CHARGING AND DISCHARGING CURRENTS IN POLYVINYLALCOHOL (PVA) POLYMER-FILMS

Charging and discharging currents in polyvinylalcohol (PVA) polymer films were measured over the temperature range 30-150 degrees C and field strengths of (2.3-23)X10(6) V m(-1). Polymer films were prepared by the isothermal immersion technique. The effect of field strength and charging temperature on the transient currents was studied. Activation energies were evaluated from quasi steady state currents. A single relaxation peak was observed both from isochronal currents and low-frequency dielectric relaxation. Activation energies evaluated from both these methods are found to be in fairly good agreement. The polarization has been considered to be due to space charge origin along with some contribution from dipolar groups.