The Role of Filler Interface in Suppressing the Erosion of Silicone Rubber Under DC Voltage

The presented paper aims to highlight the role of filler-polymer interface on the DC erosion resistance of silicone rubber (SiR) outdoor insulators. SiR composites filled with nano-sized boron nitride and fumed silica have been prepared in this study. Electrical and thermal experimental tools of the inclined plane tracking-erosion test, simultaneous thermogravimetric-differential thermal analyses, and thermal conductivity measurements are used to analyze the prepared nanocomposites. The analysis primarily investigates whether the composite's enhancement of thermal conductivity or filler interface would be more influential on erosion suppression. Literature reports that the boron nitride filler improves SiR's thermal conductivity, whereas fumed silica provides an exceptional interaction with SiR at the filler interface. SiR was filled with boron nitride at 5wt% (percent by weight) and 10wt%, while fumed silica was loaded with 5wt% and used as a reference composite in the study. The obtained results clearly indicate a superior erosion resistance of the silica filled SiR over the boron nitride filled one. An observation which seemingly could give more significant role of the filler-polymer interface on the erosion resistance of SiR used for high voltage DC outdoor insulators.