Use of graphene (go and rGO) as a reinforcement filler to increase the beta phase in fluorinated copolymer nanocomposites

The present study aims to evaluate the influence of different types of graphene, graphene oxide (GO, synthesized by the Hummers method) and reduced graphene oxide (rGO, obtained by thermal reduction of GO) on the piezoelectric properties of composites based on PVDF copolymer. Hydrogen-fluorine interaction is expected to occur between GO or rGO and the fluorinated copolymer, increasing the β-conformation content in the polymer. The samples were prepared in the molten state at two concentrations of each charge inside a twin-screw extruder with interpenetrating screws. The characterizations of the nanocomposites were made according to their thermal and electrical properties. The effect of graphene incorporation into the P(VDF-TrFE) matrix was observed from thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results obtained indicated that the incorporation of graphene contributed to the increase in the β phase content of P(VDF-TrFE), which is indicative of the increase in its piezoelectricity.