Radiation resistance of polypropylene composites by incorporating reduced graphene oxide and antioxidant: A comparison study

In this study, polypropylene (PP) composites were fabricated by incorporating reduced graphene oxide (RGO) sheets and antioxidant pentaerythritol tetra [β-(3, 5-di-tert-butyl-4-hydroxyphenyl)-propionate] (AO1010) to comparatively investigate the effect of graphene and antioxidant on the radiation resistance. Morphological observation and X-ray diffraction reveal the uniform dispersion of RGO. The incorporation of antioxidant is beneficial to the improved dispersion and exfoliation of RGO nanosheets in the PP matrix. The melting temperature decreases significantly with increasing irradiation dose, whereas the crystallinity remains almost unchanged for all the samples before and after irradiation. Tensile strength analysis demonstrates that incorporating RGO sheets is more effective for radiation protection at low doses, and adding AO1010 is more applicable to radiation resistance at high doses. Furthermore, the mechanical performance and the decomposition temperature of PP/AO1010/RGO composites by simultaneously incorporating 0.5 wt% AO1010 and 1.0 wt% RGO sheets are higher than that of PP/AO1010 and PP/RGO composites upon gamma irradiation at various doses, indicating an additive effect between RGO and AO1010 in retarding the radiation-induced degradation of PP composites. The intrinsic mechanism of radiation resistance is attributed to the free radical scavenging and oxygen barrier effect. The additive effect between RGO and AO1010 can substantially reduce the number of peroxy radicals and oxygen concentration in the composites, resulting in the remarkable improvement in radiation resistance.