Dielectric response of filled high temperature vulcanization silicone rubber

The dielectric response of three kinds of filled high temperature vulcanization (HTV) silicone rubber – SiO2 based nanocomposite with different alumina tri-hydrate (ATH) micro-filler contents are investigated over a wide range of frequency and temperature. The results are analyzed in terms of the many-body Dissado-Hill dielectric response theory. In all three kinds of silicone rubber, a quasi-DC (QDC) process, a Dissado-Hill loss peak process and a diffusion process are observed. Specifically, the ATH filler contributes a QDC electrical transport/hopping process, which at higher temperatures causes the formation of a diffusion layer at the electrodes. The nano-SiO2 particles combined with rubber matrix give a Dissado-Hill loss peak dielectric relaxation. These two dispersion processes are shown to be associated with the interior interfaces of filled HTV silicone rubber. The effects of ATH filler content and temperature on the dielectric response are also analyzed in depth.