    NARCIS (Netherlands)

    Deschamps, A.A.; van Apeldoorn, Aart A.; de Bruijn, Joost Dick; Grijpma, Dirk W.; Feijen, Jan

    2003-01-01

    Poly(ether ester amide) (PEEA) copolymers based on poly(ethylene glycol) (PEG), 1,4-butanediol and dimethyl-7,12-diaza-6,13-dione-1,18-octadecanedioate were evaluated as scaffold materials for tissue engineering. A PEEA copolymer based on PEG with a molecular weight of 300 g/mol and 25 wt% of soft

  14. 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.

  15. Maleic anhydride grafting on EPDM rubber in the melt

    NARCIS (Netherlands)

    Oostenbrink, A.J.; Oostenbrink, A.J.; Gaymans, R.J.

    1992-01-01

    The grafting of maleic anhydride on a EPDM rubber was studied with a twin screw extruder. The effect of barrel temperatures, throughput, maleic anhydride concentration and peroxide concentration [bis(t-butyl peroxy isopropyl)benzene] on the degree of grafting and melt viscosity was studied. The

  16. Development of chitosan derivatives with anhydride maleic

    International Nuclear Information System (INIS)

    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

    2015-01-01

    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)

  17. 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.

  18. Morphological studies on block copolymer modified PA 6 blends

    Energy Technology Data Exchange (ETDEWEB)

    Poindl, M., E-mail: marcus.poindl@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C., E-mail: marcus.poindl@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de [Institut für Kunststofftechnik, University of Stuttgart (Germany)

    2014-05-15

    Recent studies show that compounding polyamide 6 (PA 6) with a PA 6 polyether block copolymers made by reaction injection molding (RIM) or continuous anionic polymerization in a reactive extrusion process (REX) result in blends with high impact strength and high stiffness compared to conventional rubber blends. In this paper, different high impact PA 6 blends were prepared using a twin screw extruder. The different impact modifiers were an ethylene propylene copolymer, a PA PA 6 polyether block copolymer made by reaction injection molding and one made by reactive extrusion. To ensure good particle matrix bonding, the ethylene propylene copolymer was grafted with maleic anhydride (EPR-g-MA). Due to the molecular structure of the two block copolymers, a coupling agent was not necessary. The block copolymers are semi-crystalline and partially cross-linked in contrast to commonly used amorphous rubbers which are usually uncured. The combination of different analysis methods like atomic force microscopy (AFM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) gave a detailed view in the structure of the blends. Due to the partial cross-linking, the particles of the block copolymers in the blends are not spherical like the ones of ethylene propylene copolymer. The differences in molecular structure, miscibility and grafting of the impact modifiers result in different mechanical properties and different blend morphologies.

  19. 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.

  20. 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.

  1. Effect of acid additives on graft copolymerization and water absorption of graft copolymers of cassava starch and acrylamide/acrylic acid

    International Nuclear Information System (INIS)

    Kiatkamjornwong, Suda; Mongkolsawat, Kanlaya; Sonsuk, Manit

    2003-01-01

    Gelatinized cassava starch was radiation graft copolymerized with acrylamide or acrylic acid in the presence of sulfuric acid, nitric acid or maleic acid at a specific dose rate to a fixed total dose. Homopolymer or free copolymer was extracted by water to obtain the pure graft copolymer, which was subsequently saponified with 5% potassium hydroxide solution at room temperature for 90 min. The saponified graft copolymer was investigated for the effect of acid additives and water absorption. The addition of 2% maleic acid into the grafting reaction containing acrylamide-to-starch ratio of 2.5:1 can produce the superabsorbent copolymer having water absorption as high as 2,256 ± 25 g g -1 . The effect of acid additive was explained. (author)

  2. Studies on the antifungal activities of the novel synthesized chelating co-polymer emulsion lattices and their silver complexes

    Directory of Open Access Journals (Sweden)

    Abd-El-Ghaffar M.A.

    2008-01-01

    Full Text Available The novel binary chelating co-polymers of butyl acrylate with itaconic and maleic acids were prepared by emulsion polymerization process. The chelating co-polymers of butyl acrylate-co-itaconic acid (BuA/IA and butyl acrylate-co-maleic acid (BuA/MA and their silver complexes were characterized and identified using IR spectroscopy and differential scanning calorimetry (DSC measurements. The biological activities of these compounds were studied against various types of fungal species. The dose and the rate of leached silver ions were controlled by the type of the co-polymers used and the solubility in the medium. The results provided laboratory support for the concept that the polymers containing chemically bound biocide are useful for controlling microbial growth. The silver uptake by strains of different fungal species was studied to determine their difference in behavior to the antifungal activities of these compounds. The uptake strategy was examined by transmission electron microscopy (TEM.

  3. A Cationic Smart Copolymer for DNA Binding

    Directory of Open Access Journals (Sweden)

    Tânia Ribeiro

    2017-11-01

    Full Text Available A new block copolymer with a temperature-responsive block and a cationic block was prepared by reversible addition-fragmentation chain transfer (RAFT polymerization, with good control of its size and composition. The first block is composed by di(ethylene glycol methyl ether methacrylate (DEGMA and oligo(ethylene glycol methyl ether methacrylate (OEGMA, with the ratio DEGMA/OEGMA being used to choose the volume phase transition temperature of the polymer in water, tunable from ca. 25 to above 90 °C. The second block, of trimethyl-2-methacroyloxyethylammonium chloride (TMEC, is positively charged at physiological pH values and is used for DNA binding. The coacervate complexes between the block copolymer and a model single strand DNA are characterized by fluorescence correlation spectroscopy and fluorescence spectroscopy. The new materials offer good prospects for biomedical application, for example in controlled gene delivery.

  4. SYNTHESIS OF AMPHIPHILIC COMB-SHAPED COPOLYMERS USED FOR SURFACE MODIFICATION OF PVDF MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    徐又一

    2009-01-01

    The synthesis of a novel amphiphilic comb-shaped copolymer consisting of a main chain of styrene-(N-(4- hydroxyphenyl) maleimide)(SHMI) copolymer and poly(ethylene glycol) methyl ether methacrylate(PEGMA) side groups was achieved by atom transfer radical polymerization(ATRP).The amphiphilic copolymers were characterized by ~1H-NMR, Fourier transform infrared(FTIR) spectroscopy and gel permeation chromatography(GPC).From thermogravimetric analysis (TGA),the decomposition temperature of SHMI-g-PEGMA is low...

  5. 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)

  6. 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

  7. 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

  8. 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...

  9. Amphiphilic copolymers based on PEG-acrylate as surface active water viscosifiers : Towards new potential systems for enhanced oil recovery

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    2016-01-01

    With the purpose of investigating new potential candidates for enhanced oil recovery (EOR), amphiphilic copolymers based on Poly(ethylene glycol) methyl ether acrylate (PEGA) have been prepared by Atom Transfer Radical Polymerization (ATRP). A P(PEGA) homopolymer, a block copolymer with styrene

  10. 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)

  11. 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

  12. 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.

  13. 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)

  14. Olefin–Styrene Copolymers

    OpenAIRE

    Nunzia Galdi; Antonio Buonerba; Leone Oliva

    2016-01-01

    In this review are reported some of the most relevant achievements in the chemistry of the ethylene–styrene copolymerization and in the characterization of the copolymer materials. Focus is put on the relationship between the structure of the catalyst and that of the obtained copolymer. On the other hand, the wide variety of copolymer architecture is related to the properties of the material and to the potential utility.

  15. Small angle neutron scattering study of the micelle structure of amphiphilic block copolymers

    International Nuclear Information System (INIS)

    Yamaoka, H.; Matsuoka, H.; Sumaru, K.; Hanada, S.

    1994-01-01

    The amphiphilic block copolymers of vinyl ether were prepared by living cationic polymerization. The partially deuterated copolymers for SANS experiments were especially synthesized by introducing deuterated phenyl units in the hydrophobic chain. SANS measurements were performed for aqueous solutions of these copolymers by changing H 2 O/D 2 O ratios. The SANS profiles indicate that the micelles in the present system exhibit a core-shell structure and that the size and shape of micelles are largely dependent on the length of hydrophobic chain. The micelle of shorter hydrophobic chain was found to be nearly spherical, whereas the micelle of longer hydrophobic chain was confirmed to have an ellipsoidal shape

  16. 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.

  17. Effect of Maleic Acid Content on the Thermal Stability, Swelling Behaviour and Network Structure of Gelatin -Based Hydrogels Prepared by Gamma Irradiation

    International Nuclear Information System (INIS)

    Eid, M.; Dessouki, A.M.; Abdel-Ghaffar, M.A.

    2005-01-01

    The preparation of highly swelling hydrogels containing diprotic acid and gelatin carried out by gamma-irradiation of acrylamide/maleic acid/gelatine/water mixture at ambient temperature. Poly (acrylamide/maleic acid/gelatin) p(AAm/MA/G) hydrogels were prepared in different MA and G contents at low dose rate (0.94 kGy/h), and moderate dose rate (3.84 kGy/h). The prepared hydrogels were confirmed by FT1R . The effect of copolymer composition, dose and dose rate on the swelling behaviour and the type of water diffusion in the network structure of the hydrogels was discussed. Increasing of MA content and G in the initial mixture leads to an increase in the amount of MA and G in the gel system and decrease in the gelation percent. The swelling behaviours of the hydrogel prepared at moderate dose rate increased with increasing MA mole content in the gel system. On the other hand, no systematic dependence of swelling on MA content was observed for the hydrogels obtained at low dose rate. Pore structure of the hydrogels was monitored by using scanning electron microscopy. Systematic swelling of P(AAm/MA/G) hydrogels prepared at moderate dose rates can be explained by the homogeneous pore size distribution of network. Thermogravimetric analysis (TGA) was employed to study the effect of network structure formation on the thermal behavior of the copolymer. To give a better understanding of the thermal stability of polymers, the rate of the thermal decomposition of P(AAm/MA/G) hydrogels has been evaluated

  18. Silicon containing copolymers

    CERN Document Server

    Amiri, Sahar; Amiri, Sanam

    2014-01-01

    Silicones have unique properties including thermal oxidative stability, low temperature flow, high compressibility, low surface tension, hydrophobicity and electric properties. These special properties have encouraged the exploration of alternative synthetic routes of well defined controlled microstructures of silicone copolymers, the subject of this Springer Brief. The authors explore the synthesis and characterization of notable block copolymers. Recent advances in controlled radical polymerization techniques leading to the facile synthesis of well-defined silicon based thermo reversible block copolymers?are described along with atom transfer radical polymerization (ATRP), a technique utilized to develop well-defined functional thermo reversible block copolymers. The brief also focuses on Polyrotaxanes and their great potential as stimulus-responsive materials which produce poly (dimethyl siloxane) (PDMS) based thermo reversible block copolymers.

  19. New Linear and Star-Shaped Thermogelling Poly([R]-3-hydroxybutyrate) Copolymers.

    Science.gov (United States)

    Barouti, Ghislaine; Liow, Sing Shy; Dou, Qingqing; Ye, Hongye; Orione, Clément; Guillaume, Sophie M; Loh, Xian Jun

    2016-07-18

    The synthesis of multi-arm poly([R]-3-hydroxybutyrate) (PHB)-based triblock copolymers (poly([R]-3-hydroxybutyrate)-b-poly(N-isopropylacrylamide)-b-[[poly(methyl ether methacrylate)-g-poly(ethylene glycol)]-co-[poly(methacrylate)-g-poly(propylene glycol)

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Synthesis and evaluation of poly(styrene-co-maleic acid) micellar nanocarriers for the delivery of tanespimycin

    Science.gov (United States)

    Larson, Nate; Greish, Khaled; Bauer, Hillevi; Maeda, Hiroshi; Ghandehari, Hamidreza

    2011-01-01

    Polymeric micelles carrying the heat shock protein 90 inhibitor tanespimycin (17-N-Allylamino-17-demethoxygeldanamycin) were synthesized using poly(styrene-co-maleic acid) (SMA) copolymers and evaluated in vitro and in vivo. SMA-tanespimycin micelles were prepared with a loading efficiency of 93%. The micelles incorporated 25.6% tanespimycin by weight, exhibited a mean diameter of 74 ± 7 nm by dynamic light scattering and a zeta potential of -35 ± 3 mV. Tanespimycin was released from the micelles in a controlled manner in vitro, with 62% released in 24 hours from a pH 7.4 buffer containing bovine serum albumin. The micellar drug delivery systems for tanespimycin showed potent activity against DU145 human prostate cancer cells, with an IC50 of 230 nM. They further exhibited potent anti-cancer activity in vivo in nu/nu mice bearing subcutaneous DU145 human prostate cancer tumor xenografts, with significantly higher anticancer efficacy as measured by tumor regression when compared to free tanespimycin at an equivalent single dose of 10 mg/kg. These data suggest further investigation of SMA-tanespimycin as a promising agent in the treatment of prostate cancer. PMID:21856392

  2. Modificação de polímeros termorrígidos por separação de fases induzida por reação química: Sistema éter diglicidílico do Bisfenol-A e trietilenotetramina com copolímeros acrílicos Modification of thermosetting polymers by induced phase separation by chemical reaction: Diglycidyl ether of Bisphenol-A and triethylenetetramine with acrylic copolymers

    Directory of Open Access Journals (Sweden)

    Garcia Filiberto González

    2008-03-01

    Full Text Available O comportamento da separação de fases e da gelificação do sistema do éter diglicidílico do Bisfenol-A com trietilenotetramina modificado com diferentes copolímeros acrílicos foi estudado. As massas moleculares e as concentrações de grupos carboxílicos nos copolímeros provocaram mudanças significativas na morfologia e provocaram ligeiras mudanças para a observação da separação de fases. Contudo, não mudaram de maneira significativa os tempos de gelificação e não afetaram a velocidade da reação. O sistema modificado com os copolímeros acrílicos mostrou o efeito de retardação cinética. A morfologia foi relacionada com a aderência ao cisalhamento, em juntas de aço-aço, através de ensaios de resistência mecânica usando juntas de cisalhamento simples, as que foram produzidas com o sistema modificado com os copolímeros acrílicos segundo a norma ASTM D 1002. Amostras com a fase dispersa apresentando morfologia com partículas de diâmetro médio menor que 0,10 µm mostraram o melhor desempenho de aderência ao cisalhamento para as massas moleculares dos copolímeros estudadas. Entretanto, um melhor comportamento mecânico para as concentrações de grupos carboxílicos nos copolímeros acrílicos foi observado para a morfologia com distribuição de tamanhos de partículas na faixa de 0,20 a 0,52 µm.The cloud point and the gel time behavior of an epoxy system based on diglycidyl ether of Bisphenol-A with triethylenetetramine modified with different acrylic copolymers were studied. The molecular weights and the concentration of carboxyl groups in the copolymers affected the morphology and the cloud point, but did not affect the gel times and reaction rates significantly. The system modified with the acrylic copolymers exhibited kinetic retardation effects. The morphology was related to adherence to the lap shear in steel-steel joints, through mechanical resistance essays using a single-lap-joint, which was produced

  3. Selective hydrogenation of maleic anhydride over Pd/Al2O3 ...

    Indian Academy of Sciences (India)

    Keywords. Pd/Al2O3 catalyst; maleic anhydride; selective hydrogenation; succinic anhydride. 1. Introduction ... attracted a significant amount of attention because the majority of its ... added, and the colour of the resulting mixture turned brown.

  4. 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)

  5. Proton-conducting membranes based on benzimidazole-containing sulfonated poly(ether ether ketone) compared with their carboxyl acid form

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

    A series of sulfonated poly(ether ether ketone) containing pendant carboxyl (C-SPEEKs) have been synthesized using a nucleophilic polycondesation reaction. A condensation reaction between 1,2-diaminobenzene and carboxyl resulted in a new series of copolymers containing benzimidazole groups (SPEEK-BIms). The expected structures of the sulfonated copolymers are confirmed by {sup 1}H NMR. The dependence of ion exchange capacity, water uptake, proton conductivity and methanol diffusion coefficient of SPEEK-BIm membranes has been studied and compared with their carboxyl acid form. The results suggest that the introduction of benzimidazole groups may be responsible for many excellent properties of the membranes for fuel cell. It is noticeable that the markedly improved oxidative stability is benefit for the application of membrane. (author)

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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...

  10. Block coordination copolymers

    Science.gov (United States)

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2012-11-13

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  11. Retardation of the dewetting process due to the addition of functional copolymers at polymer-polymer interfaces

    CERN Document Server

    Wunnicke, O; Lorenz-Haas, C; Leiner, V

    2002-01-01

    We studied the retardation of the dewetting process due to the addition of a functional copolymer in a polymer bilayer film. The model system consists of fully deuterated polystyrene (PS-d) on top of an amorphous polyamide (PA) sublayer on silicon substrates. Bilayer films were prepared with different content (0, 5, 10 and 30 vol. %) of a statistical copolymer (protonated styrene maleic anhydride acid (SMA2) containing 2% MA groups along the chain) being capable of forming hydrogen bonds with PA. The as-prepared as well as the annealed samples were investigated by neutron-reflectivity (NR) experiments, scanning force microscopy and optical microscopy. A significant retardation of dewetting is observed with the addition of SMA2. From model fits of NR curves the scattering length density profiles perpendicular to the sample surface were determined and an enrichment layer of SMA2 is detected. Retardation is explained by the intermixing of SMA2 and PS-d at the interface. (orig.)

  12. 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.

  13. Barite formation in the presence of a commercial copolymer

    Science.gov (United States)

    Ruiz-Agudo, Cristina; Putnis, Christine; Ruiz-Agudo, Encarnacion; Putnis, Andrew

    2015-04-01

    Fluid composition can significantly modify the mechanisms of mineral formation. Particularly, the presence of organic additives in the aqueous media has been shown to alter the precipitation of minerals substantially (e.g. calcium carbonate, barium carbonate and barium sulfate). Despite the numerous studies dealing with barite precipitation and the influence of organic additives (e.g. Benton et al. 1993, Qi et al., 2000, Wang and Cölfen, 2006, Mavredaki et al., 2011), the details of the mechanism of barite formation in the presence of organic additives, particularly at the early stages of this process, are yet to be fully resolved. Here, we present observations on the initial stages of barite formation from aqueous solutions, as well as the alterations induced by a commercial copolymer (maleic acid/allyl sulfonic acid copolymer with phosphonate groups), commonly used as a scale inhibitor in oil recovery. Most synthetic commercial additives contain the same functional groups (e.g. carboxylate, phosphonate and/or sulfonate groups). Thus our work may help to understand the mechanism by which copolymers modify crystallization processes and aid in the selection of the most appropriate inhibitors for hindering or controlling barite scale formation. Barite scaling is one of the main problems in many industrial processes (such as, paper-making, chemical manufacturing, cement operations, off-shore oil extraction, geothermal energy production). Using Atomic Force Microscopy (AFM), we show that barite growth is significantly influenced by the presence of the copolymer. In its absence, barium sulfate growth occurs by 2D island nucleation and spreading. The addition of small amounts (0.1 ppm and 0.5 ppm) of the copolymer enhances 2D nucleation but blocks growth. Just 1 ppm of inhibitor is enough to block barite nucleation and growth by adsorption of a copolymer layer onto the barite surface. Transmission electron microscopy (TEM) was also used to gain better insights into the

  14. 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

  15. 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

  16. Block copolymer battery separator

    Science.gov (United States)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  17. 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.

  18. 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.

  19. Amphiphilic block co-polymers: preparation and application in nanodrug and gene delivery.

    Science.gov (United States)

    Xiong, Xiao-Bing; Binkhathlan, Ziyad; Molavi, Ommoleila; Lavasanifar, Afsaneh

    2012-07-01

    Self-assembly of amphiphilic block co-polymers composed of poly(ethylene oxide) (PEO) as the hydrophilic block and poly(ether)s, poly(amino acid)s, poly(ester)s and polypropyleneoxide (PPO) as the hydrophobic block can lead to the formation of nanoscopic structures of different morphologies. These structures have been the subject of extensive research in the past decade as artificial mimics of lipoproteins and viral vectors for drug and gene delivery. The aim of this review is to provide an overview of the synthesis of commonly used amphiphilic block co-polymers. It will also briefly go over some pharmaceutical applications of amphiphilic block co-polymers as "nanodelivery systems" for small molecules and gene therapeutics. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. Nitroxide-mediated radical ring-opening copolymerization: chain-end investigation and block copolymer synthesis.

    Science.gov (United States)

    Delplace, Vianney; Harrisson, Simon; Tardy, Antoine; Gigmes, Didier; Guillaneuf, Yohann; Nicolas, Julien

    2014-02-01

    Well-defined, degradable copolymers are successfully prepared by nitroxide-mediated radical ring opening polymerization (NMrROP) of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) or methyl methacrylate (MMA), a small amount of acrylonitrile (AN) and cyclic ketene acetals (CKAs) of different structures. Phosphorous nuclear magnetic resonance allows in-depth chain-end characterization and gives crucial insights into the nature of the copoly-mer terminal sequences and the living chain fractions. By using a small library of P(OEGMA-co-AN-co-CKA) and P(MMA-co-AN-co-CKA) as macroinitiators, chain extensions with styrene are performed to furnish (amphiphilic) block copolymers comprising a degradable segment. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Synthesis of an amphiphilic dendrimer-like block copolymer and its application on drug delivery

    KAUST Repository

    Wang, Shuaipeng

    2014-10-27

    Dendrimer-like amphiphilic copolymer is a kind of three-dimensional spherical structure polymer. An amphiphilic dendrimer-like diblock copolymer, PEEGE-G2-b-PEO(OH)12, constituted of a hydrophobic poly(ethoxyethyl glycidol ether) inner core and a hydrophilic poly(ethylene oxide) outer layer, has been successfully synthesized by the living anionic ring-opening polymerization method. The intermediates and targeted products were characterized with 1H NMR spectroscopy and gel permeation chromatography. The application on drug delivery of dendrimer-like diblock copolymer PEEGE-G2-b-PEO(OH)12 using DOX as a model drug was also studied. The drug loading content and encapsulation efficiency were found at 13.07% and 45.75%, respectively. In vitro release experiment results indicated that the drug-loaded micelles exhibited a sustained release behavior under acidic media.

  2. Radiation grafting of acrylamide and maleic acid on chitosan and effective application for removal of Co(II) from aqueous solutions

    Science.gov (United States)

    Saleh, Alaaeldine Sh.; Ibrahim, Ahmed G.; Elsharma, Emad M.; Metwally, Essam; Siyam, Tharwat

    2018-03-01

    The graft copolymerization has been proven as a superior polymerization technique because it combines the functional advantages of the grafted and base polymers. In this work, the radiation-induced grafting of acrylamide (AAm) and maleic acid (MA) onto chitosan (CTS) was developed and optimized by determining the grafting percentage and efficiency as a function of grafting conditions such as AAm, MA, and CTS concentrations, and absorbed dose. Fourier transform infrared spectroscopic analysis (FTIR) confirmed the graft copolymerization. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) further characterized the grafted copolymers and showed their high thermal stability. Using batch sorption experiments and 60Co as a radiotracer, poly(CTS-AAm) and poly(CTS-MA) were evaluated for Co(II) removal from aqueous solutions. The Co(II) removal increases with increasing time, pH, polymer, and Co(II) concentrations. Experimentally, P(CTS-AAm) and P(CTS-MA) show high sorption capacities of Co(II), i.e. 150 mg g-1 and 421 mg g-1, respectively, which makes them potential sorbents of Co(II) for water and wastewater treatment. Finally, the Co(II) sorption was examined using sorption isotherm and kinetic models. The sorption was best fitted to Langmuir model which suggests the sorption is of chemisorption type. On the other hand, the sorption kinetics was best represented by Elovich model which also indicates the chemical nature of Co(II) sorption on P(CTS-AAm) and P(CTS-MA).

  3. Effect of maleic acid content on the thermal stability, swelling behaviour and network structure of gelatin-based hydrogels prepared by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Eid, M. [National Center For Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo 11731 (Egypt)], E-mail: mona_eid2000@yahoo.com; Abdel-Ghaffar, M.A. [National Research Center, Dokki, Cairo (Egypt); Dessouki, A.M. [National Center For Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo 11731 (Egypt)

    2009-01-15

    The highly swelling Poly (acrylamide/maleic acid/gelatin) P(AAm/MA/G) hydrogels were prepared by gamma-irradiation at low dose rate (0.94 kGy/h) and moderate dose rate (3.84 kGy/h). The hydrogels were confirmed by FTIR. The effect of copolymer composition, dose and dose rate on the swelling behaviour was discussed. Increasing of MA content and G in the initial mixture leads to an increase in the amount of MA and G in the gel system and decrease in the gelation %. The swelling behaviours of the hydrogel prepared at moderate dose rate increased with increasing MA mole content in the gel system but, there is no systematic dependence of swelling on MA content was observed for the hydrogels obtained at low dose rate. Pore structure of the hydrogels was monitored by using scanning electron microscopy. Thermogravimetric analysis (TGA) and the rate of the thermal decomposition of P(AAm/MA/G) hydrogels has been evaluated to give a better understanding of the thermal stability of polymers, The X-ray data of P(AAm/MA/G) hydrogels was discussed to investigate some features namely the degree of ordering and crystallite size.

  4. 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)

  5. Polyether/Polyester Graft Copolymers

    Science.gov (United States)

    Bell, Vernon L., Jr.; Wakelyn, N.; Stoakley, D. M.; Proctor, K. M.

    1986-01-01

    Higher solvent resistance achieved along with lower melting temperature. New technique provides method of preparing copolymers with polypivalolactone segments grafted onto poly (2,6-dimethyl-phenylene oxide) backbone. Process makes strong materials with improved solvent resistance and crystalline, thermally-reversible crosslinks. Resulting graft copolymers easier to fabricate into useful articles, including thin films, sheets, fibers, foams, laminates, and moldings.

  6. 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

  7. 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.

  8. 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...

  9. 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.

  10. 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.)

  11. 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

  12. 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.

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

    Science.gov (United States)

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

    2014-08-01

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

  14. Synthesis and properties of the metallo-supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO3: Ag+/Cu2+ ion exchange and effective antibacterial activity

    KAUST Repository

    Xu, Feng

    2014-01-01

    The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-mono-sodium maleate) (PVM/Na-MA). By addition of AgNO 3-solution, the formation of the silver(i) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO 3 is reported. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(i) cations. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(ii) cations without disintegration of the hydrogel. The silver(i) hydrogel shows effective antibacterial activity and potential application as burn wound dressing. © the Partner Organisations 2014.

  15. 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...

  16. Effects of Electron Beam Irradiation on Binary Polyamide-6 Blends with Metallocene Copolymers

    International Nuclear Information System (INIS)

    Rosales, C.

    2006-01-01

    A versatile way to produce new materials with high Izod impact strength and reduced heat deformations is the irradiation of compatibilized blends. The effect of electron beam irradiation and different types of dispersed phase grafted copolymers on thermal and mechanical properties, and SEM morphology of polyamide-6 (PA-6) blends were investigated. Two metallocene copolymers (mEPDM and mPOE) grafted in-situ with maleic anhydride and two commercial maleated copolymers (EPDM-g-MA and mEPR-g-MA) were employed in binary blends with PA6 as matrix. The blends were prepared by extrusion with a composition of 80 wt. % of PA-6. The influence of the radical or functional groups generated in the grafting and the irradiation processes (25, 50, 100 and 200 kGy) was found by ATR-FTIR. The blends exhibited the characteristic thermal behavior of immiscible systems. All compatibilizers employed influenced the melting and crystallization behavior of the blend components without irradiation and an improvement in interface adhesion was clearly observed by SEM micrographs. The sizes of the dispersed phase in the non-irradiated reactive blends were in agreement with the viscosity ratios of the blend components. High toughness materials were obtained with ethylene-polypropylene-diene (mEPDM) grafted copolymers without significant variations in their thermal properties and Izod impact strength at room temperature and -30 degree with the irradiation doses. However, the toughness of the blends with grafted metallocene polyethylenes was affected by the irradiation doses employed. Therefore, the gel content and tensile properties of the samples depended on the chain scission, crosslinking and/or grafting reactions of the blend components

  17. Study of micro-phase separation of two polystyrene-based copolymer mixture using the combination of PALS and FT-IR

    International Nuclear Information System (INIS)

    Jiang, Z.Y.; Jiang, X.Q.; Yang, Y.X.; Huang, Y.J.; Huang, H.B.; Hsia, Y.F.

    2005-01-01

    Positron annihilation lifetime (PAL) spectroscopy, Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) have been applied to study the micro-phase separation in the blends of poly(styrene-co-methylmethacrylate) (SMMA) copolymer and poly(styrene-co-maleic anhydride) (SMA) copolymer. The DSC results indicate that the SMA/SMMA blends are miscible and weak intermolecular interactions exist between SMA and SMMA. The strength of intermolecular interactions to some degree exhibits somewhat non-monotonic variation with increasing of SMA component in the blends. The results of PAL measurement present the blend containing 20 wt% SMA is phase-separated in molecular level, which is interpreted by the results of FT-IR analysis. It was concluded that it is helpful to study the miscibility of polymer blends in molecular level by means of PAL method, accompanied with the requisite measurement of DSC and FT-IR

  18. Polyethylene-Based Tadpole Copolymers

    KAUST Repository

    Alkayal, Nazeeha; Zhang, Zhen; Bilalis, Panayiotis; Gnanou, Yves; Hadjichristidis, Nikolaos

    2017-01-01

    Novel well-defined polyethylene-based tadpole copolymers ((c-PE)-b-PS, PE: polyethylene, PS: polystyrene) with ring PE head and linear PS tail are synthesized by combining polyhomologation, atom transfer radical polymerization (ATRP), and Glaser

  19. 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.

  20. Novel proton exchange membranes based on structure-optimized poly(ether ether ketone ketone)s and nanocrystalline cellulose

    Science.gov (United States)

    Ni, Chuangjiang; Wei, Yingcong; Zhao, Qi; Liu, Baijun; Sun, Zhaoyan; Gu, Yan; Zhang, Mingyao; Hu, Wei

    2018-03-01

    Two sulfonated fluorenyl-containing poly(ether ether ketone ketone)s (SFPEEKKs) were synthesized as the matrix of composite proton exchange membranes by directly sulfonating copolymer precursors comprising non-sulfonatable fluorinated segments and sulfonatable fluorenyl-containing segments. Surface-modified nanocrystalline cellulose (NCC) was produced as the "performance-enhancing" filler by treating the microcrystalline cellulose with acid. Two families of SFPEEKK/NCC nanocomposite membranes with various NCC contents were prepared via a solution-casting procedure. Results revealed that the insertion of NCC at a suitable ratio could greatly enhance the proton conductivity of the pristine membranes. For example, the proton conductivity of SFPEEKK-60/NCC-4 (SFPEEKK with 60% fluorenyl segments in the repeating unit, and inserted with 4% NCC) composite membrane was as high as 0.245 S cm-1 at 90 °C, which was 61.2% higher than that of the corresponding pure SFPEEKK-60 membrane. This effect could be attributed to the formation of hydrogen bond networks and proton conduction paths through the interaction between -SO3H/-OH groups on the surface of NCC particles and -SO3H groups on the SFPEEKK backbones. Furthermore, the chemically modified NCC filler and the optimized chemical structure of the SFPEEKK matrix also provided good dimensional stability and mechanical properties of the obtained nanocomposites. In conclusion, these novel nanocomposites can be promising proton exchange membranes for fuel cells at moderate temperatures.

