Investigation of electrical, tracking/erosion, and water absorption resistance properties of ATH-SiO2-reinforced RTV-SiR composites for high-voltage insulations

Abstract

In this work, we have investigated the impact of micro-silica (SiO2), micro-alumina-tri-hydrate (ATH), and mixture of micro/nano-sized particles (ATH + SiO2) on electrical, tracking and erosion, and water absorption characteristics of silicone rubber (SiR)-based novel composites. SiR-blends with varying concentrations by weight percent (wt%) of ATH and SiO2 were prepared by simple blending in a two-roll mixing mill. Tracking/erosion and water absorption resistance properties of SiR-blends were analyzed using the inclined plane test and water immersion tests, respectively, according to ASTM standards. Dielectric strength, volume and surface resistivity, tracking/erosion resistance, and water penetration resistance properties of SiR composites were determined and discussed. SiR composites with ATH showed enhanced dielectric strength, volume and surface resistivity, erosion resistance, and initial tracking voltage compared to SiO2-filled composites. Further, the ATH and SiO2 co-filled specimens showed better water immersion resistance compared to samples only filled with ATH or SiO2. We presume characterization results presented in this work will help researchers to optimize the performance of SiR for outdoor high-voltage insulation applications.