TRANSIENT CURRENTS IN POLY(VINYL ALCOHOL) POLY(VINYL PYRROLIDONE) POLYMER BLEND FILMS

Transient currents (charging and discharging currents) in poly(vinyl a lcohol) (PVA)-poly(vinyl pyrrolidone) (PVP) polymer blend films were m easured over the temperature range 30-150-degrees-C at field strengths of 2.32-23.2 x 10(6) Vm-1. Polymer films were prepared by the isother mal immersion technique. Activation energies were evaluated from quasi -steady-state currents. A single relaxation peak was observed both fro m isochronal currents and low frequency dielectric relaxation. Activat ion energies evaluated from these two methods are found to be in fairl y good agreement. The polarization is considered to be due to space ch arge origin along with some contribution from dipolar groups. The maxi mum loss was observed in Sample I (PVA: PVP = 25: 75), suggesting maxi mum heterogeneity in this blend ratio.