Self-reinforced biodegradable Mg-2Zn alloy wires/polylactic acid composite for orthopedic implants

Biodegradable composite rods with polylactic acid as matrix and Mg-2Zn wires as the reinforcement body were prepared by hot press and hot drawn method in this article. The main purpose is to improve the mechanical properties based on the strengthen and toughness effect of the directionally distributed Mg-2Zn wires in PLA matrix and the improved interfacial bonding strength by MAO treated Mg-2Zn wires as well as the self-reinforcement effect of PLA after hot drawn process. The effect of hot drawn on the orientation, crystallinity and melting temperature changes of PLA were investigated by XRD and DSC method. The relationship between the bending strength and the volume content of Mg-2Zn wires in the composite rods as well as the influence of hot drawn on the mechanical properties were compared and analyzed theoretically. The regularly arrangement of PLA chains after hot drawn is benefit to increase the crystallinity, the elastic modulus as well as the mechanical strength in essence. Theoretical calculation results could provide a reference value and guide us to adjust the Mg-2Zn wires content and prepare the composite rods according to the actual application requirements.