Shaoqin (Sarah) Gong1, Lih-Sheng Turng2, Liqiang Yang3, Adam Kramschuster2, Junghoo Lee2, and Srikanth Pilla4. (1) Departments of Mechanical Engineering & Materials, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, WI 53211, (2) Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Avenue, Madison, WI 53706-1572, (3) Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, WI 53211, (4) Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, WI 53211
The effects of adding epoxy-based chain-extender on the properties of injection-molded solid and microcellular polylactide (PLA) were studied. PLA and PLA with 8 wt% chain-extender (PLA-CE) were melt-compounded using a twin-screw extruder. Solid and microcellular specimens were produced via a conventional and microcellular injection molding process, respectively. Various characterization techniques were applied to study the static and dynamic mechanical properties, cell morphology, and crystallization behavior. The addition of chain-extender reduced the cell size and increased the cell density in the microcellular specimens. It also decreased the crystallinity of PLA and increased the decomposition temperature. In addition, adding chain-extender slightly enhanced the average values of specific strength, specific toughness, and strain-at-break for both solid and microcellular PLA specimens.