Influence of the order of polymer melt on the crystallization behavior:II.Crystallization kinetics of isotactic polypropylene

摘要

The crystallization behav-ior of isotactic polypropylene (iPP) melts with a high order has been carefully examined by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The experimental results show that the helically ordered iPP melt crys-tallizes by heterogeneous nucleation with two-dimensional diffusion con-trolled growth and the Avrami ex-ponent is about 2. The data availableboth from our DSC and PLM experiments and from the literature indicate that the order of a polymer melt can speed up the crystallization process. When some unmelted ma-terials exist in the ordered melt, the crystallization will become more rapid.