Dependence of the Avrami Exponent on Supercooling During Nonisothermal Crystallization of Poly(phenylene sulfide)

Abstract

The nonisothermal crystallization behavior of poly(phenylene sulfide) (PPS) was studied by means of differential scanning calorimetry (DSC) at various cooling rates. The nonisothermal crystallization data were analyzed by the Ozawa theory. The Avrami exponent n was determined at several constant cooling rates. A notable variable trend of the Avrami exponent with the temperature was found. Within 215–238°C and 243–255°C, the Avrami exponent of PPS increases markedly with the increase of temperature, respectively, while within narrow temperature range from 238°C to 243°C, a sharp decrease of the Avrami exponent can be seen. It has been suggested that the nuclei formation and the geometry of spherulite growth in the nonisothermal crystallization of PPS are strongly affected by the temperature and correlated with the Regime Transition (the regime II→III transition for PPS).