Effect of Transformer oil on Silicon Rubber Nano-Micro Composites

Room temperature vulcanized (RTV) silicon rubber (SiR) is widely employed as the coating material for ceramic based insulating bushings of power transformers because of its excellent hydrophobicity and dielectric properties. However, due to oil leaks, transformer oil may seriously impair the performance of RTV silicon rubber coverings. The purpose of this study is to examine the decay of silicon rubber (SiR) when aged in transformer oil. Therefore, pure SiR, SiR + 40% micro Aluminium Tri Hydrate (ATH), SiR + 4% nano Silica (SiO2) and SiR + 10% micro ATH + 5% nano SiO2 blends were prepared. The degradation dynamics of all the samples post transformer oil ageing was studied using several physiochemical and electrical techniques studies viz. moisture diffusion, surface hydrophobicity, leakage current, corona inception voltage and shore A hardness measurements. In the end, based on the experimental outcomes best composite formulation is reported.