Oligoésteres e poliésteres obtidos a partir do ácido oleico modificado com forma estrela: síntese e caracterização físico-química

• Ano de defesa: 2012
• Autor(a) principal: Ziembowicz, Francieli Isa
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; BR; Química; UFSM; Programa de Pós-Graduação em Química
• Palavras-chave em Português: Ácido oleico; Poliéster; Comportamento térmico; Reologia; Oleic acid; Polyesters; Thermal behavior; Rheology; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/10527

This works investigated the curing reaction of epoxidized oleic acid starshaped with different anhydrides, forming product as oligoésteres and polyesters. Oleic acid modified was obtained by esterification of oleic acid with an aminoalcohol to the resulting aminoester, followed by epoxidation of the double bond. The polymerization reactions were carried out from the opening of epoxy rings in the presence of different cyclic acid anhydrides: phthalic anhydride (PA), maleic anhydride (MA) and succinic anhydride (SA). The structures of the products in these reactions were elucidated by nuclear magnetic resonance (NMR) 1H and 13C and infrared spectroscopy (FT-IR). The technique of Differential Scanning Calorimetry (DSC) allowed the study of the crosslinking process of the different systems studied, allowing the determination of kinetic and thermodynamic parameters. The kinetic parameters of curing reaction systems of ME/AM and ME/AS were determined by methods Osawa, Kissinger and Barret. The thermal behavior of the products obtained was analyzed using thermogravimetric analysis (TGA). It was evident that the nature of anhydrides affects the thermodynamic and kinetics parameters of the crosslinking reaction. Values of DH for the reactions of epoxy ring opening are related to factors such as the steric size of the molecule and the position of the oxirane ring in the structure of the ME. The addition of BADGE in the mixture ME/anhydride increased molar mass and improves thermal and mechanical properties of polyester. By varying the composition of the system characteristics of the samples obtained were thermoplastic or crosslinked materials. The GPC results showed that the materials in the absence of BADGE are essentially oligomers. The rheology results indicated that all samples exhibit Newtonian fluid behavior. The viscosity values of the samples without BADGE indicated that these materials exhibited characteristics of highly viscous fluids and the samples in the presence of BADGE exhibited characteristics typical of solid.