Crystallization and heat resistance of PBAT/PLLA/PDLA blends.

The effect of PBAT (poly(butylene adipate-co-terephthalate)) content and crystallization temperature on the crystallization and heat resistance of PLLA/PDLA blends are studied. The PBAT/PLLA/PDLA blends with different PBAT content were prepared by melt blending. Then, differential scanning calorimetry (DSC) and Vicat softening temperature (VST) were used to investigate the semicrystallization time (t_1/2), crystallinity and heat resistant of the blends. The results show that the incorporation of PBAT is benefit to the rate of crystallization and t_1/2 of the blends can be reduced from 1.0 min to 0.8 min at 100 °C. After annealing at 220 °C, the degree of stereo-complex (f_sc), stereocomplex crystallinity (X_c,S) and VST of PLLA/PDLA blends reaches up to 100.0%, 31.1% and 204 °C, respectively. The values of the former parameters reduce to 96.0%, 15.4% and °C 194 °C after incorporating 12% PBAT. It concludes that the crystallization under high temperature contributes to the improvement of X_c,S and heat resistance. The incorporation of PBAT into PLLA/PDLA promotes the crystallization rate, while it reduces the heat resistance of the blends [ABSTRACT FROM AUTHOR]