Crystallization of Polypropylene and Poly(Ethylene Terephthalate)

1. INTRODUCTION The prediction of polymer crystallization behavior at a reasonable semiquantitative level of accuracy is important in assessing processability and performance. For example, in both polypropylene (PP) [1–3] and poly(ethylene terephthalate) (PET), the interplay of the effects of rheology and crystallization kinetics under various types of fabrication conditions is crucial in determining the semicrystalline morphology. In turn, morphology affects the mechanical, optical, and gas barrier properties of the fabricated articles. On the other hand, since many important plastics fabrication processes are carried out with the polymer in semicrystalline state (below the crystalline melting temperature, but above the amorphous glass transition temperature), while others are carried out from the melt and above the recrystallization temperature, the crystallization kinetics and the morphology, in turn, also affect the processing of the polymer by these fabrication methods.