and Simultaneous Avrami Macrokinetic Models to Isothermal Crystallization of

Various macrokinetic models (the Avrami, Tobin, Malkin, and simultaneous Avrami models) were applied to describe the primary crystallization of syndio-tactic polypropylene (sPP) under isothermal conditions. Analysis of the experi-mental data was carried out using a direct-fitting method such that the experi-mental data were fitted directly to each macrokinetic model using a nonlinear multivariable regression program. Comparison of the kinetics parameters ob-tained from the program to those obtained from the traditional analytical proce-dure suggested that applicability and reliability of the direct-fitting method are satisfactory. Prediction of the time-dependent relative evolution of crystallinity at other crystallization temperatures was demonstrated based on the bulk kinet-ics parameters obtained from the analysis