Super-Tough Poly(Lactide)/Ethylene-Methyl Acrylate-Glycidyl Methacrylate Random Terpolymer Blends via Efficient Catalytic Interfacial Crosslinking of Environmentally Friendly Carboxyl-Functionalized Ionic Liquids

Interfacial compatibilization of polylactide/ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (PLA/EG-MA) incompatible blends is crucial for fabricating super-tough PLA materials. To regulate and control the interfacial reaction and adhesion between PLA and EG-MA, 1-carboxymethyl-3-methylimidazole bromide salt (ILs) was selected as an interfacial compatibilizer and controller for PLA/EG-MA blends. Morphologies, crystallization, and relaxation behaviors of the blends were systematically investigated. The results proved that the reaction between the end groups of PLA and the epoxy groups of EG-MA could be catalyzed by carboxyl-functionalized ILs. The phase morphology structure of blends changed from sea-island to co-continuous structure with the increase of ILs. Notably, the impact strength and elongation at break of the PLA/EG-MA/2ILs blend reached 67 kJ/m2 and 284%, respectively, which is a 71 and 22 fold increase caused by the formation of interfacial crosslinking. Vigorous interfacial adhesion obviously increased the crystallinity and induced co-continuous morphology, which triggered massive shear yielding. Super-tough PLA blends were easily fabricated owing to the interfacial catalytic crosslinking of carboxyl-functionalized ILs.