A small addition of reduced graphene oxide to protect fluorosilicone rubber from thermal oxidative degradation

As an essential elastomer used in edge technologies, fluorosilicone rubber (FSR) suffers serious oxidative aging problem when serving at high temperature. In this study, a small amount of reduced graphene oxide (rGO) was added to FSR, and the resulting rGO/FSR compounds were vulcanized using 2,5-dimethyl-2,5-di(tert-butyl) peroxyhexane as the vulcanizer. The dispersion of rGO was investigated using scanning electron microscope. The mechanical properties and thermal-oxidative stability of the rGO/FSR vulcanizates were investigated via thermal aging test at 230°C for 72 h, thermogravimetric analysis (TGA), and isothermal degradation test at 280, 320, and 350°C. The results showed the small addition of rGO (0.5 wt%) significantly improved the thermo-oxidative stability of FSR. In particular, the FSR incorporating of 0.5 wt% of rGO could maintain more than 85% of tensile strength after aging at 230°C for 72 h. The FSR incorporating of 0.5 wt% of rGO can maintain more than 90% of initial weight after aging at 350°C for 12 h. The experiment of scavenging hydroxyl radical by rGO, and quantum chemistry calculation indicated rGO containing aryloxy radicals can scavenge the initial radicals during thermal degradation of FSR, which might be prime reason for the antioxidant properties of rGO.