Resistance of Graphene/Epoxy Resin—Based Composite Materials to γ Radiation Damage and Their Mechanical Properties

This study aims to explore the role of graphene in enhancing the radiation resistance of epoxy resin (EP) composites. Through the resin transfer molding process, we prepared 0.3 wt% graphene oxide (GO) and Hummer’s method reduced graphene oxide (Hh-RGO) reinforced EP composites, respectively. By comparing the microstructure, free radical content, thermal stability, and mechanical properties of EP, GO/EP, and Hh-RGO/EP composites before and after γ-ray irradiation, we found that GO and Hh-RGO can effectively reduce the generation of free radicals in EP during irradiation, thereby reducing chemical bond breakage and enhancing its radiation resistance. Particularly, GO demonstrated stronger radiation damage resistance. The results showed that after γ-ray irradiation, the glass transition temperature, nano-indentation depth, and hardness of GO/EP composites decreased by 20.32%, 416.3 nm, and 16.00%, respectively, whereas EP decreased by 30.34%, 502.1 nm, and 41.82% respectively. This is mainly attributed to the fact that the addition of graphene nanoparticles as a reinforcement reduces the free radical content in EP and reduces the damage of free radicals to the EP crosslinked network during irradiation, thereby improving the thermal stability and mechanical properties of the composites. In addition, the Π electrons formed by the hexagonal honeycomb structure of GO and the Π-Π stacking effect formed with free radicals can slow down the aging of epoxy resin in a high-energy radiation environment, thereby prolonging its service life. This study provides important references for further optimization and application of graphene-modified epoxy resin.