Absorption and thermally stimulated depolarization currents in polypropylene

A study of absorption currents in discharging mode in polypropylene (PP) has been carried out in the temperature range 65–145°C under different fields, ranging from 25–250 kV/cm. The observed results suggest that absorption currents are governed by charge injection processes leading to space charge effects. Comparative studies of the isochronal characteristics (i.e., current versus temperature plots at fixed times) with the thermally stimulated discharge currents (TSCs) indicate a strong resemblance between two techniques. These studies suggest that the TSC peak observed at 114°C can at least partly be attributed to the dissipation of space charge during heating.