“Kinematic” analysis of growth and coalescence of spherulites for predictions on spherulitic morphology and on the crystallization mechanism

The visual analysis of a solid is a powerful means to draw reliable conclusions on the crystallization process, especially when direct observations during the phase transition are not sufficient. In this work a geometrical approach has been exploited to derive the analytical shape of interspherulitic boundaries in polymer solids and to show morphological characteristics reflecting the kinetics of crystallization. An effort has been made to combine all the published data, trying to provide a unique and exhaustive vision of the topic. Evaluations of the relative nucleation times and growth rates of impinging spherulites have been set on the base of the geometrical analysis of spherulitic interfaces. Explanatory examples of the determination of the relative nucleation times and growth rates of impinging spherulites have been given to adequately underline the potential of visual observations in understanding the crystallization mechanism of polymers. A thermal procedure, originally developed for morphological analysis of samples during crystallization, has been shown to be very useful in order to study crystallization kinetics.