Abstract
Electrical breakdown and electrical conduction of ethylene copolymers was studied. It was found that the electric strength of ethylene copolymers containing an optimum content of halogen compounds such as Bromo-phenyl and Fluoro-methyl groups was higher than that of LDPE over a wide temperature range from -196 to 90°C and that their conduction currents were suppressed at high electric fields. X-ray induced TSC revealed that halogen comonomers act as carrier traps whose depth was ca. 0.4eV. It is concluded that the introduction of comonomer containing halogen group into polyethylene supresses the electron acceleration due to an increase of the trapping and scattering of the conduction electrons, leading to an increase of electric strength which is determined by the electron avalanche breakdown.
