Analysis of dielectric behavior of PVDF: PSF polyblends at lower frequency range from measurements of transient absorption and desorption currents

Abstract

Transient current measurements were carried out for polyvinylidene fluoride:polysulfone (PVDF:PSF) blends films of different ratios under different polarizing fields and polarizing temperatures in absorption and desorption mode. The time‐dependent desorption current in polymer blend samples interprets the combined effect of dipole reorientation, space charge dissipation, and hopping of charge carriers. The activation energy has been calculated using the isochronal curve. Thermal activation behaviors of isochronal current in a specific temperature scale followed by a peak centered at about 120–160°C, have indicated the close correlation of transient currents with the dielectric loss peak. The presence of a dielectric loss peak for each polyblend concentration may be due to the existence of relaxing dipoles in the polyblend. With increasing concentration of PSF in the polyblend, this peak tends to shift toward the higher frequency range and suggests the speeding up of the dipolar relaxation process. The dielectric loss factor of polyblend thin films using transient study in absorption and desorption mode using applied step voltage f is related to Hamon's frequency (0.1/t).