Elaboração de compósitos de poliéster e amido com palha de milho: caracterização e avaliação da biodegradabilidade

• Ano de defesa: 2015
• Autor(a) principal: Paiva, Luciana Oliveira de
• Orientador(a): Leite, Marcia Christina Amorim Moreira
• Banca de defesa: Merçon, Fábio , Mello, Ivana Lourenço de , Novack, Kátia Monteiro , Pacheco, élen Beatriz Acordi Vasquez
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Química
• Departamento: Centro de Tecnologia e Ciências::Instituto de Química
• País: BR
• Palavras-chave em Português: Compósitos poliméricos; biodegradabilidade; palha de milho; ECOBRASTM
• Palavras-chave em Inglês: Polymeric composites; biodegradability; corn husks; ECOBRASTM
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA::POLIMEROS E COLOIDES
• Link de acesso: http://www.bdtd.uerj.br/handle/1/15641

The use of polymers and biodegradable composites is presented as a solution for the problem created by the discarding of a high amount of plastic residue in the environment. The conventional polymers, besides being non-biodegradable, have a non-renewable source: oil. The biodegradable polymers produced via renewable materials often present as downsides the high cost and not always satisfactory properties. In this context, the polymeric composites can be an alternative, due to the possibility of incorporation of fillers, both of vegetable and mineral origins, to alter properties, making them adequate to the destined use of this material. Other than that, there is the use of low cost fillers, such as agricultural residues, to make them economically viable. In this study, composites of poly (butylene adipate-co-terephthalate) and starch (Ecobras ) were elaborated, with corn husks, in different concentrations. Corn husks in natura, being an abundant agricultural residue, were used in order to lower costs and increase the proportion of natural materials utilized, considering Ecobras already has starch in its composition. The stress strength tests and DSC, TGA, FTIR, MO e MEV analysis were used to characterize and evaluate the properties of the composites. The polymer matrix and the composites were submitted to biodegradability trials through burying in simulated soil, according to the ASTM G 160-03 norm, for periods varying between 2, 4, 7, 12 and 17 weeks. After each trial period, the mass loss and morphology of each test subject were determined, and analysis of TGA, DSC and FTIR were made. The composites presented a higher resistance to stress strength tests than the polymer matrix. Yet still he had similar mechanical performance of biodegradable polymers such as polycaprolactone (PCL), enough to be used in artifacts. In the biodegradability trial, all composites were considered biodegradable, although the addition of corn husks increased the deterioration time. Microbial analyzes present in EcobrasTM samples free of corn straw and their composites after burial periods in simulated soil occurred in two culture media Sabouraud and Plate Count Agar (PCA) in order to observe fungi and bacteria, respectively. Moreover, the partial replacement was performed and the total carbon source of culture media, free of the EcobrasTM maize straw and their composites, which demonstrated that the micro-organism used the EcobrasTM and their composites as a source of energy. With the use of the clamping technique was observed by SEM analysis the presence of microbial colonies in the samples after 17 weeks in simulated soil burial