Abstract: PLA was modified with chain extenders, and was foamed molded through injection molding. Melt flowability, cell morphology,and mechanical properties of the foam were investigated. It was found that, there was a significant reduction in the melt flow rate and an improvement in the melt strength by the chain extender. With increasing contents of the chain extender, the foaming performance and mechanical properties of both injection and extrusion grade PLA were improved gradually. When the content of the chain extender reached 0.8 wt%, the optimal cell morphology and mechanical properties were obtained. Foamed samples of the modified injection molding grade had better mechanical properties.

Key words: poly(latic acid), chain extension, injection molding, foaming, cell morphology, melt strength, mechanical property