A new mechanism in the formation of PET extended-chain crystal

In order to obtain a better understanding of the effect of transesterification in PET extended-chain crystallization, the crystallization behaviors of the PET samples with added catalysts and inhibitors of transesterification have been investigated at high pressure. The catalyst accelerated PET crystallization in two facets: (I) increasing the crystallinity; and (II) accelerating the thickening process of lamellar crystals. On the contrary, the inhibitor hindered crystallization. This indicates that transesterification can promote PET crystallization and improve the formation of extended-chain crystals. The different effects of transesterification to crystallization in amorphous region or molten state and on folded-chain surface of lamellar crystals has also been discussed; it suggested that transesterification between lamellar crystals is more effective for lamellar crystal thickening.