  1. Synthesis and Characterization of Sulfonated Graphene Oxide Reinforced Sulfonated Poly (Ether Ether Ketone (SPEEK Composites for Proton Exchange Membrane Materials

    Directory of Open Access Journals (Sweden)

    Ning Cao

    2018-03-01

    Full Text Available As a clean energy utilization device, full cell is gaining more and more attention. Proton exchange membrane (PEM is a key component of the full cell. The commercial-sulfonated, tetrafluoroethylene-based fluoropolymer-copolymer (Nafion membrane exhibits excellent proton conductivity under a fully humidified environment. However, it also has some disadvantages in practice, such as high fuel permeability, a complex synthesis process, and high cost. To overcome these disadvantages, a low-cost and novel membrane was developed. The sulfonated poly (ether ether ketone (SPEEK was selected as the base material of the proton exchange membrane. Sulfonated graphene (SG was cross-linked with SPEEK through the elimination reaction of hydrogen bonds. It was found that the sulfonic acid groups and hydrophilic oxygen groups increased obviously in the resultant membrane. Compared with the pure SPEEK membrane, the SG-reinforced membrane exhibited better proton conductivity and methanol permeability prevention. The results indicate that the SG/SPEEK could be applied as a new proton exchange membrane in fuel cells.

  2. The simple ethers of glycerin

    International Nuclear Information System (INIS)

    Kimsanov, B.Kh.; Karimov, M.B.

    1998-01-01

    From glycerin derivatives the considerable interest is present simple ethers because many of them are biological active and found wide practical using as an effect drugs, inters for thin organic synthesis, vehicle for injections, regulators of plants growth, reagents, components for perfumery-cosmetic goods and etc

  3. (1-Adamantyl)methyl glycidyl ether: a versatile building block for living polymerization.

    Science.gov (United States)

    Moers, Christian; Wrazidlo, Robert; Natalello, Adrian; Netz, Isabelle; Mondeshki, Mihail; Frey, Holger

    2014-06-01

    (1-Adamantyl)methyl glycidyl ether (AdaGE) is introduced as a versatile monomer for oxyanionic polymerization, enabling controlled incorporation of adamantyl moieties in aliphatic polyethers. Via copolymerization with ethoxyethyl glycidyl ether (EEGE) and subsequent cleavage of the acetal protection groups of EEGE, hydrophilic linear polyglycerols with an adjustable amount of pendant adamantyl moieties are obtained. The adamantyl unit permits control over thermal properties and solubility profile of these polymers (LCST). Additionally, AdaGE is utilized as a termination agent in carbanionic polymerization, affording adamantyl-terminated polymers. Using these structures as macroinitiators for the polymerization of ethylene oxide affords amphiphilic, in-chain adamantyl-functionalized block copolymers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Synthesis, Characterization and Biocompatibility of Biodegradable Elastomeric Poly(ether-ester urethane)s Based on Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and Poly(ethylene glycol) via Melting Polymerization

    DEFF Research Database (Denmark)

    Li, Zibiao; Yang, Xiaodi; Wu, Linping

    2009-01-01

    Poly(ether-ester urethane)s (PUs) multiblock co-polymers were synthesized from telechelic hydroxylated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(ethylene glycol) (PEG) via a melting polymerization (MP) process using 1,6-hexamethylene diisocyanate (HDI) as a non-toxic couplin...

  5. Lignin poly(lactic acid) copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Johan Vilhelm; Chung, Yi-Lin; Li, Russell Jingxian; Waymouth, Robert; Sattely, Elizabeth; Billington, Sarah; Frank, Curtis W.

    2017-02-14

    Provided herein are graft co-polymers of lignin and poly(lactic acid) (lignin-g-PLA copolymer), thermoset and thermoplastic polymers including them, methods of preparing these polymers, and articles of manufacture including such polymers.

  6. 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)

  7. 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.)

  8. 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).

  9. 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

  10. 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

  11. Metallo-supramolecular block copolymer micelles

    NARCIS (Netherlands)

    Gohy, J.M.W.

    2009-01-01

    Supramolecular copolymers have become of increasing interest in recent years in the search for new materials with tunable properties. In particular, metallo-supramolecular block copolymers in which metal-ligand complexes are introduced in block copolymer architectures, have known important progress,

  12. 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)

  13. 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...

  14. 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...

  15. 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)

  16. CO2-Philic Thin Film Composite Membranes: Synthesis and Characterization of PAN-r-PEGMA Copolymer

    Directory of Open Access Journals (Sweden)

    Madhavan Karunakaran

    2017-07-01

    Full Text Available In this work, we report the successful fabrication of CO2-philic polymer composite membranes using a polyacrylonitrile-r-poly(ethylene glycol methyl ether methacrylate (PAN-r-PEGMA copolymer. The series of PAN-r-PEGMA copolymers with various amounts of PEG content was synthesized by free radical polymerization in presence of AIBN initiator and the obtained copolymers were used for the fabrication of composite membranes. The synthesized copolymers show high molecular weights in the range of 44–56 kDa. We were able to fabricate thin film composite (TFC membranes by dip coating procedure using PAN-r-PEGMA copolymers and the porous PAN support membrane. Scanning electron microscopy (SEM and atomic force microscopy (AFM were applied to analyze the surface morphology of the composite membranes. The microscopy analysis reveals the formation of the defect free skin selective layer of PAN-r-PEGMA copolymer over the porous PAN support membrane. Selective layer thickness of the composite membranes was in the range of 1.32–1.42 μm. The resulting composite membrane has CO2 a permeance of 1.37 × 10−1 m3/m2·h·bar and an ideal CO2/N2, selectivity of 65. The TFC membranes showed increasing ideal gas pair selectivities in the order CO2/N2 > CO2/CH4 > CO2/H2. In addition, the fabricated composite membranes were tested for long-term single gas permeation measurement and these membranes have remarkable stability, proving that they are good candidates for CO2 separation.

  17. CO2-Philic Thin Film Composite Membranes: Synthesis and Characterization of PAN-r-PEGMA Copolymer

    KAUST Repository

    Karunakaran, Madhavan

    2017-07-06

    In this work, we report the successful fabrication of CO2-philic polymer composite membranes using a polyacrylonitrile-r-poly(ethylene glycol) methyl ether methacrylate (PAN-r-PEGMA) copolymer. The series of PAN-r-PEGMA copolymers with various amounts of PEG content was synthesized by free radical polymerization in presence of AIBN initiator and the obtained copolymers were used for the fabrication of composite membranes. The synthesized copolymers show high molecular weights in the range of 44-56 kDa. We were able to fabricate thin film composite (TFC) membranes by dip coating procedure using PAN-r-PEGMA copolymers and the porous PAN support membrane. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to analyze the surface morphology of the composite membranes. The microscopy analysis reveals the formation of the defect free skin selective layer of PAN-r-PEGMA copolymer over the porous PAN support membrane. Selective layer thickness of the composite membranes was in the range of 1.32-1.42 mu m. The resulting composite membrane has CO2 a permeance of 1.37 x 10(-1) m(3)/m(2).h.bar and an ideal CO2/N-2, selectivity of 65. The TFC membranes showed increasing ideal gas pair selectivities in the order CO2/N-2 > CO2/CH4 > CO2/H-2. In addition, the fabricated composite membranes were tested for long-term single gas permeation measurement and these membranes have remarkable stability, proving that they are good candidates for CO2 separation.

  18. Sulfonated polyphenyl ether by electropolymerization

    International Nuclear Information System (INIS)

    Hou Hongying; Vacandio, Florence; Di Vona, Maria Luisa; Knauth, Philippe

    2012-01-01

    Highlights: ► Sulfonated polyphenyl ether was for the first time electropolymerized. ► This technique allows the economical preparation of ionomeric membranes for electrochemical energy technologies. ► The mechanism of electropolymerization was discussed in detail. - Abstract: Electropolymerization of sulfonated phenol was for the first time achieved and studied by cyclic voltammetry (CV) and chronoamperometry on stainless steel substrates. The obtained sulfonated polyphenyl ether was characterized in terms of impedance spectroscopy, nuclear magnetic resonance (NMR), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and Fourier-Transform Infrared (FTIR) spectroscopy. Dense films of micrometer thickness can be obtained; the proton conductivity is about 3 mS/cm at room temperature.

  19. 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.

  20. 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

  1. Polyethylene-Based Tadpole Copolymers

    KAUST Repository

    Alkayal, Nazeeha

    2017-02-15

    Novel well-defined polyethylene-based tadpole copolymers ((c-PE)-b-PS, PE: polyethylene, PS: polystyrene) with ring PE head and linear PS tail are synthesized by combining polyhomologation, atom transfer radical polymerization (ATRP), and Glaser coupling reaction. The -OH groups of the 3-miktoarm star copolymers (PE-OH)-b-PS, synthesized by polyhomologation and ATRP, are transformed to alkyne groups by esterification with propiolic acid, followed by Glaser cyclization and removal of the unreacted linear with Merrifield\\'s resin-azide. The characterization results of intermediates and final products by high-temperature size exclusion chromatography, H NMR spectroscopy, and differential scanning calorimetry confirm the tadpole topology.

  2. Characterization of Comb-Shaped Copolymers by Multidetection SEC, DLS and SANS

    Directory of Open Access Journals (Sweden)

    Giulia Gelardi

    2017-02-01

    Full Text Available PolyCarboxylate ether-based superplasticizers (PCEs are a type of comb-shaped copolymers used as polymeric dispersants in cementitious materials. PCEs have a high degree of dispersity, which limits the suitability of conventional characterization techniques, such as Size Exclusion Chromatography (SEC. Properties of PCEs strongly depend on their molecular structure and a comprehensive characterization is needed to fully understand the structure–property relationships. PCEs with well-defined molecular structures were synthesized to study their solution conformation by SEC and scattering techniques. The combined use of SEC, dynamic light scattering and small-angle neutron scattering allowed us to demonstrate the validity of a scaling law describing the radius of gyration of comb-shaped copolymers as a function of their molecular structure. Moreover, we show that the use of SEC with standard calibration, although widely spread, is not adequate for PCEs.

  3. Acid-Labile Amphiphilic PEO-b-PPO-b-PEO Copolymers: Degradable Poloxamer Analogs.

    Science.gov (United States)

    Worm, Matthias; Kang, Biao; Dingels, Carsten; Wurm, Frederik R; Frey, Holger

    2016-05-01

    Poly ((ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide)) triblock copolymers commonly known as poloxamers or Pluronics constitute an important class of nonionic, biocompatible surfactants. Here, a method is reported to incorporate two acid-labile acetal moieties in the backbone of poloxamers to generate acid-cleavable nonionic surfactants. Poly(propylene oxide) is functionalized by means of an acetate-protected vinyl ether to introduce acetal units. Three cleavable PEO-PPO-PEO triblock copolymers (Mn,total = 6600, 8000, 9150 g·mol(-1) ; Mn,PEO = 2200, 3600, 4750 g·mol(-1) ) have been synthesized using anionic ring-opening polymerization. The amphiphilic copolymers exhibit narrow molecular weight distributions (Ð = 1.06-1.08). Surface tension measurements reveal surface-active behavior in aqueous solution comparable to established noncleavable poloxamers. Complete hydrolysis of the labile junctions after acidic treatment is verified by size exclusion chromatography. The block copolymers have been employed as surfactants in a miniemulsion polymerization to generate polystyrene (PS) nanoparticles with mean diameters of ≈200 nm and narrow size distribution, as determined by dynamic light scattering and scanning electron microscopy. Acid-triggered precipitation facilitates removal of surfactant fragments from the nanoparticles, which simplifies purification and enables nanoparticle precipitation "on demand." © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Main-chain supramolecular block copolymers.

    Science.gov (United States)

    Yang, Si Kyung; Ambade, Ashootosh V; Weck, Marcus

    2011-01-01

    Block copolymers are key building blocks for a variety of applications ranging from electronic devices to drug delivery. The material properties of block copolymers can be tuned and potentially improved by introducing noncovalent interactions in place of covalent linkages between polymeric blocks resulting in the formation of supramolecular block copolymers. Such materials combine the microphase separation behavior inherent to block copolymers with the responsiveness of supramolecular materials thereby affording dynamic and reversible materials. This tutorial review covers recent advances in main-chain supramolecular block copolymers and describes the design principles, synthetic approaches, advantages, and potential applications.

  5. 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.

  6. 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.

  7. 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.

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

    Science.gov (United States)

    Pradipta, Rangga; Mardiyati, Steven, Purnomo, Ikhsan

    2017-03-01

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

  9. 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)

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

    Science.gov (United States)

    Guo, Haiquan; Meador, Mary Ann B.

    2015-01-01

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

  11. The radiation crosslinking of ethylene copolymers

    International Nuclear Information System (INIS)

    Burns, N.M.

    1979-01-01

    The enhanced radiation crosslinking tendency of ethylene-vinyl acetate and ethylene-ethyl acrylate copolymers over ethylene homopolymer is proportional to the comonomer content. This is caused by an increase in the amorphous polymer content and by structure-related factors. The copolymers crosslink by a random process that for ethylene-vinyl acetate copolymer involves some crosslinking through the acetoxy group of the comonomer. While knowledge of the process for the crosslinking of ethylene-ethyl acrylate copolymer is less certain, it is currently believed to occur primarily at the branch point on the polymer backbone. Data relating comonomer content and the molecular weight of the copolymers to the radiation crosslinking levels realized were developed to aid in resin selection by the formulator. Triallyl cyanurate cure accelerator was found to be less effective in ethylene-vinyl acetate copolymer than in homopolymer and to have no effect on gel development in ethylene-ethyl acrylate copolymer. (author)

  12. Fully Aromatic Block Copolymers for Fuel Cell Membranes with Densely Sulfonated Nanophase Domains

    DEFF Research Database (Denmark)

    Takamuku, Shogo; Jannasch, Patrick; Lund, Peter Brilner

    Two multiblock copoly(arylene ether sulfone)s with similar block lengths and ion exchange capacities (IECs) were prepared by a coupling reaction between a non-sulfonated precursor block and a highly sulfonated precursor block containing either fully disulfonated diarylsulfone or fully...... tetrasulfonated tetraaryldisulfone segments. The latter two precursor blocks were sulfonated via lithiation-sulfination reactions whereby the sulfonic acid groups were exclu- sively placed in ortho positions to the many sulfone bridges, giving these locks IECs of 4.1 and 4.6 meqg1, respectively. Copolymer...

  13. Polystyrene-poly(vinylphenol) copolymers as compatibilzers for organic-inorganic composites

    International Nuclear Information System (INIS)

    Landry, C.J.T.; Coltrain, B.K.; Teegarden, D.M.

    1996-01-01

    Random, graft, and block copolymers of polystyrene (PS) and poly(4-vinylphenol) (PVPh), and PVPh homopolymer are shown to act as compatibilizers for incompatible organic-inorganic composite materials. The VPh component reacts, or interacts strongly with the polymerizing inorganic (titanium or zirconium) alkoxide. The organic components studied were PS, poly(vinyl methyl ether), and poly(styrene-co-acrylonitrile). The use of such compatibilizers provides a means of combining in situ polymerized inorganic oxides and hydrophobic polymers. This is seen as a reduction in the size of the dispersed inorganic phase and results in improved optical and mechanical properties

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

    Science.gov (United States)

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

    2014-10-01

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

  15. Modeling of emulsion copolymer microstructure

    NARCIS (Netherlands)

    van Doremaele, G.H.J.; Herk, van A.M.; German, A.L.

    1992-01-01

    A model is developed to describe stages II and III of batch emulsion copolymn., and its predictive capabilities are investigated by application to the system styrene-Me acrylate. The main reaction site is the monomer-swollen polymer particle. Copolymn. rate and copolymer microstructure (molar

  16. Polyether-polyester graft copolymer

    Science.gov (United States)

    Bell, Vernon L. (Inventor)

    1987-01-01

    Described is a polyether graft polymer having improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. These polymers exhibit good solvent resistance and are well suited for aircraft parts. Previous aromatic polyethers, also known as polyphenylene oxides, have certain deficiencies which detract from their usefulness. These commercial polymers are often soluble in common solvents including the halocarbon and aromatic hydrocarbon types of paint thinners and removers. This limitation prevents the use of these polyethers in structural articles requiring frequent painting. In addition, the most popular commercially available polyether is a very high melting plastic. This makes it considerably more difficult to fabricate finished parts from this material. These problems are solved by providing an aromatic polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The graft copolymer is formed by converting the carboxyl groups of a carboxylated polyphenylene oxide polymer to ionic carbonyl groups in a suitable solvent, reacting pivalolactone with the dissolved polymer, and adding acid to the solution to produce the graft copolymer.

  17. Thermo-responsive block copolymers

    NARCIS (Netherlands)

    Mocan Cetintas, Merve

    2017-01-01

    Block copolymers (BCPs) are remarkable materials because of their self-assembly behavior into nano-sized regular structures and high tunable properties. BCPs are in used various applications such as surfactants, nanolithography, biomedicine and nanoporous membranes. In these thesis, we aimed to

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Unitary information ether and its possible applications

    International Nuclear Information System (INIS)

    Horodecki, R.

    1991-01-01

    The idea of information ether as the unitary information field is developed. It rests on the assumption that the notion of information is a fundamental category in the description of reality and that it can be defined independently from the notion of probability itself. It is shown that the information ether provides a deterministic background for the nonlinear wave hypothesis and quantum cybernetics. (orig.)

  4. 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.

  5. 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%.

  6. 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

  7. Laser-induced photochemical reaction of aqueous maleic acid solutions containing H2O2

    International Nuclear Information System (INIS)

    Shimizu, Yuichi; Kawanishi, Shunichi; Suzuki, Nobutake

    1995-01-01

    Hydroxy acid such as glycolic, tartaric and malic acids was directly produced by XeF-laser irradiation of the N 2 -saturated maleic acid aqueous solution containing H 2 O 2 . The selectivities of these products at the maximum of tartaric acid were 71, 4, and 2% at H 2 O 2 feeding rate of 3.2 ml h -1 , respectively. On the other hand, the irradiation of maleates such as dipotassium, calcium, and disodium greatly enhanced the selectivities of tartaric acid formation to 19%, and of malic acid formation to 13%, respectively, for dipotassium maleate. It may be considered from these results that the stability of the hydroxylated intermediate radical plays an important role for the efficient formations of tartaric and malic acids. (author)

  8. 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)

  9. 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

  10. Optical characterization of CdS nanoparticles embedded into the comb-type amphiphilic graft copolymer

    Science.gov (United States)

    Kalaycı, Özlem A.; Duygulu, Özgür; Hazer, Baki

    2013-01-01

    This study refers to the synthesis and characterization of a novel organic/inorganic hybrid nanocomposite material containing cadmium sulfide (CdS) nanoparticles. For this purpose, a series of polypropylene (PP)-g-polyethylene glycol (PEG), PP-g-PEG comb-type amphiphilic graft copolymers were synthesized. PEGs with Mn = 400, 2000, 3350, and 8000 Da were used and the graft copolymers obtained were coded as PPEG400, PPEG2000, PPEG3350, and PPEG8000. CdS nanoparticles were formed in tetrahydrofuran solution of PP-g-PEG amphiphilic comb-type copolymer by the reaction between aqueous solutions of Na2S and Cd(CH3COO)2 simultaneously. Micelle formation of PPEG2000 comb-type amphiphilic graft copolymer in both solvent/non-solvent (petroleum ether-THF) by transmission electron microscopy (TEM). The optical characteristics, size morphology, phase analysis, and dispersion of CdS nanoparticles embedded in PPEG400, PPEG2000, PPEG3350, and PPEG8000 comb-type amphiphilic graft copolymer micelles were determined by high resolution TEM (HRTEM), energy dispersive spectroscopy, UV-vis spectroscopy, and fluorescence emission spectroscopy techniques. The aggregate size of PPEG2000-CdS is between 10 and 50 nm; however, in the case of PPEG400-CdS, PPEG3350-CdS, and PPEG8000-CdS samples, it is up to approximately 100 nm. The size of CdS quantum dots in the aggregates for PPEG2000 and PPEG8000 samples was observed as 5 nm by HRTEM analysis, and this result was also supported by UV-vis absorbance spectra and fluorescence emission spectra.

  11. Optical characterization of CdS nanoparticles embedded into the comb-type amphiphilic graft copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Kalayc Latin-Small-Letter-Dotless-I , Oezlem A. [Bulent Ecevit University, Department of Physics (Turkey); Duygulu, Oezguer [TUBITAK Marmara Research Center, Materials Institute (Turkey); Hazer, Baki, E-mail: bkhazer@karaelmas.edu.tr [Bulent Ecevit University, Department of Chemistry (Turkey)

    2013-01-15

    This study refers to the synthesis and characterization of a novel organic/inorganic hybrid nanocomposite material containing cadmium sulfide (CdS) nanoparticles. For this purpose, a series of polypropylene (PP)-g-polyethylene glycol (PEG), PP-g-PEG comb-type amphiphilic graft copolymers were synthesized. PEGs with Mn = 400, 2000, 3350, and 8000 Da were used and the graft copolymers obtained were coded as PPEG400, PPEG2000, PPEG3350, and PPEG8000. CdS nanoparticles were formed in tetrahydrofuran solution of PP-g-PEG amphiphilic comb-type copolymer by the reaction between aqueous solutions of Na{sub 2}S and Cd(CH{sub 3}COO){sub 2} simultaneously. Micelle formation of PPEG2000 comb-type amphiphilic graft copolymer in both solvent/non-solvent (petroleum ether-THF) by transmission electron microscopy (TEM). The optical characteristics, size morphology, phase analysis, and dispersion of CdS nanoparticles embedded in PPEG400, PPEG2000, PPEG3350, and PPEG8000 comb-type amphiphilic graft copolymer micelles were determined by high resolution TEM (HRTEM), energy dispersive spectroscopy, UV-vis spectroscopy, and fluorescence emission spectroscopy techniques. The aggregate size of PPEG2000-CdS is between 10 and 50 nm; however, in the case of PPEG400-CdS, PPEG3350-CdS, and PPEG8000-CdS samples, it is up to approximately 100 nm. The size of CdS quantum dots in the aggregates for PPEG2000 and PPEG8000 samples was observed as 5 nm by HRTEM analysis, and this result was also supported by UV-vis absorbance spectra and fluorescence emission spectra.

  12. Polyketones as alternating copolymers of carbon monoxide

    International Nuclear Information System (INIS)

    Belov, Gennady P; Novikova, Elena V

    2004-01-01

    Characteristic features of the catalytic synthesis of alternating copolymers of carbon monoxide with various olefins, dienes, styrene and its derivatives are considered. The diversity of catalyst systems used for the copolymerisation of carbon monoxide is demonstrated and their influence on the structure and the molecular mass of the resulting copolymers is analysed. The data on the structure and physicochemical and mechanical properties of this new generation of functional copolymers are generalised and described systematically for the first time.

  13. Polyether ether ketone film. Polyether ether ketone film

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S. (Sumitomo Chemical Co. Ltd., Tokyo (Japan))

    1990-07-05

    The characteristics and the film making process of polyether ether ketone (PEEK) resin, and the characteristics and the applications of PEEK film, are described. PEEK is aromatic polyketone with super thermal resistance. Though it is a crystalline polymer of which the crystallinity is controlled to 48% in a highest degree, it has also amorphous property, thus it shows unique property. The characteristics of PEEK resin are found in thermal resistance, incombusti-bility, transparency, chemical resistance, light resistance and radiation resistance. As for the film making process, casting method by T-die is generally adopted. The general properties of PEEK film are excellent in high thermal resistance, good electrical properties, chemical resistance, hydrolysis resistance, radiation resistance and imcombusti-bility. In the application of PEEK film, new development is expected in following fields; a high performance composite, flexible print substrate with high thermal resistance, insulating tape with thermal resistance, and a general film in the nuclear energy industry. 5 figs., 5 tabs.

  14. Copolymers of fluorinated polydienes and sulfonated polystyrene

    Science.gov (United States)

    Mays, Jimmy W [Knoxville, TN; Gido, Samuel P [Hadley, MA; Huang, Tianzi [Knoxville, TN; Hong, Kunlun [Knoxville, TN

    2009-11-17

    Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

  15. Effects of Poly(cyclohexanedimethylene terephthalate on Microstructures, Crystallization Behavior and Properties of the Poly(ester ether Elastomers

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Feng

    2017-06-01

    Full Text Available To understand the role of molecular structure on the crystallization behavior of copolyester in thermoplastic poly(ether ester elastomers (TPEEs, series of poly(butylene-co-1,4-cyclohexanedimethylene terephthalate (P(BT-co-CT-b-poly(tetramethylene glycol (PTMG are synthesized through molten polycondensation process. The effects of poly(cyclohexanedimethylene terephthalate (PCT content on the copolymer are investigated by Fourier transform infrared spectroscopy (FT-IR, 1H and 13C nuclear magnetic resonance (NMR, gel permeation chromatographs (GPC, wide-angle X-ray diffraction (WAXD, differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, mechanical, and visible light transmittance tests. FT-IR and NMR results confirm the incorporation of PCT onto the copolymer. WAXD and DSC indicate that the crystalline structure of the copolymers changed from α-PBT lattice to trans-PCT lattice when the molar fraction of PCT (MPCT is above 30%, while both crystallization and melting temperatures reach the minima. An increase in MPCT led to an increase in the number sequence length of PCT, the thermal stability and the visible light transmittance of the copolymer, but to a slight decrease in tensile strength and elastic modulus.

  16. Synthesis of biodegradable styrene copolymers

    OpenAIRE

    Gevers, Dries; Kobben, Stephan; Junkers, Tanja; Copinet, Alain; Buntinx, Mieke; Peeters, Roos

    2017-01-01

    Polystyrene (PS), a versatile polymer with many applications (e.g. packaging) representing about 10% of the total annual polymer consumption, shows practically no biodegradability. In this study a styrene (ST) based copolymer is synthesized and examined regarding its ability to degrade in a composting test. As second monomer, to introduce biodegradable ester groups, 5,6-benzo-2-metylene-dioxepane (BMDO) has been used in radical copolymerization reactions performed in inert and stirred 10 m...

  17. 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.

  18. Side-chain sulfonated poly(ether sulfone)s for PEM applications

    Energy Technology Data Exchange (ETDEWEB)

    Meier-Haack, J.; Butwilowski, W.; Quetschke, A.; Vogel, C. [Leibniz Institute of Polymer Research Dresden, Dresden (Germany)

    2010-07-01

    Copoly(arylene ether sulfone)s from bis-(4-fluoro phenyl)sulfone (DFDPhS), bis(4-trimethylsiloxy phenyl)sulfone (DHDPhS), and 2,5-diphenylhydroquinone trimethylsilylether (Bis-TMS-DPhHQ) were obtained by nucleophilic displacement polycondensation with high molecular weights (M{sub n} up to 70,000 g/mol; {eta}{sub inh} up to 0.93 dl/g) and narrow molecular weight distributions (2.1 - 2.9). All copolymers showed a single glass-transition temperature (T{sub g}) around 230 C. Upon sulfonation with concentrated sulfuric acid, the T{sub g}s (from samples in the protonated form) were shifted to higher temperatures (+ 35 {+-} 5 C). NMR spectra and the determined ion-exchange capacities (IEC; 1.46 - 2.05 mmol/g), which were close to the theoretical values, indicating that only the pendant phenyl rings of the 2,5- diphenylhydroquinone moieties in the polymer backbone were sulfonated. Membranes prepared from N-methyl- 2-pyrrolidone (NMP) solutions were transparent and soft. The water-uptake at room temperature increased from 30% to 80% with increasing IEC. Samples from random copolymers with an IEC {>=} 1.8 mmol/g were soluble in water at 90 C. While the proton conductivity of the low IEC samples (random copolymer) (1.46 mmol/g) was lower than that of Nafion {sup registered}, the conductivities of the high IEC samples were superior to Nafion {sup registered}. In general membranes from blockcopolymers showed lower water-uptake, higher dimensional stability and higher proton conductivities as compared to samples from random copolymers with similar monomer composition and ion-exchange capacities. (orig.)

  19. 21 CFR 177.2470 - Polyoxymethylene copolymer.

    Science.gov (United States)

    2010-04-01

    ... Components of Articles Intended for Repeated Use § 177.2470 Polyoxymethylene copolymer. Polyoxymethylene copolymer identified in this section may be safely used as an article or component of articles intended for... are available from the Center for Food Safety and Applied Nutrition (HFS-200), Food and Drug...

  20. Radiation resistance of ethylene-styrene copolymers

    International Nuclear Information System (INIS)

    Matsumoto, Kaoru; Ikeda, Masaaki; Ohki, Yoshimichi; Kusama, Yasuo; Harashige, Masahiro; Yazaki, Fumihiko.

    1988-01-01

    In this paper, the radiation resistance of ethylene-styrene copolymer, a polymeric resin developed newly by the authors, is reported. Resin examined were five kinds of ethylene-styrene copolymers: three random and two graft copolymers with different styrene contents. Low-density polyethylene was used as a reference. The samples were irradiated by 60 Co γ-rays to total absorbed doses up to 10 MGy. The mechanical properties of the smaples were examined. Infrared spectroscopy, differential scanning calorimetry and X-ray scattering techniques were used to examine the morphology of the samples. The random copolymers are soft and easy to extend, because benzene rings which exisist highly at random hinder the crystallization. As for the radiation resistance, they are highly resistant to γ-rays in the aspects of carbonyl group formation, gel formation, and elongation. Further, they show even better radiation resistance when proper additives were compounded in. The graft copolymers are hard to extend, because they consist of segregated polystyrene and polyethylene regions which are connected with each other. The tensile strength of irradiated graft copolymers does not decrease below that of unirradiated copolymers, up to a total dose of 10 MGy. As a consequence, it can be said that ethylene-styrene copolymers have good radiation resistance owing to the so-called 'sponge' effect of benzene rings. (author)

  1. Copolymers at the solid - liquid interface

    NARCIS (Netherlands)

    Wijmans, C.M.

    1994-01-01

    Copolymers consisting of both adsorbing and nonadsorbing segments can show an adsorption behaviour which is very different from that of homopolymers. We have mainly investigated the adsorption of AB diblock copolymers, which have one adsorbing block (anchor) and one nonadsorbing block

  2. Amphiphilic copolymers for fouling-release coatings

    DEFF Research Database (Denmark)

    Noguer, Albert Camós; Olsen, Stefan Møller; Hvilsted, Søren

    of the coatings [9,10,11]. This work shows the effect of an amphiphilic copolymer that induces hydrophilicity on the surface of the silicone-based fouling release coatings. The behaviour of these copolymers within the coating upon immersion and the interaction of these surface-active additives with other...

  3. Poly(ferrocenylsilane)-block-Polylactide Block Copolymers

    NARCIS (Netherlands)

    Roerdink, M.; van Zanten, Thomas S.; Hempenius, Mark A.; Zhong, Zhiyuan; Feijen, Jan; Vancso, Gyula J.

