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/spl deg/C. At a heating rate of 2/spl deg/C/min, these peaks appeared at 43.5, 92, 121, 163, and 193/spl deg/C, respectively. Based on differential scanning calorimetry and literature data, the a peak at 43.5/spl deg/C and the b peak at 92/spl deg/C were attributed to the dielectric manifestation of sub-T/sub g/ and T/sub g/ transitions, respectively. The c peak at 121/spl deg/C was demonstrated to be caused by the crystallization of the amorphous part during the heating run. The d peak at 163/spl deg/C was likely associated with the slight crosslinking and/or chain extension of the polymers during the sample preparation. The e peak at 193/spl deg/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.<>