Semi Ipn
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Proton conductive membranes based on poly (styrene-co-allyl alcohol) semi-IPN
The optimization of fuel cell materials, particularly polymer membranes, for PEMFC has driven the development of methods and alternatives to achieve systems with more adequate properties to this application. The sulfonation of poly (styrene-co-allyl alcohol) (PSAA), using sulfonating agent:styrene ratios of 2:1, 1:1, 1:2, 1:4, 1:6, 1:8 and 1:10, was previous
Polímeros. Publicado em: 10/06/2014
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2. Desenvolvimento de membranas mistas a base de poli(indeno) sulfonado e PVA reticulado com objetivo de aplicação em célula a combustível tipo PEM
The study on alternative membranes for use in fuel cells PEM (Proton Exchange Membrane) has been conducted by different research groups worldwide. As the commercial membranes still have high cost and performance limitations in certain operating conditions of fuel cells powered by hydrogen and alcohol. This study aimed to evaluate non-fluorinated membranes pr
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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3. Estudio cinético del efecto de polifenilsulfona sobre el curado de una resina epoxi/amina mediante calorimetría diferencial de barrido convencional y modulada con temperatura: parte II
In this work we studied the effect of the addition of the linear thermoplastic polyphenyl sulfone (PPSU) on the cure kinetics and the thermal properties of a resin based on diglycidyl ether of bisphenol-A (DGEBA), cured with 4,4´-diaminodiphenyl sulfone (DDS). The kinetic study and the characterization process have been carried out by using differential sca
Polímeros. Publicado em: 12/11/2010
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4. Study of castor oil polyurethane - poly (methyl methacrylate) semi-interpenetrating polymer network (SIPN) reaction parameters using a 2³ factorial experimental design
In this work was employed a 23 factorial experiment design to evaluate the castor oil polyurethane- poly(methyl methacrylate) semi-IPN synthesis. The reaction parameters used as independent variables were NCO/OH molar ratio, polyurethane polymerization time and methyl methacrylate (MMA) content. The semi-IPNs were cured over 28 h using two thermal treatments
Publicado em: 2010
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5. Obtenção de polieletrólitos a partir de copolímero estireno-indeno para aplicação em célula a combustível tipo PEM
Neste trabalho foram desenvolvidas membranas eletrólito poliméricas, a partir de copolímero estireno-indeno (St-In) e poli(álcool vinílico) (PVA) para avaliação de seu desempenho em célula a combustível. Para tanto o copolímero estireno-indeno foi sulfonado com sulfato de acetila obtido pela reação de anidrido acético e ácido sulfúrico, com in
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2010
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6. Hidrogéis semi-IPN baseados em rede de alginato-Ca2+ com PNIPAAm entrelaçado: propriedades hidrofílicas, morfológicas e mecânicas
Neste trabalho, a termossensibilidade dos hidrogéis do tipo semi-IPN baseados em rede de alginato-Ca2+com poli(N-isopropil acrilamida) (PNIPAAm) entrelaçado, com diferentes teores de alginato e de PNIPAAm, foi caracterizada por meio de medidas de grau de intumescimento (Q), microscopia eletrônica de varredura (MEV) e propriedades mecânicas [tensão máxi
Polímeros. Publicado em: 2008-06
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7. Caracterização de hidrogéis condutores constituídos por PAAm e PEDOT/PSS por meio de planejamento fatorial
Neste trabalho, hidrogéis condutores do tipo semi-IPN constituídos por poliacrilamida (PAAm) e polímero intrinsecamente condutor poli(3,4-etileno dioxitiofeno)/poli(estireno-sulfonato) (PEDOT/PSS) foram sintetizados e suas propriedades hidrofílicas, mecânicas, condutoras e ópticas foram caracterizadas por meio de planejamento fatorial completo 2³ com
Polímeros. Publicado em: 2008-06
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8. Poly(vinyl alcohol)/sulfonated polyester hydrogels produced by freezing and thawing technique: preparation and characterization
Poly(vinyl alcohol) (PVA) hydrogels were obtained by freezing (-22 °C) and thawing (+25 °C) process, resulting in a semi-interpenetrating polymer network (s-IPN) with a sulfonated polyester (PES). The cryo-gels samples were analysed in terms of its water uptake capacity (WU) as a function of pH, temperature and ionic strength. WU of all samples were relati
Materials Research. Publicado em: 2007-03
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9. Resistência mecânica de hidrogéis termo-sensíveis constituídos de Alginato-Ca2+ / PNIPAAm, tipo Semi-IPN
Thermosensitive hydrogels were synthesized using alginate-Ca2+ in association with a thermosensitive polymer, such as PNIPAAm. The mechanical properties of the hydrogels were determined measuring the maximum tension of deformation. With the increase of the temperature by 25 to 40 ºC above the LCST the chains of PNIPAAm collapsed, dragging the alginate net a
Química Nova. Publicado em: 2007
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10. Study of castor oil polyurethane - poly(methyl methacrylate) semi-interpenetrating polymer network (SIPN) reaction parameters using a 2³ factorial experimental design
In this work was employed a 2³ factorial experiment design to evaluate the castor oil polyurethane-poly(methyl methacrylate) semi-IPN synthesis. The reaction parameters used as independent variables were NCO/OH molar ratio, polyurethane polymerization time and methyl methacrylate (MMA) content. The semi-IPNs were cured over 28 h using two thermal treatments
Materials Research. Publicado em: 2004-12
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11. Materiais condutores constituidos de polipirrol e borracha de EPDM
Este trabalho trata da preparação de misturas de polipirrol, PPi, e borracha de EPDM, um terpolímero de etileno-propileno-5-etiledeno-2-norborneno. Os materiais foram preparados pela oxidação química do pirrol em matrizes de EPDM preparadas de diversas formas. Obteve-se blendas de PPi/ EPDM a partir da incorporação mecânica do oxidante na forma de p
Publicado em: 1994
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12. Mechanically Robust and Bioadhesive Collagen and Photocrosslinkable Hyaluronic Acid Semi-Interpenetrating Networks
In this work, we present a class of hydrogels that leverage the favorable properties of the photo-cross-linkable hyaluronic acid (HA) and semi-interpenetrating collagen components. The mechanical properties of the semi-interpenetrating-network (semi-IPN) hydrogels far surpass those achievable with collagen gels or collagen gel–based semi-IPNs. Furthermore,
Mary Ann Liebert.