The curing retardation and mechanism of high temperature vulcanizing silicone rubber filled with superconductive carbon blacks

Abstract

AbstractThe curing retardation and mechanism of high‐temperature vulcanizing silicone rubber (HTV SR) filled with superconductive carbon black (CB) BP2000 have been studied experimentally and theoretically. The results show that both rubber matrix and CBs have influences on the peroxide curing of rubber/CBs composites. The retardation does not appear as prominent in nature rubber (NR)/BP2000 composites as in HTV SR/BP2000 composites. Quantum chemistry calculations reveal that the curing retardation of HTV SR/BP2000 composite should not be attributed to the curing reaction dynamics of HTV SR molecules. Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) analyses of CBs show that the effect of radical scavenging of phenol‐OH groups existing on BP2000 surface is the main reason for the retardation in the peroxide curing reaction. The effect is found to be more effective in HTV SR/BP2000 composite and thus retards its curing. The curing retardation does not appear in silicone rubber (SR)/BP2000 composites vulcanized by condensation reaction, and the resulting vulcanizates have excellent physical properties. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.