Influence of electrode interface on insulation property of hydrocarbon-based thermosetting composite with silica filler

We have been studying electrical insulation properties of hydrocarbon-based thermosetting composite as a development of new functional polymeric insulating material. Our previous reports showed that the composite has advantages in high heat resistance, low dielectric constant and low dielectric loss. These evaluations were performed for the specimen with a shape of plane. Practical application of the composite to the insulation system of high voltage power apparatus needs to estimate properties for molded electrode configuration. However, the hydrocarbon-based thermosetting resin has relatively poor adhesiveness with a metallic material such as a high voltage conductor. Thus, poor adhesion to metal material may cause lowering of the insulation properties. This paper deals with influence of the electrode interface on the insulation properties of the composite specimen filled with silica filler. As a result, it was found that both the rough surface treatment on the electrode and the adhesive monomer loading can avoid formation of void at the interface between the electrode and specimen, resulting in relatively high breakdown strength.