Made available in DSpace on 2014-10-09T12:49:47Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:58Z (GMT). No. of bitstreams: 1 10382.pdf: 2748014 bytes, checksum: abae13684ec54f32e7a024de8f8bb50f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Made available in DSpace on 2014-10-09T12:33:18Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:16Z (GMT). No. of bitstreams: 0 / Este trabalho tem por objetivo a comparação das propriedades da superfície da poliamida 6.6 tratada por plasma e por radiação ionizante, assim como determinar qual a melhor técnica e condição para ativação da superfície, visando a adesão da mesma e borracha poliacrílica utilizada na fabricação de retentores automotivos. O tratamento da poliamida 6.6 por plasma foi realizado utilizando um equipamento Electronic DIENER Plasma Surface- Technology LFG40, com gás nitrogênio à pressão de 1,40 kg/cm2. As amostras de poliamida 6.6 também foram tratadas por radiação ionizante, à pressão atmosférica e em vácuo, utilizando um acelerador industrial de elétrons, Dynamitron JOB 188, com dose de radiação de 5, 10, 20, 40, 50, 100, 200, 300, 400 e 500kGy com taxa de dose de 11,22 kGy/s para todas as doses e taxa de 11,22 kGy/s e 22,38 kGy/s para a dose de 20kGy. Após os processos de modificação da superfície da poliamida 6.6, parte das amostras não tratadas, tratadas por plasma e por radiação ionizante foram incorporadas à borracha poliacrílica, e outra parte foi destinada a caracterização da superfície utilizando as técnicas de MEV/EDS, FT-IR, PIXE/RBS, AFM e ângulo de contato. As amostras não tratadas e as amostras irradiadas não aderiram à borracha poliacrílica. As amostras tratadas por plasma aderiram à borracha poliacrílica com eficiência e apresentaram diferenças de rugosidade, nas análises de MEV e AFM, e aumento no ângulo de contato quando comparado com as amostras não tratadas. As amostras irradiadas não apresentaram diferenças significativas de propriedades nas análises utilizadas neste trabalho, quando comparadas com as amostras não tratadas. A radiação ionizante não foi eficiente na modificação da superfície da poliamida 6.6 para aderência à borracha poliacrílica. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Orientador: Edison Bittencourt / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T16:21:18Z (GMT). No. of bitstreams: 1 Gasi_Fernando_M.pdf: 2453931 bytes, checksum: 454740009e7dabf55dc28cd805033c10 (MD5) Previous issue date: 2008 / Resumo: O presente trabalho, ¿Avaliação da Eficácia de Materiais Têxteis na Atividade Física¿, comparou como as diferenças de propriedades das fibras, o algodão e a poliamida 6.6, influenciam no desempenho esportivo. Avaliou a melhoria do rendimento físico durante a prática de atividade física devido ao uso de roupas confeccionadas com tecidos de alta tecnologia. Para este estudo comparativo escolheu-se duas matérias-primas, o algodão e a poliamida 6.6, e através das propriedades dessas amostras, como condutividade térmica, resistência térmica, retenção de água, absorção de umidade, e tempo de secagem, estudou-se o comportamento destes tecidos, comparando-os. O balanço térmico do corpo humano, os mecanismos de troca de calor da superfície da pele até a parte externa da roupa, da superfíce da vestimenta para o ambiente, as trocas de calor por condução, convecção, evaporação, respiração, radiação foram analisadas e discutidas. A medição da temperatura corpórea dos grupos de voluntários e sua correlação com o desempenho durante a atividade física foram estudadas através de metodologia estatística, utlizando-se o programa Minitab. Esta pesquisa mostrou claramente a influência das propriedades das fibras no desempenho de uma atividade esportiva, sendo de grande importância para a melhoria contínua dos atletas durante o exercício físico. O tecido de poliamida 6.6 apresentou uma menor perda de temperatura corpórea ao longo da atividade física, quando comparado ao tecido de algodão. A existência de correlação significativa da temperatura corpórea com a redução do índice de lactato foi comprovada por este estudo. Esta correlação mostrou a importância da variação da temperatura corpórea durante o desempenho de uma atividade, quanto menor essa variação, maior a redução do índice de lactato / Abstract: The present study ¿Evaluation of Textile Materials Efficiency in Physical Activity¿ compared how the different properties of fibers, like cotton and polyamide 6.6, affect sportive performance. The purpose of this study was to evaluate the improvement of physical performance during physical activities due the use of clothing made with high technology fabrics. For this comparative study, two raw material were chosen, cotton and polyamide 6.6, and through the properties of these samples, such as thermal conductivity, thermal resistance, water retention, moisture absorption and drying time, these fabrics behavior was studied, comparing them. Heat balance of human body, the mechanisms of heat transfer from skin surface to the external side of clothes, from clothing surfaces to the environment, heat transfer by conduction, convection, evaporation, respiration and radiation were analyzed and discussed. Corporeal temperature measurement of volunteers and its correlation with performance during physical activities were analysed through statistical methodology, using a statistical program. This research clearly demonstrated the influence of fibers properties in sports performance, being of great importance to athletes continuous improvement during physical exercices. Polyamide 6.6 fabric presented a lesser loss of corporeal temperature during physical activity when compared to cotton fabric. The existence of a significant correlation between corporeal temperature and lactate index reduction was proved by this study. This correlation shows the importance of corporeal temperature variation during an activity performance: the lower is this variation, the greater is the reduction in the lactate index / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química

No description available.

