The influence of oxidation on thermally stimulated currents from trapped carriers in high density polyethylene

Abstract

Thermally stimulated currents (TSC) were measured from oxidized and unoxidized high-density polyethylene with prior X-ray irradiation. Six TSC peaks due to trapped carriers were observed in the unoxidized samples. Slight oxidation introduced a new peak around 180K, which was ascribed to unstable intermediates in the oxidation process. Further oxidation reduced the TSC below 340K and enhanced the TSC peak around 360K ascribed to stable oxidation products such as carbonyl groups. The TSC without X-ray irradiation were also reduced by oxidation. These reductions are considered to be closely related to the introduction of deep traps responsible for the TSC peak around 360K.