Preparation and dielectric properties of epoxy/silica nanocomposites

In this paper, epoxy resin based composites filled with nano-silica were fabricated. The relationships between the dielectric properties as well as glass transition temperature (Tg) and nano-filler content were investigated. The results showed that, relative permittivity (¿_r) and dielectric loss tangent (tan¿) decreased when filler content was no more than 0.3 wt.%, and reached minimum value at 0.3 wt.%, but above this filler loading, ¿_r and tan¿ started to increase with increasing filler content. The DC volume resistivity decreased with the introduction of nano-silica, and the value of Tg did not appear to change significantly with filler content.