Estudo das propriedades reológicas do poliuretano à base de polibutadieno líquido hidroxilado
Carregando...
Data
2024-01-29
Autores
Petroro, André Luis [UNIFESP]
Orientadores
Bonsanto, Fabiana Perrechil [UNIFESP]
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Os poliuretanos - PU representam um dos mais versáteis polímeros, amplamente utilizados em diversos setores industriais, como indústrias automotivas, da construção civil, marítimas, aeroespaciais, dentre outras. Estes compostos possuem durabilidade e tenacidade similares aos metais, elasticidade similares a borrachas. São produzidos a partir da reação química de isocianatos e polióis, tais como diisocianato de isoforona - IPDI e polibutadieno líquido hidroxilado - PBLH. Este trabalho teve como objetivo estudar as propriedades reológicas na formação do poliuretano, de forma a avaliar a influência de diferentes parâmetros neste processo. Para a formação do poliuretano foram utilizados polibutadieno líquido hidroxilado - PBLH e diisocianato de isoforona - IPDI em razão de equivalente igual a 1,00, com diferentes concentrações de catalisador dibutil di laurato de estanho - DBTL (0,1, 1,0, 3,0, 5,0, 7,0, 9,0 e 10,0 % m/m). Foi estudada a reação de cura / polimerização do material em condições isotérmicas em diferentes temperaturas (60, 70 e 80 ºC). Com avaliação de parâmetros em função do tempo, tais como, o módulo de elástico - G’ e o módulo de viscoso - G’’, a viscosidade complexa - η*, o logaritmo da viscosidade complexa - ln (η*) e avaliação do espectro mecânico - o módulo de elástico - G’ e o módulo de viscoso - G’’ em função da frequência. Avaliou-se o comportamento térmico das amostras por calorimetria de varredura diferencial - DSC, para a determinação dos valores de temperatura de transição vítrea - Tg de cada amostra. Demostraram que a utilização da concentração de 9,0 % de catalisador apresentou melhores valores, porém, uma descoberta interessante foi a utilização da concentração de 5,0 % de catalisador apresentou resultados similares aos anterior, sendo assim, melhores condições na utilização em reações de polibutadieno líquido hidroxilado - PBLH com o diisocianato de isoforona - IPDI, com catalisador dibutil di laurato de estanho - DBTL nas temperaturas de (60, 70 e 80 ºC).
Polyurethanes - PU represent one of the most versatile polymers, widely used in various industrial sectors, such as the automotive, construction, maritime, aerospace industries, among others. These compounds have durability and tenacity similar to metals, elasticity similar to rubber. They are produced from the chemical reaction of isocyanates and polyols, such as isophorone diisocyanate - IPDI and hydroxyl-terminated polybutadiene - HTPB. This work aimed to study the rheological properties in the formation of polyurethane, in order to evaluate the influence of different parameters in this process. To form polyurethane, hydroxyl-terminated polybutadiene - HTPB and isophorone diisocyanate - IPDI were used in an equivalent ratio of 1.00, with different concentrations of dibutyl tin dilaurate catalyst - DBTDL (0.1, 1.0, 3.0, 5.0, 7.0, 9.0 and 10.0 % m/m). The curing/polymerization reaction of the material was studied under isothermal conditions at different temperatures (60, 70 and 80 ◦C). With evaluation of parameters as a function of time, such as the elastic modulus - G’ and the viscous modulus - G”, the complex viscosity - η∗, the logarithm of the complex viscosity - ln ( η∗) and evaluation of the mechanical spectrum - the elastic modulus - G’ and the viscous modulus - G” as a function of time. The thermal behavior of the samples was evaluated using differential scanning calorimetry - DSC, to determine the glass transition temperature values - Tg of each sample. They demonstrated that the use of a concentration of 9.0 % of catalyst presented better values, however, an interesting discovery was the use of a concentration of 5.0 % of catalyst presented results similar to the previous one, thus providing better conditions for use in reactions of hydroxyl-terminated polybutadiene - HTPB with isophorone diisocyanate - IPDI, with dibutyl tin dilaurate catalyst - DBTDL at temperatures of (60, 70 and 80 ◦C).
Polyurethanes - PU represent one of the most versatile polymers, widely used in various industrial sectors, such as the automotive, construction, maritime, aerospace industries, among others. These compounds have durability and tenacity similar to metals, elasticity similar to rubber. They are produced from the chemical reaction of isocyanates and polyols, such as isophorone diisocyanate - IPDI and hydroxyl-terminated polybutadiene - HTPB. This work aimed to study the rheological properties in the formation of polyurethane, in order to evaluate the influence of different parameters in this process. To form polyurethane, hydroxyl-terminated polybutadiene - HTPB and isophorone diisocyanate - IPDI were used in an equivalent ratio of 1.00, with different concentrations of dibutyl tin dilaurate catalyst - DBTDL (0.1, 1.0, 3.0, 5.0, 7.0, 9.0 and 10.0 % m/m). The curing/polymerization reaction of the material was studied under isothermal conditions at different temperatures (60, 70 and 80 ◦C). With evaluation of parameters as a function of time, such as the elastic modulus - G’ and the viscous modulus - G”, the complex viscosity - η∗, the logarithm of the complex viscosity - ln ( η∗) and evaluation of the mechanical spectrum - the elastic modulus - G’ and the viscous modulus - G” as a function of time. The thermal behavior of the samples was evaluated using differential scanning calorimetry - DSC, to determine the glass transition temperature values - Tg of each sample. They demonstrated that the use of a concentration of 9.0 % of catalyst presented better values, however, an interesting discovery was the use of a concentration of 5.0 % of catalyst presented results similar to the previous one, thus providing better conditions for use in reactions of hydroxyl-terminated polybutadiene - HTPB with isophorone diisocyanate - IPDI, with dibutyl tin dilaurate catalyst - DBTDL at temperatures of (60, 70 and 80 ◦C).