Silicone rubber (SR) filled with carbon nanotubes (CNTs), copper oxide (CuO) and CuO modified CNTs (CuO-CNTs) were prepared to detect the effects of these additives on thermal stability of SR by thermogravimetric analysis and tensile testing before and after aging. Flynn-Wall-Ozawa method was also employed to analyze the thermal degradation kinetics. The results indicated that all the additives could increase the initial thermal degradation temperature and thermal oxidative aging properties of SR and a synergistic effect was found in CuO-CNTs/SR. Meanwhile, activation energies of SR filled with additives increased significantly relative to neat SR and found to be optimal for CuO-CNTs/SR with activation energy increasing to 231.29, 121.68 kJ·mol-1 larger than that of blank sample. It is because that CNTs and CuO could promote each other to capture the free radicals generated by thermal oxidative reaction of the methyl side groups and thereby terminate the process.

Keywords: silicone rubber; copper oxide; carbon nanotubes; thermal stability