Performance of Silicone Rubber Composites Filled with Aluminum Nitride and Alumina Tri-Hydrate

In this study, silicone rubber (SR) composites were prepared with various amounts of aluminum nitride (AlN) and alumina tri-hydrate (ATH), and vinyl tri-methoxysilane (VTMS) was also introduced to prepare SR/ATH/AlN-VTMS composites for comparison. Compared to the SR/ATH composites, the SR/ATH/AlN composites with higher AlN loading exhibited higher breakdown strength and thermal conductivity, which were further improved by the addition of VTMS. Such results were related to the enhanced rubber-filler interfacial interactions from VTMS coupling, as demonstrated by scanning electron microscopy (SEM) analysis and the curing behaviors of the SR composites. Moreover, by replacing ATH with VTMS-coupled AlN, the SR/ATH/AlN-VTMS composites also exhibited lower dielectric loss along with an increased dielectric constant, suggesting the promising application of VTMS-coupled AlN as a filler for the preparation of the SR composites as high-voltage insulators.