    2007-01-01

    A PFS/PLA block copolymer was studied to probe the effect of strong surface interactions on pattern formation in PFS block copolymer thin films. Successful synthesis of PFS-b-PLA was demonstrated. Thin films of these polymers show phase separation to form PFS microdomains in a PLA matrix, and

  4. Solution Construction of Multigeometry Nanoparticles and Multicompartment Superstructures from Block Copolymer Mixtures

    Science.gov (United States)

    Zhu, Jiahua; Zhang, Shiyi; Wooley, Karen; Pochan, Darrin

    2013-03-01

    Novel soft objects with both compositional and geometric complexity at nanoscale have been constructed through solution supramolecular assembly from block copolymer mixtures due to their non-ergodic character. The mixture is composed of two block copolymers with distinctive hydrophobic blocks but the same poly(acrylic acid) hydrophilic block. First, multigeometry nanoparticles, due to segregation of unlike block copolymer molecules into multiple subdomains trapped within the same micelle-like structures, have been assembled in tetrahydrofuran/water solution. Through carefully designed molecular architecture, mixing ratio and pathway kinetics, both size and shape of subdomains can be controlled to produce a novel class of multigeometry nanoparticles, including sphere-sphere, sphere-cylinder, cylinder-cylinder, cylinder-disk, and sphere-disk hybrid nanoparticles. Second, hierarchical multicompartment superstructures including particle chains, rings and other nano to micro cluster formations, have been built up from pre-formed multigeometry nanoparticles by taking advantage of their surface anisotropy and the controlled particle-particle association. The interparticle association can be achieved via either covalent or non-covalent bindings due to different post-polymerization chemical modifications with hydroxyethyl acrylate or crown ether functionalities, respectively.

  5. 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)

  6. SULFONATED POLY(ARYLENE ETHER BENZIMIDAZOLE COPOLYMER MEMBRANE SYNTHESIS AND CHARACTERIZATION

    Directory of Open Access Journals (Sweden)

    Çağla TOSUN

    2015-05-01

    Full Text Available Hidrojenden elektrik enerjisi üretiminde kullanılan yakıt hücreleri, geleceğin çevre dostu ve yüksek verimli enerji üretimine alternatif olarak kabul görmektedirler. Nafion gibi perflorosülfonik asit bazlı membranlar polimer elektrolit membran yakıt hücreleri (PEMHY’nde sıklıkla kullanılmaktadırlar. Ancak Nafion membranların yüksek sıcaklıklarda proton iletkenliklerinin düşmesi ve fiyatlarının yüksek olması nedeniyle alternatif polimer elektrolit membran (PEM’lar üzerine araştırmalar devam etmektedir. Bu çalışmanın ilk aşamasında, disodyum-3,3’-disülfonat-4,4’-diklorodifenilsülfon (SDCDPS ve benzimidazol bisfenol (HPBI monomerlerinin sentezi gerçekleştirilmiştir. Daha sonra sentezlenen monomerlerden nükleofilik aromatik polikondenzasyon reaksiyonu ile poli(arilen eter benzimidazol kopolimeri sentezlenmiştir. Sentezlenen monomerlerin 1H NMR ve FTIR, kopolimerin ise 1H NMR, FTIR ve termogravimetrik analizleri (TGA gerçekleştirilmiştir. Yapılan analizler sonucunda kopolimerin sentezlendiği açıkça ortaya konulmuştur. TGA eğrisi sentezlenen kopolimerin ısıl kararlılığının yüksek olduğunu (~400 oC ve yüksek sıcaklık uygulamalarında kullanılabilirliğini göstermiştir

  7. 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

  8. 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.

  9. 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.

  10. 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).

  11. 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)

  12. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian

    2012-01-01

    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......, 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...

  13. Rapid self-assembly of block copolymers to photonic crystals

    Science.gov (United States)

    Xia, Yan; Sveinbjornsson, Benjamin R; Grubbs, Robert H; Weitekamp, Raymond; Miyake, Garret M; Atwater, Harry A; Piunova, Victoria; Daeffler, Christopher Scot; Hong, Sung Woo; Gu, Weiyin; Russell, Thomas P.

    2016-07-05

    The invention provides a class of copolymers having useful properties, including brush block copolymers, wedge-type block copolymers and hybrid wedge and polymer block copolymers. In an embodiment, for example, block copolymers of the invention incorporate chemically different blocks comprising polymer size chain groups and/or wedge groups that significantly inhibit chain entanglement, thereby enhancing molecular self-assembly processes for generating a range of supramolecular structures, such as periodic nanostructures and microstructures. The present invention also provides useful methods of making and using copolymers, including block copolymers.

  14. 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.

  15. 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)

  16. 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.

  17. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis.

    Directory of Open Access Journals (Sweden)

    Govinda Rizal

    Full Text Available An efficient method for crossing green foxtail (Setaria viridis is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH, and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria.

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

    International Nuclear Information System (INIS)

    Yu Jiaguo; Tang Hua; Cheng Bei; Zhao Xiujian

    2004-01-01

    Calcium oxalate (CaOx) particles exhibiting different shapes and phase structures were fabricated by a simple precipitation reaction of sodium oxalate with calcium chloride in the absence and presence of poly-(styrene-alt-maleic acid) (PSMA) as a crystal modifier at room temperature. The as-obtained products were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of reaction conditions including pH, [Ca 2+ ]/[C 2 O 4 2- ] ratio and concentration of PSMA and CaC 2 O 4 on the crystal forms and morphologies of the as-obtained calcium oxalate were investigated. The results show that various crystal morphologies of calcium oxalate, such as parallelograms, plates, spheres, bipyramids etc. can be obtained depending on the experimental conditions. Higher polymer concentration favors formation of the metastable calcium oxalate dihydrate (COD) crystals. Lower pH is beneficial to the formation of plate-like CaOx crystals. Especially, the monodispersed parallelogram-like CaOx crystals can be produced by PSMA as an additive at pH 2. PSMA may act as a good inhibitor for urolithiasis since it induces the formation of COD and reduces the particle size of CaOx. This research may provide new insight into the morphological control of CaOx particles and the prevention of urolithiasis

  19. 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.

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

    Czech Academy of Sciences Publication Activity Database

    Výprachtický, Drahomír; Mikeš, F.; Lokaj, Jan; Pokorná, Veronika; Cimrová, Věra

    2015-01-01

    Roč. 160, April (2015), s. 27-34 ISSN 0022-2313 R&D Projects: GA ČR GAP106/12/0827; GA ČR(CZ) GA13-26542S Institutional support: RVO:61389013 Keywords : energy transfer * terbium luminescence * quinolinone donor Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.693, year: 2015

  1. Block copolymer membranes for aqueous solution applications

    KAUST Repository

    Nunes, Suzana Pereira

    2016-03-22

    Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

  2. Block copolymer membranes for aqueous solution applications

    KAUST Repository

    Nunes, Suzana Pereira

    2016-01-01

    Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

  3. Distribution of short block copolymer chains in Binary Blends of Block Copolymers Having Hydrogen Bonding

    Science.gov (United States)

    Kwak, Jongheon; Han, Sunghyun; Kim, Jin Kon

    2014-03-01

    A binary mixture of two block copolymers whose blocks are capable of forming the hydrogen bonding allows one to obtain various microdomains that could not be expected for neat block copolymer. For instance, the binary blend of symmetric polystyrene-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) and polystyrene-block-polyhydroxystyrene copolymer (PS-b-PHS) blends where the hydrogen bonding occurred between P2VP and PHS showed hexagonally packed (HEX) cylindrical and body centered cubic (BCC) spherical microdomains. To know the exact location of short block copolymer chains at the interface, we synthesized deuterated polystyrene-block-polyhydroxystyrene copolymer (dPS-b-PHS) and prepared a binary mixture with PS-b-P2VP. We investigate, via small angle X-ray scattering (SAXS) and neutron reflectivity (NR), the exact location of shorter dPS block chain near the interface of the microdomains.

  4. 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.

  5. 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

  6. 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

  7. 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,

  8. Micellization and Dynamics of a Block Copolymer

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2006-01-01

    and copolymer mixtures, and evidence in favor of a multi-equilibria unimer-micelle model will be presented. Results obtained by liquid chromatographic methods will be shown and it will be demonstrated that commercial EPE copolymers are inhomogeneous at several levels and many of their unusual properties reflect...... ratios and temperature. The micellization process with increasing temperature has been followed by a number of techniques including differential scanning calorimetry, liquid chromatography, and surface tension measurements. Different micellization models have been tested for purified copolymers...

  9. PEO-related block copolymer surfactants

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems...... of such PEG-based block copolymers in aqueous suspensions are reviewed. Based on scattering experiments using either X-ray or neutrons, the phase behavior is characterized, showing that the thermo-reversible gelation is a result of micellar ordering into mesoscopic crystalline phases of cubic, hexagonal...

  10. Synthesis and characterization of sulfonated cardo poly(arylene ether sulfone)s for fuel cell proton exchange membrane application

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.M.; Jang, H.H.; Lim, Y.D.; Seo, D.W.; Kim, W.G. [Department of Applied Chemistry, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, T.H.; Hong, Y.T. [Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Kim, D.M. [Material Engineering and Science, Hongik Univ, Jochiwon-eup, Yeongi-gun, Chungnam (Korea, Republic of)

    2012-12-15

    Sulfonated cardo poly(arylene ether sulfone)s (SPPA-PES) with various degrees of sulfonation (DS) were prepared by post-sulfonation of synthesized phenolphthalein anilide (PPA; N-phenyl-3,3'-bis(4-hydroxyphenyl)-1-isobenzopyrolidone) poly(arylene ether sulfone)s (PPA-PES) by using concentrated sulfuric acid. PPA-PES copolymers were synthesized by direct polycondensation of PPA with bis-(4-fluorophenyl)-sulfone and 4,4'-sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA-PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT-IR) spectroscopy, {sup 1}H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA-PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA-PES membranes was in the range of 20-72%, compared with 28% for Nafion 211 registered. The SPPA-PES membranes showed proton conductivities of 23-82 mS cm{sup -1}, compared with 194 mS cm{sup -1} for Nafion 211 registered, under 100% relative humidity (RH) at 80 C. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Dissociative Photoionization of Diethyl Ether.

    Science.gov (United States)

    Voronova, Krisztina; Mozaffari Easter, Chrissa M; Covert, Kyle J; Bodi, Andras; Hemberger, Patrick; Sztáray, Bálint

    2015-10-29

    The dissociative photoionization of internal energy selected diethyl ether ions was investigated by imaging photoelectron photoion coincidence spectroscopy. In a large, 5 eV energy range Et2O(+) cations decay by two parallel and three sequential dissociative photoionization channels, which can be modeled well using statistical theory. The 0 K appearance energies of the CH3CHOCH2CH3(+) (H-loss, m/z = 73) and CH3CH2O═CH2(+) (methyl-loss, m/z = 59) fragment ions were determined to be 10.419 ± 0.015 and 10.484 ± 0.008 eV, respectively. The reemergence of the hydrogen-loss ion above 11 eV is attributed to transition-state (TS) switching, in which the second, outer TS is rate-determining at high internal energies. At 11.81 ± 0.05 eV, a secondary fragment of the CH3CHOCH2CH3(+) (m/z = 73) ion, protonated acetaldehyde, CH3CH═OH(+) (m/z = 45) appears. On the basis of the known thermochemical onset of this fragment, a reverse barrier of 325 meV was found. Two more sequential dissociation reactions were examined, namely, ethylene and formaldehyde losses from the methyl-loss daughter ion. The 0 K appearance energies of 11.85 ± 0.07 and 12.20 ± 0.08 eV, respectively, indicate no reverse barrier in these processes. The statistical model of the dissociative photoionization can also be used to predict the fractional ion abundances in threshold photoionization at large temperatures, which could be of use in, for example, combustion diagnostics.

  12. 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.

  13. Functional Nanoporous Polymers from Block Copolymer Precursors

    DEFF Research Database (Denmark)

    Guo, Fengxiao

    Abstract Self-assembly of block copolymers provides well-defined morphologies with characteristic length scales in the nanometer range. Nanoporous polymers prepared by selective removal of one block from self-assembled block copolymers offer great technological promise due to their many potential...... functionalities remains a great challenge due to the limitation of available polymer synthesis and the nanoscale confinement of the porous cavities. The main topic of this thesis is to develop methods for fabrication of functional nanoporous polymers from block copolymer precursors. A method has been developed......, where living anionic polymerization and atom transfer radical polymerization (ATRP) are combined to synthesize a polydimethylsiloxane-b-poly(tert-butyl acrylate)-b-polystyrene (PDMS-b-PtBA-b-PS) triblock copolymer precursor. By using either anhydrous hydrogen fluoride or trifluoroacetic acid, PtBA block...

  14. Block Copolymers: Synthesis and Applications in Nanotechnology

    Science.gov (United States)

    Lou, Qin

    This study is focused on the synthesis and study of (block) copolymers using reversible deactivation radical polymerizations (RDRPs), including atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization. In particular, two primary areas of study are undertaken: (1) a proof-of-concept application of lithographic block copolymers, and (2) the mechanistic study of the deposition of titania into block copolymer templates for the production of well-ordered titania nanostructures. Block copolymers have the ability to undergo microphase separation, with an average size of each microphase ranging from tens to hundreds of nanometers. As such, block copolymers have been widely considered for nanotechnological applications over the past two decades. The development of materials for various nanotechnologies has become an increasingly studied area as improvements in many applications, such as those found in the semiconductor and photovoltaic industries are constantly being sought. Significant growth in developments of new synthetic methods ( i.e. RDRPs) has allowed the production of block copolymers with molecular (and sometimes atomic) definition. In turn, this has greatly expanded the use of block copolymers in nanotechnology. Herein, we describe the synthesis of statistical and block copolymers of 193 nm photolithography methacrylate and acrylate resist monomers with norbornyl and adamantyl moieties using RAFT polymerization.. For these resist (block) copolymers, the phase separation behaviors were examined by atomic force microscopy (AFM). End groups were removed from the polymers to avoid complications during the photolithography since RAFT end groups absorb visible light. Poly(glycidyl methacrylate-block-polystyrene) (PGMA-b-PS) was synthesize by ATRP and demonstrated that this block copolymer acts as both a lithographic UV (365 nm) photoresist and a self-assembly material. The PGMA segments can undergo cationic

  15. Responsive Copolymers for Enhanced Petroleum Recovery

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, C.; Hester, R.

    2001-02-27

    The objectives of this work was to: synthesize responsive copolymer systems; characterize molecular structure and solution behavior; measure rheological properties of aqueous fluids in fixed geometry flow profiles; and to tailor final polymer compositions for in situ rheology control under simulated conditions. This report focuses on the synthesis and characterization of novel stimuli responsive copolymers, the investigation of dilute polymer solutions in extensional flow and the design of a rheometer capable of measuring very dilute aqueous polymer solutions at low torque.

  16. Reactivity Ratios for Organotin Copolymer Systems

    Directory of Open Access Journals (Sweden)

    Mohamed H. El-Newehy

    2010-04-01

    Full Text Available Di(tri-n-butyltin itaconate (DTBTI and monoethyl tributyltin fumarate (METBTF were synthesized as organotin monomers. The organotin monomers were copolymerized with styrene (ST and methyl methacrylate (MMA via a free radical polymerization technique. The overall conversion was kept low (£15% wt/wt for all studied samples and the copolymer composition was determined from tin analysis. The synthesized monomers and copolymers were characterized by elemental analysis, 1H- and 13C-NMR, and FTIR spectroscopy.

  17. Injection characteristics of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Glensvig, M.

    1996-09-01

    Dimethyl ether (DME) has proved to be a new ultra-clean alternative fuel for diesel engines. Engine tests have shown considerably lower NO{sub x} emissions, no particle emissions and lower noise compared to that obtained from normal diesel engine operation. DME also has demonstrated favorable response to Exhaust Gas Recirculation (EGR). The purpose of this investigation was to achieve a better understanding of the fundamental spray behavior of DME. Fundamental spray behaviour was characterized by fuel spray penetration and angle, atomization and droplet size and evaporation. The influence of fuel characteristics, nozzle geometry and ambient pressure on the DME and diesel spray behavior was investigated. Fuel was injected into an unheated injection chamber with a ambient pressure of 15 bar and 25 bar, respectively, giving a simplified simulation of the environment in an operating engine. Two nozzles were studied: a single hole nozzle and a pintle nozzle. A conventional fuel injection system was used for both nozzles. Injection parameters of RPM, throttle position, fuel line length and chamber environment were held constant for both nozzles. The sprays were visualized using schlieren and high speed photography. Results show that the general appearance of the DME spray is similar to that of diesel spray. The core of the DME spray seems less dense and the spray tip less sharp compared to diesel spray, indicating smaller droplets with a lower momentum in the core of the DME spray. Schlieren film shows that with both DME and diesel fuel, the spray tip only consists of liquid and that evaporation occurs after a brief time interval. Penetration of DME is about one third that of diesel using the pintle nozzle. Also, the spray angle is considerably larger for the DME spray compared to the diesel spray. A comparatively smaller difference in penetration is observed using the hole nozzle. Differences in penetration for the hole nozzle are within the limit of the penetration

  18. Radiation-induced transformations of cellulose ethers

    International Nuclear Information System (INIS)

    Nud'ga, L.A.; Petropavlovskii, G.S.; Plisko, E.A.; Isakova, O.V.; Ershov, B.G.

    1988-01-01

    The purpose of this investigation was to study the transformation which take place under the action of γ-radiation in a number of cellulose ethers containing both saturated (carboxymethyl, hydroxyethyl) and unsaturated (allyl, methacryloyl) groups. Irradiation was carried out on a 60 Co unit in air at 77 and 300 K; the dose rate was 37 and 50 kGy/h respectively. The EPR spectra of γ-irradiated hydroxyethyl- and allylhydroxyethylcelluloses are identical. Under the action of γ-radiation extensive changes took place in cellulose ethers which are exhibited in degradation or the formation of three-dimensional structures and are accompanied by a change in the functional composition. The efficiency in the formation of radicals and their localization are determined by the nature and number of substituents in the cellulose ethers

  19. 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.

  20. The influence of chain stretching on the phase behavior of multiblock copolymer and comb copolymer melts

    NARCIS (Netherlands)

    Angerman, HJ; ten Brinke, G

    The subject of this paper is inspired by microphase-separated copolymer melts in which a small-scale structure is present inside one of the phases of a large-scale structure. Such a situation can arise in a diblock copolymer melt, if one of the blocks of the diblock is in itself a multiblock

  1. 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

  2. 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 ...

  3. Well-defined copolymers synthesized by RAFT polymerization as effective modifiers to enhance the photocatalytic performance of TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Vasilaki, E., E-mail: euavasilakh@gmail.com [Department of Chemistry, University of Crete, 710 03, Heraklion, Crete (Greece); Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Kaliva, M. [Institute of Electronic Structure and Laser, Foundation for Research & Technology-Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Department of Materials Science and Technology, University of Crete, 710 03, Heraklion, Crete (Greece); Katsarakis, N. [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Institute of Electronic Structure and Laser, Foundation for Research & Technology-Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Vamvakaki, M. [Institute of Electronic Structure and Laser, Foundation for Research & Technology-Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Department of Materials Science and Technology, University of Crete, 710 03, Heraklion, Crete (Greece)

    2017-03-31

    Highlights: • Well-defined, random functional copolymers were synthesized by RAFT polymerization. • Novel TiO{sub 2} particles in-situ modified with copolymers were synthesized. • The hybrid catalysts exhibited reduced aggregation and particle size. • The photocatalytic removal of methylene blue was higher for the hybrid catalysts. - Αbstract: The enhancement of the photocatalytic performance of anatase TiO{sub 2} nanoparticles is demonstrated by a facile route, involving their in-situ surface modification with preformed polymer chains. Random copolymers of poly(ethylene glycol) methyl ether acrylate-co-methacrylic acid (PEGA-co-MAA) or poly(ethylene glycol) methyl ether acrylate-co-dopamine methacrylamide (PEGA-co-DMA) were synthesized by reversible addition−fragmentation chain-transfer (RAFT) polymerization and were bound onto the surface of anatase titania nanoparticles via the “grafting to” method. The hybrid nanocatalysts were characterized by fourier transform infrared spectroscopy, zeta-potential measurements, X-ray powder diffraction, thermogravimetric analysis and transmission electron microscopy. Their photocatalytic performance was evaluated by the decoloration of methylene blue (MB) dye in aqueous media under UV–vis light irradiation. The enhanced photoactivity and reusability of the polymer modified photocatalysts compared to that of bare TiO{sub 2} nanoparticles was attributed to their improved dispersability and colloidal stability, the smaller particle size that leads to a larger surface area and the increased adsorption capacity of the dye onto the polymer modified nanoparticles.

  4. Well-defined copolymers synthesized by RAFT polymerization as effective modifiers to enhance the photocatalytic performance of TiO_2

    International Nuclear Information System (INIS)

    Vasilaki, E.; Kaliva, M.; Katsarakis, N.; Vamvakaki, M.

    2017-01-01

    Highlights: • Well-defined, random functional copolymers were synthesized by RAFT polymerization. • Novel TiO_2 particles in-situ modified with copolymers were synthesized. • The hybrid catalysts exhibited reduced aggregation and particle size. • The photocatalytic removal of methylene blue was higher for the hybrid catalysts. - Αbstract: The enhancement of the photocatalytic performance of anatase TiO_2 nanoparticles is demonstrated by a facile route, involving their in-situ surface modification with preformed polymer chains. Random copolymers of poly(ethylene glycol) methyl ether acrylate-co-methacrylic acid (PEGA-co-MAA) or poly(ethylene glycol) methyl ether acrylate-co-dopamine methacrylamide (PEGA-co-DMA) were synthesized by reversible addition−fragmentation chain-transfer (RAFT) polymerization and were bound onto the surface of anatase titania nanoparticles via the “grafting to” method. The hybrid nanocatalysts were characterized by fourier transform infrared spectroscopy, zeta-potential measurements, X-ray powder diffraction, thermogravimetric analysis and transmission electron microscopy. Their photocatalytic performance was evaluated by the decoloration of methylene blue (MB) dye in aqueous media under UV–vis light irradiation. The enhanced photoactivity and reusability of the polymer modified photocatalysts compared to that of bare TiO_2 nanoparticles was attributed to their improved dispersability and colloidal stability, the smaller particle size that leads to a larger surface area and the increased adsorption capacity of the dye onto the polymer modified nanoparticles.

  5. 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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-06-01

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

  8. Solvent polarity effects on supramolecular chirality of a polyfluorene-thiophene copolymer.

    Science.gov (United States)

    Hirahara, Takashi; Yoshizawa-Fujita, Masahiro; Takeoka, Yuko; Rikukawa, Masahiro

    2018-06-01

    This study demonstrates the supramolecular chirality control of a conjugated polymer via solvent polarity. We designed and synthesized a chiral polyfluorene-thiophene copolymer having two different chiral side chains at the 9-position of the fluorene unit. Chiral cyclic and alkyl ethers with different polarities were selected as the chiral side chains. The sign of the circular dichroism spectra in the visible wavelength region was affected by the solvent system, resulting from the change of supramolecular structure. The estimation of the solubility parameter revealed that the solubility difference of the side chains contributed to the change of the circular dichroism sign, which was also observed in spin-coated films prepared from good solvents having different polarities. © 2018 Wiley Periodicals, Inc.

  9. Children's exposure to polybrominated diphenyl ethers.

    NARCIS (Netherlands)

    Zuurbier, M.; Leijs, M.; Schoeters, G.; Tusscher, G. Ten; Koppe, J.G.

    2006-01-01

    Background: Polybrominated biphenyl ethers (PBDEs), a class of brominated flame retardants, are frequently used in consumer products. PBDEs levels in environmental and human samples have increased in recent decades. Children are exposed to PBDEs through diet, mainly through fish, meat and milk.

  10. Polybrominated diphenyl ethers and novel flame retardants

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Nielsen, Jesper Bo

    ,4,6-tribromophenyl ether (TBP-DBPE) and dechlorane plus (DDC-CO) have been detected in the same dust samples previously analysed for PBDEs and are currently being analysed in the corresponding human milk samples. [1] Stapleon H.M., Eagle S., Sjödin A., Webster T.F. (2012). Serum PBDEs in a North Carolina Toddler...

  11. [Visualisation methods for etheric formative forces].

    Science.gov (United States)

    Burkhard, B; Kittel, R

    2009-09-01

    Rudolf Steiner, the founder of anthroposophy, suggested the development of visualisation methods for "etheric formative forces". The essential methods, their "spiritual scientific" basis and indications are described and their claims critically tested. The methods are not validated, the key criteria for diagnostic tests (reproducibility, sensitivity, specifity) are not given.

  12. 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

  13. Selective crystallization of cations with crown ethers

    International Nuclear Information System (INIS)

    Heffels, Dennis Egidius

    2014-01-01

    The aim of this work was to study the selectivity and preferences of the incorporation of differently sized cations in the cavities of various crown ethers and the characterization of the resulting compounds. The coordination preferences of crown ethers with different cavities have long been known, and the impact of other effects on the structure formation have increasingly become the focus of attention. In this work a comparative overview of the coordination preferences depending on various factors was undertaken. The focus was mainly on the variation of the cavity of the crown ether in the presence of differently sized cations. In addition, the effects of the solvent and differently coordinating anions have been investigated. Within the framework of this work, basic coordination preferences could be detected with rare earth nitrates, which are affected particularly by the choice of the solvent. The formation of different types of structures could be controlled by varying the conditions such that the incorporation of the cation in the cavity of the crown ether was influenced and the formation of a particular type of structure can be influenced partly by the choice of solvent. In this case no direct preferences for the incorporation into the cavity of the crown ether in relation to the cation size were observed for rare earth cations. However, the coordination of the crown ether leads in each case - for lanthanides - to rather high coordination numbers. A total of five new rare earth complexes and two structural variants could be observed with crown ethers. In the study of the selectivity of the incorporation into the cavity, known structures were also reproduced and further structures were characterized but the crystal structures not entirely solved. With the use of monovalent cations such as potassium, lithium or silver a total of nine new compounds could be synthesized, while no clear preferences for the incorporation of certain cations were detected. The

  14. Multiblock copolymers synthesized in aqueous dispersions using multifunctional RAFT agents

    NARCIS (Netherlands)

    Bussels, R.; Bergman-Göttgens, C.M.; Meuldijk, J.; Koning, C.E.

    2005-01-01

    Triblock copolymers were synthesized in aqueous dispersions in two polymerization steps using a low molar mass difunctional dithiocarbamate-based RAFT agent, and in merely one polymerization step using a macromolecular difunctional dithiocarbamate-based RAFT agent. Segmented block copolymers

  15. Polyamide copolymers having 2,5-furan dicarboxamide units

    Science.gov (United States)

    Chisholm, Bret Ja; Samanta, Satyabrata

    2017-09-19

    Polyamide copolymers, and methods of making and using polyamide copolymers, having 2,5-furan dicarboxamide units are disclosed herein. Such polymers can be useful for engineering thermoplastics having advantageous physical and/or chemical properties.

  16. 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

  17. Determination of Glyphosate, Maleic Hydrazide, Fosetyl Aluminum, and Ethephon in Grapes by Liquid Chromatography/Tandem Mass Spectrometry.

    Science.gov (United States)

    Chamkasem, Narong

    2017-08-30

    A simple high-throughput liquid chromatography/tandem mass spectrometry (LC-MS-MS) method was developed for the determination of maleic hydrazide, glyphosate, fosetyl aluminum, and ethephon in grapes using a reversed-phase column with weak anion-exchange and cation-exchange mixed mode. A 5 g test portion was shaken with 50 mM HOAc and 10 mM Na 2 EDTA in 1/3 (v/v) MeOH/H 2 O for 10 min. After centrifugation, the extract was passed through an Oasis HLB cartridge to retain suspended particulates and nonpolar interferences. The final solution was injected and directly analyzed in 17 min by LC-MS-MS. Two MS-MS transitions were monitored in the method for each target compound to achieve true positive identification. Four isotopically labeled internal standards corresponding to each analyte were used to correct for matrix suppression effects and/or instrument signal drift. The linearity of the detector response was demonstrated in the range from 10 to 1000 ng/mL for each analyte with a coefficient of determination (R 2 ) of ≥0.995. The average recovery for all analytes at 100, 500, and 2000 ng/g (n = 5) ranged from 87 to 111%, with a relative standard deviation of less than 17%. The estimated LOQs for maleic hydrazide, glyphosate, fosetyl-Al, and ethephon were 38, 19, 29, and 34 ng/g, respectively.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Oil recovery with vinyl sulfonic acid-acrylamide copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-12-18

    An aqueous polymer flood containing sulfomethylated alkali metal vinyl sulfonate-acrylamide copolymers was proposed for use in secondary or tertiary enhanced oil recovery. The sulfonate groups on the copolymers sustain the viscosity of the flood in the presence of brine and lime. Injection of the copolymer solution into a waterflooded Berea core, produced 30.5 percent of the residual oil. It is preferred that the copolymers are partially hydrolyzed.

  20. Styrene maleic acid encapsulated raloxifene micelles for management of inflammatory bowel disease.

    Science.gov (United States)

    Greish, Khaled; Taha, Safa; Jasim, Anfal; Elghany, Sara Abd; Sultan, Ameera; AlKhateeb, Ali; Othman, Manal; Jun, Fang; Taurin, Sebastien; Bakhiet, Moiz

    2017-12-01

    Inflammatory bowel disease (IBD) comprises a group of disorders that manifest through chronic inflammation of the colon and small intestine. Although the exact cause of IBD is still unclear, dysfunctional immunoregulation involving overproduction of inflammatory cytokines such as TNF-α, and IL-6 have been implicated in pathogenesis. Current therapy relies on immunosuppression, cytotoxic drugs, and monoclonal antibodies against TNF-α. These classes of drugs have severe side-effects, especially when used for long duration. Our previous work with raloxifene, a selective estrogen receptor modulator, has shown that the drug, and to a greater extent its micellar formulation, has a significant suppressive effect on NF-κB, an essential immune-regulator. This finding directed the current work towards testing the anti-inflammatory and immunomodulatory effects of raloxifene using cell lines, as well as testing the potential use of the styrene maleic acid (SMA) micelles loaded with raloxifene (SMA-Ral) against dextran sulfate sodium (DSS) induced colitis in an in vivo model of IBD. Treatment of MCF-7 cells with TNF-α was shown to protect the cells from the cytotoxic effect of raloxifene (42 vs. 10% cell death, with TNF-α. Treating CaCo-2 cells with both free and SMA-Ral improved cell survival after exposure to 2% DDS with significantly higher protection with SMA-Ral. Treatment of U-937 with SMA-Ral and free-Ral resulted in down-regulation of TNF-α, IL-1β, IL-6, and MIP1α, with greater inhibition of the SMA-Ral, compared to free Ral. Balb/c mice treated with raloxifene and SMA-Ral showed weight gain at 14 days, compared to the control group (122, and 115% respectively). Treatment with raloxifene prevented DSS-induced diarrhea in 6/6 of free raloxifene treated mice and in 5/6 mice treated with SMA-Ral. Control group of DSS-treated mice showed average colon length of 7.4 cm compared to 13 cm in the control group. The average colon length was 12.3 and 11.5 cm for

  1. 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.

  2. 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

  3. Photo-Induced Micellization of Block Copolymers

    Directory of Open Access Journals (Sweden)

    Satoshi Kuwayama

    2010-11-01

    Full Text Available We found novel photo-induced micellizations through photolysis, photoelectron transfer, and photo-Claisen rearrangement. The photolysis-induced micellization was attained using poly(4-tert-butoxystyrene-block-polystyrene diblock copolymer (PBSt-b-PSt. BSt-b-PSt showed no self-assembly in dichloromethane and existed as isolated copolymers. Dynamic light scattering demonstrated that the copolymer produced spherical micelles in this solvent due to irradiation with a high-pressure mercury lamp in the presence of photo-acid generators, such as bis(alkylphenyliodonium hexafluorophosphate, diphenyliodonium hexafluorophosphate, and triphenylsulfonium triflate. The 1H NMR analysis confirmed that PBSt-b-PSt was converted into poly(4-vinylphenol-block-PSt by the irradiation, resulting in self-assembly into micelles. The irradiation in the presence of the photo-acid generator also induced the micellization of poly(4-pyridinemethoxymethylstyrene-block-polystyrene diblock copolymer (PPySt-b-PSt. Micellization occurred by electron transfer from the pyridine to the photo-acid generator in their excited states and provided monodispersed spherical micelles with cores of PPySt blocks. Further, the photo-Claisen rearrangement caused the micellization of poly(4-allyloxystyrene-block-polystyrene diblock copolymer (PASt-b-PSt. Micellization was promoted in cyclohexane at room temperature without a catalyst. During micellization, the elimination of the allyl groups competitively occurred along with the photorearrangement of the 4-allyloxystyrene units into the 3-allyl-4-hydroxystyrene units.

