Synergistic toughening of poly(lactic acid) by poly(butylene adipate-co-terephthalate) and poly(methyl methacrylate)-poly(butyl acrylate)-poly(methyl methacrylate) block copolymer

Poly(butyleneadipate-co-terephthalate) (PBAT) was used to toughen poly(lactic acid) (PLA) with the addition of poly(methyl methacrylate)-poly(butyl acrylate)-poly(methyl methacrylate) (MAM) through melt blending. The impact toughness and tensile toughness of the PLA/PBAT/MAM ternary blends were greatly enhanced when the MAM content was higher than 5%. For PLA/PBAT/MAM (80/15/5) blend, the notched impact strength was as high as 42.4 kJ/m(2), and the elongation at break reached 194.7%. The structure-property relationship of the PLA/PBAT/MAM ternary blends were studied through scanning electron microscopy, dynamic mechanical analysis, and contact angle measurements. It is found MAM and PBAT have a synergistic toughening effect on PLA, the MAM acts as not only a compatibilizer but also a toughening agent, which can improve the compatibility and enhance the interfacial adhesion between PLA and PBAT. As a result, the overall mechanical properties of PLA blends were improved significantly. This result provides a simple to operate and more efficient method for PLA toughening.

Automated summary

Poly(butyleneadipate-co-terephthalate) (PBAT) was used to toughen poly(lactic acid) (PLA) with the addition of poly(methyl methacrylate)-poly(butyl acrylate)-poly(methyl methacrylate) (MAM) through melt blending. The impact toughness and tensile toughness of the PLA/PBAT/MAM ternary blends were greatly enhanced when the MAM content was higher than 5%. The synergistic toughening effect of MAM and PBAT on PLA was observed, improving the compatibility and interfacial adhesion between PLA and PBAT, thus significantly enhancing the overall mechanical properties of PLA blends.