Effect of Amino Silane Coupling Agent on the AC Electrical Breakdown Phenomena of Epoxy/Layered Silicate Nanocomposite in Needle-plate Electrodes

The effects of amino silane coupling agent on the AC electrical treeing and breakdown behaviors in an epoxy/layeredsilicate (1 wt%) were examined in needle-plate electrode geometry. A layered silicate was exfoliated in an epoxy baseresin by using our AC electric field apparatus. To measure the tree initiation and propagation and the breakdown rate,an alternating current (AC) of 10 kV (60 Hz) was applied to the specimen in needle-plate electrode arrangement witha 30℃ insulating oil bath. In the epoxy/amino silane system, the tree initiation time was 11.5 times higher and thebreakdown time was 17.9 times higher than those of the neat epoxy resin. The tree initiation time in the epoxy/layeredsilicate (1 wt%) system with the amino silane was 2.0 times higher, and the breakdown time was 1.5 times higher thanthose of the epoxy/layered silicate (1 wt%) system.