<p>In this study, we successfully synthesized a partially degradable graft copolymer featuring polyethylene as the main chain and polylactic acid as the side chain, utilizing a post-functionalization modification strategy on polyolefin resin. Initially, we performed alcoholysis on the commercial ethylene-vinyl acetate copolymer to obtain the precursor of the partially degradable graft copolymer: hydroxyl-functionalized polyethylene. Subsequently, using hydroxyl-functionalized polyethylene as the initiator, we conducted the ring-opening polymerization of lactide in the presence of a catalyst, resulting in the formation of the desired partially degradable graft copolymer. This process introduces degradable polylactic acid segments onto the non-degradable polyethylene main chain, thereby achieving the preparation of the partially degradable graft copolymers. The graft copolymers were characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, and thermal differential scanning calorimetry. Additionally, their mechanical properties were analyzed and tested. The results demonstrate that under identical experimental conditions, the copolymer exhibits a lower elastic modulus, tensile fracture stress, tensile strength, and tensile yield stress compared to pure PLA, while its fracture elongation increases with the grafting amount. This indicates that incorporating polyethylene as a backbone into polylactic acid effectively enhances its toughness. This this grafted copolymer serves as a toughening modifier for PLA, exhibiting significant toughening and modification effects.</p> Graphical abstract <p></p>