Espumas de poliuretano à base de poliol de fonte renovável: estudo da biodegradação em meio enzimático e pela técnica de respirometria
Polyurethanes (PU) are the products of a reaction between an isocyanate and a polyol. Catalysts, additives, colorants, fillers, among others, can also be added in the reaction medium to improve the characteristics and properties of the final product. The nature of the reactants and the composition o...
| Autor principal: | Penha, Pamella Kunzendorff da |
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| Formato: | Trabalho de Conclusão de Curso (Graduação) |
| Idioma: | Português |
| Publicado em: |
Universidade Tecnológica Federal do Paraná
2020
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| Assuntos: | |
| Acesso em linha: |
http://repositorio.utfpr.edu.br/jspui/handle/1/9157 |
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| Resumo: |
Polyurethanes (PU) are the products of a reaction between an isocyanate and a polyol. Catalysts, additives, colorants, fillers, among others, can also be added in the reaction medium to improve the characteristics and properties of the final product. The nature of the reactants and the composition of the formulation, offer a great flexibility to this class of polymer, which makes it important in the world market. Among the types of polyurethanes are foams, which can be rigid, semi-rigid or flexible. The foams have great applicability in the market of mattresses, upholstered, protectors of electronic equipment, acoustic and thermal insulation. However, the disposal and accumulation of these products is a growing environmental problem. In this way, the industry looks for ways to reduce the environmental impact using new technologies, such as obtaining biodegradable polymers. Against this background, a Bioespuma® is commercially available, a polyurethane foam which uses an alternative source of polyol for its production. The aim of this work was to study the biodegradation of polyurethane foams based on renewable source polyol (Bioespuma®) by enzymatic means, using extracts of the fungi Trametes sp. and Pleurorus ostreatus and by respirometric analysis, by Bartha and Pramer method. The polyurethane samples were previously characterized by infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) techniques. The structural characterization of the polyurethanes, through FTIR, showed in all products characteristic bands of the urethane function. The SEM images showed that Bioespuma® has cells with spherical morphology and irregular sizes, while the synthetic foam has more organized cells of regular sizes. The DSC curves for the foams presented a similar profile, with the presence of glass transition temperature (Tg). In relation to biodegradation tests, it can be concluded that the enzymatic method was promising, but more studies are needed to correlate the biodegradation of the foam with a specific enzyme. The respirometric method was also interesting to analyze the biodegradation of rigid PU foams in the studied time (90 days), however, the synthetic foam (petrochemical polyol) showed greater signs of biodegradation than Bioespuma®, which was not expected. Through the statistical analysis, using a complete factorial design 22, it was observed that the presence of urea favors respirometry. The evaluation of the biodegradation using the techniques used was of great importance and more detailed studies of these should be carried out in future works. |
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