Characterization of poly(p-phenylene sulfide) polymers by thermally stimulated charging/discharging currents measurements

Five current peaks were observed in the thermally stimulated current (TSC) spectra of poly(p-phenylene sulfide) (PPS) films over the temperature range of 25 to 250°C. At a heating rate of 2°C/min, these peaks appeared at 43.5, 92, 121, 163, and 193°C, respectively. Based on differential scanning calorimetry and literature data, the a peak at 43.5°C and the b peak at 92°C were attributed to the dielectric manifestation of sub-T_g and T_g transitions, respectively. The c peak at 121°C was demonstrated to be caused by the crystallization of the amorphous part during the heating run. The d peak at 163°C was likely associated with the slight crosslinking and/or chain extension of the polymers during the sample preparation. The e peak at 193°C was attributed to the release of injected space charges trapped at the amorphous-crystal interfaces. A two-step molding method which greatly improved the PPS films´ preparation was also developed