M. S.

M.S.

Poly(arylene ether)s (PAEs) were synthesized via the silyl ether displacement route. Both AA, BB, and AB silylated monomers were prepared by partial or complete hydrolysis of the dihalide using potassium hydroxide in aqueous dimethyl sulfoxide followed by silylation with hexamethyl disilazane. Both linear and star-branched structures of PAEs were synthesized and this polymerization route allowed both random and block copolymers to be prepared. Triaryl phosphine oxide containing homo-& co-PAEs exhibited very high char yields, which suggested that these polymers were potentially flame-resistant materials. The AB type halogenophenols were also polymerized in the presence of diphenylsulfone as a diluent and potassium carbonate as a base at elevated temperatures. Poly(ε-caprolactam) (Nylon 6) copolymers were prepared by the incorporation of controlled molecular weight poly(arylene ether sulfone) (PES) oligomer segments into the polymer backbone which were functionalized with carboxyl end groups. A hydrolytic melt polymerization process was used to copolymerize the oligomers with ε-caprolactam. Two series of the copolymers, with varying weight ratios and PES segment lengths, were investigated. Extensive characterization experiments including thermal analysis, mechanical property measurement, wide angle x-ray diffraction and dynamic mechanical analysis were performed to illustrate that the copolymers displayed a good balance of properties. Hydrolytically stable triaryl phosphine oxide containing dicarboxylic acid monomers were synthesized and were chemically incorporated into the poly(hexamethylene adipamide) backbone to produce improved flame-resistant copolymers. The content of triaryl phosphine oxide comonomer in the melt synthesized copolymers was controlled from 0-30 mole%. The copolymers were melt crystallizable only at 10 and 20 mole% incorporation of the phosphine oxide comonomer. Cone calorimetric tests were employed to investigate the fundamental flame retardancy behavior of the copolymers. The tests were conducted in a constant heat environment (40 kW/m²). Significantly depressed heat release rates were observed for the copolymers containing phosphine oxide moiety. The results of the cone calorimetric tests and TGA data suggested that the triaryl phosphine oxide containing nylon 6,6 copolymers had improved flame resistance properties. The triaryl phosphine oxide dicarboxylic methyl ester was also introduced into poly(ethylene terephthalate) via melt transesterification to produce copolymers which had increased char yields as the P(O) content increased. However, crystallinity was totally disrupted at 20 mole percent P(O) incorporation in compression molded specimen. Novel star-branched liquid crystalline polyarylates (LCP) were made via melt acidolysis which were subsequently transformed to liquid crystalline foams by supersaturation of carbon dioxide followed by thermal blowing. It was found that the AB type monomers were essential to generate star shaped LCPs without crosslinking. The branching agents were necessary to control the molecular weights, disrupt crystallinity and to allow for higher gas uptake by the polymer matrix. / Ph. D.

Cette thèse a pour but la synthèse de nouveaux polymères par polymérisation anionique et organo-catalyse de polymérisation par activation du monomère. Ce sujet s’articule autour de deux axes majeurs : 1) La synthèse de nouveaux polyamides par activation d’amines aromatiques ou de dérivés acrylamides 2) L’étude de l’ouverture de cycle d’aziridines activées catalysée par les carbènes N-heterocycliques. Le but de cette thèse est donc d’étudier les mécanismes mis en jeu lors de ces polymérisations. Les polymères obtenus seront caractérisés par les méthodes d’analyses classiques (RMN, chromatographie par exclusion stérique, analyses thermiques, spectrométrie de masse, etc.) / In this thesis, the ring-opening polymerization by a monomer activation strategy of heterocyclic monomers such as lactams and aziridines was investigated. In the first part, we described that covalently activated aziridines, i.e. N-sulfonyl aziridines, could be subjected to the N-heterocyclic carbene organocatalyzed ring-opening polymerization (NHC-OROP) in a living/controlled manner. Secondary activated amine, non-activated secondary amine as well as functional initiators were used to promote the ring-opening polymerization of N-activated aziridines. The high tolerance to various chemical functions and the high level of control of the so-called NHC-OROP have allowed the synthesis of well-defined and original aziridine-based block copolymers. On the other hand, the simultaneous combination of anionic ring-opening of ε-caprolactam and condensation reactions of aminobenzoate derivatives was shown to occur in a « one-step » bulk copolymerization allowing the preparation of aliphatic-aromatic copolyamides with enhanced thermal properties (including the glass transition temperature). Alternatively, other methodologies such as covalent activation of lactams with electron withdrawing group or the hydrogen transfer polymerization of acrylamide derivatives were investigated for the synthesis of new polyamides.