Thermally stimulated current study of amorphous phase of PPS

Polarization phenomena of unoriented and uniaxially oriented poly(p-phenylene sulfide) (PPS) have been investigated around the glass transition by thermally stimulated current (TSC) spectroscopy. The samples are characterized by a primary peak at 95 degrees C and a secondary peak at 75 degrees C for unoriented PPS and at 65 degrees C for uniaxially oriented PPS. According to differential scanning calorimetry data, they have been associated with the glass and subglass transition, respectively. The analysis of TSC relaxation modes reveals the presence of a higher local order in the amorphous phase of uniaxially oriented PPS than that of unoriented PPS. Moreover, molecular orientation has been found to increase the magnitude of the process of free volume diffusion, associated with conformational changes.<
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