Relaxation investigations in polysulfone: Thermally stimulated discharge current and dielectric spectroscopy

The temperature and electric field dependence of dielectric relaxation have been investigated in amorphous polysulfone (PSF) samples using thermally stimulated discharge current (TSDC) and AC dielectric measurement. All measurements were performed on solution grown thin films of thickness 50 μm. The nature of relaxation mechanisms in amorphous PSF is discussed on the basis of TSDC and dielectric measurement results. The comparative studies of dielectric properties with TSDC indicated a strong resemblance between the two techniques. Polysulfone (PSF) films are characterized by two TSDC peaks, i.e. β peak at 348 K and α peak at 470 K. The depolarization current for the β peak increases linearly with poling field. The peak obtained at lower temperature (i.e. β peak) is associated with dipolar relaxation and the other one obtained at high temperature (i.e. α peak), which appears due to the α relaxation.