  4. Nanoparticles based on novel amphiphilic polyaspartamide copolymers

    International Nuclear Information System (INIS)

    Craparo, Emanuela Fabiola; Teresi, Girolamo; Ognibene, Maria Chiara; Casaletto, Maria Pia; Bondi, Maria Luisa; Cavallaro, Gennara

    2010-01-01

    In this article, the synthesis of two amphiphilic polyaspartamide copolymers, useful to obtain polymeric nanoparticles without using surfactants or stabilizing agents, is described. These copolymers were obtained starting from α,β-poly-(N-2-hydroxyethyl)-dl-aspartamide (PHEA) by following a novel synthetic strategy. In particular, PHEA and its pegylated derivative (PHEA-PEG 2000 ) were functionalized with poly(lactic acid) (PLA) through 1,1'-carbonyldiimidazole (CDI) activation to obtain PHEA-PLA and PHEA-PEG 2000 -PLA graft copolymers, respectively. These copolymers were properly purified and characterized by 1 H-NMR, FT-IR, and Size Exclusion Chromatography (SEC) analyses, which confirmed that derivatization reactions occurred. Nanoparticles were obtained from PHEA-PLA and PHEA-PEG 2000 -PLA graft copolymers by using the high pressure homogenization-solvent evaporation method, avoiding the use of surfactants or stabilizing agents. Polymeric nanoparticles were characterized by dimensional analysis, before and after freeze-drying process, and Scanning Electron Microscopy (SEM). Zeta potential measurements and X-ray Photoelectron Spectroscopy (XPS) analysis demonstrated the presence of PEG and/or PHEA onto the PHEA-PEG 2000 -PLA and PHEA-PLA nanoparticle surface, respectively.

  5. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

  6. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be safely...

  7. 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...

  8. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-ethyl acrylate copolymers. 177.1320... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1320 Ethylene-ethyl acrylate copolymers. Ethylene-ethyl acrylate copolymers may be safely used to produce packaging materials, containers...

  9. 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...

  10. Effect of diblock copolymer properties on the photophysical properties of dendrimer silicon phthalocyanine nanoconjugates

    Science.gov (United States)

    Chen, Kuizhi; Pan, Sujuan; Zhuang, Xuemei; Lv, Hafei; Que, Shoulin; Xie, Shusen; Yang, Hongqin; Peng, Yiru

    2016-07-01

    1-2 generation poly(benzyl aryl ether) dendrimer silicon phthalocyanines with axially disubstituted cyano terminal functionalities (G n -DSiPc(CN)4 n , (G n = n-generation dendrimer, n = 1-2)) were synthesized. Their structures were characterized by elemental analysis, IR, 1H NMR, and ESI-MS. Polymeric nanoparticles (G n -DSiPc(CN)4 n /m) were formed through encapsulating G n -DSiPc(CN)4 n into three monomethoxyl poly(ethylene glycol)-poly(ɛ-caprolactone) diblock copolymers (MPEG-PCL) with different hydrophilic/hydrophobic proportion, respectively. The effect of dendritic generation and the hydrophilic/hydrophobic proportion of diblock copolymers on the UV/Vis and fluorescence spectra of G n -DSiPc(CN)4 n and G n -DSiPc(CN)4 n /m were studied. The photophysical properties of polymeric nanoparticles exhibited dendritic generation and hydrophilic/hydrophobic proportion dependence. The fluorescence intensities and lifetimes of G n -DSiPc(CN)4 n /m were lower than the corresponding free dendrimer phthalocyanines. G n -DSiPc(CN)4 n encapsulated into MPEG-PCL with hydrophilic/hydrophobic molecular weight ratio 2000:4000 exhibited excellent photophysical property. The mean diameter of MPEG2000-PCL2000 micelles was about 70 nm, which decreased when loaded with G n -DSiPc(CN)4 n .

  11. Functionalization of Block Copolymer Vesicle Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang Meier

    2011-01-01

    Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

  12. Amphiphilic block copolymers for biomedical applications

    Science.gov (United States)

    Zupancich, John Andrew

    Amphiphilic block copolymer self-assembly provides a versatile means to prepare nanoscale objects in solution. Control over aggregate shape is granted through manipulation of amphiphile composition and the synthesis of well-defined polymers offers the potential to produce micelles with geometries optimized for specific applications. Currently, polymer micelles are being investigated as vehicles for the delivery of therapeutics and attempts to increase efficacy has motivated efforts to incorporate bioactive ligands and stimuli-responsive character into these structures. This thesis reports the synthesis and self-assembly of biocompatible, degradable polymeric amphiphiles. Spherical, cylindrical, and bilayered vesicle structures were generated spontaneously by the direct dispersion of poly(ethylene oxide)-b-poly(gamma-methyl-ε-caprolactone) block copolymers in water and solutions were characterized with cryogenic transmission electron microscopy (cryo-TEM). The dependence of micelle structure on diblock copolymer composition was examined through the systematic variation of the hydrophobic block molecular weight. A continuous evolution of morphology was observed with coexistence of aggregate structures occurring in windows of composition intermediate to that of pure spheres, cylinders and vesicles. A number of heterobifunctional poly(ethylene oxide) polymers were synthesized for the preparation of ligand-functionalized amphiphilic diblock copolymers. The effect of ligand conjugation on block copolymer self-assembly and micelle morphology was also examined. An RGD-containing peptide sequence was efficiently conjugated to a set of well characterized poly(ethylene oxide)-b-poly(butadiene) copolymers. The reported aggregate morphologies of peptide-functionalized polymeric amphiphiles deviated from canonical structures and the micelle clustering, cylinder fragmentation, network formation, and multilayer vesicle generation documented with cryo-TEM was attributed to

  13. 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.)

  14. PDMS-modified poly(styrene-alt-maleic anhydride)s as water-borne coatings based on surfactant-free latexes

    NARCIS (Netherlands)

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

    2013-01-01

    In this work, two series of PDMS-modified poly(styrene-alt-maleic anhydride)s (PSMA) were prepared by the partial imidization of their anhydride groups with mono-functional, amine-terminated polydimethyl siloxanes (PDMS-NH2) with two different molecular weights. Subsequently, surfactant-free

  15. Dynamics of Block Copolymer Nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Mochrie, Simon G. J.

    2014-09-09

    A detailed study of the dynamics of cadmium sulfide nanoparticles suspended in polystyrene homopolymer matrices was carried out using X-ray photon correlation spectroscopy for temperatures between 120 and 180 °C. For low molecular weight polystyrene homopolymers, the observed dynamics show a crossover from diffusive to hyper-diffusive behavior with decreasing temperatures. For higher molecular weight polystyrene, the nanoparticle dynamics appear hyper-diffusive at all temperatures studied. The relaxation time and characteristic velocity determined from the measured hyper-diffusive dynamics reveal that the activation energy and underlying forces determined are on the order of 2.14 × 10-19 J and 87 pN, respectively. We also carried out a detailed X-ray scattering study of the static and dynamic behavior of a styrene– isoprene diblock copolymer melt with a styrene volume fraction of 0.3468. At 115 and 120 °C, we observe splitting of the principal Bragg peak, which we attribute to phase coexistence of hexagonal cylindrical and cubic double- gyroid structure. In the disordered phase, above 130 °C, we have characterized the dynamics of composition fluctuations via X-ray photon correlation spectroscopy. Near the peak of the static structure factor, these fluctuations show stretched-exponential relaxations, characterized by a stretching exponent of about 0.36 for a range of temperatures immediately above the MST. The corresponding characteristic relaxation times vary exponentially with temperature, changing by a factor of 2 for each 2 °C change in temperature. At low wavevectors, the measured relaxations are diffusive with relaxation times that change by a factor of 2 for each 8 °C change in temperature.

  16. Co-polymer Films for Sensors

    Science.gov (United States)

    Ryan, Margaret A. (Inventor); Jewell, April D. (Inventor); Taylor, Charles (Inventor); Yen, Shiao-Pin S. (Inventor); Kisor, Adam (Inventor); Manatt, Kenneth S. (Inventor); Blanco, Mario (Inventor); Goddard, William A. (Inventor); Homer, Margie L. (Inventor); Shevade, Abhijit V. (Inventor)

    2012-01-01

    Embodiments include a sensor comprising a co-polymer, the co-polymer comprising a first monomer and a second monomer. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is polystyrene and the second monomer is poly-2-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium benzylamine chloride. Other embodiments are described and claimed.

  17. Ordering phenomena in ABA triblock copolymer gels

    DEFF Research Database (Denmark)

    Reynders, K.; Mischenko, N.; Kleppinger, R.

    1997-01-01

    Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network). The lat......Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network...

  18. Synthesis and Properties of the Metallo-Supramolecular Polymer Hydrogel Poly[methyl vinyl ether-alt-mono-sodium maleate]∙AgNO3

    KAUST Repository

    Al-Dossary, Mona S.

    2014-05-01

    Gels are a special class of materials which are composed of 3D networks of crosslinked polymer chains that encapsulate liquid/air in the matrix. They can be classified into organogels or hydrogels (organic solvent for organogel and water for hydrogel). For hydrogels that contain metallic elements in the form of ions, the term of metallo-supramolecular polymer hydrogel (MSPHG) is often used. The aim of this project is to develop a kind of new MSPHG and investigate its properties and possible applications. The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-monosodium maleate) (PVM/Na-MA). By addition of AgNO3-solution, the formation of the silver(I) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]∙AgNO3 is obtained. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(I) cations. The supercritical CO2 dried silver(I) hydrogel was characterized by FT-IR, SEM-EDAX, TEM, TGA and Physical adsorption (BET) measurements. The intact silver(I) hydrogel was characterized by cryo-SEM. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(II) cations without disintegration of the hydrogel. The silver(I) hydrogel shows effective antibacterial activity and potential application as burn wound dressing.

  19. Block copolymer assisted self-assembly of nanoparticles into Langmuir–Blodgett films: Effect of polymer concentration

    International Nuclear Information System (INIS)

    Martín-García, Beatriz; Velázquez, M. Mercedes

    2013-01-01

    We propose to use the self-assembly ability of a block copolymer to obtain CdSe quantum dots (QDs) structures of different morphology. The methodology proposed consist in transferring mixed Langmuir monolayers of QDs and the polymer poly (styrene-co-maleic anhydride) partial 2 buthoxy ethyl ester cumene terminated, PS-MA-BEE onto mica by the Langmuir–Blodgett (LB) methodology. The morphology of the LB films was analyzed by AFM and TEM measurements. Our results show that it is possible to modulate the self-assembly process by modifying the composition of the mixed Langmuir monolayer precursor of the LB film. The different morphologies are interpreted according to two different dewetting mechanisms, growth of holes and spinodal-like dewetting. The growth of holes dewetting process is driven by gravitatory effects and was observed for LB films obtained by transferring Langmuir monolayer of the smallest elasticity values in which the polymer is in brush conformation. The spinodal dewetting mechanism prevailed when the Langmuir monolayer presents the highest elasticity values. - Graphical abstract: Display Omitted - Highlights: • Effect of the surface composition on the LB films architecture. • QDs/polymer LB films morphology interpreted in terms of dewetting mechanism. • The dewetting mechanism depends on the Langmuir monolayer state

  20. Block copolymer assisted self-assembly of nanoparticles into Langmuir–Blodgett films: Effect of polymer concentration

    Energy Technology Data Exchange (ETDEWEB)

    Martín-García, Beatriz; Velázquez, M. Mercedes, E-mail: mvsal@usal.es

    2013-08-15

    We propose to use the self-assembly ability of a block copolymer to obtain CdSe quantum dots (QDs) structures of different morphology. The methodology proposed consist in transferring mixed Langmuir monolayers of QDs and the polymer poly (styrene-co-maleic anhydride) partial 2 buthoxy ethyl ester cumene terminated, PS-MA-BEE onto mica by the Langmuir–Blodgett (LB) methodology. The morphology of the LB films was analyzed by AFM and TEM measurements. Our results show that it is possible to modulate the self-assembly process by modifying the composition of the mixed Langmuir monolayer precursor of the LB film. The different morphologies are interpreted according to two different dewetting mechanisms, growth of holes and spinodal-like dewetting. The growth of holes dewetting process is driven by gravitatory effects and was observed for LB films obtained by transferring Langmuir monolayer of the smallest elasticity values in which the polymer is in brush conformation. The spinodal dewetting mechanism prevailed when the Langmuir monolayer presents the highest elasticity values. - Graphical abstract: Display Omitted - Highlights: • Effect of the surface composition on the LB films architecture. • QDs/polymer LB films morphology interpreted in terms of dewetting mechanism. • The dewetting mechanism depends on the Langmuir monolayer state.

  1. Radiolytic decomposition of 4-bromodiphenyl ether

    International Nuclear Information System (INIS)

    Tang Liang; Xu Gang; Wu Wenjing; Shi Wenyan; Liu Ning; Bai Yulei; Wu Minghong

    2010-01-01

    Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of e sol - in the reduction system was measured at 2.7 x 10 10 L · mol -1 · s -1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing e sol - in radiolytic process. (authors)

  2. Molecular Interaction Control in Diblock Copolymer Blends and Multiblock Copolymers with Opposite Phase Behaviors

    Science.gov (United States)

    Cho, Junhan

    2014-03-01

    Here we show how to control molecular interactions via mixing AB and AC diblock copolymers, where one copolymer exhibits upper order-disorder transition and the other does lower disorder-order transition. Linear ABC triblock copolymers possessing both barotropic and baroplastic pairs are also taken into account. A recently developed random-phase approximation (RPA) theory and the self-consistent field theory (SCFT) for general compressible mixtures are used to analyze stability criteria and morphologies for the given systems. It is demonstrated that the copolymer systems can yield a variety of phase behaviors in their temperature and pressure dependence upon proper mixing conditions and compositions, which is caused by the delicate force fields generated in the systems. We acknowledge the financial support from National Research Foundation of Korea and Center for Photofunctional Energy Materials.

  3. Model for Photodegradation of Polybrominated Diphenyl Ethers

    Czech Academy of Sciences Publication Activity Database

    Veselý, M.; Vajglová, Zuzana; Kotas, Petr; Křišťál, Jiří; Ponec, Robert; Jiřičný, Vladimír

    2015-01-01

    Roč. 22, č. 7 (2015), s. 4949-4963 ISSN 0944-1344 R&D Projects: GA ČR GA104/09/0880; GA ČR(CZ) GAP105/12/0664 Institutional support: RVO:67985858 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * photodegradation model * quantum chemical calculation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.760, year: 2015

  4. 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

  5. Nikola Tesla, the Ether and his Telautomaton

    Science.gov (United States)

    Milar, Kendall

    2014-03-01

    In the nineteenth century physicists' understanding of the ether changed dramatically. New developments in thermodynamics, energy physics, and electricity and magnetism dictated new properties of the ether. These have traditionally been examined from the perspective of the scientists re-conceptualizing the ether. However Nikola Tesla, a prolific inventor and writer, presents a different picture of nineteenth century physics. Alongside the displays that showcased his inventions he presented alternative interpretations of physical, physiological and even psychical research. This is particularly evident in his telautomaton, a radio remote controlled boat. This invention and Tesla's descriptions of it showcase some of his novel interpretations of physical theories. He offered a perspective on nineteenth century physics that focused on practical application instead of experiment. Sometimes the understanding of physical theories that Tesla reached was counterproductive to his own inventive work; other times he offered new insights. Tesla's utilitarian interpretation of physical theories suggests a more scientifically curious and invested inventor than previously described and a connection between the scientific and inventive communities.

  6. Shear instability of a gyroid diblock copolymer

    DEFF Research Database (Denmark)

    Eskimergen, Rüya; Mortensen, Kell; Vigild, Martin Etchells

    2005-01-01

    -induced destabilization is discussed in relation to analogous observations on shear-induced order-to-order and disorder-to-order transitions observed in related block copolymer systems and in microemulsions. It is discussed whether these phenomena originate in shear-reduced fluctuations or shear-induced dislocations....

  7. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  8. Substrate tolerant direct block copolymer nanolithography

    DEFF Research Database (Denmark)

    Li, Tao; Wang, Zhongli; Schulte, Lars

    2016-01-01

    Block copolymer (BC) self-assembly constitutes a powerful platform for nanolithography. However, there is a need for a general approach to BC lithography that critically considers all the steps from substrate preparation to the final pattern transfer. We present a procedure that significantly sim...... plasma treatment enables formation of the oxidized PDMS hard mask, PS block removal and polymer or graphene substrate patterning....

  9. Micellization and Characterization of Block Copolymer Detergents

    DEFF Research Database (Denmark)

    Hvidt, Søren

    and different models have been proposed. Results obtained by a range of liquid chromatographic methods will be shown and it will be demonstrated that commercial EPE copolymers are inhomogeneous at several levels and many of their unusual properties reflect the presence of impurities....

  10. Cyclic olefin copolymer-silica nanocomposites foams

    Czech Academy of Sciences Publication Activity Database

    Pegoretti, A.; Dorigato, A.; Biani, A.; Šlouf, Miroslav

    2016-01-01

    Roč. 51, č. 8 (2016), s. 3907-3916 ISSN 0022-2461 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : cyclic olefin copolymer * nanocomposites * silica Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.599, year: 2016

  11. 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

  12. Preparation and Characterization of Sulfonic Acid Functionalized Silica and Its Application for the Esterification of Ethanol and Maleic Acid

    Science.gov (United States)

    Sirsam, Rajkumar; Usmani, Ghayas

    2016-04-01

    The surface of commercially available silica gel, 60-200 mesh size, was modified with sulfonic acid through surface activation, grafting of 3-Mercaptopropyltrimethoxysilane, oxidation and acidification of 3-Mercaptopropylsilica. Sulfonic Acid Functionalization of Silica (SAFS) was confirmed by Fourier Transform Infra-red (FTIR) spectroscopy and thermal gravimetric analysis. Acid-base titration was used to estimate the cation exchange capacity of the SAFS. Catalytic activity of SAFS was judged for the esterification of ethanol with maleic acid. An effect of different process parameters viz. molar ratio, catalyst loading, speed of agitation and temperature were studied and optimized by Box Behnken Design (BBD) of Response Surface Methodology (RSM). Quadratic model developed by BBD-RSM reasonably satisfied an experimental and predicted values with correlation coefficient value R2 = 0.9504.

  13. 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

  14. 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)

  15. 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.)

  16. Research Update: Triblock copolymers as templates to synthesize inorganic nanoporous materials

    OpenAIRE

    Yunqi Li; Bishnu Prasad Bastakoti; Yusuke Yamauchi

    2016-01-01

    This review focuses on the application of triblock copolymers as designed templates to synthesize nanoporous materials with various compositions. Asymmetric triblock copolymers have several advantages compared with symmetric triblock copolymers and diblock copolymers, because the presence of three distinct domains can provide more functional features to direct the resultant nanoporous materials. Here we clearly describe significant contributions of asymmetric triblock copolymers, especially p...

  17. 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 ...

  18. Preliminary Investigation of Poly-Ether-Ether-Ketone Based on Fused Deposition Modeling for Medical Applications

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2018-02-01

    Full Text Available Poly-ether-ether-ketone (PEEK fabricated by fused deposition modeling for medical applications was evaluated in terms of mechanical strength and in vitro cytotoxicity in this study. Orthogonal experiments were firstly designed to investigate the significant factors on tensile strength. Nozzle temperature, platform temperature, and the filament diameter were tightly controlled for improved mechanical strength performance. These sensitive parameters affected the interlayer bonding and solid condition in the samples. Fourier transform infrared (FTIR spectrometry analysis was secondly conducted to compare the functional groups in PEEK granules, filaments, and printed parts. In vitro cytotoxicity test was carried out at last, and no toxic substances were introduced during the printing process.

  19. Synthesis and characteristics of polyarylene ether sulfones

    Science.gov (United States)

    Viswanathan, R.; Johnson, B. C.; Ward, T. C.; Mcgrath, J. E.

    1981-01-01

    A method utilizing potassium carbonate/dimethyl acetamide, as base and solvent respectively, was used for the synthesis of several homopolymers and copolymers derived from various bisphenols. It is demonstrated that this method deviates from simple second order kinetics; this deviation being due to the heterogeneous nature of the reaction. Also, it is shown that a liquid induced crystallization process can improve the solvent resistance of these polymers. Finally, a Monte Carlo simulation of the triad distribution of monomers in nonequilibrium copolycondensation is discussed.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. An Exposure Assessment of Polybrominated Diphenyl Ethers ...

    Science.gov (United States)

    EPA announced the availability of the final report, An Exposure Assessment of Polybrominated Diphenyl Ethers. This report provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure. This final report addresses the exposure assessment needs identified in the OPBDE Workgroup project plan. It provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure.

  6. Copper Promoted Synthesis of Diaryl Ethers

    OpenAIRE

    Ghosh, Rajshekhar; Samuelson, Ashoka G

    2004-01-01

    An efficient protocol using copper based reagents for the coupling of aryl halides with phenols to generate diaryl ethers is described. Acopper( I) complex, [ Cu( CH3CN) (4)] ClO4, or the readily available copper( II) source, CuCO3 . Cu( OH) (2) . H2O ( in combination with potassium phosphate), can be used. Aryl halides and phenols with different steric and electronic demands have been used to assess the efficiency of the procedure. The latter source of copper gives better yields under all co...

  7. Gamma-radiolysis of benzosubstituted crown ethers

    International Nuclear Information System (INIS)

    Grigor'ev, E.I.; Nesterov, S.V.; Mikhalitsyna, O.V.; Trakhtenberg, L.I.; Myasoedova, T.G.

    1992-01-01

    The products of gamma-radiolysis of benzosubstituted crown ethers, which are distiguished by the size of polyether ring, and alkylsubstituted DB18C6 are studied by the methods of ESR and mass-spectrometry. A mechanism of the radiolysis of the radiolysis of the studied compounds in the solid phase is proposed. It is shown that the prinicple radiolysis process is the rupture of C-O bond resulting in the stabilization of H atoms from group -CH 2 - of polyether ring is realized with a lower probability

  8. Phase behavior of model ABC triblock copolymers

    Science.gov (United States)

    Chatterjee, Joon

    The phase behavior of poly(isoprene-b-styrene- b-ethylene oxide) (ISO), a model ABC triblock copolymer has been studied. This class of materials exhibit self-assembly, forming a large array of ordered morphologies at length scales of 5-100 nm. The formation of stable three-dimensionally continuous network morphologies is of special interest in this study. Since these nanostructures considerably impact the material properties, fundamental knowledge for designing ABC systems have high technological importance for realizing applications in the areas of nanofabrication, nanoporous media, separation membranes, drug delivery and high surface area catalysts. A comprehensive framework was developed to describe the phase behavior of the ISO triblock copolymers at weak to intermediate segregation strengths spanning a wide range of composition. Phases were characterized through a combination of characterization techniques, including small angle x-ray scattering, dynamic mechanical spectroscopy, transmission electron microscopy, and birefringence measurements. Combined with previous investigations on ISO, six different stable ordered state symmetries have been identified: lamellae (LAM), Fddd orthorhombic network (O70), double gyroid (Q230), alternating gyroid (Q214), hexagonal (HEX), and body-centered cubic (BCC). The phase map was found to be somewhat asymmetric around the fI = fO isopleth. This work provides a guide for theoretical studies and gives insight into the intricate effects of various parameters on the self-assembly of ABC triblock copolymers. Experimental SAXS data evaluated with a simple scattering intensity model show that local mixing varies continuously across the phase map between states of two- and three-domain segregation. Strategies of blending homopolymers with ISO triblock copolymer were employed for studying the swelling properties of a lamellar state. Results demonstrate that lamellar domains swell or shrink depending upon the type of homopolymer that

  9. Poly (fluorenyl ether ketone) ionomers containing separated hydrophilic multiblocks used in fuel cells as proton exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, H.; Xiao, M.; Wang, S.J.; Meng, Y.Z. [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); The Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Sun Yat-Sen University, Guangzhou 510275 (China)

    2010-01-15

    A series of sulfonated poly(fluorenyl ether ketone) with different hydrophilic block lengths were synthesized via a two-step one-pot polymerization from 9,9'-bis(4-Hydroxypheyl) fluorine, 3,3'-disulfonated-4,4'-difluorobenzophenone, and 4,4'-difluorobenzophenone. The resulting sulfonated block polymers with high inherent viscosity (0.8-1.37 dL/g) were very soluble in polar organic solvents and can form flexible and transparent membranes by casting from their solutions. Transmission electron microscope (TEM) was used to examine the microstructure of the membranes and the results revealed that significant hydrophilic/hydrophobic microphase separation was produced. The effects of the multiblock structure and/or length were investigated by comparison of the properties of the multiblock copolymer and the corresponding random structure. The multiblock structure can provide enhanced proton transport, especially under partially hydrated conditions. The as-made membranes can also exhibit better oxidative stability and single cell performance than random copolymer. The multiblock structure design method provides a useful way to prepare proton exchange membrane used in PEM fuel cells. (author)

  10. Sulfonated poly(fluorenyl ether ketone nitrile) electrolyte membrane with high proton conductivity and low water uptake

    Energy Technology Data Exchange (ETDEWEB)

    Tian, S.H.; Wang, S.J.; Xiao, M.; Meng, Y.Z. [State Key Laboratory of Optoelectronic Materials and Technologies/Institute of Optoelectronic and Functional Composite Materials, Sun Yat-sen University, Guangzhou 510275 (China); Shu, D. [School of Chemistry and Environmental, South China Normal University, Guangzhou 510006 (China)

    2010-01-01

    High molecular weight sulfonated poly(fluorenyl ether ketone nitrile)s with different equivalent weight (EW) from 681 to 369 g mequiv.{sup -1} are synthesized by the nucleophilic substitution polycondensation of various amounts of sulfonated difluorobenzophenone (SDFBP) and 2,6-difluorobenzonitrile (DFBN) with bisphenol fluorene (BPF). The synthesized copolymers are characterized by {sup 1}H NMR, FT-IR, TGA, and DSC techniques. The membranes cast from the corresponding copolymers exhibit superior thermal stability, good oxidative stability and high proton conductivity, but low water uptake due to the strong nitrile dipole interchain interactions that combine to limit swelling. Among all the membranes, the membrane with EW of 441 g mequiv.{sup -1} shows optimum properties of both high proton conductivity of 41.9 mS cm{sup -1} and low water uptake of 42.6%. Accordingly, That membrane is fabricated into a membrane electrode assembly (MEA) and evaluated in a single proton exchange membrane fuel cell (PEMFC). The experimental results indicate its similar cell performance as that of Nafion {sup registered} 117 at 70 C, but much better cell performance at higher temperatures. At the potential of 0.6 V, the current density of fuel cell using the prepared membrane and Nafion {sup registered} 117 is 0.46 and 0.25 A cm{sup -2}, respectively. The highest current density of the former reaches as high as 1.25 A cm{sup -2}. (author)

  11. Preparation and characterization of novel zwitterionic poly(arylene ether sulfone) ultrafiltration membrane with good thermostability and excellent antifouling properties

    Science.gov (United States)

    Rong, Guolong; Zhou, Di; Han, Xiaocui; Pang, Jinhui

    2018-01-01

    Zwitterionic poly(arylene ether sulfone) (PAES-NS) was synthesized via copolymerization by using a bisphenol monomer with a pyridine group. The chemical structures of the copolymers were confirmed by using Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectroscopy; the copolymers showed good thermal stability. A series of polyphenysulfone (PPSU)/PAES-NS blend ultrafiltration (UF) membranes was prepared via conventional immersion precipitation phase inversion methods The morphologies of the modified membranes were investigated by scanning electron microscopy (SEM). The surface hydrophilicity of the UF membranes was studied by water contact angle measurement, indicating that the zwitterionic group increased the membrane hydrophilicity. UF of solvated model pollutants using the membranes showed a significant reduction of the irreversible adsorption of the foulants, illustrating the excellent anti-fouling properties of the membrane. The water flux of the PAES-NS membrane was significantly enhanced, being almost three times higher than that of the pristine PPSU membrane, with retention of a high rejection level. After three UF cycles, the water flux recovery of the PAES-NS membrane was as high as 96%.

  12. Renewable Pentablock Copolymers Containing Bulky Natural Rosin for Tough Bioplastics

    Science.gov (United States)

    Rahman, Md Anisur; Ganewatta, Mitra S.; Lokupitiya, Hasala N.; Liang, Yuan; Stefik, Morgan; Tang, Chuanbing

    Renewable polymers have received significant attention due to environmental concerns on petrochemical counterparts. One of the most abundant natural biomass is resin acids. However, most polymers derived from resin acids are low molecular weight and brittle because of the high chain entanglement molecular weight resulted from the bulky hydrophenanthrene pendant group. It is well established that the brittleness can be overcome by synthesizing multi-block copolymers with low entanglement molecular weight components. We investigated the effects of chain architecture and microdomain orientation on mechanical properties of both tri and pentablock copolymers. We synthesized rosin-containing A-B-A-B-A type pentablock and A-B-A type triblock copolymers to improve their mechanical properties. Pentablock copolymers showed higher strength and better toughness as compared to triblock copolymers, both superior to homopolymers. The greater toughness of pentablock copolymers is due to the presence of the rosin based midblock chains that act as bridging chains between two polynorbornene blocks.

  13. 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)

  14. Antibacterial modification of an injectable, biodegradable, non-cytotoxic block copolymer-based physical gel with body temperature-stimulated sol-gel transition and controlled drug release.

    Science.gov (United States)

    Wang, Xiaowen; Hu, Huawen; Wang, Wenyi; Lee, Ka I; Gao, Chang; He, Liang; Wang, Yuanfeng; Lai, Chuilin; Fei, Bin; Xin, John H

    2016-07-01

    Biomaterials are being extensively used in various biomedical fields; however, they are readily infected with microorganisms, thus posing a serious threat to the public health care. We herein presented a facile route to the antibacterial modification of an important A-B-A type biomaterial using poly (ethylene glycol) methyl ether (mPEG)- poly(ε-caprolactone) (PCL)-mPEG as a typical model. Inexpensive, commercial bis(2-hydroxyethyl) methylammonium chloride (DMA) was adopted as an antibacterial unit. The effective synthesis of the antibacterial copolymer mPEG-PCL-∼∼∼-PCL-mPEG (where ∼∼∼ denotes the segment with DMA units) was well confirmed by FTIR and (1)H NMR spectra. At an appropriate modification extent, the DMA unit could render the copolymer mPEG-PCL-∼∼∼-PCL-mPEG highly antibacterial, but did not largely alter its fascinating intrinsic properties including the thermosensitivity (e.g., the body temperature-induced sol-gel transition), non-cytotoxicity, and controlled drug release. A detailed study on the sol-gel-sol transition behavior of different copolymers showed that an appropriate extent of modification with DMA retained a sol-gel-sol transition, despite the fact that a too high extent caused a loss of sol-gel-sol transition. The hydrophilic and hydrophobic balance between mPEG and PCL was most likely broken upon a high extent of quaternization due to a large disturbance effect of DMA units at a large quantity (as evidenced by the heavily depressed PCL segment crystallinity), and thus the micelle aggregation mechanism for the gel formation could not work anymore, along with the loss of the thermosensitivity. The work presented here is highly expected to be generalized for synthesis of various block copolymers with immunity to microorganisms. Light may also be shed on understanding the phase transition behavior of various multiblock copolymers. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. 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.

