Dielectric relaxation behaviour of electrically (AC) aged polyethylene in humid environment

Abstract

The dielectric spectroscopy of the unaged and AC aged (6 kV/mm, 2.5 kHz, 0.1N NaCl, 69 hours) LDPE samples with three different experimental conditions (i.e., at room temperature, at room temperature after additional DC poling at 70/spl deg/C with 2 kV/mm for 1 hour followed by cooling down to room temperature in the presence of the field, and at 70/spl deg/C), are presented. It is shown that a parallel combination of the "universal relaxation law" and "low frequency dispersion" relaxation can account for the observed behaviour. The observed changes in the low frequency range (10/sup -5/Hz to 10/sup -2/Hz) appear to be most significant regarding the electrical ageing.<>