Thermally stimulated discharge and polarization currents in aromatic polyamides

Studies carried out on the Thermally Stimulated Discharge (TSD) and Thermally Stimulated Polarization (TSP) currents in aromatic polyamides are presented. TSD currents are measured at various poling fields, duration of poling. Annealing time and rate of heating during release of charges. The currents show a peak at 135°C for a rate of heating of 1 k/min and the peak shifts to a higher value with increase of rate of heating. Thermally stimulated polarization currents are also measured and the influence of various parameters are investigated. The results show that a dipolar process is applicable which is replaced by interfacial polarization as the temperature is increased. The latter is the predominant mechanism at 200°C, which is in agreement with the charging current measurements in the same material