Structure-properties of super-tough PLA alloy with excellent heat resistance

Poly(lactic acid) (PLA) was toughed by blending hydrogenated styrene-butadiene-styrene block copolymer (SEBS) with the aid of reactive compatibilizer, poly(ethylene-co-glycidyl methacrylate) (EGMA). The high temperature property and thermal aging resistance were improved by further incorporating polycarbonate (PC), the ductile polymer with high glass transition temperature. On the basis of transmission electron microscopy, differential scanning calorimetry, and dynamic mechanical analysis, the outstanding toughness and aging resistance of the 4 component alloy; e.g., PLA/PC/SEBS/EGMA = 40/40/5/5 (wt. ratio), seems to come from the negative pressure effect of SEBS that dilates the plastic matrix consisting of PLA and PC to enhance the local segment motions.