Abstract
Studies on the mechanical and electrical properties of epoxy/silica nanocomposite using hydrophilic and hydrophobic silica is reported in this paper, which revealed that, while epoxy nanocomposite with hydrophilic nano-silica (NC-hydrophilic) excels in partial discharge resistance, epoxy nanocomposite with hydrophobic nano-silica (NC-hydrophobic) has better performance on fracture toughness and treeing resistance. Investigations into the morphology of nano-silica dispersion in epoxy resin, along with quantum chemistry based simulation analysis to the models of NC-hydrophilic and NC-hydrophobic, suggest that the formation of a network structure by hydrophobic nano-silica may lead to the observed excellent properties of NC-hydrophobic on fracture toughness and treeing resistance. Moreover, the homogeneous dispersion of nano silica achieved by hydrophilic nano-silica in NC-hydrophilic is considered to be the optimal condition to improve partial discharge resistance.