  16. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    OpenAIRE

    Hoarfrost, Megan Lane

    2012-01-01

    Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the additio...

  17. Synthesis and Properties of Poly(ether sulfone)s with Clustered Sulfonic Groups for PEMFC Applications under Various Relative Humidity.

    Science.gov (United States)

    Lee, Shih-Wei; Chen, Jyh-Chien; Wu, Jin-An; Chen, Kuei-Hsien

    2017-03-22

    Novel sulfonated poly(ether sulfone) copolymers (S4PH-x-PSs) based on a new aromatic diol containing four phenyl substituents at the 2, 2', 6, and 6' positions of 4,4'-diphenyl ether were synthesized. Sulfonation was found to occur exclusively on the 4 position of phenyl substituents by NMR spectroscopy. The ion exchange capacity (IEC) values can be controlled by adjusting the mole percent (x in S4PH-x-PS) of the new diol. The fully hydrated sulfonated poly(ether sulfone) copolymers had good proton conductivity in the range 0.004-0.110 S/cm at room temperature. The surface morphology of S4PH-x-PSs and Nafion 212 was investigated by atomic force microscopy (tapping-mode) and related to the percolation limit and proton conductivity. Single H 2 /O 2 fuel cell based on S4PH-40-PS loaded with 0.25 mg/cm 2 catalyst (Pt/C) exhibited a peak power density of 462.6 mW/cm 2 , which was close to that of Nafion 212 (533.5 mW/cm 2 ) at 80 °C with 80% RH. Furthermore, fuel cell performance of S4PH-35-PS with various relative humidity was investigated. It was confirmed from polarization curves that the fuel cell performance of S4PH-35-PS was not as high as that of Nafion 212 under fully hydrated state due to higher interfacial resistance between S4PH-35-PS and electrodes. While under low relative humidity (53% RH) at 80 °C, fuel cells based on S4PH-35-PS showed higher peak power density (234.9 mW/cm 2 ) than that (214.0 mW/cm 2 ) of Nafion 212.

  18. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

    Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

  19. Rapid ordering of block copolymer thin films

    International Nuclear Information System (INIS)

    Majewski, Pawel W; Yager, Kevin G

    2016-01-01

    Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times—hours or days—required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems. (topical review)

  20. Nanostructured Polysulfone-Based Block Copolymer Membranes

    KAUST Repository

    Xie, Yihui

    2016-05-01

    The aim of this work is to fabricate nanostructured membranes from polysulfone-based block copolymers through self-assembly and non-solvent induced phase separation. Block copolymers containing polysulfone are novel materials for this purpose providing better mechanical and thermal stability to membranes than polystyrene-based copolymers, which have been exclusively used now. Firstly, we synthesized a triblock copolymer, poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) through polycondensation and reversible addition-fragmentation chain-transfer polymerization. The obtained membrane has a highly porous interconnected skin layer composed of elongated micelles with a flower-like arrangement, on top of the graded finger-like macrovoids. Membrane surface hydrolysis was carried out in a combination with metal complexation to obtain metal-chelated membranes. The copper-containing membrane showed improved antibacterial capability. Secondly, a poly(acrylic acid)-b-polysulfone-b-poly(acrylic acid) triblock copolymer obtained by hydrolyzing poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) formed a thin film with cylindrical poly(acrylic acid) microdomains in polysulfone matrix through thermal annealing. A phase inversion membrane was prepared from the same polymer via self-assembly and chelation-assisted non-solvent induced phase separation. The spherical micelles pre-formed in a selective solvent mixture packed into an ordered lattice in aid of metal-poly(acrylic acid) complexation. The space between micelles was filled with poly(acrylic acid)-metal complexes acting as potential water channels. The silver0 nanoparticle-decorated membrane was obtained by surface reduction, having three distinct layers with different particle sizes. Other amphiphilic copolymers containing polysulfone and water-soluble segments such as poly(ethylene glycol) and poly(N-isopropylacrylamide) were also synthesized through coupling reaction and copper0-mediated

  1. The Ether Wind and the Global Positioning System.

    Science.gov (United States)

    Muller, Rainer

    2000-01-01

    Explains how students can perform a refutation of the ether theory using information from the Global Positioning System (GPS). Discusses the functioning of the GPS, qualitatively describes how position determination would be affected by an ether wind, and illustrates the pertinent ideas with a simple quantitative model. (WRM)

  2. 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.)

  3. Influence of structure of crown ethers on their radiation stability

    International Nuclear Information System (INIS)

    Grigor'ev, E.I.; Myasoedova, T.G.; Nesterov, S.V.; Trakhtenberg, L.I.

    1988-01-01

    Primary products of γ-radiolysis of crown ethers with the same size of the macrocyclic ring and different substituents were studied by EPR and mass spectrometry. It was shown that introduction of substituents into the polyether ring increases the radiation stability of crown ethers due to intramolecular transfer of energy from the polyether ring to a substituent

  4. Congenital malformations and maternal occupational exposure to glycol ethers

    NARCIS (Netherlands)

    Cordier, S; Bergeret, A; Goujard, J; Ha, MC; Ayme, S; Calzolari, E; DeWalle, HEK; KnillJones, R; Candela, S; Dale, [No Value; Dananche, B; deVigan, C; Fevotte, J; Kiel, G; Mandereau, L

    Glycol ethers are found in a wide range of domestic and industrial products, many of which are used in women's work environments. Motivated by concern about their potential reproductive toxicity, we have evaluated the risk of congenital malformations related to glycol ether exposure during preg

  5. Application of simplified PC-SAFT to glycol ethers

    DEFF Research Database (Denmark)

    Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2012-01-01

    The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2...

  6. SANS study of coated block copolymer micelles

    Czech Academy of Sciences Publication Activity Database

    Pleštil, Josef; Kříž, Jaroslav; Koňák, Čestmír; Pospíšil, Herman; Kadlec, Petr; Sedláková, Zdeňka; Grillo, I.; Cubitt, R.

    2005-01-01

    Roč. 206, č. 12 (2005), s. 1206-1215 ISSN 1022-1352 R&D Projects: GA ČR GA203/03/0600; GA AV ČR IAA1050201; GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z40500505 Keywords : block copolymer micelles * core-shell polymers * nanoparticles Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.111, year: 2005

  7. Increased radiation degradation in methyl methacrylate copolymers

    International Nuclear Information System (INIS)

    Helbert, J.N; Wagner, G.E.; Caplan, P.J.; Poindexter, E.H.

    1975-01-01

    The effect of polar substituents at the quaternary carbon on degradation processes in several polymers and 10 to 20 percent copolymers of methyl methacrylate was explored. EPR was used to monitor radiation degradation products and to determine radiation G values. Irradiations were carried out at 77 0 K in a gamma irradiator at a dose rate of 0.3 Mrad/hr. (U.S.)

  8. 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.

  9. 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.

  10. 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

  11. 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.%

  12. Evaluation of genotoxic activity of maleic hydrazide, ethyl methane sulfonate, and N-nitroso diethylamine in Tradescantia.

    Science.gov (United States)

    Alvarez-Moya, C; Santerre-Lucas, A; Zúñiga-González, G; Torres-Bugarín, O; Padilla-Camberos, E; Feria-Velasco, A

    2001-01-01

    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). 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 (NDEA) at 1, 5, 10 mM, maleic hydrazide (MH) at 1, 5, 10 mM and ethyl methane sulfonate (EMS) at 15, 30 and 45 mM; and used in both pink mutation assay and comet assay using cellular nuclei from Tradescantia staminal hairs. The observation of staminal hair was realized along eight days (6-14) after treatment), flowers produced day 14 after treatment were utilized done according to Underbrink. In previous reports on plants, were comet assay was used, breaking cellular wall and separating by centrifugation gradient are necessary. Here, nuclei from staminal hairs were obtained by squashing the cells (is not necessary to utilize to break special procedure cellular wall), collected using a nylon mesh of 80 Mm and next the comet assay was applied. Student's T test was the statistical test used for analyzing the comet assay data. Both assays showed a great sensitivity to the studied mutagens. A relationship between the dose-pink event and the dose-tail length was evident. Even though the Tradescantia mutation assay is a sensitive test with MH and EMS, low doses of NDEA were not able to induce a significant increase in the pink event frequencies; however, the comet assay was able to detect the mutagenic effect of NDEA at the same dose. Thus, it is clear that the comet assay is highly sensitive to the lowest dose of chemical mutagens. The comet assay on nuclei from Tradescantia staminal hairs is a useful tool to monitor genotoxic agents; it is simple, highly sensitive, and faster than the pink mutation test.

  13. Evaluation of genotoxic activity of maleic hydrazide, ethyl methane sulfonate, and N-nitroso diethylamine in Tradescantia

    Directory of Open Access Journals (Sweden)

    Alvarez-Moya Carlos

    2001-01-01

    Full Text Available 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 (NDEA at 1, 5, 10 mM, maleic hidrazide (MH at 1, 5, 10 mM and ethyl methane sulfonate (EMS at 15, 30 and 45 mM; and used in both pink mutation assay and comet assay using cellular nuclei from Tradescantia staminal hairs. The observation of staminal hair was realized along eight days (6-14 after treatment, flowers produced day 14 after treatment were utilized done according to Underbrink. In previous reports on plants, were comet assay was used, breaking cellular wall and separating by centrifugation gradient are necessary. Here, nuclei from staminal hairs were obtained by squashing the cells (is not necessary to utilize to break special procedure cellular wall, collected using a nylon mesh of 80Mm and next the comet assay was applied. Student's T test was the statistical test used for analyzing the comet assay data. Results. Both assays showed a great sensitivity to the studied mutagens. A relationship between the dose-pink event and the dose-tail length was evident. Even though the Tradescantia mutation assay is a sensitive test with MH and EMS, low doses of NDEA were not able to induce a significant increase in the pink event frequencies; however, the comet assay was able to detect the mutagenic effect of NDEA at the same dose. Thus, it is clear that the comet assay is highly sensitive to the lowest dose of chemical mutagens. Conclusions. The comet assay on nuclei from Tradescantia staminal hairs is a useful tool to monitor genotoxic agents; it is simple

  14. Fluorinated poly(ether sulfone) ionomers with disulfonated naphthyl pendants for proton exchange membrane applications

    Science.gov (United States)

    Hu, Zhaoxia; Lu, Yao; Zhang, Xulve; Yan, Xiaobo; Li, Na; Chen, Shouwen

    2018-06-01

    Proton exchange membranes based on fluorinated poly(ether sulfone)s with disulfonated naphthyl pendants (sSPFES) have been successfully prepared by post functionalization through polymeric SNAr reaction. Copolymer structure was confirmed by H-nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy, the physico-chemical properties of the sSPFES membranes were evaluated by thermogravimetric analysis, gel permeation chromatography, electro-chemical impedance spectroscopy, atomic force microscopy, Fenton, water-swelling and fuel cell test. The pendant grafting degree was controlled by varying the feeding amount of the disulfonaphthols, resulting in the ion exchange capacity about 1.28-1.73 mmol/g. The obtained sSPFES membranes were thermal stable, mechanical ductile, and exhibited dimensional change less than 17%, water uptake below 70%, and proton conductivity as high as 0.17-0.28 S/cm at 90°C in water. In a single H2/O2 fuel cell test at 80°C, the sSPFES-B-3.2 membrane (1.61 mmol/g) showed the maximum power output of 593-658 mW/cm2 at 60%-80% relative humidity, indicating their rather promising potential for fuel cell applications.

  15. Hydroperoxide Traces in Common Cyclic Ethers as Initiators for Controlled RAFT Polymerizations.

    Science.gov (United States)

    Eggers, Steffen; Abetz, Volker

    2018-04-01

    Herein, a reversible addition-fragmentation chain transfer (RAFT) polymerization is introduced for reactive monomers like N-acryloylpyrrolidine or N,N-dimethylacrylamide working without a conventional radical initiator. As a very straightforward proof of principle, the method takes advantage of the usually inconvenient radical-generating hydroperoxide contaminations in cyclic ethers like tetrahydrofuran or 1,4-dioxane, which are very common solvents in polymer sciences. The polymerizations are surprisingly well controlled and the polymers can be extended with a second block, indicating their high livingness. "Solvent-initiated" RAFT polymerizations hence prove to be a feasible access to tailored materials with minimal experimental effort and standard laboratory equipment, only requiring the following ingredients: hydroperoxide-contaminated solvent, monomer, and RAFT agent. In other respects, however, the potential coinitiating ability of the used solvent is to be considered when investigating the kinetics of RAFT polymerizations or aiming for the synthesis of high-livingness polymers, e.g., multiblock copolymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Structuring of poly ether ether ketone by ArF excimer laser radiation in different atmospheres

    International Nuclear Information System (INIS)

    Feng, Y.; Gottmann, J.; Kreutz, E.W.

    2003-01-01

    Structuring of poly ether ether ketone (PEEK) by 193 nm ArF excimer laser radiation has been investigated. Experiments were carried out in different atmospheres (air, vacuum, Ar, O 2 ) in order to study its influence on the quality of the structures and the formation of the debris. Repetition rate makes little effect on the ablation rate and roughness of the structure in presence of any kind of atmosphere, indicating for the structuring of PEEK by ArF laser radiation a large window of processing. The roughness at the bottom of the structures and the morphology of the side walls are strongly affected by the properties of the atmosphere. The smallest roughness is achieved at 0.6 J/cm 2 for all kinds of processing gases. Debris around the structures can be diminished by structuring in vacuum. Plasma expansion speed has been measured by using high speed photography

  17. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

    2011-01-01

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang, E-mail: wolfgang.bacsa@cemes.fr [CEMES-CNRS and University of Toulouse, 29 Jeanne Marvig, 31055 Toulouse (France); Boyer, François; Olivier, Philippe [Université de Toulouse, Institut Clément Ader, I.U.T. Université Paul Sabatier - 133C Avenue de Rangueil - B.P. 67701, 31077 Toulouse CEDEX 4 (France); Sapelkin, Andrei [School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, E1 4NS London (United Kingdom); King, Stephen; Heenan, Richard [ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot (United Kingdom); Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri [AIRBUS FRANCE (B.E. M and P Toulouse), 316 Route de Bayonne, 31060 Toulouse (France)

    2014-06-21

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

  20. 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

  1. Poly (ether ether ketone) derivatives: Synthetic route and characterization of nitrated and sulfonated polymers

    International Nuclear Information System (INIS)

    Conceicao, T.F.; Bertolino, J.R.; Barra, G.M.O.; Pires, A.T.N.

    2009-01-01

    Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 deg. C. The substitution degree was obtained through the TG curves, and values were in agreement with 1 H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10 -2 S cm -1 , an important characteristic in some applications, such as in fuel cells

  2. Characterization of melt-blended graphene – poly(ether ether ketone) nanocomposite

    International Nuclear Information System (INIS)

    Tewatia, Arya; Hendrix, Justin; Dong, Zhizhong; Taghon, Meredith; Tse, Stephen; Chiu, Gordon; Mayo, William E.; Kear, Bernard; Nosker, Thomas; Lynch, Jennifer

    2017-01-01

    Using a high shear melt-processing method, graphene-reinforced polymer matrix composites (G-PMCs) were produced with good distribution and particle–matrix interaction of bi/trilayer graphene at 2 wt. % and 5 wt. % in poly ether ether ketone (2Gn-PEEK and 5Gn-PEEK). The morphology, structure, thermal properties, and mechanical properties of PEEK, 2Gn-PEEK and 5 Gn-PEEK were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), flexural mechanical testing, and dynamic mechanical analysis (DMA). Addition of graphene to PEEK induces surface crystallization, increased percent crystallinity, offers a composite that is thermally stable until 550 °C and enhances thermomechanical properties. Results show that graphene was successfully melt-blended within PEEK using this method.

  3. Analysis of electron-irradiated poly-ether ether ketone by X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Oyabu, Matashige; Kobayashi, Yoshinori; Seguchi, Tadao; Sasuga, Tsuneo; Kudoh, Hisaaki.

    1995-01-01

    Organic polymers used in atomic power plants or space are damaged by ionizing irradiation. Radicals produced by irradiation cause oxidation, chain scission and crosslinking, all of which lead to degradation of the material. In this paper, the surface of electron-irradiated poly-ether ether ketone (PEEK) was studied by X-ray photoelectron spectroscopy (XPS). The irradiation in air was found to oxidize the PEEK surface producing carboxyl groups, the content of which dependant on the dose. Carboxyl groups were not produced in helium gas. Quantitative spectral analysis indicated that the aromatic structure might be decomposed. Some comparison was made between the semicrystalline and amorphous samples. The oxygen content resulting from irradiation, of semicrystalline PEEK increased more than that of amorphous PEEK. (author)

  4. Enhanced osteogenic activity of poly ether ether ketone using calcium plasma immersion ion implantation.

    Science.gov (United States)

    Lu, Tao; Qian, Shi; Meng, Fanhao; Ning, Congqin; Liu, Xuanyong

    2016-06-01

    As a promising implantable material, poly ether ether ketone (PEEK) possesses similar elastic modulus to that of cortical bones yet suffers from bio-inertness and poor osteogenic properties, which limits its application as orthopedic implants. In this work, calcium is introduced onto PEEK surface using calcium plasma immersion ion implantation (Ca-PIII). The results obtained from scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirm the modified layer with varying contents of calcium are formed on PEEK surfaces. Water contact angle measurements reveal the increasing hydrophobicity of both Ca-PIII treated surfaces. In vitro cell adhesion, viability assay, alkaline phosphatase activity and collagen secretion analyses disclose improved the adhesion, proliferation, and osteo-differentiation of rat bone mesenchymal stem cells (bMSCs) on Ca-PIII treated surfaces. The obtained results indicate that PEEK surface with enhanced osteogenic activity can be produced by calcium incorporation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Characterization of melt-blended graphene – poly(ether ether ketone) nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Tewatia, Arya; Hendrix, Justin [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States); Dong, Zhizhong [Department of Mechanical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854 (United States); Taghon, Meredith [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States); Tse, Stephen [Department of Mechanical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854 (United States); Chiu, Gordon; Mayo, William E.; Kear, Bernard; Nosker, Thomas [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States); Lynch, Jennifer, E-mail: jklynch@rci.rutgers.edu [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States)

    2017-02-15

    Using a high shear melt-processing method, graphene-reinforced polymer matrix composites (G-PMCs) were produced with good distribution and particle–matrix interaction of bi/trilayer graphene at 2 wt. % and 5 wt. % in poly ether ether ketone (2Gn-PEEK and 5Gn-PEEK). The morphology, structure, thermal properties, and mechanical properties of PEEK, 2Gn-PEEK and 5 Gn-PEEK were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), flexural mechanical testing, and dynamic mechanical analysis (DMA). Addition of graphene to PEEK induces surface crystallization, increased percent crystallinity, offers a composite that is thermally stable until 550 °C and enhances thermomechanical properties. Results show that graphene was successfully melt-blended within PEEK using this method.

  6. Poly (ether ether ketone) derivatives: Synthetic route and characterization of nitrated and sulfonated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, T.F.; Bertolino, J.R. [Grupo de Estudo em Materiais Polimericos-Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Barra, G.M.O. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Pires, A.T.N. [Grupo de Estudo em Materiais Polimericos-Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil)], E-mail: alfredotiburcio@pq.cnpq.br

    2009-03-01

    Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 deg. C. The substitution degree was obtained through the TG curves, and values were in agreement with {sup 1}H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10{sup -2} S cm{sup -1}, an important characteristic in some applications, such as in fuel cells.

  7. 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)

  8. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    International Nuclear Information System (INIS)

    Silva, V.S.; Ruffmann, B.; Vetter, S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M.; Nunes, S.P.

    2006-01-01

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion[reg] 112 was used as reference material. DMFC tests were also performed at 50 deg. C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion[reg] 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD = 71% showed to have similar performance, or even better, as that of Nafion[reg] 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD = 52%

  9. Effect of diblock copolymer properties on the photophysical properties of dendrimer silicon phthalocyanine nanoconjugates

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kuizhi [Fujian Normal University, College of Materials Science & Engineering, Fujian Provincial Key Laboratory of Polymer Materials (China); Pan, Sujuan [Fujian Normal University, College of Chemistry & Engineering (China); Zhuang, Xuemei [Fuzhou No.2 Hospital (China); Lv, Hafei; Que, Shoulin [Fujian Normal University, College of Chemistry & Engineering (China); Xie, Shusen; Yang, Hongqin, E-mail: hqyang@fjnu.edu.cn [Fujian Normal University, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education (China); Peng, Yiru, E-mail: yirupeng@fjnu.edu.cn [Fujian Normal University, College of Chemistry & Engineering (China)

    2016-07-15

    1–2 generation poly(benzyl aryl ether) dendrimer silicon phthalocyanines with axially disubstituted cyano terminal functionalities (G{sub n}-DSiPc(CN){sub 4n}, (G{sub n} = n-generation dendrimer, n = 1–2)) were synthesized. Their structures were characterized by elemental analysis, IR, {sup 1}H NMR, and ESI-MS. Polymeric nanoparticles (G{sub n}-DSiPc(CN){sub 4n}/m) were formed through encapsulating G{sub n}-DSiPc(CN){sub 4n} into three monomethoxyl poly(ethylene glycol)-poly(ε-caprolactone) diblock copolymers (MPEG–PCL) with different hydrophilic/hydrophobic proportion, respectively. The effect of dendritic generation and the hydrophilic/hydrophobic proportion of diblock copolymers on the UV/Vis and fluorescence spectra of G{sub n}-DSiPc(CN){sub 4n} and G{sub n}-DSiPc(CN){sub 4n}/m were studied. The photophysical properties of polymeric nanoparticles exhibited dendritic generation and hydrophilic/hydrophobic proportion dependence. The fluorescence intensities and lifetimes of G{sub n}-DSiPc(CN){sub 4n}/m were lower than the corresponding free dendrimer phthalocyanines. G{sub n}-DSiPc(CN){sub 4n} encapsulated into MPEG–PCL with hydrophilic/hydrophobic molecular weight ratio 2000:4000 exhibited excellent photophysical property. The mean diameter of MPEG{sub 2000}–PCL{sub 2000} micelles was about 70 nm, which decreased when loaded with G{sub n}-DSiPc(CN){sub 4n}.Graphical abstract .

  10. Crown ether derivatives of EDTA: Pt. 6

    International Nuclear Information System (INIS)

    Liu Zhongqun; Qin Shengying; Chen Shaojin; Tan Lin

    1988-01-01

    EDTA-diaminodibenzo-18-crown-6 (cis- and trans-) condensation polymer is a new compound of crown ether derivatives of EDTA. In this paper the adsorption behaviors of U(IV) and U(VI) on this polymer from chloride solutions and effects of hydrochloric acid concentrations, salting-out agents and organic solvents on distribution coefficient (K d ) of uranium are investigated. Adsorption mechanism of uranyl ion (UO 2 2+ ) on this polymer was studied with IR spectra and by means of the adsorption behaviors of compounds of similar structure. Experimental results show that both polyether section and carboxyl groups in EDTA-diaminodibenzo-18-crown-6 take part in complexation with uranyl ion and synergistic effect appeared

  11. Effect of ethylene glycol monomethyl ether and diethylene glycol monomethyl ether on hepatic metabolizing enzymes.

    Science.gov (United States)

    Kawamoto, T; Matsuno, K; Kayama, F; Hirai, M; Arashidani, K; Yoshikawa, M; Kodama, Y

    1990-06-01

    Glycol ethers have been extensively used in industry over the past 40-50 years. Numerous studies on the toxicity of glycol ethers have been performed, however, the effects of glycol ethers on the hepatic drug metabolizing enzymes are still unknown. We studied the changes of the putative metabolic enzymes, that is, the hepatic microsomal mixed function oxidase system and cytosolic alcohol dehydrogenase, by the oral administration of diEGME and EGME. Adult male Wistar rats were used. DiEGME was administered orally; 500, 1000, 2000 mg/kg for 1, 2, 5 or 20 days and EGME was 100, 300 mg/kg for 1, 2, 5 or 20 days. Decreases in liver weights were produced by highest doses of diEGME (2000 mg/kg body wt/day for 20 days) and EGME (300 mg/kg body wt/day for 20 days). DiEGME increased hepatic microsomal protein contents and induced cytochrome P-450, but not cytochrome b5 or NADPH-cytochrome c reductase. The activity of cytosolic ADH was not affected by diEGME administration. On the other hand, EGME did not change cytochrome P-450, cytochrome b5 or NADPH-cytochrome c reductase. The activity of cytosolic ADH was increased by repeated EGME treatment. Therefore it is suspected that the enzyme which takes part in the metabolism of diEGME is different from that of EGME, although diEGME is a structural homologue of EGME.

  12. Biosynthesis of archaeal membrane ether lipids

    Directory of Open Access Journals (Sweden)

    Samta eJain

    2014-11-01

    Full Text Available A vital function of the cell membrane in all living organism is to maintain the membrane permeability barrier and fluidity. The composition of the phospholipid bilayer is distinct in archaea when compared to bacteria and eukarya. In archaea, isoprenoid hydrocarbon side chains are linked via an ether bond to the sn-glycerol-1-phosphate backbone. In bacteria and eukarya on the other hand, fatty acid side chains are linked via an ester bond to the sn-glycerol-3-phosphate backbone. The polar head groups are globally shared in the three domains of life. The unique membrane lipids of archaea have been implicated not only in the survival and adaptation of the organisms to extreme environments but also to form the basis of the membrane composition of the last universal common ancestor (LUCA. In nature, a diverse range of archaeal lipids is found, the most common are the diether (or archaeol and the tetraether (or caldarchaeol lipids that form a monolayer. Variations in chain length, cyclization and other modifications lead to diversification of these lipids. The biosynthesis of these lipids is not yet well understood however progress in the last decade has led to a comprehensive understanding of the biosynthesis of archaeol. This review describes the current knowledge of the biosynthetic pathway of archaeal ether lipids; insights on the stability and robustness of archaeal lipid membranes; and evolutionary aspects of the lipid divide and the last universal common ancestor LUCA. It examines recent advances made in the field of pathway reconstruction in bacteria.

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

    Directory of Open Access Journals (Sweden)

    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%.

  14. 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.

  15. 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.

  16. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. 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.

  2. Mutagenic interactions between maleic hydrazide and X rays in the stamen hairs of Tradescantia clone BNL 4430

    International Nuclear Information System (INIS)

    Xiao, Ling-Zhi; Ichikawa, Sadao

    1995-01-01

    Mutagenic interactions between maleic hydrazide (MH; a promutagen known to be activated into a mutagen in plant cells) and X rays were studied in the stamen hairs of Tradescantia clone BNL 4430, a blue/pink heterozygote. The young inflorescence-bearing shoots with roots cultivated in the nutrient solution circulating growth chamber were used as tester plants. After determining dose-response curves for X rays and for MH, nine combined treatments with MH (0.5 and 1 mM) and X rays (292 to 1,240 mGy) were conducted, exposing to X rays either 20 or 44 h before, at the midpoint of, or 2 or 44 h after the MH treatments for 4h. Clear synergistic effects in inducing somatic pink mutations were detected when X rays were given before the MH treatments. On the contrary, however, antagonistic effects were often observed when X-ray treatments were carried out during or after the MH treatments. The synergistic effects detected were thought to be the results of interactions between DNA strand breaks (and the resultant chromosomal breaks) induced by X rays and those by MH, whereas the antagonistic effects observed were presumed to have resulted from X-ray-caused inhibition of the activation of MH in the stamen-hair cells. (author)

  3. 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.

  4. Evaluation of final irrigation regimens with maleic acid for smear layer removal and wettability of root canal sealer.

    Science.gov (United States)

    Ballal, Nidambur Vasudev; Ferrer-Luque, Carmen Maria; Sona, Mrunali; Prabhu, K Narayan; Arias-Moliz, Teresa; Baca, Pilar

    2018-04-01

    To evaluate the smear layer removal and wettability of AH Plus sealer on root canal dentin treated with MA (maleic acid), MA + CTR (cetrimide) and MA + CTR + CHX (chlorhexidine) as final irrigating regimens. For smear layer removal, 40 teeth were instrumented to size F4 and divided into four groups: (1) 7% MA, (2) 7% MA + 0.2% CTR, (3) 7% MA + 0.2% CTR + 2% CHX, (4) distilled water (control). After irrigation, teeth were subjected to SEM analysis. For contact angle analysis, 20 teeth were split longitudinally and divided into four groups similar to smear layer analysis. AH plus sealer was placed on each specimen and contact angle was analysed. In both smear layer (p = .393) and contact angle analysis (p = .961), there was no significant difference between the groups MA and MA + CTR. However, MA + CTR + CHX removed smear layer less effectively (p = .023) and increased the contact angle of the sealer (p = .005). In smear layer analysis, specimens in negative control group were heavily smeared. In case of contact angle analysis, samples in the control group had least contact angle. MA alone or in combination with CTR removed smear layer effectively and increased the wettability of AH plus sealer to root canal dentin.

  5. Effect of styrene maleic acid WIN55,212-2 micelles on neuropathic pain in a rat model.

    Science.gov (United States)

    Linsell, Oliver; Brownjohn, Philip W; Nehoff, Hayley; Greish, Khaled; Ashton, John C

    2015-05-01

    Cannabinoid receptor agonists are moderately effective at reducing neuropathic pain but are limited by psychoactivity. We developed a styrene maleic acid (SMA) based on the cannabinoid WIN 55,212-2 (WIN) and tested in a rat model of neuropathic pain and in the rotarod test. We hypothesized that miceller preparation can ensure prolonged plasma half-life being above the renal threshold of excretion. Furthermore, SMA-WIN could potentially reduce the central nervous system effects of encapsulated WIN by limiting its transport across the blood-brain barrier. Using the chronic constriction injury model of sciatic neuropathy, the SMA-WIN micelles were efficacious in the treatment of neuropathic pain for a prolonged period compared to control (base WIN). Attenuation of chronic constriction injury-induced mechanical allodynia occurred for up to 8 h at a dose of 11.5 mg/kg of SMA-WIN micelles. To evaluate central effects on motor function, the rotarod assessment was utilized. Results showed initial impairment caused by SMA-WIN micelles to be identical to WIN control for up to 1.5 h. Despite this, the SMA-WIN micelle formulation was able to produce prolonged analgesia over a time when there was decreased impairment in the rotarod test compared with base WIN.

  6. Surface morphology of PS-PDMS diblock copolymer films

    DEFF Research Database (Denmark)

    Andersen, T.H.; Tougaard, S.; Larsen, N.B.

    2001-01-01

    Spin coated thin films (∼400 Å) of poly(styrene)–poly(dimethylsiloxane) (PS–PDMS) diblock copolymers have been investigated using X-ray Photoelectron Spectroscopy and Atomic Force Microscopy. Surface segregation of the poly(dimethylsiloxane) blocks was studied for five diblock copolymers which ra...

