Estudo da influência dos procedimentos de síntese do óxido de grafeno e do processamento na obtenção de nanocompósitos de polipropileno

• Autor(a) principal: Oliveira, Yuri Durighetto Coelho de
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/26438
• topic: nanocompósito PP/mGO; processamento; óxido de grafeno; polipropileno; fotodegradação; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

In this work, polypropylene polymer-based nanocomposites with graphene-multilayer oxide, obtained by different synthesis proceedings and processing techniques, were studied. The first variation was in the synthesis method of graphene oxide nanostructures. The second variation was in the methods of processing the nanocomposites. These variations in processing techniques were designed to investigate the best combination of mGO nanostructure with processing method to promote a better physical affinity between a matrix of PP and GO. It was verified that the technique of synthesis of mGO denominated P, presented material with a greater degree of oxidation, about 5% more than the material L. After analysis of AFM the nanostructures of GO were then classified as graphite oxide multilayer (mGO) for presenting between 6 and 11 layers. In general, the PP/mGO nanocomposites presented improvements in the thermal stability properties of the material up to 60 ° C difference and increase in the crystallization temperature of the nanocomposites, indicating that mGO acts as a nucleating agent. A lubricating effect of mGO nanostructures was observed on the viscosity of the PP/mGO nanocomposites with 2% by mass mGO, where viscosity drops dramatically when compared to pure polypropylene. For the mGO-L nanocomposites, an increase in modulus of elasticity of up to 11% was observed when compared to pure polypropylene. When subjected to accelerate aging, nanocomposites presented higher thermal stability and lower photodegradation effect, an improvement in UV radiation resistance about 3X when compared to pure polypropylene. This is because mGO nanostructures block the passage of incident UV radiation (screen effect), reducing the direct effect on polypropylene.