Effects of Platinum Catalyst on the Dielectric Properties of Addition Cure Silicone Rubber/SiO2 Nanocomposites

Herein, the influence of platinum (Pt) catalyst on the interface between SiO₂ nanofiller and addition cure silicone rubber (ALSR) matrix is investigated with different concentrations of Pt catalyst. It is found through various tests that Si-O-Si covalent bonds and hydrogen bonds form at the interface with a moderate amount of Pt catalyst. Based on these observations, a model for the interfacial structure of ALSR/SiO₂ nanocomposites is proposed. In particular, it is demonstrated, without changing the mass fraction and surface modifier of the filler, a more compact interface is obtained by increasing the amount of added Pt catalyst by a few ppm, resulting in a 25% increase of breakdown strength, 10% increase in thermal conductivity, 50% increase in tensile strength, and a 31% increase in the elongation at break.