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Segmented polyurethaneureas (SPUU) are thermoplastic elastomers with excellent elastic properties, high abrasion resistance and tear strength, making them very useful in numerous industrial applications ranging from microelectronics (slurry pad) to biomedical (artificial heart vessels) applications. The elastic and mechanical properties of these materials are strongly influenced by their two phase morphology. The factors that influence phase separation include difference in polarity between the hard and soft phases, composition and temperature. In general good phase separation results in materials with superior mechanical and elastic properties. Due to the immense potential applications of SPUU elastomers, there is a need for materials with higher strength. However, higher strength is not desired at the detriment of elasticity. If fact, stronger materials with enhanced elasticity are desired. In this thesis, high-strength SPUU elastomers were synthesized by incorporating reactive Laponite particles with surface-active free amine. The synthesis of pure SPUU is very complex, and addition of a reactive silicate further increases the complexity. To remedy this challenge, combinatorial methods and high-throughput screening techniques were used to optimize the diamine concentration and cure temperature. It was determined that pure SPUU elastomers prepared at a diamine stoichiometry of 85 100 mole %, and cured at 90 95 oC produced materials with higher strength and elongation at break. SPUU nanocomposites were prepared by maintaining the overall diamine stoichiometry at 95 mole %, and cured at 90 oC. Uniaxial tensile strength was optimized at a particle weight fraction of 1 wt. %, with a nearly 200 % increase in tensile strength and a 40 % increase in elongation at break, compared to pristine SPUU.

A series of segmented poly (epsilon-caprolactone) polyurethane-ureas (PCLUUs) were prepared from poly (epsilon-caprolactone) (PCL) diol, different dissociates and chain extenders to improve the recovery stress of shape memory polymers. NMR and FT-IR were used to identify the structure of the synthesized shape memory polyurethane-ureas. Parameters such as soft segment content (molecular weight and content), chain extender and the rigidity of the main chain were investigated to understand the structure-property relationships of the shape memory polymer systems through DSC, DMA, physical property test, etc. Cyclic thermal mechanic tests were applied to measure the shape memory properties which showed that the recovery stress can be improved above 200% simply by modifying the chain extender. Meanwhile, the synthesis process was optimized to be similar to that of Spandex /LYCRA®. Continuous fibers were made from a wet spinning process, which indicated excellent spinnability of the polymer solution. Small angle neutron scattering (SANS) was used to study the morphology of the hard segment at different temperatures and stretch rates and found that the monodisperse rigid cylinder model fit the SANS data quite well. From the cylinder model, the radius of the cylinder increases with the increasing hard segment content. The SANS results revealed phase separation of hard and soft segments into nano scale domains.

Cellulose nanowhisker (CNW) prepared by acid hydrolysis of softwood Kraft pulp was incorporated as nanofiller in rigid polyurethane (PU) foam synthesis. The density, morphology, chemical structure, mechanical properties and thermal behavior of the products were characterized. The nanocomposites exhibited better performance especially at high CNW¡¯s content which was probably due to the high specific strength and aspect ratio of CNW, the hydrogen bonding and crosslinking between CNW and polymer matrix, a higher crosslinking density compared to the control, and the function of CNW as an insulator and mass transfer insulator. Lignin polyol was synthesized through oxypropylation and used for rigid PU foam preparation. The density, morphology, chemical structure, compressive property and thermal behavior of the product were characterized. Lingin-based rigid PU foam showed improved compressive property compared to its commercial counterpart. Ethanol organosolv lignin-based PU showed a slightly stronger compressive property than Kraft lignin-based PU. The enhancement was primarily attributed to the rigid phenolic structure and the high hydroxyl functionality of lignin. Lignin-based PU generated more char than common PUs which was possibly related to the better flame retardant property. This study provided an alternative way to valorize the two most abundant biopolymers and resulted in relatively environmentally benign rigid PU nanocomposite foam.

