Enhancing the compatibility and ductility of poly(lactic acid) and poly(ethylene oxide) blends by a multi-epoxy compatibilizer.

In recent years, environmentally friendly polymers have gained increasing attention and application worldwide. In this study, bio-degradable and bio-based poly(lactic acid) (PLA) was melt-blended with biodegradable poly(ethylene oxide) (PEO) and a novel multi-epoxy compatibilizer pentaerythritol glycidyl ether (PGE) was introduced to enhance the compatibility and properties of the blends. The addition of PGE improved interfacial adhesion between PLA and PEO phases, and reduced the non-Newtonian behavior and melt viscosity of the PLA and PEO blends. The crystallization of PLA significantly enhanced by the incorporation of PEO; however, the presence of PGE reduced the crystallization capacity of PLA in the blends. Compared to PLA/PEO blends, the spherulitic size in PLA/PEO/PGE blends decreased markedly, which was attributed to the nucleating effect of the branched copolymers formed through the compatibilization reaction. The PLA/PEO/PGE blends also exhibited a remarkable improvement in ductility. In particular, the PLA/PEO/PGE (80/18/2) blend achieved an ultimate strain of 336.2 %, approximately 40 times greater than that of pure PLA. Owing to their excellent mechanical properties, these blends have potential applications in various degradable packaging and products.