Thermally stimulated discharge current studies on low‐temperature relaxations in polycarbonate

Abstract

AbstractThe β‐relaxation in polycarbonate has been investigated by the thermally stimulated discharge current (TSC) technique. The polarization of the β‐peak in polycarbonate is shown to be uniform. Two broad peaks centered at 130° and 200°K were observed. Furthermore, two single relaxation processes were resolved for the lower temperature peak. The high temperature peak was also resolved into two peaks, however, only one of them was a single relaxation process. The individual peaks satisfied the dipolar theory, and the three peaks are associated with activation energies of 0.24, 0.27, and 0.47 eV, and temperatures of the peak maxima were 121°, 131°, and 193°K, respectively. The mechanism attributed to each peak is discussed and does not appear to contradict the results of conventional dielectric and mechanical relaxation and NMR measurements on the β‐relaxation in polycarbonate.