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: John L. Brash. Includes bibliographical references. Also available online.

Artigos de couro estão associados com tendências de moda e sofisticação em produtos de consumo. No processamento do couro, a fase de acabamento consiste de um conjunto de operações e tratamentos, essencialmente de superfície, que conferem características finais ao produto. Os objetivos do acabamento são reduzir defeitos visíveis, modificar as propriedades superficiais e melhorar os atributos de uso. Nesta fase final, são aplicadas, dentre outros produtos, resinas, geralmente, poliacrilatos e poliuretanos, e algumas vezes caseínas e outros polímeros que formam filmes de recobrimento protetores sobre o couro. Nesse contexto, este trabalho visa a uma avaliação dos filmes formados com resinas comerciais utilizadas industrialmente no acabamento de couros, relacionando a composição destes materiais com características sensoriais, com resistência mecânica, através de testes de tração, com estabilidade à água ou a solvente orgânico, com análise de dureza, e através de caracterizações por infravermelho e DSC. Ensaios de tração mostraram que as resinas poliuretânicas, no geral, apresentam uma maior resistência à tração quando comparadas com resinas acrílicas, assim como os valores de tenacidade, indicando que esses filmes suportam um maior impacto para levar o material à ruptura. A adição de pigmentos diminui essa resistência, tanto em resinas acrílicas quanto em resinas poliuretânicas, enquanto que a produção de filmes compactos apresenta características intermediárias com relação aos componentes puros. Todos os filmes acrílicos testados apresentaram uma maior capacidade de alongamento. Com relação à dureza, as resinas que se mostraram mais flexíveis e com maior alongamento, foram as que apresentaram menor dureza. A estabilidade dos filmes com relação à água e solventes mostrou que os componentes solúveis em água e em solvente aumentam com a presença de pigmento e que a absorção de água é maior e de solvente é menor em filmes com pigmento, tanto para acrilatos quanto para poliuretanos. As caracterizações a partir de análise por FTIR e DSC indicaram os grupamentos químicos e picos de temperaturas característicos dos acrilatos e poliuretanos, respectivamente. / Leather goods are associated with fashion trends and sophistication in consumer products. In the leather processing, the finishing phase consists of a series of operations and treatments, essentially in surface, conferring its final characteristics. The objectives are to reduce visible defects, modify surface properties and improve the usage attributes In this final stage are applied, among other products, resins, generally polyacrylates and polyurethanes, sometimes casein and other polymers, which form protective coating films on leather. In this context, this paper evaluates the films formed with commercial polymeric resins used industrially in finishing leather, relating the composition of these materials with their sensory characteristics, with their strength by tensile testing, with its stability to water or organic solvent, with analysis of hardness and characterizations by IR and DSC. Tensile tests showed that the polyurethane resins in general have a higher tensile strength when compared with acrylic resins, as well as the toughness values, indicating that these films support a greater impact to bring the material to rupture. The addition of pigments decreases this resistance, for acrylic resins and polyurethane resins, while the production of compact film has intermediate characteristics with respect to the pure components. All acrylic films tested had a higher elongation. With respect to hardness, the resins that were more flexible and more stretching, showed the lowest hardness. The stability of the films with respect to water and solvents has shown that water soluble solvent components increased by the presence of pigment and the water absorption is higher and the solvent is lower in pigmented films to acrylates and polyurethanes. The characterizations from IR and DSC analysis indicated the chemical groups and characteristic temperatures peaks of acrylates and polyurethanes, respectively.

