Effect of Curing By-Products Coating on Localized Heat Generation and Dielectric Breakdown in Low-Density Polyethylene Film

Abstract

This paper describes the experimental results of localized heat generation and dielectric breakdown in lowdensity polyethylene (LDPE) film where curing by-products were coated on the surface. The variations of temperature distribution were observed by thermography. Under dc voltage application, localized heat generation of LDPE film with curing by-products, especially acetophenone, was observed under lower field than that of uncoated specimen, and the breakdown strength decreased considerably. The dc conduction current was significantly enhanced by the coating. Under ac voltage application, it was also observed that localized heat generation increase and the breakdown occurred under somewhat lower field. It was considered that the increase of heat generation was caused by promotion of electronic carrier injection due to the existence of curing by-products at the electrode interface and enhancement of the carrier mobility due to their permeation into the film.