Mechanical Properties and In Vitro Degradation Study of Modified‐Polylactic Acid Block Copolymers/Polyetheretherketone Biocomposites

ABSTRACT Polylactic acid (PLA) plays a crucial role in addressing global environmental concerns, particularly the challenges of achieving carbon peak and neutrality goals. Polyetheretherketone (PEEK) has emerged as a potential orthopedic implant material due to its excellent mechanical properties, elastic modulus similar to human bone, wear resistance, and good biocompatibility. In this study, PEEK/PLA (PEEK/PLA) composites were prepared using a film‐casting method. PEEK exhibits a spherical structure and can be dispersed in the PLA matrix, demonstrating good compatibility with PLA. Additionally, PEEK acts as a heterogeneous nucleating agent, reducing the surface free energy barrier for the crystallization nucleation of PLA molecules and promoting PLA crystallization. When the PEEK content is 8%, the tensile strength and Young's modulus of the composite material increase by 15.45% and 91.23%, respectively, compared to pure PLA. Furthermore, the introduction of the copolymer (PC x L y A) not only improves the compatibility between PLA and the blend but also successfully regulates the mechanical properties and in vitro degradation of the composite by adjusting the ratio of ε‐caprolactone and L‐lactide in the copolymer. This study not only delves into the modification strategies and methods for PLA composites but also provides new insights for developing biomedical materials with excellent properties.