The intrinsic thermal-oxidative stabilization effect of chemically reduced graphene oxide on polypropylene

The antioxidative effect of chemically reduced graphene oxide (rGO) on the thermal-oxidative stability of polypropylene (PP) was evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). rGO was prepared by reduction of graphene oxide (GO) and characterized by atomic force microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. PP/rGO nanocomposites were then prepared without using a compatibilizer by melt blending. It was found that the thermal-oxidative degradation of PP was retarded noticeably by the rGO. The stabilization mechanism of rGO was discussed in terms of the changes in carbonyl bands and oxygen diffusion. It was proposed that the improved thermal-oxidation stability of PP/rGO nanocomposites can be attributed to the decline in both the concentration of peroxy radicals and oxygen permeability. The acceptor-like electronic property afforded by the long conjugated C=C bonds and the barrier effect of rGO were suggested to be responsible for the improved thermal-oxidation stability of PP.