Crystallization, morphology, and thermal behavior of poly(p-phenylene sulfide)

Abstract

This article deals with the structure, crystallization, morphology, and thermal behavior of poly(p-phenylene sulfide) (PPS) with low-molecular mass, probed by DSC, optical, and electron microscopy. The growth rates of spherulites were measured over the temperature range 235-275 °C. A regime II-III transition was found at T = 250 °C. The regime transition was accompanied by a morphological change from sheaflike structure to classical spherulites. The Avrami equation poorly described the isothermal crystallization of PPS, for the occurrence of mixed growth mechanisms and secondary crystallization, in agreement with the morphology and the thermal behavior. Two melting peaks were detected on DSC curves and attributed to the melting of crystals formed isothermally at Tc by primary and secondary crystallization.