Polarization temperature effect on liquid-liquid transition and space charge detrapping behavior in atactic polystyrene by thermally stimulated depolarization current

Thermally stimulated depolarization current (TSDC) experiments were carried out to investigate the effect of polarization temperature (T (p)) on liquid-liquid transition and space charge detrapping behavior in atactic polystyrene. Differential scanning calorimetry (DSC) measurement was applied as a complementary method. When T (p) is 130 A degrees C, there are four distinct peaks (alpha, rho(1), LL, and rho(2)) showed in TSDC spectrum in the range of 30-200 A degrees C. Compared with the result of DSC, TSDC spectrum show that peak alpha corresponds to glass transition, peak LL is related to liquid-liquid transition, and peak rho(1) and peak rho(2) belong to the space charge current peak. As T (p) increases from 100 to 150 A degrees C, the intensity of peak LL maximum increases and that of space charge peaks maxima decreases, which is attributed to different mechanism between liquid-liquid transition and space charge detrapping behavior. In addition, their corresponding characteristic parameters versus T (p) are also analyzed in detail.