Abstract: The poly(lactic acid) (PLA)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) blends were prepared by a melt-blending method using a chain extender (TMP-6000) as a compatibilizer. The effect of TMP-6000 on the crystallization behavior, microstructure and mechanical properties of PLA/PHBV blends was investigated. The DSC analysis results indicated that the addition of amorphous PLA prevented the crystallization of PHBV and depressed the crystallinity of the blends. However, the cold crystallization temperature of PLA was improved. The cold crystallization peak of PLA domain tended to disappear for the blends with 0.5 wt % TMP-6000. The glass transition temperature of PHBV phase increased with the addition of an appropriate amount of TMP-6000. The morphological observation indicated that PHBV was dispersed homogenously in the PLA matrix in the presence of TMP-6000, and an optimal compatibility was achieved for the blends with the addition of 0.7 wt % TMP-6000. Moreover, the addition of TMP-6000 increased the molecular weight of PLA/PHBV blends significantly. The interface adhesion and tensile strength of the blends were enhanced due to the introduction of TMP-6000, and however the elongation at break decreased slightly.

Key words: poly(lactic acid);poly(3-hydroxybutyrate-co-3-hydroxyvalerate);crystallization prop erty, compatibility