Tailoring the properties of epoxy/silicone blends for high-voltage capacitor applications

In recent decades, high dielectric constant (k) polymer nanocomposites have proved excellent potential in dielectric and energy storage applications. Epoxy/silicon rubber composite materials have shown promising properties in applications such as high-voltage insulation. Three types of nanomaterials (SiO2, TiO2, and TiO2@SiO2) with distinct intrinsic properties are carefully chosen to build high-k epoxy/silicone polymer nanocomposites in this study. To raise the value of K, this work tailored the polarizing ability or permittivity of dielectric material by inserting different weight ratios of nano-fillers (SiO2, TiO2, TiO2@SiO2) in the base matrix of dielectric material in epoxy and silicon rubber blends. With a base matrix containing 75% epoxy and 25% liquid silicone rubber concentration, the maximum value of K obtained is K = 158 for 5% TiO2 and there is an increase in the dielectric strength to 398 kV/mm. The obtained results indicate that, among the three different kinds of epoxy/silicone, TiO2@SiO2 has the most potential in enhancing the energy storage capabilities of the proposed nanocomposites, owing to the largest increase in k while maintaining low dielectric loss and leakage current.