Effects of different coupling agents on the heat and oxidative aging performance of silicone rubber

Abstract

Composite insulators are widely used in power transmission systems because of their excellent mechanical and electrical properties. However, composite insulators are easy to age. This paper studied the effect of different amount of silane coupling agent and titanate coupling agent on the silicone rubber. The initial properties (tensile strength, elongation at break, tear strength, and breakdown strength) of silicone rubber and those properties after aging were measured. The conclusion is drawn that silane coupling agent can improve the mechanical strength of silicone rubber. For tensile strength, it is suitable to add 1.0phr silane coupling agent. For tear strength, it is suitable to add 1.5phr silane coupling agent. Titanate coupling agent can improve the elongation of silicone rubber with the amount of 1.5phr. The breakdown strength can be enhanced by adding 1.0phr titanate coupling agent or 0.5phr silane coupling agent. After aging, the tensile strength and breakdown strength increase. The coupling agent addition of best thermal aging resistance for tensile strength and breakdown strength is 1.5phr silane coupling agent and 1.5phr titanate coupling agent relatively. The tear strength and elongation at break decrease. The coupling agent addition of best thermal aging resistance for them is 1.5phr titanate coupling agent and 1.5phr silane coupling agent relatively. As the amount of coupling agent increases, the change of the mechanical properties and breakdown strength of silicone rubber after thermal and oxygen aging almost reduce.