Effect of hydraulic oil on Silicone Rubber at elevated temperature

Silicone rubber (SiR) is a widely used insulating material. The study provides the experimental analysis to explore the effect of accelerated aging of SiR in Hydraulic oil (H-oil) medium. SiR samples are immersed in H-oil at 100±2°C for 720 hours. Fourier Transform Infrared (FTIR) spectroscopy confirms that oil contamination is not effective in molecular level of SiR. Mass change is analyzed to understand the macro properties of SiR before and after H-oil accelerated ageing. Surface resistivity, volume resistivity and AC dielectric breakdown voltage measurements are carried out to check the effect of H-oil on the electrical insulation properties of SiR. The adverse effect of H-oil on volume resistivity has been observed. Whereas, H-oil shows trivial influence on surface resistivity. Irreversible H-oil absorption improves AC breakdown voltages of the SiR. Additionally, it is observed that the AC breakdown voltage distribution is fitting to the Weibull distribution and scale and shape parameters are also reported.