Thermally stimulated polarization in dye doped polystyrene explained via the Williams-Watts α-β relaxation model

A simplified version of the alpha-beta Williams-Watts relaxation model has been applied to interpret thermally stimulated polarization (TSP) currents obtained in dye doped polystyrene. The system showed the beta and alpha relaxation processes typically observed in polymers, but the amount attributed to each process changed from experiment to experiment. However, this peculiar behaviour has been matched by changing alpha and beta content parameters as allowed by the model. in order to help in the fitting, some parameters were tentatively derived from isothermal current decay experiments, but they did not provide a good fitting in the alpha region, Improvement obtained by relaxing the above-mentioned condition seems to imply that even near the glass transition temperature T-g the guest dye molecules were not under thermal equilibrium in the TSP experiments probably due to the large size of the molecules. The concept of intrinsic time was used in order to describe a non-isothermal process.