Chemical Modification Of Polymers
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. Hybrids membranes with potential for fuel cells – Part 3: extruded films of nanocomposites based on sepiolite and PC/sulfonated PC blends
Abstract Fuel Cells based in polymers are an alternative for the conventional energetic matrices. However, materials currently available still present disadvantages to overcome. Membranes of polycarbonate (PC)/sulfonated polycarbonate (PCs) blend/sepiolite nanocomposites have previously been studied by the authors, resulting in good mechanical properties an
Polímeros. Publicado em: 21/05/2018
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2. Modification of thermal and rheological behavior of asphalt binder by the addition of an ethylene-methyl acrylate-glycidyl methacrylate terpolymer and polyphosphoric acid
Abstract This study evaluated the modification effects of adding ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMGMA) in the presence of polyphosphoric acid (PPA) to an asphalt binder graded as 50/70 (0.1mm) in the Brazilian penetration grade specification (AC 50/70). The EMGMA terpolymer has been presented as a new alternative to modify asphalt
Polímeros. Publicado em: 2017-12
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3. Cholesterol improves the transfection efficiency of polyallylamine as a non-viral gene delivery vector
ABSTRACT Cationic polymers such as polyallylamine (PAA) having primary amino groups are poor transfection agents and possess a high cytotoxicity index when used without any chemical modification. In this study, PAA was modified with cholesterol in order to improve transfection efficiency and to reduce cytotoxicity. PAA polymers with molecular weights of 15 a
Braz. J. Pharm. Sci.. Publicado em: 26/10/2017
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4. Aplicações de enzimas na síntese e na modificação de polímeros
Enzymes are biological catalysts that offer great potential for use in the synthesis and modification of polymers, being more specific and greener than chemical catalysts. In this work, enzymes from the classes of hydrolases (lipase, cutinase and protease) and of oxidoreductases (horseradish peroxidase, manganese peroxidase and laccase) were identified as th
Quím. Nova. Publicado em: 2014
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5. Copolymer of acrylonitrile and vinyl-imidazole from the chemical modification of polyacrylonitrile / Obtenção do copolímero de acrilonitrila e vinil-imidazol a partir da modificação química da poliacrilonitrila
Polymers containing heterocyclic rings such as imidazole, have a great scientific and commercial interest due to its use in several areas. Such polymers can be obtained by chemical modification of polymers such as polyacrylonitrile commercial. Generally, this type of reaction is carried out by conventional heating (thermal). However, more recently, the micro
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2012
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6. Síntese e caracterização de poliuretano à base de óleo de Mabea fistulifera Mart. e sua utilização para remoção de corantes têxteis / Synthesis and characterization of Mabea fistulifera Mart. oil based polyurethane its use for textile dyes removal
Hard polyurethane polymers (PU-1, PU-2, PU-3 and PU-4) were developed in this study, obtained from polyols derived from Mabea fistulifera Mart oil. The chemical modification of the oil occurred through an in situ hydroxylation reaction employing acetic acid, hydrogen peroxide and sulfuric acid. The reaction conditions were optimized using a factorial composi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/05/2011
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7. Aplicações da celulose de palha de cana-de-açúcar: obtenção de derivados partindo de celulose branqueada e de biocompósitos com poliuretana obtida a partir de óleo de mamona (Ricinus communis L.) / Applications of sugarcane straw cellulose: obtainment of derivatives from bleached cellulose and biocomposites with polyurethane obtained from castor oil (Ricinus communis L.)
The sugarcane processing generates various agricultural byproducts such as bagasse and straw, which is considered one of the main waste generated due to the mechanization of the harvest in Brazil. Thus, the availability and composition of sugarcane straw have driven a great effort to develop technologies that provide its effective utilization. This study aim
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/04/2011
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8. Síntese e caracterização de derivados do politiofeno para utilização em sensores / Synthesis and characterization of polythiophene derivatives and their use in VOCs sensor applications
The conjugated polymers, especially polythiophenes, have emerged as alternative materials to obtain chemically selective layers in gas sensors. The main advantages of these materials are the possibility of obtaining sensing devices that operate at room temperature and the diversity of materials. For example, a simple modification of the side chain of polythi
Publicado em: 2010
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9. Sodium lignosulphonate as agent of modification of lignocellulosic fiber surface and formulation of phenolic thermoset / Lignosulfonato de sódio como agente de modificação da superfície de fibras lignocelulósicas e da formulação de termorrígido fenólico
Due to the great current interest in biocomposites because of both the use of lignocellulosic fibers as reinforcers of polymer matrices and the production of matrices prepared from renewable raw material, this study has sought to improve the properties of phenolic thermosets using sodium lignosulphonate as a macromonomer, and the insertion of sisal fibers, e
Publicado em: 2010
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10. Preparação e caracterização de pentóxido de vanádio mesoporoso e reações de intercalação / Synthesis and characterization of mesoporous vanadium pentoxide and intercalation reaction
Synthesis, characterization of vanadium pentoxide mesoporous and studies of properties of hybrids compound based on vanadium oxide xerogel and vanadium pentoxide mesoporous, intercalated with guest species have been the main of this thesis. The interest in those materials, that present a considerable structural and chemical modification, is due to the possib
Publicado em: 2007
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11. Estudo das condições operacionais na produção de xan-tana por X. arboricola pv pruni para aplicação em fluido de perfuração de poços de petróleo / Study of operational conditions in xanthan production by Xanthomonas arboricola pv pruni for oilwell drilling fluid
Xanthan yield and physical and chemical characteristics can be improved by modification in culture conditions, as well as, by post-fermentation treatments in order to obtain a xanthan with the required characteristics. The aim of this work was to study the operational conditions in xanthan production by Xanthomonas arborícola pv pruni strains 106 and 115 to
Publicado em: 2007
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12. "Biodegradação de poliuretano derivado do óleo de mamona" / "Biodegradation of poliurethane derived of castor oil"
The environment requires polymers that can be completely biodegraded through the action of several environmental factors, including microorganisms. The present work studied biodegradation of polyurethane foam obtained from castor oil, a renewable natural material, constituting a viable alternative to traditional PU foams. Biodegradation was compared for cast
Publicado em: 2006