Functionalized graphene as an effective antioxidant in natural rubber

To improve the thermo-oxidative aging resistance of natural rubber, a kind of functionalized graphene (FGE) was prepared by grafting 2-tert-butyl-6-(3-tertbutyl-2-hydroxy-5-methylphenyl) methyl-4-methylp-henyl acrylate (GM) onto graphene oxide (GO) using (3-mercaptopropyl) trimethoxysilane as bridging agent. In comparison to GO, FGE appeared more curled surface and reached the higher water contact angle of 134°. By latex-mixing method, the uniformly dispersed FGE endowed NR vulcanizates with obviously improved thermal stability. Importantly, the NR/FGE nanocomposites exhibitd excellent thermo-oxidative aging resistance, which was attributed to not only the synergistic antioxidative effect of hindered phenol groups and thioether bonds, but also the barrier role of graphene sheets to oxygen. Our findings provide a new strategy to prepare functionalized graphene as effective antioxidant for rubber and other polymer materials.