Artigos de couro estão associados com tendências de moda e sofisticação em produtos de consumo. No processamento do couro, a fase de acabamento consiste de um conjunto de operações e tratamentos, essencialmente de superfície, que conferem características finais ao produto. Os objetivos do acabamento são reduzir defeitos visíveis, modificar as propriedades superficiais e melhorar os atributos de uso. Nesta fase final, são aplicadas, dentre outros produtos, resinas, geralmente, poliacrilatos e poliuretanos, e algumas vezes caseínas e outros polímeros que formam filmes de recobrimento protetores sobre o couro. Nesse contexto, este trabalho visa a uma avaliação dos filmes formados com resinas comerciais utilizadas industrialmente no acabamento de couros, relacionando a composição destes materiais com características sensoriais, com resistência mecânica, através de testes de tração, com estabilidade à água ou a solvente orgânico, com análise de dureza, e através de caracterizações por infravermelho e DSC. Ensaios de tração mostraram que as resinas poliuretânicas, no geral, apresentam uma maior resistência à tração quando comparadas com resinas acrílicas, assim como os valores de tenacidade, indicando que esses filmes suportam um maior impacto para levar o material à ruptura. A adição de pigmentos diminui essa resistência, tanto em resinas acrílicas quanto em resinas poliuretânicas, enquanto que a produção de filmes compactos apresenta características intermediárias com relação aos componentes puros. Todos os filmes acrílicos testados apresentaram uma maior capacidade de alongamento. Com relação à dureza, as resinas que se mostraram mais flexíveis e com maior alongamento, foram as que apresentaram menor dureza. A estabilidade dos filmes com relação à água e solventes mostrou que os componentes solúveis em água e em solvente aumentam com a presença de pigmento e que a absorção de água é maior e de solvente é menor em filmes com pigmento, tanto para acrilatos quanto para poliuretanos. As caracterizações a partir de análise por FTIR e DSC indicaram os grupamentos químicos e picos de temperaturas característicos dos acrilatos e poliuretanos, respectivamente. / Leather goods are associated with fashion trends and sophistication in consumer products. In the leather processing, the finishing phase consists of a series of operations and treatments, essentially in surface, conferring its final characteristics. The objectives are to reduce visible defects, modify surface properties and improve the usage attributes In this final stage are applied, among other products, resins, generally polyacrylates and polyurethanes, sometimes casein and other polymers, which form protective coating films on leather. In this context, this paper evaluates the films formed with commercial polymeric resins used industrially in finishing leather, relating the composition of these materials with their sensory characteristics, with their strength by tensile testing, with its stability to water or organic solvent, with analysis of hardness and characterizations by IR and DSC. Tensile tests showed that the polyurethane resins in general have a higher tensile strength when compared with acrylic resins, as well as the toughness values, indicating that these films support a greater impact to bring the material to rupture. The addition of pigments decreases this resistance, for acrylic resins and polyurethane resins, while the production of compact film has intermediate characteristics with respect to the pure components. All acrylic films tested had a higher elongation. With respect to hardness, the resins that were more flexible and more stretching, showed the lowest hardness. The stability of the films with respect to water and solvents has shown that water soluble solvent components increased by the presence of pigment and the water absorption is higher and the solvent is lower in pigmented films to acrylates and polyurethanes. The characterizations from IR and DSC analysis indicated the chemical groups and characteristic temperatures peaks of acrylates and polyurethanes, respectively.

