The effect of reduction temperature of graphene oxide on the structure and properties of polystyrene/thermally reduced graphene oxide nanocomposites

The adoption of an eco-friendly approach to reduce graphene oxide (GO) and the employment of the obtained reduced graphene oxide (rGO) to prepare high-performance polymer nanocomposites represent a considerable challenge. Vacuum assisted low temperatures were used to obtain rGO from GO. GO was reduced at 130, 165 and 200 °C for 24 h to produce rGOs of different degrees of reduction. Fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy confirmed a successful reduction of GO and the preparation of rGOs with different degrees of reduction. To study the effect of rGOs on the structure and properties of polymers, rGOs were mixed with polystyrene (PS) at 1.0 mass% loading to prepare nanocomposites using a solution blending method. The results of FTIR, XRD, and scanning electron microscopy showed a possible interaction and good dispersion of GO and its reduced forms within the host medium of PS. Differential scanning calorimetry, TGA, and dynamic mechanical analysis showed that thermal and thermomechanical behaviour were improved with the incorporation of rGOs as compared with nanocomposite reinforced with pristine GO and the neat polymer. The higher values of thermal degradation temperature, glass transition temperature and storage modulus for PS/rGOs as compared with PS/GO and the neat polymer confirmed the role of rGO in achieving better performance for the nanocomposites.