  7. Rheological Behavior of Entangled Polystyrene-Polyhedral Oligosilsesquioxane (POSS) Copolymer

    National Research Council Canada - National Science Library

    Wu, Jian; Mather, Patrick T; Haddad, Timothy S; Kim, Gyeong-Man

    2006-01-01

    ...: random copolymers of polystyrene (PS) and styryl-based polyhedral oligosilsesquioxane (POSS), R7(Si8O12)(C6H4CH=CH2), with R = isobutyl (iBu). A series of styrene-styryl POSS random copolymers with 0, 6, 15, 30, 50 wt...

  8. Adsorption of charged diblock copolymers : effect on colloidal stability

    NARCIS (Netherlands)

    Israels, R.

    1994-01-01

    In this thesis we present Scheutjens-Fleer (SF) calculations on the adsorption of diblock copolymers. More specifically, we restrict ourselves to adsorption at uncharged surfaces, while the specific type of block copolymers we consider have one uncharged adsorbing "anchor" block and one

  9. Amphiphilic brushes from metallo-supramolecular block copolymers

    NARCIS (Netherlands)

    Guillet, P.; Fustin, C.A.; Wouters, D.; Höppener, S.; Schubert, U.S.; Gohy, J.M.W.

    2009-01-01

    A novel strategy to control the formation of amphiphilic brushes from metallo-supramol. block copolymers is described. The investigated copolymer consists of a polystyrene block linked to a poly(ethylene oxide) one via a charged bis-terpyridine ruthenium(ii) complex (PS-[Ru]-PEO). The initial

  10. Polyether based segmented copolymers with uniform aramid units

    NARCIS (Netherlands)

    Niesten, M.C.E.J.

    2000-01-01

    Segmented copolymers with short, glassy or crystalline hard segments and long, amorphous soft segments (multi-block copolymers) are thermoplastic elastomers (TPE’s). The hard segments form physical crosslinks for the amorphous (rubbery) soft segments. As a result, this type of materials combines

  11. Antimicrobial activity of poly(acrylic acid) block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  12. Antimicrobial activity of poly(acrylic acid) block copolymers

    International Nuclear Information System (INIS)

    Gratzl, Günther; Paulik, Christian; Hild, Sabine; Guggenbichler, Josef P.; Lackner, Maximilian

    2014-01-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed

  13. Radiation crosslinked block copolymer blends with improved impact resistance

    International Nuclear Information System (INIS)

    Saunders, F.L.; Pelletier, R.R.

    1976-01-01

    Polymer blends having high impact resistance after mechanical working are produced by blending together a non-elastomeric monovinylidene aromatic polymer such as polystyrene with an elastomeric copolymer, such as a block copolymer of styrene and butadiene, in the form of crosslinked, colloidal size particles

  14. Characteristics of immobilized aminoacylase from Aspergillus oryzae on macroporous copolymers.

    Science.gov (United States)

    He, B L; Jiang, P; Qiu, Y B

    1990-01-01

    Aminoacylase from Aspergillus oryzae was adsorbed on functionallized macroporous copolymers where the enzyme showed excellent catalyzing activity and operation stability. Various factors which effect the activity of the immobilized aminoacylase such as temperature, pH and ionic strength were investigated. The continuous operation of the enzyme immobilized on macroporous copolymers was compared with that of the enzyme immobilized on DEAE-Sephadex.

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

    Science.gov (United States)

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

    2017-04-01

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

  16. Multiblock copolymers with highly sulfonated blocks containing di- and tetrasulfonated arylene sulfone segments for proton exchange membrane fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Takamuku, Shogo; Jannasch, Patric [Polymer and Materials Chemistry, Department of Chemistry, Lund University (Sweden)

    2012-01-15

    Multiblock copoly(arylene ether sulfone)s with different block lengths and ionic contents are tailored for durable and proton-conducting electrolyte membranes. Two series of fully aromatic copolymers are prepared by coupling reactions between non-sulfonated hydrophobic precursor blocks and highly sulfonated hydrophilic precursor blocks containing either fully disulfonated diarylsulfone or fully tetrasulfonated tetraaryldisulfone segments. The sulfonic acid groups are exclusively introduced in ortho positions to the sulfone bridges to impede desulfonation reactions and give the blocks ion exchange capacities (IECs) of 4.1 and 4.6 meq. g{sup -1}, respectively. Solvent cast block copolymer membranes show well-connected hydrophilic nanophase domains for proton transport and high decomposition temperatures above 310 C under air. Despite higher IEC values, membranes containing tetrasulfonated tetraaryldisulfone segments display a markedly lower water uptake than the corresponding ones with disulfonated diarylsulfone segments when immersed in water at 100 C, presumably because of the much higher chain stiffness and glass transition temperature of the former segments. The former membranes have proton conductivities in level of a perfluorosulfonic acid membrane (NRE212) under fully humidified conditions. A membrane with an IEC of 1.83 meq. g{sup -1} reaches above 6 mS cm{sup -1} under 30% relative humidity at 80 C, to be compared with 10 mS cm{sup -1} for NRE212 under the same conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

    Science.gov (United States)

    Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

    2016-06-01

    Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

  18. Synthesis and characterization of waterborne polyurethane acrylate copolymers

    International Nuclear Information System (INIS)

    Sultan, Misbah; Bhatti, Haq Nawaz; Zuber, Mohammad; Barikani, Mehdi

    2013-01-01

    Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties

  19. Sulfomethylated graft copolymers of xanthan gum and polyacrylamide

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, I.W.; Empey, R.A.; Racciato, J.S.

    1978-08-08

    A water-soluble anionic graft copolymer of xanthan gum and polyacrylamide is described in which at least part of the amide function of the acrylamide portion of the copolymer is sulfomethylated and the xanthan gum portion of the copolymer is unreacted with formaldehyde. The copolymer is sulfomethylated by reaction with formaldehyde and sodium metabisulfite. The formaldehyde does not cause any appreciable cross-linking between hydroxyl groups of the xanthan moieties. The sulfomethylation of the acrylamido group takes place at temperatures from 35 to 70 C. The pH is 10 or higher, typically from 12 to 13. The degree of anionic character may be varied by adjusting the molar ratio of formaldehyde and sodium metabisulfite with respect to the copolymer. 10 claims.

  20. Process of irradiating an ethylene-vinyl acetate copolymer to produce low melt index copolymers, and products of said process

    International Nuclear Information System (INIS)

    Potts, J.E.

    1976-01-01

    Application of ionizing radiation in a dose between 0.5 and 1.5 megareps to copolymers of ethylene and vinyl acetate lowers the melt index and increases the toughness and flexibility of the copolymers without substantially decreasing solubility or thermoplasticity. The increased toughness and flexibility carries over into blends with wax or polyethylene. (author)

  1. Ionization of amphiphilic acidic block copolymers.

    Science.gov (United States)

    Colombani, Olivier; Lejeune, Elise; Charbonneau, Céline; Chassenieux, Christophe; Nicolai, Taco

    2012-06-28

    The ionization behavior of an amphiphilic diblock copolymer poly(n-butyl acrylate(50%)-stat-acrylic acid(50%))(100)-block-poly(acrylic acid)(100) (P(nBA(50%)-stat-AA(50%))(100)-b-PAA(100), DH50) and of its equivalent triblock copolymer P(nBA(50%)-stat-AA(50%))(100)-b-PAA(200)-b-P(nBA(50%)-stat-AA(50%))(100) (TH50) were studied by potentiometric titration either in pure water or in 0.5 M NaCl. These polymers consist of a hydrophilic acidic block (PAA) connected to a hydrophobic block, P(nBA(50%)-stat-AA(50%))(100), whose hydrophobic character has been mitigated by copolymerization with hydrophilic units. We show that all AA units, even those in the hydrophobic block could be ionized. However, the AA units within the hydrophobic block were less acidic than those in the hydrophilic block, resulting in the preferential ionization of the latter block. The preferential ionization of PAA over that of P(nBA(50%)-stat-AA(50%))(100) was stronger at higher ionic strength. Remarkably, the covalent bonds between the PAA and P(nBA(50%)-stat-AA(50%))(100) blocks in the diblock or the triblock did not affect the ionization of each block, although the self-association of the block copolymers into spherical aggregates modified the environment of the PAA blocks compared to when PAA was molecularly dispersed.

  2. Amphiphilic block copolymers for drug delivery.

    Science.gov (United States)

    Adams, Monica L; Lavasanifar, Afsaneh; Kwon, Glen S

    2003-07-01

    Amphiphilic block copolymers (ABCs) have been used extensively in pharmaceutical applications ranging from sustained-release technologies to gene delivery. The utility of ABCs for delivery of therapeutic agents results from their unique chemical composition, which is characterized by a hydrophilic block that is chemically tethered to a hydrophobic block. In aqueous solution, polymeric micelles are formed via the association of ABCs into nanoscopic core/shell structures at or above the critical micelle concentration. Upon micellization, the hydrophobic core regions serve as reservoirs for hydrophobic drugs, which may be loaded by chemical, physical, or electrostatic means, depending on the specific functionalities of the core-forming block and the solubilizate. Although the Pluronics, composed of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide), are the most widely studied ABC system, copolymers containing poly(L-amino acid) and poly(ester) hydrophobic blocks have also shown great promise in delivery applications. Because each ABC has unique advantages with respect to drug delivery, it may be possible to choose appropriate block copolymers for specific purposes, such as prolonging circulation time, introduction of targeting moieties, and modification of the drug-release profile. ABCs have been used for numerous pharmaceutical applications including drug solubilization/stabilization, alteration of the pharmacokinetic profile of encapsulated substances, and suppression of multidrug resistance. The purpose of this minireview is to provide a concise, yet detailed, introduction to the use of ABCs and polymeric micelles as delivery agents as well as to highlight current and past work in this area. Copyright 2003 Wiley-Liss, Inc. and the American Pharmacists Association

  3. 21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly-1-butene resins and butene/ethylene copolymers... resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers identified... the catalytic polymerization of 1-butene liquid monomer. Butene/ethylene copolymers are produced by...

  4. Fabrication of Hyperbranched Block-Statistical Copolymer-Based Prodrug with Dual Sensitivities for Controlled Release.

    Science.gov (United States)

    Zheng, Luping; Wang, Yunfei; Zhang, Xianshuo; Ma, Liwei; Wang, Baoyan; Ji, Xiangling; Wei, Hua

    2018-01-17

    Dendrimer with hyperbranched structure and multivalent surface is regarded as one of the most promising candidates close to the ideal drug delivery systems, but the clinical translation and scale-up production of dendrimer has been hampered significantly by the synthetic difficulties. Therefore, there is considerable scope for the development of novel hyperbranched polymer that can not only address the drawbacks of dendrimer but maintain its advantages. The reversible addition-fragmentation chain transfer self-condensing vinyl polymerization (RAFT-SCVP) technique has enabled facile preparation of segmented hyperbranched polymer (SHP) by using chain transfer monomer (CTM)-based double-head agent during the past decade. Meanwhile, the design and development of block-statistical copolymers has been proven in our recent studies to be a simple yet effective way to address the extracellular stability vs intracellular high delivery efficacy dilemma. To integrate the advantages of both hyperbranched and block-statistical structures, we herein reported the fabrication of hyperbranched block-statistical copolymer-based prodrug with pH and reduction dual sensitivities using RAFT-SCVP and post-polymerization click coupling. The external homo oligo(ethylene glycol methyl ether methacrylate) (OEGMA) block provides sufficient extracellularly colloidal stability for the nanocarriers by steric hindrance, and the interior OEGMA units incorporated by the statistical copolymerization promote intracellular drug release by facilitating the permeation of GSH and H + for the cleavage of the reduction-responsive disulfide bond and pH-liable carbonate link as well as weakening the hydrophobic encapsulation of drug molecules. The delivery efficacy of the target hyperbranched block-statistical copolymer-based prodrug was evaluated in terms of in vitro drug release and cytotoxicity studies, which confirms both acidic pH and reduction-triggered drug release for inhibiting proliferation of He

  5. Sulfonated Magnetic Nanocomposite Based on Reactive PGMA-MAn Copolymer@Fe3O4 Nanoparticles: Effective Removal of Cu(II Ions from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Reza Hasanzadeh

    2016-01-01

    Full Text Available Chelating magnetic nanocomposites have been considered as suitable materials for removal of heavy metal ions for water treatment. In this work poly(glycidyl methacrylate-maleic anhydride copolymer (PGMA-MAn is modified with 4-aminobenzenesulfonic acid (ABSAc and subsequently the product reacted with modified Fe3O4 nanoparticles and 1,2-ethanedithiol (EDT in the presence of ultrasonic irradiation for preparation of tridimensional chelating magnetic nanocomposite. Synthesized magnetic nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, X-ray diffraction analysis (XRD, vibrating sample magnetometer (VSM, energy dispersive X-ray analysis (EDX, elemental mapping analysis (EMA, Brunauer-Emmett-Teller (BET, and thermal gravimetric analysis (TGA. The adsorption behavior of Cu(II ions was investigated by synthesized nanocomposite in various parameters such as pH, contact time, metal ion concentration, and adsorbent dosage. The equilibrium distribution coefficient (kd was determined and the findings prove that the kd value is approximately high in the case of all selected metal ions. The synthesized nanocomposite exhibited good tendency for removing Cu(II ions from aqueous solutions even at an acidic pH.

  6. Evaluation of crystallization kinetics of poly (ether-ketone-ketone and poly (ether-ether-ketone by DSC

    Directory of Open Access Journals (Sweden)

    Gibran da Cunha Vasconcelos

    2010-08-01

    Full Text Available The poly (aryl ether ketones are used as matrices in advanced composites with high performance due to its high thermal stability, excellent environmental performance and superior mechanical properties. Most of the physical, mechanical and thermodynamic properties of semi-crystalline polymers depend on the degree of crystallinity and morphology of the crystalline regions. Thus, a study on the crystallization process promotes a good prediction of how the manufacturing parameters affect the developed structure, and the properties of the final product. The objective of this work was to evaluate the thermoplastics polymers PEKK e PEEK by DSC, aiming to obtain the relationship between kinetics, content, nucleation and geometry of the crystalline phases, according to the parameters of the Avrami and Kissinger models. The analysis of the Avrami exponents obtained for the studied polymers indicates that both showed the formation of crystalline phases with heterogeneous nucleation and growth geometry of the type sticks or discs, depending on the cooling conditions. It was also found that the PEEK has a higher crystallinity than PEKK.

  7. Nickel-catalyzed direct synthesis of dialkoxymethane ethers

    Indian Academy of Sciences (India)

    MURUGAN SUBARAMANIAN

    Nickel catalysis; alcohol; paraformaldehyde; ether; solvent-free condition. 1. Introduction ..... oxidation and Dopamine Release with Protective Effects. Against Central ... P, Ghosh A, Saha R and Saha B 2016 A Review on the. Advancement of ...

  8. 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.

  9. Chemical Composition and Cytotoxic Activities of Petroleum Ether ...

    African Journals Online (AJOL)

    Methods: The composition of petroleum ether extract was analyzed by gas ... acids, sterides, pregnanones, terpenes, alkaloids, alkenes, alcohols, ketones, aldehydes and other compounds. .... and mass spectra with those obtained from the.

  10. Poly (ether imide sulfone) membranes from solutions in ionic liquids

    KAUST Repository

    Kim, Dooli; Nunes, Suzana Pereira

    2017-01-01

    A membrane manufacture method based on non-volatile solvents and a high performance polymer, poly (ether imide sulfone) (EXTEM™), is proposed, as greener alternative to currently industrial process. We dissolved EXTEM™ in pure ionic liquids: 1-ethyl

  11. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  12. 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.

  13. Investigation of ammonium trinitratouranylate complexing with diethyl ether

    International Nuclear Information System (INIS)

    Khod'ko, N.N.; Kolevich, T.A.; Umrejko, D.S.

    1989-01-01

    Interaction of ammonium trinitratouranylate (ATNU) with diethyl ether is investigated. It is shown, that adduct of UO 2 (NO 3 ) 2 · 2(C 2 H 5 ) 2 O coposition is formed in the indicated solvent due to incongruent solubility of ANTU. Analogous compound is obtained at ether effect on uranyl anhydrous nitrate. The matter is determined and investigated by means of chemical, thermal analyses and oscillating spectroscopy

  14. Glycerol tertiary butyl ethers via etherification of glycerol with isobutene

    Energy Technology Data Exchange (ETDEWEB)

    Behr, A. [Dortmund Univ. (Germany). Chair of Chemical Process Development/Technical Chemistry A

    2007-07-01

    Glycerol and isobutene can react to a mixture of glycerol tertiary butyl ethers (GTBE) which can be used as additives for gasoline, diesel or biodiesel. This reaction was investigated in lab scale yielding a proposal for a process flow diagram containing reaction, extraction, flash and rectification units. This process has the advantages that only the suitable higher ethers are formed and that both glycerol and isobutene are fully converted. The homogeneous acid catalyst is low-priced and can be completely recycled. (orig.)

  15. 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.

  16. Anomalous Micellization of Pluronic Block Copolymers

    Science.gov (United States)

    Leonardi, Amanda; Ryu, Chang Y.

    2014-03-01

    Poly(ethylene oxide) - poly(propylene oxide) - poly(ethylene oxide) (PEO-PPO-PEO) block copolymers, commercially known as Pluronics, are a unique family of amphiphilic triblock polymers, which self-assemble into micelles in aqueous solution. These copolymers have shown promise in therapeutic, biomedical, cosmetic, and nanotech applications. As-received samples of Pluronics contain low molecular weight impurities (introduced during the manufacturing and processing), that are ignored in most applications. It has been observed, however, that in semi-dilute aqueous solutions, at concentrations above 1 wt%, the temperature dependent micellization behavior of the Pluronics is altered. Anomalous behavior includes a shift of the critical micellization temperature and formation of large aggregates at intermediate temperatures before stable sized micelles form. We attribute this behavior to the low molecular weight impurities that are inherent to the Pluronics which interfere with the micellization process. Through the use of Dynamic Light Scattering and HPLC, we compared the anomalous behavior of different Pluronics of different impurity levels to their purified counterparts.

  17. Responsive linear-dendritic block copolymers.

    Science.gov (United States)

    Blasco, Eva; Piñol, Milagros; Oriol, Luis

    2014-06-01

    The combination of dendritic and linear polymeric structures in the same macromolecule opens up new possibilities for the design of block copolymers and for applications of functional polymers that have self-assembly properties. There are three main strategies for the synthesis of linear-dendritic block copolymers (LDBCs) and, in particular, the emergence of click chemistry has made the coupling of preformed blocks one of the most efficient ways of obtaining libraries of LDBCs. In these materials, the periphery of the dendron can be precisely functionalised to obtain functional LDBCs with self-assembly properties of interest in different technological areas. The incorporation of stimuli-responsive moieties gives rise to smart materials that are generally processed as self-assemblies of amphiphilic LDBCs with a morphology that can be controlled by an external stimulus. Particular emphasis is placed on light-responsive LDBCs. Furthermore, a brief review of the biomedical or materials science applications of LDBCs is presented. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Bactericidal and Hemocompatible Coating via the Mixed-Charged Copolymer.

    Science.gov (United States)

    Fan, Xiao-Li; Hu, Mi; Qin, Zhi-Hui; Wang, Jing; Chen, Xia-Chao; Lei, Wen-Xi; Ye, Wan-Ying; Jin, Qiao; Ren, Ke-Feng; Ji, Jian

    2018-03-28

    Cationic antibacterial coating based on quaternary ammonium compounds, with an efficient and broad spectrum bactericidal property, has been widely used in various fields. However, the high density of positive charges tends to induce weak hemocompatibility, which hinders the application of the cationic antibacterial coating in blood-contacting devices and implants. It has been reported that a negatively charged surface can reduce blood coagulation, showing improved hemocompatibility. Here, we describe a strategy to combine the cationic and anionic groups by using mixed-charged copolymers. The copolymers of poly (quaternized vinyl pyridine- co- n-butyl methacrylate- co-methacrylate acid) [P(QVP- co- nBMA- co-MAA)] were synthesized through free radical copolymerization. The cationic group of QVP, the anionic group of MAA, and the hydrophobic group of nBMA were designed to provide bactericidal capability, hemocompatibility, and coating stability, respectively. Our findings show that the hydrophilicity of the copolymer coating increased, and its zeta potential decreased from positive charge to negative charge with the increase of the anionic/cationic ratio. Meanwhile, the bactericidal property of the copolymer coating was kept around a similar level compared with the pure quaternary ammonium copolymer coating. Furthermore, the coagulation time, platelet adhesion, and hemolysis tests revealed that the hemocompatibility of the copolymer coating improved with the addition of the anionic group. The mixed-charged copolymer combined both bactericidal property and hemocompatibility and has a promising potential in blood-contacting antibacterial devices and implants.

  19. Distribution of Europium between poly-maleic acid in solution or adsorbed onto alumina and Bacillus subtilis

    International Nuclear Information System (INIS)

    Markai, S.

    2002-07-01

    In order to understand the interactions of radionuclides under natural water conditions, the interactions were studied in a quaternary system composed of well characterized reference substances: europium as a heavy metal, poly-maleic acid (PMA) as model of humic substances, alumina as mineral phase and Bacillus subtilis representing biomass. The work was performed at pH=5 in 0,1 mol/L of NaClO 4 . The fundamental question addressed was to know if parameters deduced from the quantitative study of the reference systems Eu/PMA, Eu/PMA-Al 2 O 3 and Eu/Bacillus subtilis, could be used to quantify the distribution of Eu in the multi-substrate systems Eu/PMA/Bacillus subtilis and Eu/PMA-Al 2 O 3 /Bacillus subtilis. The experimental interaction data were described by a Langmuir-type model or by a surface complexation model, with surface speciation assessment by time resolved laser induced fluorescence spectroscopy. The study of the Eu/PMA system showed similarities with the Eu/ humic substances system as far as interaction strength and the nature of Eu environment were concerned. When PMA was adsorbed onto Al 2 O 3 , its complexation properties towards Eu were different. For high concentrations of Eu, a ternary complex was formed in which Eu was bound to a carboxylic function of PMA and to an aluminol function of Al 2 O 3 . For the Eu/B.subtilis system, Eu was bound to a carboxylic function and to a phosphate function. For the PMA/Eu/bacteria system, the reference systems were reversible and the parameters deduced from sub-systems allowed to quantify the distribution of Eu in the global system. In the PMA A l 2 O 3 /Eu/bacteria system, the equilibrium Eu/PMA-Al 2 O 3 was not reversible due to a diffusion of Eu in the adsorbed layer of PMA, reducing its bio-availability. (author)

  20. Children's exposure to polybrominated diphenyl ethers.

    Science.gov (United States)

    Zuurbier, Moniek; Leijs, Marike; Schoeters, Greet; ten Tusscher, Gavin; Koppe, Janna G

    2006-10-01

    Polybrominated biphenyl ethers (PBDEs), a class of brominated flame retardants, are frequently used in consumer products. PBDEs levels in environmental and human samples have increased in recent decades. Children are exposed to PBDEs through diet, mainly through fish, meat and milk. Total dietary exposure of children in Europe was calculated to be 2-3 ng/kg b.w./day. For nursing infants the main source of PBDE exposure is breast milk; exposure levels are around 15 ng/kg b.w./day. PBDE exposure levels in North America are 10 to a 100 times higher. Because of their persistence and their similarity to polychlorinated biphenyls (PCBs), concern has been raised about the effects of PBDEs on human health. Exposure to penta- and octa-BDE led to learning impairment and impaired motor behaviour in rodents. Exposure to penta-, octa- and also deca-BDE caused effects on thyroid homeostasis in animals. The EU has banned the production and use of penta- and octa-BDE since 2004; however, exposure will continue during the coming decades. Based upon current toxicological evidence, human exposure to deca-BDEs is not expected to lead to health effects, but data on exposure to deca-BDE and data on toxicity of deca-BDE are scarce. Therefore, monitoring studies and toxicity studies on deca-BDEs and other BDEs should continue.

  1. Radiation induced crosslinking of cellulose ethers

    International Nuclear Information System (INIS)

    Wach, A.R.; Mitomo, H.; Yoshii, F.; Kume, T.

    2002-01-01

    The effects of high-energy radiation on four ethers of cellulose: carboxymethyl (CMC); hydroxypropyl (HPC), hydroxyethyl (HEC) and methylcellulose (MC) were investigated. Polymers are irradiated in solid state and in aqueous solutions at various concentrations. Degree of substitution (DS) of the derivatives, the concentration of their aqueous solutions and irradiation conditions had a significant impact on the obtained products. Irradiation of polymers in solid state and in diluted aqueous solutions resulted in their degradation. However, it was found that for concentrated solutions gel formation occurred. Paste-like form of the initial material, when water plasticizes the bulk of polymer as well as the high dose rate, what prevents oxygen penetration of the polymer during irradiation, have been found favourable for hydrogel formation. Up to 95% of gel fraction was obtained from solutions of CMC with concentration over 50% irradiated by γ-rays or electron beam. It was pointed out that the ability to the formation of the three-dimensional network is related to the DS of anhydroglucose units and a type of chemical group introduced to main chain of cellulose. Produced hydrogels swelled markedly in water. Despite of the crosslinked structure they underwent degradation by the action of cellulase enzyme or microorganisms from compost, and can be included into the group of biodegradable materials. (author)

  2. Multifunctional PEG-carboxylate copolymer coated superparamagnetic iron oxide nanoparticles for biomedical application

    Science.gov (United States)

    Illés, Erzsébet; Szekeres, Márta; Tóth, Ildikó Y.; Szabó, Ákos; Iván, Béla; Turcu, Rodica; Vékás, Ladislau; Zupkó, István; Jaics, György; Tombácz, Etelka

    2018-04-01

    Biocompatible magnetite nanoparticles (MNPs) were prepared by post-coating the magnetic nanocores with a synthetic polymer designed specifically to shield the particles from non-specific interaction with cells. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers and acrylic acid (AA) small molecular monomers were chemically coupled by quasi-living atom transfer radical polymerization (ATRP) to a comb-like copolymer, P(PEGMA-co-AA) designated here as P(PEGMA-AA). The polymer contains pendant carboxylate moieties near the backbone and PEG side chains. It is able to bind spontaneously to MNPs; stabilize the particles electrostatically via the carboxylate moieties and sterically via the PEG moieties; provide high protein repellency via the structured PEG layer; and anchor bioactive proteins via peptide bond formation with the free carboxylate groups. The presence of the P(PEGMA-AA) coating was verified in XPS experiments. The electrosteric (i.e., combined electrostatic and steric) stabilization is efficient down to pH 4 (at 10 mM ionic strength). Static magnetization and AC susceptibility measurements showed that the P(PEGMA-AA)@MNPs are superparamagnetic with a saturation magnetization value of 55 emu/g and that both single core nanoparticles and multicore structures are present in the samples. The multicore components make our product well suited for magnetic hyperthermia applications (SAR values up to 17.44 W/g). In vitro biocompatibility, cell internalization, and magnetic hyperthermia studies demonstrate the excellent theranostic potential of our product.

  3. Hydrogen Bond Induces Hierarchical Self-Assembly in Liquid-Crystalline Block Copolymers.

    Science.gov (United States)

    Huang, Shuai; Pang, Linlin; Chen, Yuxuan; Zhou, Liming; Fang, Shaoming; Yu, Haifeng

    2018-03-01

    Microphase-separated structures of block copolymers (BCs) with a size of sub-10 nm are usually obtained by hydrogen-bond-induced self-assembly of BCs through doping with small molecules as functional additives. Here, fabrication of hierarchically self-assembled sub-10 nm structures upon microphase separation of amphiphilic liquid-crystalline BCs (LCBCs) at the existence of hydrogen bonds but without any dopants is reported. The newly introduced urethane groups in the side chain of the hydrophobic block of LCBCs interact with the ether groups of the hydrophilic poly(ethylene oxide) (PEO) block, leading to imperfect crystallization of the PEO blocks. Both crystalline and amorphous domains coexist in the separated PEO phase, enabling a lamellar structure to appear inside the PEO nanocylinders. This provides an elegant method to fabricate controllable sub-10 nm microstructures in well-defined polymer systems without the introduction of any dopants. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Incorporation of fluconazole in copolymer PMMA-g-PEG derivatives

    International Nuclear Information System (INIS)

    Silveira, B.M.; Santos, V.M.R. dos; Novack, K.M.; Lopes, S.A.

    2014-01-01

    The graft copolymer PMMA-g-PEG went through chemical transformations in its chain through acetylation, halogenation, methylation and esterification followed by hydrolysis reactions. Subsequently, the copolymer PMMA-g-PEG derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Derivatives copolymers were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) after incorporation in order to evaluate their effectiveness. The efficiency of incorporation was observed and it was also verified that the complexity of polymer chain influence in the incorporated fluconazole content. (author)

  5. 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)

  6. 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.

  7. 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

  8. Patchy micelles based on coassembly of block copolymer chains and block copolymer brushes on silica particles.

    Science.gov (United States)

    Zhu, Shuzhe; Li, Zhan-Wei; Zhao, Hanying

    2015-04-14

    Patchy particles are a type of colloidal particles with one or more well-defined patches on the surfaces. The patchy particles with multiple compositions and functionalities have found wide applications from the fundamental studies to practical uses. In this research patchy micelles with thiol groups in the patches were prepared based on coassembly of free block copolymer chains and block copolymer brushes on silica particles. Thiol-terminated and cyanoisopropyl-capped polystyrene-block-poly(N-isopropylacrylamide) block copolymers (PS-b-PNIPAM-SH and PS-b-PNIPAM-CIP) were synthesized by reversible addition-fragmentation chain transfer polymerization and chemical modifications. Pyridyl disulfide-functionalized silica particles (SiO2-SS-Py) were prepared by four-step surface chemical reactions. PS-b-PNIPAM brushes on silica particles were prepared by thiol-disulfide exchange reaction between PS-b-PNIPAM-SH and SiO2-SS-Py. Surface micelles on silica particles were prepared by coassembly of PS-b-PNIPAM-CIP and block copolymer brushes. Upon cleavage of the surface micelles from silica particles, patchy micelles with thiol groups in the patches were obtained. Dynamic light scattering, transmission electron microscopy, and zeta-potential measurements demonstrate the preparation of patchy micelles. Gold nanoparticles can be anchored onto the patchy micelles through S-Au bonds, and asymmetric hybrid structures are formed. The thiol groups can be oxidized to disulfides, which results in directional assembly of the patchy micelles. The self-assembly behavior of the patchy micelles was studied experimentally and by computer simulation.

  9. 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)

  10. Rheological, mechanical and tribological properties of carbon-nanofibre reinforced poly (ether ether ketone composites

    Directory of Open Access Journals (Sweden)

    Volker Altstaedt

    2003-12-01

    Full Text Available Poly(ether ether ketone nanocomposites containing vapour-grown carbon nanofibres (CNF were produced using standard polymer processing techniques. At high shear rates no significant increase in resin viscosity was observed. Nevertheless, the addition of the CNFs results in a higher melt strength at 360°C. Electron microscopy confirmed the homogeneous dispersion and alignment of nanofibres in the polymer matrix. Evaluation of the mechanical composite properties revealed a linear increase in tensile stiffness and strength with nanofibre loading fractions up to 15 wt% whilst matrix ductility was maintained up to 10 wt%. An interpretation of the composite performance by short-fibre theory resulted in rather low intrinsic stiffness properties of the vapour-grown CNF. Differential scanning calorimetry was used to investigate crystallization kinetics and degree of crystallinity. The CNFs were found not to act as nucleating sites. Furthermore, unidirectional sliding tests against two different counterpart materials (100Cr6 martensitic bearing steel, X5CrNi18-10 austenitic stainless steel were performed. The carbon nanofibres were found to reduce the wear rate of PEEK significantly.

