Post-chemical grafting poly(methyl methacrylate) to commercially renewable elastomer as effective modifiers for polylactide blends.

A novel poly(epichlorohydrin-co-ethylene oxide)-g-poly(methyl methacrylate) copolymer (ECO-g-PMMA) was successfully synthesized from a commercially renewable elastomer via the ATRP method. The graft copolymer was investigated as a toughening agent and compatibilizer for polylactide (PLA) and PLA/ECO blends, respectively. Binary blending PLA with the copolymers (5-15 wt%) significantly improved the strain at break of PLA above 200% without a great strength loss. More importantly, the ternary PLA/ECO/ECO-g-PMMA copolymer blends exhibited a remarkably high impact strength of 96.9 kJ/m2 with non-broken behaviors. An interesting phase structure transformation from a typical sea-island structure to a unique quasi-continuous network structure was observed with varying the content of ECO-g-PMMA from 0 to 15 wt% in the ternary blends. The native toughening mechanism analysis indicated the synergistic toughening effect of the good interfacial adhesion and unique quasi-continuous morphology endowed the ternary blends with excellent mechanical performance.