Abstract: The PLA/OMMT composites were prepared by a torque rheometer and then blended with PBAT to obtain the PLA/OMMT/PBAT ternary composites in the two-step process. Meanwhile, the ternary composites were also prepared by melt blending in the one-step process for comparative investigation. The interfacial tension of two types of composites was evaluated, their microstructures were observed by TEM and SEM, and their melting and crystallization behaviors were analyzed by DSC. The results indicated that the addition of OMMT reduced the size of PBAT domain and improved the compatibility between PLA and PBAT. OMMT could generate a better compatibilizing effect on the PLA/PBAT blends when the composites were prepared in the two-step process. OMMT tended to be distributed in the PLA phase and on the interface between PLA and PBAT due to a good affinity. There is a synergistic toughening effect of OMMT and PBAT on PLA.

Key words: poly(lactic acid);poly(butylenes adipate-co-terephthalate);organically modified montmorillonite, ternarycomposite;microstructure;twostep process