Effect of Reprocessing on the Crystallization of Different Polyesters

Abstract

The changes in crystallization characteristics of four polyesters were investigated during multiple processing. Two of these were petroleum-based materials: poly (ethylene terephthalate) (PET) and poly (butylene terephthalate) (PBT), and two were bio-based materials: poly (lactic acid) (PLA) and poly (butylene succinate) (PBS). We found that during non-isothermal crystallization the different type of polyesters shown different behaviour: the PET and PLA materials were more sensitive to the cooling rate than the PBT and PBS. Interestingly, at low cooling rates, the number of reprocessing steps had no significant effect on the crystallinity of PBT and PBS, but reduced it for PET, but increased it for PBT.