Effects of hydroxy silicone fluids on insulation properties of silicone rubber

The hydroxy silicone(HS) fluids in silicone rubber(SIR) have been generally used as processing agent. The addition of HS fluids to SIR for insulator housing material is required to meet the good electrical performance and the good processability. In this study, SIR with HS fluids was evaluated to investigate how the kinds of them affect insulation properties. The contact angle of the virgin sample of 40-HS SIR was low and its recovery rate was also slow. The recovery rate of 50-HS SIR was the highest being decreased with the viscosity increase of HS fluids. The recovery rate of 1,040-HS SIR was a little slow at the initial stage. But the contact angle of that increased rapidly at the medium stage. The tracking resistances and the corona aging resistance of 70-HS SIR and 1,040-HS SIR were excellent. It is clear that resistances on discharges like corona, tracking, and arc depends largely on heat resistance of silicone fluids.