Thermally stimulated discharge current (TSDC) measurement was utilized to study the pure Polymethyl methacrylate (PMMA), Polyvinyl pyrrolidone (PVP) and their blends films, measured at 70°C as a function of poling fields (50, 70, 90, and 110 kV/cm) and weight ratios (100: 0, 95: 05, 90: 10, 85: 15, 80: 20 and 0: 100). The relaxation processes for PMMA and PVP shows two peaks observed at around 90 ± 5 and 150 ± 5°C but in the blend samples only one peak can be seen at higher temperature range 155 ± 10°C. The first peak is α-peak which is due to micro-brownian motion of the main chain segments and the higher temperature peak is ρ-peak is due to space charge near the electrodes. The order of current was found to increases with increase in weight percent of PVP in PMMA and the main reason is the formation of phase between PVP and PMMA. A decrease in activation energy observed with the increase in polarizing fields and weight% composition. This suggest that peak is not due to a discrete level having a single relaxation but is a complex one having distributed activation energies.
Polymethyl methacrylate, Polyvinyl pyrrolidone, Thermally stimulated discharge current, Blends, Space charge mechanism
