Effect of PTSA on the polarization and depolarization behavior of poly(4-vinyl pyridine)(P4VP)

Thermally stimulated depolarization behavior of high molecular weight poly(4vinylpyridine)(P4VP) doped with P-toluene sulfonic acid(PTSA) has been studied in the temperature range 300–450 K for different polarizing temperatures. Three characteristic peaks are observed for pure P4VP and doped samples. The total charge produced is found to be high unlike pure or blended polymeric electrets. The peaks observed are assigned to electrode injected trapped charges, different dipole orientations, space charge relaxation and also some of the inherent properties of the polymer like microbrownian relaxation movements of functional groups, deorientation of molecular aggregates, large chain segmental relaxation and discharging of the ionomers in the charge transfer complex or polyelectrolytes formed. The depolarization current produced at lower temperatures is high in the present electret system unlike other polymeric electret systems reported earlier. There is a decrease in the peak current for high temperature poling. Possible relaxation mechanisms are discussed in detail.