Cure Retarding Phenomena and Mechanism of High Temperature Vulcanising Silicone Rubber Filled with Super Conductive Carbon Black

摘要

This work has investigated the cure retarding phenomena of high temperature vulcanising (HTV) silicone rubber (SR) filled with super conductive carbon black (CB) BP2000. It has been found that when enough OH groups exist on the CB surface, HTV SR will have cure retarding phenomena. But this phenomenon does not appear in the case of NR/BP2000 composites. The quantum chemistry calculations reveal that there is a little difference between silicone rubber and natural rubber ( NR) with respect to peroxide cure reactions barriers. It was therefore suggested that the effects of radical scavenging of OH groups in radical reaction are more effective in silicone rubber/BP2000 and, consequently, retard the curing of silicone rubber. The effects of the OH groups on cure retarding of silicone rubber can be avoided in the case of condensation-cure silicone rubber/BP2000. This result explains that the given explanation for cure retarding of HTV SR filled with BP2000 is reasonable.