Polymer crystallization kinetics, master quotients, master curves and Nakamura-Ozawa-equations of iPP and PTFE

Evaluation concepts related to Avrami master curves are described for the analysis of isothermal and non-isothermal kinetic processes exhibiting topological nucleation and growth characteristics. These evaluation concepts are shown to be helpful for studies focusing on kinetic data of polymer crystallization experiments with iPP (isotactic polypropylene) and PTFE (polytetrafluoroethylene). An apparent m-order reaction model is discussed with respect to the isokinetic nucleation and growth model of Nakamura as well as to the non-isothermal crystallization kinetics theory of Ozawa. Thus, the cooling functions chi(T) of iPP and PTFE, obtained by analyzing DSC (differential scanning calorimetry) experiments with constant cooling rates, are calculated in two alternative ways by using clearly different mathematical approaches. Finally, master quotients, theoretical crystallization limits, and further types of master curves are defined. (C) 2004 Society of Plastics Engineers.