  11. An improved synthesis process of calixcrown ethers and synthesis of novel calixcrown ether

    International Nuclear Information System (INIS)

    Wang Hairong; Zhang Ping; Wang Chunmiao; Wang Jianchen; Chen Jing

    2007-01-01

    The synthesis method of calixcrown ethers was simplified and improved, and 10 L- scale synthesis was carried out. In the synthesis of the intermediates of the first three steps, the synthesis of 5, 11, 17, 23-tetra-tert-butyl-25, 26, 27, 28-tetrahydroxyl-calix[4] and its dehydroxylation were considered together, the purification procedures of the former, including re-crystallization in toluene and decolorization with activated carbon, were cancelled, and thus these steps were simplified. In the synthesis of oligoethylene glycol ditosylate, the purification method was also improved and the time-consuming column chromatography was left out. In the final step, impurities were removed by repeating stirring-settlement steps, by following recrystallization, the pure product was obtained. With these measures, the whole process could be implemented easily. The industrial scale production of calixcrown ethers could be fulfilled with the improved process. In addition, a new extracant, 25, 27-bis (n-propyloxy)calix[4]-26, 28-crown-6, is prepared and identified. (authors)

  12. Development and characterization of poli composites (ether ether ketone)(PEEK)(Hydroxyapatite(HA)

    International Nuclear Information System (INIS)

    Ferreira, V.P.; Santos, F.S.F.; Sa, M.D. de; Fook, M.V.L.

    2016-01-01

    The objective of this work was to develop PEEK / HA composites, combining the biological activity of the ceramic phase with the properties of the polymer phase, the materials used in this research were Poly (ether-ether-ketone) (PEEK) and Hydroxyapatite (HA) (50, 60, 70 and 80% m / v HA), this material was subjected to a load of two tons followed by a thermal treatment at 390 ° for a period of 30 minutes. Then they were characterized by FTIR, DRX and MO. In the physical-chemical characterization of FTIR and XRD, it was not possible to identify significant alterations. In the FTIR spectra of the composites, there is no formation of new identifiable chemical bonds. In the composites XRD diffractograms a profile similar to the ceramic phase was observed, with peaks increasing in intensity and narrowing proportional to the increase of the hydroxyapatite concentration in the composites. In optical microscopy it is possible to observe surfaces with heterogeneous morphology, with signs of roughness and in the cross section we observe a heterogeneous aspect, rich in regions with large agglomerates and lighter particles. Considering the processing aspects, the technique proved to be effective for the development of PEEK /HA composites. (author)

  13. Enhanced osteoblast responses to poly ether ether ketone surface modified by water plasma immersion ion implantation.

    Science.gov (United States)

    Wang, Heying; Lu, Tao; Meng, Fanhao; Zhu, Hongqin; Liu, Xuanyong

    2014-05-01

    Poly ether ether ketone (PEEK) offers a set of characteristics superior for human implants; however, its application is limited by the bio-inert surface property. In this work, PEEK surface was modified using single step plasma immersion ion implantation (PIII) treatment with a gas mixture of water vapor as a plasma resource and argon as an ionization assistant. Field emission scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy were used to investigate the microstructure and composition of the modified PEEK surface. The water contact angle and zeta-potential of the surfaces were also measured. Osteoblast precursor cells MC3T3-E1 and rat bone mesenchymal stem cells were cultured on the PEEK samples to evaluate their cytocompatibility. The obtained results show that the hydroxyl groups as well as a "ravined structure" are constructed on water PIII modified PEEK. Compared with pristine PEEK, the water PIII treated PEEK is more favorable for osteoblast adhesion, spreading and proliferation, besides, early osteogenic differentiation indicated by the alkaline phosphatase activity is also up-regulated. Our study illustrates enhanced osteoblast responses to the PEEK surface modified by water PIII, which gives positive information in terms of future biomedical applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. Mechanical properties of weakly segregated block copolymers : 1. Synergism on tensile properties of poly(styrene-b-n-butylmethacrylate) diblock copolymers

    NARCIS (Netherlands)

    Weidisch, R.; Michler, G.H.; Fischer, H.; Arnold, M.; Hofmann, S.; Stamm, M.

    1999-01-01

    Mechanical properties of poly(styrene-b-n-butylmethacrylate) diblock copolymers, PS-b-PBMA, with different lengths of the polystyrene block were investigated. The copolymers display a composition range where the tensile strength of the block copolymers exceeds the values of the corresponding

  17. High pressure injection of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Glensvig, M.; Sorenson, S.C.; Abata, D.L.

    1997-08-01

    The purpose of this investigation was to achieve a better understanding of the fundamental spray behavior of DME (Dimenthyl Ether) using a standard diesel pump with pintle and hole nozzles. Fundamental spray behavior was characterized by determining fuel spray penetration and angle, atomization and evaporation. The influences of opening pressure, nozzle geometry and ambient pressure above and below the critical pressure of the fuel on the spray behavior were investigated. The influence of opening pressures on the spray characteristics for the hole nozzle was investigated. The results showed that for opening pressures of 120 bar and 180 bar the spray has a similar appearance. For the higher opening pressure (200 bar and 240 bar), the initial spray breaks up very rapidly giving a high initial spray angle. The opening pressure had little influence on spray penetration. The spray angle later in the injection increased as the opening pressure was decreased. Above the critical pressure, the spray from the hole nozzle had a more irregular shape. Penetration decreased and the spray angle increased above the critical pressure. Three pintle nozzles with different geometries and opening pressures were tested. The appearance of the three sprays were very similar. The sprays seemed to be more sharply pointed as the nozzle hole angle decreased. The nozzle with the 4 deg. hole nozzle angle and an opening pressure of 280 bar had the highest penetration and highest initial spray angle. The pintle nozzle with the 12 deg. hole nozzle angle and opening pressure of approx. 450 bar was tested above the critical ambient pressure. Penetration was very similar for injection above and below the critical ambient pressure, while the spray angle decreased for the spray above the critical ambient pressure. (au)

  18. Mutagenicity testing of diethylene glycol monobutyl ether.

    Science.gov (United States)

    Thompson, E D; Coppinger, W J; Valencia, R; Iavicoli, J

    1984-01-01

    The mutagenic potential of diethylene glycol monobutyl ether (diEGBE) was examined with a Tier I battery of in vitro assays followed by a Tier II in vivo Drosophila sex-linked recessive lethal assay. The in vitro battery consisted of: the Salmonella mutagenicity test, the L5178Y mouse lymphoma test, a cytogenetics assay using Chinese hamster ovary cells and the unscheduled DNA synthesis (UDS) assay in rat hepatocytes. Results of the Salmonella mutagenicity test, the cytogenetics test, and the rat hepatocyte assay were negative at concentrations up to 20 microL/plate, 7.92 microL/mL, and 4.4 microL/mL, respectively. Toxicity was clearly demonstrated at all high doses. A weak, but dose-related increase in the mutation frequency (4-fold increase over the solvent control at 5.6 microL/mL with 12% survival) was obtained in the L5178Y lymphoma test in the absence of metabolic activation. Results of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay results were assessed by performing the Tier II sex-linked recessive lethal assay in Drosophila in which the target tissue is maturing germinal cells. Both feeding (11,000 ppm for 3 days) and injection (0.3 microL of approximately 14,000 ppm solution) routes of administration were employed in the Drosophila assay. Approximately 11,000 individual crosses with an equal number of negative controls were performed for each route of administration. diEGBE produced no increase in recessive lethals under these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6389113

  19. Synthesis of graft copolymers onto starch and its semiconducting properties

    Directory of Open Access Journals (Sweden)

    Nevin Çankaya

    Full Text Available Literature review has revealed that, although there are studies about grafting on natural polymers, especially on starch, few of them are about electrical properties of graft polymers. Starch methacrylate (St.met was obtained by esterification of OH groups on natural starch polymer for this purpose. Grafting of synthesized N-cyclohexyl acrylamide (NCA and commercial methyl methacrylate (MMA monomers with St.met was done by free radical polymerization method. The graft copolymers were characterized with FT-IR spectra, thermal and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis method and thermal stability of the copolymers is decreased via grafting. The electrical conductivity of the polymers was measured as a function of temperature and it has been observed that electrical conductivity increases with increasing temperature. The absorbance and transmittance versus wavelength of the polymers have been measured. Keywords: Starch, Graft copolymer, Semiconducting, Thermal stability, Starch methacrylate

  20. HPMA and HEMA copolymer bead interactions with eukaryotic cells

    Directory of Open Access Journals (Sweden)

    Cristina D. Vianna-Soares

    2004-09-01

    Full Text Available Two different hydrophilic acrylate beads were prepared via aqueous suspension polymerization. Beads produced of a hydroxypropyl methacrylate (HPMA and ethyleneglycol methacrylate (EDMA copolymer were obtained using a polyvinyl alcohol suspending medium. Copolymers of 2hydroxyethyl methacrylate (HEMA, methyl methacrylate (MMA and ethyleneglycol methacrylate (EDMA beads were obtained using magnesium hydroxide as the suspending agent. Following characterization by scanning electron microscopy (SEM, nitrogen sorption analysis (NSA and mercury intrusion porosimetry (MIP, the beads were cultured with monkey fibroblasts (COS7 to evaluate their ability to support cell growth, attachment and adhesion. Cell growth behavior onto small HPMA/EDMA copolymer beads and large HEMA/MMA/EDMA copolymer beads is evaluated regarding their hidrophilicity/hidrophobicity and surface roughness.

  1. Controlled Synthesis of Fluorinated Copolymers with Pendant Sulfonates

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2008-01-01

    Novel fluorinated copolymers of different architectures and bearing sulfopropyl groups were synthesized by atom transfer radical polymerization (ATRP) of aromatic fluorinated monomers and two modification reactions performed on the polymer chain - demethylation followed by sulfopropylation. As a ...

  2. Fast & scalable pattern transfer via block copolymer nanolithography

    DEFF Research Database (Denmark)

    Li, Tao; Wang, Zhongli; Schulte, Lars

    2015-01-01

    A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin-casting of s......A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin...... on long range lateral order, including fabrication of substrates for catalysis, solar cells, sensors, ultrafiltration membranes and templating of semiconductors or metals....

  3. Self-Assembly of Rod-Coil Block Copolymers

    National Research Council Canada - National Science Library

    Jenekhe, S

    1999-01-01

    ... the self-assembly of new rod-coil diblock, rod- coil-rod triblock, and coil-rod-coil triblock copolymers from solution and the resulting discrete and periodic mesostmctares with sizes in the 100...

  4. Design of block copolymer membranes using segregation strength trend lines

    KAUST Repository

    Sutisna, Burhannudin; Polymeropoulos, Georgios; Musteata, Valentina-Elena; Peinemann, Klaus-Viktor; Avgeropoulos, Apostolos; Smilgies, Detlef-M.; Hadjichristidis, Nikolaos; Nunes, Suzana Pereira

    2016-01-01

    composition, polymer molecular weights, casting solution concentration, and evaporation time. We propose here an effective method for designing new block copolymer membranes. The method consists of predetermining a trend line for the preparation of isoporous

  5. Opto-electronic devices from block copolymers and their oligomers.

    NARCIS (Netherlands)

    Hadziioannou, G

    1997-01-01

    This paper presents research activities towards the development of polymer materials and devices for optoelectronics, An approach to controlling the conjugation length and transferring the luminescence properties of organic molecules to polymers through black copolymers containing well-defined

  6. Blends of caprolactam/caprolactone copolymers and chlorinated polymers

    NARCIS (Netherlands)

    Alberda van Ekenstein, G.O.R.; Deuring, H.; ten Brinke, G.; Ellis, T.S.

    The phase behaviour of blends of chlorinated polyethylene, polyvinyl chloride (PVC) and chlorinated PVC with random copolymers of caprolactone and caprolactam has been investigated and the results correlated with a binary interaction model. The known miscibility of polycaprolactone in the

  7. Molecular weight and its distribution of tetrafluoroethylene and propylene copolymer

    International Nuclear Information System (INIS)

    Watanabe, Hiromasa; Okamoto, Jiro; Yamaguchi, Koichi.

    1978-04-01

    In comparison of molecular structure of tetrafluoroethylene and propylene copolymer produced by radiation and chemical initiators respectively, both were fractionated by elution method and fine structure was examined. For the fractionated sample by radiation, the relation between molecular weight anti Mn and intrinsic viscosity ( eta] is ( eta] = 3.97 x 10 -4 anti Mnsup(0.630) The result is not in agreement with that of the unfractionated sample by radiation, and similar to those of samples by chemical initiators. There is no difference, however, in the elution method of GPC between both these copolymers; the elution behavior agrees with that of standard polystyrene. Long chain branching thus exists little in the copolymer of tetrafluoroethylene and propylene. To reveal the relations between reaction conditions and molecular weight and its distribution of the copolymer produced by flow apparatus, the molecular weight distribution was measured by GPC. The method of analysis could evaluate molecular weight distribution changing constantly. (auth.)

  8. Designing block copolymer architectures for targeted membrane performance

    KAUST Repository

    Dorin, Rachel Mika; Phillip, William A.; Sai, Hiroaki; Werner, Jö rg; Elimelech, Menachem; Wiesner, Ulrich

    2014-01-01

    Using a combination of block copolymer self-assembly and non-solvent induced phase separation, isoporous ultrafiltration membranes were fabricated from four poly(isoprene-b-styrene-b-4-vinylpyridine) triblock terpolymers with similar block volume

  9. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland; Neelakanda, Pradeep; Behzad, Ali Reza; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

    2014-01-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene

  10. Fluctuations, conformational asymmetry and block copolymer phase behaviour

    DEFF Research Database (Denmark)

    Bates, F.S.; Schulz, M.F.; Khandpur, A.K.

    1994-01-01

    Phase behaviour near the order-disorder transition (ODT) of 58 model hydrocarbon diblock copolymers, representing four different systems, is summarized. Six distinct ordered-state microstructures are reported, including hexagonally modulated lamellae (HML), hexagonally perforated layers (HPL) and...

  11. Surface dynamics of micellar diblock copolymer films

    Science.gov (United States)

    Song, Sanghoon; Cha, Wonsuk; Kim, Hyunjung; Jiang, Zhang; Narayanan, Suresh

    2011-03-01

    We studied the structure and surface dynamics of poly(styrene)-b-poly(dimethylsiloxane) (PS-b-PDMS) diblock copolymer films with micellar PDMS surrounded by PS shells. By `in-situ' high resolution synchrotron x-ray reflectivity and diffuse scattering, we obtained exact thickness, electron density and surface tension. A segregation layer near the top surface was appeared with increasing temperature Surface dynamics were measured as a function of film thickness and temperature by x-ray photon correlation spectroscopy. The best fit to relaxation time constants as a function of in-plane wavevectors were analyzed with a theory based on capillary waves with hydrodynamics with bilayer model Finally the viscosities for the top segregated layer as well as for the bottom layer are obtained at given temperatures This work was supported by National Research Foundation of Korea (R15-2008-006-01001-0), Seoul Research and Business Development Program (10816), and Sogang University Research Grant (2010).

  12. Restructuring in block copolymer thin films

    DEFF Research Database (Denmark)

    Posselt, Dorthe; Zhang, Jianqi; Smilgies, Detlef-M.

    2017-01-01

    Block copolymer (BCP) thin films have been proposed for a number of nanotechnology applications, such as nanolithography and as nanotemplates, nanoporous membranes and sensors. Solvent vapor annealing (SVA) has emerged as a powerful technique for manipulating and controlling the structure of BCP...... thin films, e.g., by healing defects, by altering the orientation of the microdomains and by changing the morphology. Due to high time resolution and compatibility with SVA environments, grazing-incidence small-angle X-ray scattering (GISAXS) is an indispensable technique for studying the SVA process......, providing information of the BCP thin film structure both laterally and along the film normal. Especially, state-of-the-art combined GISAXS/SVA setups at synchrotron sources have facilitated in situ and real-time studies of the SVA process with a time resolution of a few seconds, giving important insight...

  13. Thin Film Assembly of Spider Silk-like Block Copolymers

    Science.gov (United States)

    2011-01-01

    Shipley, N. H.; Lewis, R. V. Int. J. Biol.Macromol. 1999, 24, 271. (c) Thiel, B. L.; Guess, K. B.; Viney, C. Biopolymers 1997, 41, 703. (13) Silk ...Film Assembly of Spider Silk -like Block Copolymers Sreevidhya T. Krishnaji,†,‡ Wenwen Huang,§ Olena Rabotyagova,†,‡ Eugenia Kharlampieva, ) Ikjun Choi...Received November 26, 2010 We report the self-assembly of monolayers of spider silk -like block copolymers. Langmuir isotherms were obtained for a series of

  14. Theory of Primary Photoexcitations in Donor-Acceptor Copolymers

    OpenAIRE

    Aryanpour, Karan; Dutta, Tirthankar; Huynh, Uyen N. V.; Vardeny, Zeev Valy; Mazumdar, Sumit

    2015-01-01

    We present a generic theory of primary photoexcitations in low band gap donor-acceptor conjugated copolymers. Because of the combined effects of strong electron correlations and broken symmetry, there is considerable mixing between a charge-transfer exciton and an energetically proximate triplet-triplet state with an overall spin singlet. The triplet-triplet state, optically forbidden in homopolymers, is allowed in donor-acceptor copolymers. For an intermediate difference in electron affiniti...

  15. Biodegradable copolymers carrying cell-adhesion peptide sequences.

    Science.gov (United States)

    Proks, Vladimír; Machová, Lud'ka; Popelka, Stepán; Rypácek, Frantisek

    2003-01-01

    Amphiphilic block copolymers are used to create bioactive surfaces on biodegradable polymer scaffolds for tissue engineering. Cell-selective biomaterials can be prepared using copolymers containing peptide sequences derived from extracellular-matrix proteins (ECM). Here we discuss alternative ways for preparation of amphiphilic block copolymers composed of hydrophobic polylactide (PLA) and hydrophilic poly(ethylene oxide) (PEO) blocks with cell-adhesion peptide sequences. Copolymers PLA-b-PEO were prepared by a living polymerisation of lactide in dioxane with tin(II)2-ethylhexanoate as a catalyst. The following approaches for incorporation of peptides into copolymers were elaborated. (a) First, a side-chain protected Gly-Arg-Gly-Asp-Ser-Gly (GRGDSG) peptide was prepared by solid-phase peptide synthesis (SPPS) and then coupled with delta-hydroxy-Z-amino-PEO in solution. In the second step, the PLA block was grafted to it via a controlled polymerisation of lactide initiated by the hydroxy end-groups of PEO in the side-chain-protected GRGDSG-PEO. Deprotection of the peptide yielded a GRGDSG-b-PEO-b-PLA copolymer, with the peptide attached through its C-end. (b) A protected GRGDSG peptide was built up on a polymer resin and coupled with Z-carboxy-PEO using a solid-phase approach. After cleavage of the delta-hydroxy-PEO-GRGDSG copolymer from the resin, polymerisation of lactide followed by deprotection of the peptide yielded a PLA-b-PEO-b-GRGDSG block copolymer, in which the peptide is linked through its N-terminus.

  16. Microbial production of polyhydroxyalkanoate block copolymer by recombinant Pseudomonas putida.

    Science.gov (United States)

    Li, Shi Yan; Dong, Cui Ling; Wang, Shen Yu; Ye, Hai Mu; Chen, Guo-Qiang

    2011-04-01

    Polyhydroxyalkanoate (PHA) synthesis genes phaPCJ(Ac) cloned from Aeromonas caviae were transformed into Pseudomonas putida KTOY06ΔC, a mutant of P. putida KT2442, resulting in the ability of the recombinant P. putida KTOY06ΔC (phaPCJ(A.c)) to produce a short-chain-length and medium-chain-length PHA block copolymer consisting of poly-3-hydroxybutyrate (PHB) as one block and random copolymer of 3-hydroxyvalerate (3HV) and 3-hydroxyheptanoate (3HHp) as another block. The novel block polymer was studied by differential scanning calorimetry (DSC), nuclear magnetic resonance, and rheology measurements. DSC studies showed the polymer to possess two glass transition temperatures (T(g)), one melting temperature (T(m)) and one cool crystallization temperature (T(c)). Rheology studies clearly indicated a polymer chain re-arrangement in the copolymer; these studies confirmed the polymer to be a block copolymer, with over 70 mol% homopolymer (PHB) of 3-hydroxybutyrate (3HB) as one block and around 30 mol% random copolymers of 3HV and 3HHp as the second block. The block copolymer was shown to have the highest tensile strength and Young's modulus compared with a random copolymer with similar ratio and a blend of homopolymers PHB and PHVHHp with similar ratio. Compared with other commercially available PHA including PHB, PHBV, PHBHHx, and P3HB4HB, the short-chain- and medium-chain-length block copolymer PHB-b-PHVHHp showed differences in terms of mechanical properties and should draw more attentions from the PHA research community. © Springer-Verlag 2010

  17. Novel block, graft and random copolymers for biomedical applications

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Jankova Atanasova, Katja; Tanaka, Masaru

    Despite the simple structure, poly(2-methoxyethyl acrylate) (PMEA) shows excellent blood compatibility [1]. Both the freezing-bound water (intermediate water: preventing the biocomponents from directly contacting the polymer surface) and non-freezing water on the polymer surface play important...... copolymers with MMA [4] utilizing ATRP. Here we present other block, graft and random copolymers of MEA intended for biomedical applications. These macromolecular architectures have been constructed by employing controlled radical polymerization methods such as RAFT and ATRP....

  18. Synthesis and Characterization of Novel Magnetite Nanoparticle Block Copolymer Complexes

    OpenAIRE

    Zhang, Qian

    2007-01-01

    Superparamagnetic Magnetite (Fe3O4) nanoparticles were synthesized and complexed with carboxylate-functionalized block copolymers, and aqueous dispersions of the complexes were investigated as functions of their chemical and morphological structures. The block copolymer dispersants possessed either poly(ethylene oxide), poly(ethylene oxide-co-propylene oxide), or poly(ethylene oxide-b-propylene oxide) outer blocks, and all contained a polyurethane center block with pendant carboxylate functi...

  19. Electrorheological Properties of Suspensions Prepared from Polystyrene- Block- Polyisoprene Copolymer

    OpenAIRE

    YAVUZ, Mustafa

    2014-01-01

    Considerable scientific and industrial interest is currently being focused on a class of materials known as electrorheological (ER) fluids, which display remarkable rheological behaviour, being able to convert rapidly and repeatedly from a liquid to solid when an electric field (E) is applied or removed. In this article, the synthesis, characterization, partial hydrolysis and ER properties of polystyrene- block}-polyisoprene copolymer (COP) were investigated. The block copolymer was ...

  20. On the ether-like Lorentz-breaking actions

    International Nuclear Information System (INIS)

    Petrov, A.Yu; Nascimento, J.R.; Gomes, M.; Silva, A. J. da

    2011-01-01

    We demonstrate the generation of the CPT-even, ether-like Lorentz-breaking actions for the scalar and electro-magnetic fields via their appropriate Lorentz-breaking coupling to spinor fields in three, four and five space-time dimensions. Besides, we show that the ether-like terms for the spinor field also can be generated as a consequence of the same couplings. The key result which will be presented here is the finiteness of the ether-like term for the electromagnetic field not only in three and five space-time dimensions where it is natural due to known effects of the dimensional regularization but also in four space-time dimensions. Moreover, we present the calculation of the last result within different calculational schemes and conclude that the result for the four-dimensional ether-like term for the electromagnetic field essentially depending on the calculation scheme, similarly to the result for the Carroll-Field-Jackiw (CFJ) term which probably signalizes a possibility for arising of a new anomaly. Also we discuss the dispersion relations in the theories with ether-like Lorentz-breaking terms which allows to discuss the consistency of the Lorentz-breaking modified theories for different (space-like or time-like) Lorentz-breaking vectors and find the tree-level effective (Breit) potential for fermion scattering and the one-loop effective potential corresponding to the action of the scalar field. (author)

  1. 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.

  2. 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.

  3. Mechanical Properties Optimization of Poly-Ether-Ether-Ketone via Fused Deposition Modeling

    Directory of Open Access Journals (Sweden)

    Xiaohu Deng

    2018-01-01

    Full Text Available Compared to the common selective laser sintering (SLS manufacturing method, fused deposition modeling (FDM seems to be an economical and efficient three-dimensional (3D printing method for high temperature polymer materials in medical applications. In this work, a customized FDM system was developed for polyether-ether-ketone (PEEK materials printing. The effects of printing speed, layer thickness, printing temperature and filling ratio on tensile properties were analyzed by the orthogonal test of four factors and three levels. Optimal tensile properties of the PEEK specimens were observed at a printing speed of 60 mm/s, layer thickness of 0.2 mm, temperature of 370 °C and filling ratio of 40%. Furthermore, the impact and bending tests were conducted under optimized conditions and the results demonstrated that the printed PEEK specimens have appropriate mechanical properties.

  4. Mechanical Properties Optimization of Poly-Ether-Ether-Ketone via Fused Deposition Modeling.

    Science.gov (United States)

    Deng, Xiaohu; Zeng, Zhi; Peng, Bei; Yan, Shuo; Ke, Wenchao

    2018-01-30

    Compared to the common selective laser sintering (SLS) manufacturing method, fused deposition modeling (FDM) seems to be an economical and efficient three-dimensional (3D) printing method for high temperature polymer materials in medical applications. In this work, a customized FDM system was developed for polyether-ether-ketone (PEEK) materials printing. The effects of printing speed, layer thickness, printing temperature and filling ratio on tensile properties were analyzed by the orthogonal test of four factors and three levels. Optimal tensile properties of the PEEK specimens were observed at a printing speed of 60 mm/s, layer thickness of 0.2 mm, temperature of 370 °C and filling ratio of 40%. Furthermore, the impact and bending tests were conducted under optimized conditions and the results demonstrated that the printed PEEK specimens have appropriate mechanical properties.

  5. Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

    International Nuclear Information System (INIS)

    Montero, Juan F.D.; Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C.; Benfatti, Cesar A.M.; Magini, Ricardo S.; Pimenta, Andréa L.; Souza, Júlio C.M.

    2017-01-01

    Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL −1 ) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL −1 was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

  6. Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

    Energy Technology Data Exchange (ETDEWEB)

    Montero, Juan F.D. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C. [Department of Mechanical Engineering (EMC), Federal University of Santa Catarina (UFSC), Florianópolis, SC 88040-900 (Brazil); Benfatti, Cesar A.M.; Magini, Ricardo S. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Pimenta, Andréa L. [Integrated Laboratories Technologies (InteLAB), Dept. Chemical Engineering (EQA), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-970 (Brazil); Department of Biologie, Université de Cergy Pontoise, 2, Av. Adolphe Chauvin, 95302 Cergy Pontoise (France); Souza, Júlio C.M., E-mail: julio.c.m.souza@ufsc.br [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Center for Microelectromechanical Systems (CMEMS), Dept. Mechanical Engineering (DEM), Campus Azurém, 4800-058 Guimarães (Portugal)

    2017-01-01

    Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL{sup −1}) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL{sup −1} was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

  7. Fuel cell performance of pendent methylphenyl sulfonated poly(ether ether ketone ketone)s

    Science.gov (United States)

    Zhang, Hanyu; Stanis, Ronald J.; Song, Yang; Hu, Wei; Cornelius, Chris J.; Shi, Qiang; Liu, Baijun; Guiver, Michael D.

    2017-11-01

    Meta- and para-linked homopolymers bearing 3-methylphenyl (Me) pendent groups were postsulfonated to create sulfonated poly(ether ether ketone ketone) (SPEEKK) backbone isomers, which are referred to as Me-p-SPEEKK and Me-m-SPEEKK. Their thermal and oxidative stability, mechanical properties, dimensional stability, methanol permeability, and proton conductivity are characterized. Me-p-SPEEKK and Me-m-SPEEKK proton conductivities at 100 °C are 116 and 173 mS cm-1, respectively. Their methanol permeabilities are 3.3-3.9 × 10-7 cm2 s-1, and dimensional swelling at 100 °C is 16.4-17.5%. Me-p-SPEEKK and Me-m-SPEEKK were fabricated into membrane electrode assemblies (MEAs), and electrochemical properties were evaluated within a direct methanol fuel cell (DMFC) and proton-exchange membrane fuel cell (PEMFC). When O2 is used as the oxidant at 80 °C and 100% RH, the maximum power density of Me-m-SPEEKK reaches 657 mW cm-2, which is higher than those of Nafion 115 (552 mW cm-2). DMFC performance is 85 mW cm-2 at 80 °C with 2.0 M methanol using Me-p-SPEEKK due to its low MeOH crossover. In general, these electrochemical results are comparable to Nafion. These ionomer properties, combined with a potentially less expensive and scalable polymer manufacturing process, may broaden their potential for many practical applications.

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

    Science.gov (United States)

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

    2012-05-01

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

  9. Spontaneous Generation of Chirality in Simple Diaryl Ethers.

    Science.gov (United States)

    Lennartson, Anders; Hedström, Anna; Håkansson, Mikael

    2015-07-01

    We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems. © 2015 Wiley Periodicals, Inc.

  10. Enzymatic network for production of ether amines from alcohols

    DEFF Research Database (Denmark)

    Palacio, Cyntia M.; Crismaru, Ciprian G.; Bartsch, Sebastian

    2016-01-01

    We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production...... of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed...... for reactions containing 10mM alcohol and up to 280mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up....

  11. Self-assembled Block Copolymer Membranes with Bioinspired Artificial Channels

    KAUST Repository

    Sutisna, Burhannudin

    2018-04-01

    Nature is an excellent design that inspires scientists to develop smart systems. In the realm of separation technology, biological membranes have been an ideal model for synthetic membranes due to their ultrahigh permeability, sharp selectivity, and stimuliresponse. In this research, fabrications of bioinspired membranes from block copolymers were studied. Membranes with isoporous morphology were mainly prepared using selfassembly and non-solvent induced phase separation (SNIPS). An effective method that can dramatically shorten the path for designing new isoporous membranes from block copolymers via SNIPS was first proposed by predetermining a trend line computed from the solvent properties, interactions and copolymer block sizes of previously-obtained successful systems. Application of the method to new copolymer systems and fundamental studies on the block copolymer self-assembly were performed. Furthermore, the manufacture of bioinspired membranes was explored using (1) poly(styrene-b-4-hydroxystyrene-b-styrene) (PS-b-PHS-b-PS), (2) poly(styrene-bbutadiene- b-styrene) (PS-b-PB-b-PS) and (3) poly(styrene-b-γ-benzyl-L-glutamate) (PSb- PBLG) copolymers via SNIPS. The structure formation was investigated using smallangle X-ray scattering (SAXS) and time-resolved grazing-Incidence SAXS. The PS-b- PHS-b-PS membranes showed preferential transport for proteins, presumably due to the hydrogen bond interactions within the channels, electrostatic attraction, and suitable pore dimension. Well-defined nanochannels with pore sizes of around 4 nm based on PS-b- PB-b-PS copolymers could serve as an excellent platform to fabricate bioinspired channels due to the modifiable butadiene blocks. Photolytic addition of thioglycolic acid was demonstrated without sacrificing the self-assembled morphology, which led to a five-fold increase in water permeance compared to that of the unmodified. Membranes with a unique feather-like structure and a lamellar morphology for dialysis and

  12. Radiation-induced glycoside bond breaking in cellulose methyl ethers

    International Nuclear Information System (INIS)

    Petryaev, E.P.; Boltromeyuk, V.V.; Kovalenko, N.I.; Shadyro, O.I.

