Biodegradable poly-lactic acid based-composite reinforced unidirectionally with high-strength magnesium alloy wires

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Composites

Background:

• Biodegradable polymers like poly-lactic acid (PLA) are crucial for medical implants.
• Enhancing the mechanical properties and controlling degradation are key challenges for PLA-based materials.
• Load-bearing applications require composites with superior strength and toughness.

Purpose of the Study:

• To fabricate and characterize biodegradable poly-lactic acid (PLA)-based composites reinforced with magnesium alloy wires (MAWs).
• To investigate the mechanical properties and degradation behavior of these novel composites.
• To explore potential applications in bone fracture fixation.

Main Methods:

• Fabrication of composites using a heat-compressing process.
• Experimental and theoretical analysis of mechanical properties (bending strength, impact strength).
• Evaluation of degradation behavior and strength retention.
• Development of a numerical model (equivalent section method - ESM) for bending strength prediction.
• Application of micro arc oxidization (MAO) for interfacial strengthening.

Main Results:

• Composites with 40 vol% MAWs achieved a bending strength of 190 MPa and impact strength of 150 kJ/m².
• Magnesium alloy wires significantly improved strengthening and toughening properties.
• Micro arc oxidization proved effective for interfacial strengthening.
• Composites demonstrated high strength retention during degradation, with PLA showing a reduced degradation rate compared to pure PLA.

Conclusions:

• Biodegradable PLA-MAW composites exhibit enhanced mechanical properties and controlled degradation.
• Interfacial modifications, such as MAO, further improve composite performance.
• These novel composites show significant potential for load-bearing bone fracture fixation applications.