Oyama [20] introduced 3 wt.% of glycidyl methacrylate into the EGMA random copolymer to induce a reaction between the epoxide groups of the EGMA and the acid groups of PLA to achieve in situ compatibilization. Anderson and Hillmyer [19] and Ho et al. [23] used pre-made PLA-PE block copolymer and TPO–g-PLA copolymer respectively to improve the compatibility of PLA and ethylene-octene copolymers. As a result, a finer morphology and a higher toughness of the PLA/poly(ethylene-co-octene) blends were obtained.