Experimental study on degradation of mechanical properties of biodegradable magnesium alloy (AZ31) wires/poly(lactic acid) composite for bone fracture healing applications

Abstract

In recent years, biodegradable materials have garnered increasing attention from researchers for use as orthopedic implants. In this study, the fabrication of unidirectional magnesium alloy (AZ31) wire-reinforced poly (lactic acid) (PLA) composites by lamina stacking is presented for bone fracture healing. The tensile and flexural properties of unidirectional composites with wire volume contents of 20%, 30%, 40%, and 50% were measured. Under the simulated human body temperature of 37 degrees C and accelerated environment of 50 degrees C, the degradation behaviors of 50-Mg/PLA composite (50% Mg wires by volume) and pure PLA were evaluated by testing water uptake, mass loss, and pH variation. Scanning electron microscopy helped to understand the fracture mode and degradation of magnesium wires inside the composites. Moreover, energy-dispersive spectroscopy confirmed the formation of an apatite layer that mainly consisted of a Ca-P phase deposited on the composite surface and wires, which is essential for bone healing.