Nanocompósitos de matriz epoxídica com reforços produzidos a partir do grafite natural

Abstract

Graphite is the cheapest and the most abundant source to obtain graphene. For its production and application in nanocomposites in industrial scale, reduction of the graphite oxide (GO) has been the most used method lately. Graphite oxidation promotes the insertion of functional groups in its layers which lead to an increase in graphite interlayer distance, producing GO. The GO can be reduced either by chemical or thermal methods, which partially removes the functional groups inserted during oxidation, partially reestablishing the graphitic structure. Several polymer matrices have been utilized to produce graphene nanocomposites, including the epoxy resins. One of the challenges to produce polymer nanocomposites is the total dispersion of the nanofillers into the matrix and a strong matrix/nanofillers interfacial adhesion to obtain enhanced final properties. Therefore, the aim of this work was the characterization of morphological, mechanical and thermal properties of epoxy matrix based on diglycidyl ether of bisphenol-A (DGBEA) nanocomposites with reinforcements produced from natural graphite, such as sonicated graphite (SG), GO and expanded GO (EGO) at the concentrations of 0.1 wt%. The most promising system to enhance mechanical properties of epoxy resin nanocomposites was the EGO system, since it showed an increase of ~37% in tensile strength. The results showed no significant change on thermal stability of the nanocomposites indicating the absence of a percolation network with the amount of reinforcement studied.