Cause of the higher breakdown strength in Ethylene-Styrene copolymer, a new insulating material

The breakdown strength of an ethylene-styrene copolymer is reported to be higher than that of a low-density polyethylene. In order to understand the phenomena high energy electrons are injected into polyethylene and copolymer samples. The injected electrons passing through the materials and entering into vacuum are energy analyzed. The electrons are found to be more effectively decelerated in the copolymer. The energy absorption property of the benzene ring might be responsible for the effect.