Polymeric materials are essentially insulating, but they have unique properties such as low density, high resistance to corrosion, ease of processing and lower cost compared to metallic and ceramic materials. Polymethyl methacrylate (PMMA), a polymer commercially known as acrylic, is known as a low-cost material with very interesting properties to be applied in engineering, such as transparency, mechanical resistance, electrical insulation and good thermal stability [1] [2]. Since the discovery of graphene, polymeric composite materials based on graphene and its derivatives have been explored in both academic and industrial research, due to the possible dispersion of carbon in the polymeric material, offering thermal and electrical properties to the polymer. The structure of graphene is made up of a two-dimensional sheet with a network of hexagons, formed by carbon atoms with sp^2 hybridization [3]. Graphene oxide can be obtained by functionalizing graphene through its exfoliation, presenting intercalated regions with sp^2 and sp^3 hybridized carbons, as well as hydroxyl and epoxy functional groups on its basal planes, which increase its interaction with the polymer matrix. This interaction improves the mechanical fit at the interface between the filler and the matrix, and its two-dimensional geometry may be responsible for increasing the stiffness of the composite [4].

Therefore, microcomposite films of PMMA and rGO with different concentrations were produced. The physicochemical changes were evaluated by differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FT-IR). The morphological characteristics were observed by scanning electron microscopy (SEM).

The DSC test showed that the addition of filler to the polymer made the material (microcomposite) more thermally stable and indicated greater rigidity of the PMMA macromolecules in the microcomposites as the concentration of rGO increased.  FT-IR analysis revealed the characteristic groupings of both PMMA and rGO, indicating that the matrix interacted with the filler, as was also observed in the topography of the material by SEM. These factors indicate that the higher the concentration of rGO, the greater the chance that PMMA, being an insulating material, will be transformed into a semiconductor/conductor material.