Properties of Functionalized Graphene/Room Temperature Vulcanized Silicone Rubber Composites Prepared by an In-situ Reduction Method

Functionalized graphene oxide (FGO) was prepared by treating graphene oxide with γ-aminopropyl triethoxysilane (KH-550) before the mixture was dispersed into α, ω-dihydroxy polydimethylsiloxane to get room temperature vulcanized (RTV) silicone rubber composites by solution casting. The cured composites were then reduced with hydrazine hydrate to obtain functionalized graphene (FG)/RTV silicone rubber composites. The structures of FGO and the resultant composites were characterized by atomic force microscopy, FT-IR spectra and X-ray diffraction. KH-550 was found to be grafted onto graphene sheets, leading to an increased interlayer spacing. Significant improvements in thermal and mechanical properties were obtained. Both the FGO/RTV silicone rubber composite contain 1.0 wt% of FGO, and its reduced product showed an increase of one-step weight loss temperature with 61 ℃ and 133 ℃ higher than that of pure silicone rubber. Tensile strength and elongation at break of FG/RTV silicone rubber composite (with 0.5 wt% FGO content) increased by 175% and 67%, respectively, compared with those of pure silicone rubber.