Temperature dependence of ac conductivity of PMMA with ZnO nanocomposites

The dielectric permittivity as function temperature in the range of 40 to 120°C for the polymer film of PMMA and its composite film of PMMA with ZnO at 10 weight percent is studied at different frequency. The peak of nonlinear curves occurred at temperature of 108°C shifts slightly towards the higher temperature at 110°C as frequency of the polymer film increased. The A C conductivity shows almost constant as temperature increased except very small variation for all the frequencies. But temperature of 100°C onwards even at higher frequencies the A C conductivity decreased suddenly it may be due to the sample reached the molten state. The A C conductivity increased as frequency increased at any given value of temperature within 100°C. This may be due to greater freedom of movement of the dipole molecular chains within the polymer at high temperature.