    1988-01-01

    Radiation-induced destruction of cellulose methyl ethers of different degree of esterification in aqueous solutions with and without acceptors: (N 2 O, O 2 , H 2 O + , Co(2), Cu(2)) is investigated. It is established that OH radicals make main contribution into radiolytic transformations of cellulose ethers in aqueous solutions. Reactions of radicals with free valency on carbon atoms containing secondary nonsubstituted hydroxyl groups lead also to glycoside bond breaking besides the reaction of β-fragmentation and hydrolysis of radicals with an unpaired electron localized near C 1 , C 4 , C 5 aroms

  13. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  14. The Use of Radioactive Marker as a Tool to Evaluate the Drug Release in Plasma and Particle Biodistribution of Block Copolymer Nanoparticles

    Directory of Open Access Journals (Sweden)

    Sharon Johnstone

    2011-01-01

    Full Text Available Diblock copolymer nanoparticles encapsulating a paclitaxel prodrug, Propac 7, have been used to demonstrate the usefulness of a nonmetabolizable radioactive marker, cholesteryl hexadecyl ether (CHE, to evaluate nanoparticle formulation variables. Since CHE did not exchange out of the nanoparticles, the rate of clearance of the CHE could be used as an indicator of nanoparticle stability in vivo. We simultaneously monitored prodrug circulation and carrier circulation in the plasma and the retention of CHE relative to the retention of prodrug in the plasma was used to distinguish prodrug release from nanoparticle plasma clearance. Nanoparticles labelled with CHE were also used to evaluate accumulation of nanoparticles in the tumour. This marker has provided relevant data which we have applied to optimise our nanoparticle formulations.

  15. 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.

  16. 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

  17. A Study on Copolymer Systems of Styrene with Diethanolamine Side Group and Methyl Methacrylate

    Directory of Open Access Journals (Sweden)

    Aslisah Acikses

    2018-01-01

    Full Text Available 4-Diethanolaminomethyl styrene (DEAMSt monomer was prepared by the modification of 4-chloromethyl styrene with diethanolamine. The copolymers in different combinations (0.11, 0.19, and 0.30 by mole of DEAMSt and methyl methacrylate (MMA were prepared by free radical polymerization method at 60°C in the presence of 1,4-dioxane and AIBN as initiator. The structures of DEAMSt and DEAMSt-MMA copolymer were characterized by FT-IR and 1H-NMR. The glass transition temperature (Tg of the copolymers was measured by DSC. Thermal decomposition behavior of the copolymers was investigated by TGA. The average molecular weights of the copolymers were determined by GPC. The dye uptaking properties of the copolymers were investigated using bromocresol green. Then, the dielectric constant, dielectric loss factor, and conductivity of copolymers were investigated as a function of temperature and frequency. The activation energies (Ea of the copolymers were determined by impedance analyzer.

  18. Tuning the Optoelectronic Properties of Vinylene-Linked Donor−Acceptor Copolymers for Organic Photovoltaics

    KAUST Repository

    Ko, Sangwon; Mondal, Rajib; Risko, Chad; Lee, Jung Kyu; Hong, Sanghyun; McGehee, Michael D.; Brédas, Jean-Luc; Bao, Zhenan

    2010-01-01

    -property relationships in organic photovoltaic devices. Both alternating (P) and random copolymers (P1-P4) were prepared via Suzuki and Stille polycondensations, respectively. The cyclopentadithiophene copolymers (P2 and P4) have smaller electrochemical band gaps (1

  19. Monte Carlo simulations of the phase separation of a copolymer blend in a thin film

    KAUST Repository

    Wang, Zhexiao

    2014-12-11

    Monte Carlo simulations were carried out to study the phase separation of a copolymer blend comprising an alternating copolymer and/or block copolymer in a thin film, and a phase diagram was constructed with a series of composed recipes. The effects of composition and segregation strength on phase separation were discussed in detail. The chain conformation of the block copolymer and alternating copolymer were investigated with changes of the segregation strength. Our simulations revealed that the segment distribution along the copolymer chain and the segregation strength between coarse-grained beads are two important parameters controlling phase separation and chain conformation in thin films of a copolymer blend. A well-controlled phase separation in the copolymer blend can be used to fabricate novel nanostructures.

  20. Triplet State Formation in Photovoltaic Blends of DPP-Type Copolymers and PC71BM

    KAUST Repository

    Ochsmann, Julian R.; Chandran, Deepak; Gehrig, Dominik W.; Anwar, Husna; Madathil, Pramod Kandoth; Lee, Kwang-Sup; Laquai, Fré dé ric

    2015-01-01

    The exciton dynamics in pristine films of two structurally related low-bandgap diketopyrrolopyrrole (DPP)-based donor–acceptor copolymers and the photophysical processes in bulk heterojunction solar cells using DPP copolymer:PC71BM blends

  1. CO2-Philic Thin Film Composite Membranes: Synthesis and Characterization of PAN-r-PEGMA Copolymer

    KAUST Repository

    Karunakaran, Madhavan; Kumar, Mahendra; Shevate, Rahul; Akhtar, Faheem Hassan; Peinemann, Klaus-Viktor

    2017-01-01

    amounts of PEG content was synthesized by free radical polymerization in presence of AIBN initiator and the obtained copolymers were used for the fabrication of composite membranes. The synthesized copolymers show high molecular weights in the range of 44

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

    Science.gov (United States)

    2010-07-01

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

  3. Incomplete copolymer degradation of in situ chemotherapy.

    Science.gov (United States)

    Bourdillon, Pierre; Boissenot, Tanguy; Goldwirt, Lauriane; Nicolas, Julien; Apra, Caroline; Carpentier, Alexandre

    2018-02-17

    In situ carmustine wafers containing 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) are commonly used for the treatment of recurrent glioblastoma to overcome the brain-blood barrier. In theory, this chemotherapy diffuses into the adjacent parenchyma and the excipient degrades in maximum 8 weeks but no clinical data confirms this evolution, because patients are rarely operated again. A 75-year-old patient was operated twice for recurrent glioblastoma, and a carmustine wafer was implanted during the second surgery. Eleven months later, a third surgery was performed, revealing unexpected incomplete degradation of the wafer. 1H-Nuclear Magnetic Resonance was performed to compare this wafer to pure BCNU and to an unused copolymer wafer. In the used wafer, peaks corresponding to hydrophobic units of the excipient were no longer noticeable, whereas peaks of the hydrophilic units and traces of BCNU were still present. These surprising results could be related to the formation of a hydrophobic membrane around the wafer, thus interfering with the expected diffusion and degradation processes. The clinical benefit of carmustine wafers in addition to the standard radio-chemotherapy remains limited, and in vivo behavior of this treatment is not completely elucidated yet. We found that the wafer may remain after several months. Alternative strategies to deal with the blood-brain barrier, such as drug-loaded liposomes or ultrasound-opening, must be explored to offer larger drug diffusion or allow repetitive delivery.

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

    Science.gov (United States)

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

    2018-01-01

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

  5. Design of block copolymer membranes using segregation strength trend lines

    KAUST Repository

    Sutisna, Burhannudin

    2016-05-18

    Block copolymer self-assembly and non-solvent induced phase separation are now being combined to fabricate membranes with narrow pore size distribution and high porosity. The method has the potential to be used with a broad range of tailor-made block copolymers to control functionality and selectivity for specific separations. However, the extension of this process to any new copolymer is challenging and time consuming, due to the complex interplay of influencing parameters, such as solvent composition, polymer molecular weights, casting solution concentration, and evaporation time. We propose here an effective method for designing new block copolymer membranes. The method consists of predetermining a trend line for the preparation of isoporous membranes, obtained by computing solvent properties, interactions and copolymer block sizes for a set of successful systems and using it as a guide to select the preparation conditions for new membranes. We applied the method to membranes based on poly(styrene-b-ethylene oxide) diblocks and extended it to newly synthesized poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-b-P2VP-b-PEO) terpolymers. The trend line method can be generally applied to other new systems and is expected to dramatically shorten the path of isoporous membrane manufacture. The PS-b-P2VP-b-PEO membrane formation was investigated by in situ Grazing Incident Small Angle X-ray Scattering (GISAXS), which revealed a hexagonal micelle order with domain spacing clearly correlated to the membrane interpore distances.

  6. SANS and SAXS study of block copolymer/homopolymer mixtures

    International Nuclear Information System (INIS)

    Hasegawa, Hirokazu; Tanaka, Hideaki; Hashimoto, Takeji; Han, C.C.

    1991-01-01

    The lateral and vertical components of the radius of gyration for a single block copolymer chain and those of a single homopolymer chain in the lamellar microdomain space formed by a mixture of diblock copolymers and homopolymers were investigated by means of small-angle neutron scattering (SANS) and the microdomain structures by small-angle X-ray scattering (SAXS). The homopolymers whose molecular weights are much smaller than that of the corresponding chains of the block copolymers were used so that the homopolymers were uniformly solubilized in the corresponding microdomains. The SANS result suggests that the homopolymer chains in the microdomain space as well as the block copolymer chains are more compressed in the direction parallel to the interface and more stretched in the direction perpendicular to the interface than the corresponding unperturbed polymer chains with the same molecular weight. On increasing the volume fraction of the homopolymers the thickness of the lamellar microdomains increases. The block copolymer chains were found to undergo an isochoric affine deformation on addition of the homopolymers or with the change of the thickness of the lamellar microdomains. (orig.)

  7. Relaxation processes in a lower disorder order transition diblock copolymer

    International Nuclear Information System (INIS)

    Sanz, Alejandro; Ezquerra, Tiberio A.; Nogales, Aurora; Hernández, Rebeca; Sprung, Michael

    2015-01-01

    The dynamics of lower disorder-order temperature diblock copolymer leading to phase separation has been observed by X ray photon correlation spectroscopy. Two different modes have been characterized. A non-diffusive mode appears at temperatures below the disorder to order transition, which can be associated to compositional fluctuations, that becomes slower as the interaction parameter increases, in a similar way to the one observed for diblock copolymers exhibiting phase separation upon cooling. At temperatures above the disorder to order transition T ODT , the dynamics becomes diffusive, indicating that after phase separation in Lower Disorder-Order Transition (LDOT) diblock copolymers, the diffusion of chain segments across the interface is the governing dynamics. As the segregation is stronger, the diffusive process becomes slower. Both observed modes have been predicted by the theory describing upper order-disorder transition systems, assuming incompressibility. However, the present results indicate that the existence of these two modes is more universal as they are present also in compressible diblock copolymers exhibiting a lower disorder-order transition. No such a theory describing the dynamics in LDOT block copolymers is available, and these experimental results may offer some hints to understanding the dynamics in these systems. The dynamics has also been studied in the ordered state, and for the present system, the non-diffusive mode disappears and only a diffusive mode is observed. This mode is related to the transport of segment in the interphase, due to the weak segregation on this system

  8. Highly conductive side chain block copolymer anion exchange membranes.

    Science.gov (United States)

    Wang, Lizhu; Hickner, Michael A

    2016-06-28

    Block copolymers based on poly(styrene) having pendent trimethyl styrenylbutyl ammonium (with four carbon ring-ionic group alkyl linkers) or benzyltrimethyl ammonium groups with a methylene bridge between the ring and ionic group were synthesized by reversible addition-fragmentation radical (RAFT) polymerization as anion exchange membranes (AEMs). The C4 side chain polymer showed a 17% increase in Cl(-) conductivity of 33.7 mS cm(-1) compared to the benzyltrimethyl ammonium sample (28.9 mS cm(-1)) under the same conditions (IEC = 3.20 meq. g(-1), hydration number, λ = ∼7.0, cast from DMF/1-propanol (v/v = 3 : 1), relative humidity = 95%). As confirmed by small angle X-ray scattering (SAXS), the side chain block copolymers with tethered ammonium cations showed well-defined lamellar morphologies and a significant reduction in interdomain spacing compared to benzyltrimethyl ammonium containing block copolymers. The chemical stabilities of the block copolymers were evaluated under severe, accelerated conditions, and degradation was observed by (1)H NMR. The block copolymer with C4 side chain trimethyl styrenylbutyl ammonium motifs displayed slightly improved stability compared to that of a benzyltrimethyl ammonium-based AEM at 80 °C in 1 M NaOD aqueous solution for 30 days.

  9. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  10. Controlling block copolymer phase behavior using ionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Ray, D.; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India E-mail: debes.phys@gmail.com (India)

    2016-05-23

    The phase behavior of poly(ethylene oxide)-poly(propylene oxide-poly(ethylene oxide) PEO-PPO-PEO triblock copolymer [P85 (EO{sub 26}PO{sub 39}EO{sub 26})] in presence of anionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution as a function of temperature has been studied using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactants. Each of the individual components (block copolymer and surfactant) and the nanoparticle–surfactant mixed system have been examined at varying temperature. The block copolymer P85 forms spherical micelles at room temperature whereas shows sphere-to-rod like micelle transition at higher temperatures. On the other hand, SDS surfactant forms ellipsoidal micelles over a wide temperature range. Interestingly, it is found that phase behavior of mixed micellar system (P85 + SDS) as a function of temperature is drastically different from that of P85, giving the control over the temperature-dependent phase behavior of block copolymers.

  11. High Resolution Rotational Spectroscopy of a Flexible Cyclic Ether

    Science.gov (United States)

    Gámez, F.; Martínez-Haya, B.; Blanco, S.; López, J. C.; Alonso, J. L.

    2011-06-01

    Crown ethers stand as one cornerstone molecular class inhost-guest Supramolecular Chemistry and constitute building blocks for a broad range of modern materials. We report here the first high resolution rotational study of a crown ether: 1,4,7,10,13-pentaoxacyclopentadecane (15-crown-5 ether,15c5). Molecular beam Fourier transform microwave spectroscopy has been employed. The liquid sample of 15c5 has been vaporized using heating methods. The considerable size of 15c5 and the broad range of conformations allowed by the flexibility of its backbone pose important challenges to spectroscopy approaches. In fact, the ab-initio computational study for isolated 15c5, yields at least six stable conformers with relative free energies within 2 kJ Mol-1 (167 Cm-1). Nevertheless, in this investigation it has been possible to identify and characterize in detail one stable rotamer of the 15c5 molecule and to challenge different quantum methods for the accurate description of this system. The results pave the ground for an extensive description of the conformational landscape of 15c5 and related cyclic ethers in the near term. J. L. Alonso, F. J. Lorenzo, J. C. López, A. Lesarri, S. Mata and H. Dreizler, Chem. Phys., 218, 267 (1997) S. Blanco, J.C López, J.L. Alonso, P. Ottaviani, W. Caminati, J. Chem. Phys. 119, 880 (2003) S.E. Hill, D. Feller, Int. J. Mass Spectrom. 201, 41 (2000)

  12. Direct transformation of silyl enol ethers into functionalized allenes.

    Science.gov (United States)

    Langer, P; Döring, M; Seyferth, D; Görls, H

    2001-02-02

    The first elimination reactions of silyl enol ethers to lithiated allenes are reported. These reactions allow a direct transformation of readily available silyl enol ethers into functionalized allenes. The action of three to four equivalents of lithium diisopropylamide (LDA) on silyl enol ethers results in the formation of lithiated allenes by initial allylic lithiation, subsequent elimination of a lithium silanolate, and finally, lithiation of the allene thus formed. Starting with amide-derived silyl imino ethers, lithiated ketenimines are obtained. A variety of reactions of the lithiated allenes with electrophiles (chlorosilanes, trimethylchlorostannane, dimethyl sulfate and ethanol) were carried out. Elimination of silanolate is observed only for substrates that contain the hindered SiMe2tBu or Si(iPr)3 moiety, but not for the SiMe3 group. The reaction of 1,1-dilithio-3,3-diphenylallene with ketones provides a convenient access to novel 1,1-di(hydroxymethyl)allenes which undergo a domino Nazarov-Friedel-Crafts reaction upon treatment with p-toluenesulfonic acid.

  13. Ether lipids of planktonic archae in the marine water column

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hoefs, M.J.L.; Schouten, S.; King, L.L.; Wakeham, S.G.; Leeuw, J.W. de

    1997-01-01

    Acyclic and cyclic biphytanes derived from the membrane ether lipids of archaea were found in water column particulate and sedimentary organic matter from several oxic and anoxic marine environments. Compound-specific isotope analyses of the carbon skeletons suggest that planktonic archaea utilize

  14. Diethyl Ether Production as a Substitute for Gasoline

    Directory of Open Access Journals (Sweden)

    Alviany Riza

    2018-01-01

    Full Text Available Diethyl ether is one of alternative fuel that could be used as a significant component of a blend or as a complete replacement for transportation fuel. The aim of this research is to produce diethyl ether through dehydration reaction of ethanol with fixed bed reactor using nanocrystalline γ-Al2O3 catalyst. Nanocrystalline γ-Al2O3 catalyst was synthesized by precipitation method using Al(NO33.9H2O as precursors and NH4OH as the precipitating agent. Dehydration reaction was performed at temperature range of 125 to 225°C. The result shows that synthesized γ-Al2O3 catalyst gave higher ethanol conversion and diethyl ether yield than that of commercial Al2O3 catalyst. The use of synthesized γ-Al2O3 catalyst could reach ethanol conversion as high as 94.71% and diethyl ether yield as high as 11,29%.

  15. Diethyl Ether Production Process with Various Catalyst Type

    Directory of Open Access Journals (Sweden)

    Widayat Widayat

    2012-12-01

    Full Text Available Several H-zeolite and HZSM-5 catalysts was preparated and their characters have also been investigated. H-zeolit Catalyst was preparated from Natural Zeolite that obtained from Malang District and Gunung Kidul District. Diethyl ether was produced by Ethanol with concentration of 95%. This research use fixed bed reactor that 1 gram of catalyst as bed catalyst, atmospheric pressure and temperature 140oC as the operating condition. Ethanol vapor from vaporization tank was driven by 200 ml/min Nitrogen stream. The responds in this research is liquid product concentration; diethyl ether, ethanol, methanol and water concentration. The results showed that the largest ethanol conversion was produced by the use of 56.44% HZSM-5 and the largest yield of diethyl ether diethyl was produced by the use of alumina and H-zeolite catalyst. The larger ratio between natural zeolite with HCl solvent will produce the larger surface area of catalyst and ethanol conversion. The largest ethanol conversion was produced at reactan ratio 1:20. [Keywords:  catalyst; ethanol conversion; dehydration process; yield of diethyl ether; natural zeolite].

  16. Photodegradation of poly(ether sulphone). Part 2

    DEFF Research Database (Denmark)

    Norrman, K.; Krebs, Frederik C

    2004-01-01

    The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

  17. Radiation chemistry of alternative fuel oxygenates - substituted ethers

    International Nuclear Information System (INIS)

    Mezyk, S. P.; Cooper, W. J.; Bartels, D. M.; Tobien, T.; O'Shea, K. E.

    1999-01-01

    The electron beam process, an advanced oxidation and reduction technology, is based in the field of radiation chemistry. Fundamental to the development of treatment processes is an understanding of the underlying chemistry. The authors have previously evaluated the bimolecular rate constants for the reactions of methyl tert-butyl ether (MTBE) and with this study have extended their studies to include ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE) and tert-amyl methyl ether (TAME) with the hydroxyl radical, hydrogen atom and solvated electron using pulse radiolysis. For all of the oxygenates the reaction with the hydroxyl radical appears to be of primary interest in the destruction of the compounds in water. The rates with the solvated electron are limiting values as the rates appear to be relatively low. The hydrogen atom rate constants are relatively low, coupled with the low yield in radiolysis, they concluded that these are of little significance in the destruction of the alternative fuel oxygenates (and MTBE)

  18. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety asp...

  19. Formation and Structural Analysis of Novel Dibornyl Ethers | Kaye ...

    African Journals Online (AJOL)

    One- and two-dimensional NMR spectroscopy has been used to establish the regio- and stereochemistry of novel dibornyl ethers, obtained by acid-catalysed condensation of camphor-derived a-hydroxybornanones. South African Journal of Chemistry Vol.55 2002: 111-118 ...

  20. Enzymatic network for production of ether amines from alcohols

    NARCIS (Netherlands)

    Palacio, Cyntia M.; Crismaru, Gica Ciprian; Bartsch, Sebastian; Navickas, Vaidotas; Ditrich, Klaus; Breuer, Michael; Abu, Rohana; Woodley, John; Baldenius, Kai-Uwe; Wu, Bian; Janssen, Dick

    We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production of the

  1. Ether and interpretation of some physical phenomena and concepts

    International Nuclear Information System (INIS)

    Rzayev, S.G.

    2008-01-01

    On the basis of the concept of existence of an ether representation about time, space, matters and physical field are profound and also the essence of such phenomena, as corpuscular - wave dualism, change of time, scale and mass at movement body's is opened. The opportunity of transition from probability-statistical interpretation of the quantum phenomena to Laplace's determinism is shown

  2. Polystyrene-b-polyethylene oxide block copolymer membranes, methods of making, and methods of use

    KAUST Repository

    Peinemann, Klaus-Viktor; Karunakaran, Madhavan

    2015-01-01

    Embodiments of the present disclosure provide for polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer nanoporous membranes, methods of making a PS-b-PEO block copolymer nanoporous membrane, methods of using PS-b-PEO block copolymer nanoporous membranes, and the like.

  3. 78 FR 20032 - Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-04-03

    ...-Ethylene-Propylene Block Copolymer; Tolerance Exemption AGENCY: Environmental Protection Agency (EPA... for residues of styrene-ethylene-propylene block copolymer (CAS Reg. No. 108388-87-0) when used as an...-ethylene-propylene block copolymer on food or feed commodities. DATES: This regulation is effective April 3...

  4. 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...

  5. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...

  6. Realization of an integrated VDF/TrFE copolymer-on-silicon pyroelectric sensor

    NARCIS (Netherlands)

    Setiadi, D.; Setiadi, D.; Regtien, Paulus P.L.; Sarro, P.M.

    1995-01-01

    An integrated pyroelectric sensor based on a vinylidene fluoride trifluoroethylene (VDF/TrFE) copolymer is presented. A silicon substrate that contains FET readout electronics is coated with the VDF/TrFE copolymer film using a spin-coating technique. On-chip poling of the copolymer has been applied

  7. 40 CFR 180.1162 - Acrylate polymers and copolymers; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acrylate polymers and copolymers... RESIDUES IN FOOD Exemptions From Tolerances § 180.1162 Acrylate polymers and copolymers; exemption from the requirement of a tolerance. (a) Acrylate polymers and copolymers are exempt from the requirement of a...

  8. Polystyrene-b-polyethylene oxide block copolymer membranes, methods of making, and methods of use

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-04-16

    Embodiments of the present disclosure provide for polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer nanoporous membranes, methods of making a PS-b-PEO block copolymer nanoporous membrane, methods of using PS-b-PEO block copolymer nanoporous membranes, and the like.

  9. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may be...

  10. Basic randomness of nature and ether-drift experiments

    International Nuclear Information System (INIS)

    Consoli, M.; Pluchino, A.; Rapisarda, A.

    2011-01-01

    Highlights: ► We re-consider the idea of a basic randomness of nature. ► We adopt Stochastic Electro Dynamics as a heuristic model. ► We represent the vacuum as a form of turbulent ether. ► This picture can be tested with forthcoming ether-drift experiments. - Abstract: We re-consider the idea that quantum fluctuations might reflect the existence of an ‘objective randomness’, i.e. a basic property of the vacuum state which is independent of any experimental accuracy of the observations or limited knowledge of initial conditions. Besides being responsible for the observed quantum behavior, this might introduce a weak, residual form of ‘noise’ which is intrinsic to natural phenomena and could be important for the emergence of complexity at higher physical levels. By adopting Stochastic Electro Dynamics as a heuristic model, we are driven to a picture of the vacuum as a form of highly turbulent ether, which is deep-rooted into the basic foundational aspects of both quantum physics and relativity, and to search for experimental tests of this scenario. An analysis of the most precise ether-drift experiments, operating both at room temperature and in the cryogenic regime, shows that, at present, there is some ambiguity in the interpretation of the data. In fact the average amplitude of the signal has precisely the magnitude expected, in a ‘Lorentzian’ form of relativity, from an underlying stochastic ether and, as such, might not be a spurious instrumental effect. This puzzle, however, should be solved in a next future with the use of new cryogenically cooled optical resonators whose stability should improve by about two orders of magnitude. In these new experimental conditions, the persistence of the present amplitude would represent a clean evidence for the type of random vacuum we are envisaging.

  11. Mixture Genotoxicity of 2,4-Dichlorophenoxyacetic Acid, Acrylamide, and Maleic Hydrazide on Human Caco-2 Cells Assessed with Comet Assay

    DEFF Research Database (Denmark)

    Syberg, Kristian; Binderup, Mona-Lise; Cedergreen, Nina

    2015-01-01

    Assessment of genotoxic properties of chemicals is mainly conducted only for single chemicals, without taking mixture genotoxic effects into consideration. The current study assessed mixture effects of the three known genotoxic chemicals, 2,4-dichlorophenoxyacetic acid (2,4-D), acrylamide (AA......), and maleic hydrazide (MH), in an experiment with a fixed ratio design setup. The genotoxic effects were assessed with the single-cell gel electrophoresis assay (comet assay) for both single chemicals and the ternary mixture. The concentration ranges used were 0-1.4, 0-20, and 0-37.7 mM for 2,4-D, AA, and MH......, respectively. Mixture toxicity was tested with a fixed ratio design at a 10:23:77% ratio for 2.4-D:AA:MH. Results indicated that the three chemicals yielded a synergistic mixture effect. It is not clear which mechanisms are responsible for this interaction. A few possible interactions are discussed...

  12. 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.

  13. 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.

  14. Effects of Polyethylene Grafted Maleic Anhydride on the Mechanical, Morphological, and Swelling Properties of Poly (Vinyl Chloride / Epoxidized Natural Rubber / Kenaf Core Powder Composites

    Directory of Open Access Journals (Sweden)

    Rohani Abdul Majid

    2014-10-01

    Full Text Available The effects of polyethylene grafted maleic anhydride (PE-g-MA on the properties of poly (vinyl chloride/epoxidized natural rubber (PVC/ENR kenaf core powder composites were studied, with four different loadings of kenaf core powder (5, 10, 15, and 20 phr. The tensile properties indicated that the strength and elongation at break of the composites exhibited an increase for samples with PE-g-MA. Morphological analysis using a scanning electron microscope (SEM showed better dispersion of kenaf fiber with the addition of PE-g-MA and less kenaf powder agglomeration. Furthermore, the swelling index indicated that composites with PE-g-MA showed lower toluene absorption than composites without PE-g-MA.

  15. A mild and efficient procedure for the synthesis of ethers from various alkyl halides

    Directory of Open Access Journals (Sweden)

    Mosstafa Kazemi

    2013-10-01

    Full Text Available A simple, mild and practical procedure has been developed for the synthesis of symmetrical and unsymmetrical ethers by using DMSO, TBAI in the presence of K2CO3. We extended the utility of Potassium carbonate as an efficient base for the preparation of ethers. A wide range of alkyl aryl and dialkyl ethers are synthezied from treatment of aliphatic alcohols and phenols with various alkyl halides in the prescence of efficient base Potassium carbonate. Secondary alkyl halides were easily converted to corresponding ethers in releatively good yields . This is a mild, simple and practical procedure for the preparation of ethers in high yields and suitable times under mild condition.

  16. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland

    2014-12-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer.

  17. Morphologies of precise polyethylene-based acid copolymers and ionomers

    Science.gov (United States)

    Buitrago, C. Francisco

    Acid copolymers and ionomers are polymers that contain a small fraction of covalently bound acidic or ionic groups, respectively. For the specific case of polyethylene (PE), acid and ionic pendants enhance many of the physical properties such as toughness, adhesion and rheological properties. These improved properties result from microphase separated aggregates of the polar pendants in the non-polar PE matrix. Despite the widespread industrial use of these materials, rigorous chemical structure---morphology---property relationships remain elusive due to the inevitable structural heterogeneities in the historically-available acid copolymers and ionomers. Recently, precise acid copolymers and ionomers were successfully synthesized by acyclic diene metathesis (ADMET) polymerization. These precise materials are linear, high molecular weight PEs with pendant acid or ionic functional groups separated by a precisely controlled number of carbon atoms. The morphologies of nine precise acid copolymers and eleven precise ionomers were investigated by X-ray scattering, solid-state 13C nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). For comparison, the morphologies of linear PEs with pseudo-random placement of the pendant groups were also studied. Previous studies of precise copolymers with acrylic acid (AA) found that the microstructural precision produces a new morphology in which PE crystals drive the acid aggregates into layers perpendicular to the chain axes and presumably at the interface between crystalline and amorphous phases. In this dissertation, a second new morphology for acid copolymers is identified in which the aggregates arrange on cubic lattices. The fist report of a cubic morphology was observed at room and elevated temperatures for a copolymer functionalized with two phosphonic acid (PA) groups on every 21st carbon atom. The cubic lattice has been identified as face-centered cubic (FCC). Overall, three morphology types have been

  18. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    /mol and minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...... for polystyrene-b-polyisoprene-b-polystyrene (SIS) block copolymers. The end use properties of SIS plasticized with polystyrene-b-alkyl, measured as tensile strength, is higher than for SIS plasticized with dioctyl adipate. The polystyrene-b-polybutadiene-b-polystyrene and polystyrene-bpoly(propylene glycol...

  19. Water stale and structure analysis of Konjac irradiation copolymer

    International Nuclear Information System (INIS)

    Geng Shengrong; Xia Hezhou; Chen Xueling; Ye Lixiu; Hua Yuejin

    2011-01-01

    To study the absorption performance of Konjac-AA copolymer prepared by using irradiation, the water absorption capacity, sorbent speed and water keeping ability were determined, DSC and TEM analysis were used to investigate the water content and structure characters. The results showed that the largest water absorption speed was 16 g · -1 · min -1 at room temperature, and the largest water absorption was 400 times within 60 minutes. The water absorption was affected by granularity, temperature, ion content and ion type, especially the ion type. The water keeping ability was affected by temperature and time, which was up to 35% of absorbed water when the fully water absorbed copolymer was kept under room temperature for 15 d. The free and bounder water content which could be assimilated by the plants was 99.617%. The water stale copolymer has a three-dimensional spiral structure. (authors)

  20. Thermoresponsive behavior of chitosan-g-N-isopropylacrylamide copolymer solutions.

    Science.gov (United States)

    Recillas, Maricarmen; Silva, Luisa L; Peniche, Carlos; Goycoolea, Francisco M; Rinaudo, Marguerite; Argüelles-Monal, Waldo M

    2009-06-08

    Chitosan-g-N-isopropylacrylamide (NIPAm) water-soluble copolymers were synthesized and characterized by FTIR and (1)H NMR spectroscopies combined with conductometric and potentiometric titrations. Their thermoresponsive, fully reversible, behavior in aqueous solutions was characterized by means of microcalorimetry and rheology. During heating of copolymer solutions there is a well-known endothermic effect, which coincides with a marked increase in G' and a moderate decrement in G'' due to the formation of a hydrophobic network at the expense of the net amount of sol fraction. It was also found that a straight dependence between the values of G' above the LCST and the enthalpies associated with the transition reflecting that the connectivity in the gel network is governed by the net number of formed enthalpic-hydrophobic driven-junctions. Both the LCST and the enthalpy change vary with the ionic strength of copolymer solutions, but no dependence was found with the neutralization of the polyelectrolyte chain.