Different voltage endurance characteristics of epoxy/silica nanocomposites prepared by two kinds of dispersion methods

It was elucidated that treeing lifetime can be drastically extended especially under the condition of electric field as low as design field in epoxy/silica nanocomposites, if nano fillers are properly dispersed in good contact with surrounding polymer matrices. It was actually found that there is a distinctive difference in V-t characteristics between two kinds of epoxy/silica nanocomposites. It is certainly surprising that similar epoxy/silica nanocomposites exhibit dissimilar behaviors. This will bring about in-depth insight on how nano fillers and their interfaces with surrounding polymer would work for voltage endurance. Specimens of the former kind were prepared in a way that hydrophilic fumed silica nano particles were dispersed in uncured epoxy, while specimens of the latter kind were produced from nano silica fillers densely dispersed uncured epoxy. Voltage endurance characteristics were evaluated by treeing growth and breakdown time.