Made available in DSpace on 2015-05-14T16:53:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-05-26Bitstream added on 2015-05-14T16:59:09Z : No. of bitstreams: 1 000816204.pdf: 522472 bytes, checksum: 25779cbe8f027d47edb97dfc753e8174 (MD5) / Objetivo: Visando acrescentar novos conceitos na área da reconstrução da cavidade anoftálmica e utilizando conhecimento adquirido na Cirurgia Plástica, o presente estudo foi desenvolvido com o objetivo de avaliar a integração dos implantes hemi-esféricos de silicone em gel coesivo com três diferentes tipos de superfície (lisa, texturizada e de poliuretano), empregados para devolução do volume perdido de cavidades evisceradas de coelhos. Método: Foram utilizados 45 coelhos albinos, machos, espécie Orictolagus cuniculus, que tiveram o olho direito eviscerado, sendo feita a colocação de implantes hemi-esféricos de silicone em gel coesivo na cavidade orbitária. Os implantes diferiram entre si pelos revestimentos, que foram de três tipos: liso (Grupo (GI)), texturizado (GII) ou de poliuretano (GIII). Cada grupo foi constituído por 15 animais, sendo que 5 animais de cada grupo foram sacrificados 7 (M7), 30 (M30) ou 90 (M90) dias após a cirurgia de evisceração e colocação do implante. Foram realizadas avaliações clínica, laboratorial (exame de creatinina sérica e de 2,4 toluenodiamina - TDA), tomográfica usando o programa OsiriX® (posição e área do implante), histológica e morfométrica (medida da espessura da pseudocápsula e da celularidade). Os resultados obtidos foram submetidos à avaliação estatística comparando-se os grupos com diferentes tipos de revestimentos dos implantes, nos três momentos de sacrifício. Resultados: Houve boa evolução em todos os grupos experimentais, não se observando extrusão ou processos infecciosos ao longo do período experimental. A avaliação histológica mostrou que os implantes de superfície lisa (GI), texturizada (GII) ou de poliuretano (GIII) tiveram boa integração tecidual, com maior reação inflamatória e espessura da pseudocápsula nos implantes de GIII. No exame tomográfico, os implantes de GI mudaram mais de posição e foram evidenciadas deformidades nos ... / Purpose: In order to add new concepts in the area of the anophthalmic socket reconstruction and using knowledge acquired in Plastic Surgery, this study was developed to evaluate the integration of hemi-spherical cohesive gel silicone implants coated by three different surfaces (smooth, textured and polyurethane) used to replace the missed volume in eviscerated cavities of rabbits. Methods: Forty-five albino male rabbits of the specie Oryctolagus cuniculus had their right eye eviscerated and hemi-spherical cohesive gel silicone implants were inserted in the orbital socket to replace volume. The implants were coated by three different types of surfaces: smooth (Group (IG)), textured (GII) or polyurethane (GIII). Each group was composed by 15 animals and five of them in each group were sacrificed seven (M7), 30 (M30) and 90 (M90) days after evisceration surgery and implant placement. Clinical and laboratorial assessments (creatinine test and 2,4 toluene diamine- TDA), histologic and morphometric exam (measurement of the thickness of pseudocapsule and cellularity) and tomographic (CT scan) evaluation using the OsiriX program (position and area of the implant) were performed. The results were analyzed statistically comparing groups that differ by the coating of implants in the three moments of sacrifice. Results: There was good evolution in all experimental groups and extrusion or infectious processes was not observed throughout the experimental period. Histological evaluation showed that implants with a smooth (GI), textured (GII) or polyurethane surface (GIII) had good tissue integration and GIII implants showed greater inflammatory reaction and thickness of the pseudocapsule. On CT scan, the GI implants changed over position and deformities were observed in the GIII implants. Using OsiriX® program was possible to evaluate the area of the implants. The 2,4 TDA was not found in any of the experimental groups. Conclusion: Cohesive gel ...

Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-02-24T18:40:16Z No. of bitstreams: 1 OLIVEIRA_Elisangela_2015.pdf: 17350237 bytes, checksum: a1efb77501c4df3e09734ffce33e70c1 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-02-24T18:40:29Z (GMT) No. of bitstreams: 1 OLIVEIRA_Elisangela_2015.pdf: 17350237 bytes, checksum: a1efb77501c4df3e09734ffce33e70c1 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-02-24T18:40:35Z (GMT) No. of bitstreams: 1 OLIVEIRA_Elisangela_2015.pdf: 17350237 bytes, checksum: a1efb77501c4df3e09734ffce33e70c1 (MD5) / Made available in DSpace on 2017-02-24T18:40:41Z (GMT). No. of bitstreams: 1 OLIVEIRA_Elisangela_2015.pdf: 17350237 bytes, checksum: a1efb77501c4df3e09734ffce33e70c1 (MD5) Previous issue date: 2015-03-19 / Não recebi financiamento / One of the most remarkable and diverse physical characteristics among human beings - and, thus, fundamental for personal identity - is hair. The search for personal hair care products has been increasing in the last years and Brazil is the third largest consumer market for these products. There is a constant quest for cosmetic products able to align, relax and treat hair fibers. There are some products for this purpose, such as smart brushes, Japanese brushes and definitive brushes, among others. In this context, the aim of this project was to synthesize and characterize polyurethane obtained from a renewable source as well as evaluate its effectiveness as a hair treatment agent. Therefore, scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR), nearinfrared reflectance spectroscopy (NIRS) and mechanical tests for tensile properties were used. The FTIR results confirmed the synthesis of the polyurethane. The polymer was associated with citric acid, glycolic acid, lactic acid, and sodium hydroxide with glycose, in order to increase adhesion of the polymer onto the hair fiber. After application, better hair fiber alignment and increased hair roughness were noticed. Through the spectroscopic analysis it was established that a chemical interaction between the polymer, its associations and hair was present. The micrographs also suggested that there was a deposition of the polymer on the hair fibers. The results indicated that the polyurethane and their associations with citric acid and sodium hydroxide with glycose, are promising for applications in hair care products. / Os cabelos constituem uma das características físicas mais marcante e variável dos seres humanos, tornando-se fundamental para a identidade pessoal. Assim, é cada vez maior a busca por produtos para os cuidados dos mesmos. O Brasil é o terceiro maior mercado consumidor de produtos para os cabelos, e existe uma busca constante pelas empresas do setor de cosméticos por produtos capazes de alinhar, relaxar e tratar os fios. Neste sentido podemos encontrar produtos para essa finalidade, com as mais variadas denominações, como as escovas: inteligente, japonesa, definitiva entre outras. Dentro desse contexto, o objetivo do presente projeto foi sintetizar e caracterizar um poliuretano a partir de um poliol obtido de fonte renovável, e avaliar sua eficácia após aplicação do mesmo visando tratamento capilar. Para tanto, foram utilizadas técnicas de microscopia eletrônica de varredura (MEV), microscopia de força atômica (AFM), espectroscopias de infravermelho por transformada de Fourier (FTIR) e espetroscopia de refletância no infravermelho próximo (NIRS) e ensaios mecânicos pelo módulo de tração. Os resultados de FTIR confirmaram a síntese do poliuretano, o qual foi associado aos Ácidos Cítrico, Glicólico, Lático e Hidróxido de Sódio com Glicose com o intuito de aumentar a aderência do polímero na fibra capilar. Após a aplicação verificou-se um melhor alinhamento dos fios e aumento na rugosidade. Através das análises de espectroscopia foi possível constatar que houve uma interação química entre o polímero, suas associações e os cabelos. As eletromicrografias também sugerem que houve uma deposição do polímero sobre as fibras do cabelo. Os resultados obtidos indicaram que o poliuretano e suas associações com ácido cítrico e hidróxido de sódio e com glicose, são promissores para aplicações em produtos capilares.

Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2016-11-30T10:53:42Z No. of bitstreams: 2 Dissertacao Michele Savaris.pdf: 2989179 bytes, checksum: 88ffa39c239bce7b722fda3a46552a44 (MD5) Dissertacao Michele Savaris.pdf: 199756 bytes, checksum: 4cdc9043cbc4c957c4347cba34d5b222 (MD5) / Made available in DSpace on 2016-11-30T10:53:42Z (GMT). No. of bitstreams: 2 Dissertacao Michele Savaris.pdf: 2989179 bytes, checksum: 88ffa39c239bce7b722fda3a46552a44 (MD5) Dissertacao Michele Savaris.pdf: 199756 bytes, checksum: 4cdc9043cbc4c957c4347cba34d5b222 (MD5) Previous issue date: 2016-11-28