A technique for improving dispersion within polymer-glass composites using polymer precipitation

• Published in: arXiv.org 2021-12
• Main Authors: Oosterbeek, Reece N, Zhang, Xiang C, Best, Serena M, Cameron, Ruth E
• Format: Article
• Language: English
• Subjects: Agglomeration; Biocompatibility; Biomedical materials; Ethanol; High temperature; Injection molding; Particulate composites; Polymer matrix composites; Polymers; Stiffness; Surgical implants; Thermal degradation
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2112.07329

Particulate reinforcement of polymeric matrices is a powerful technique for tailoring the mechanical and degradation properties of bioresorbable implant materials. Dispersion of inorganic particles is critical to achieving optimal properties, however established techniques such as twin-screw extrusion or solvent casting can have significant drawbacks including excessive thermal degradation or particle agglomeration. We present a facile method for production of polymer-inorganic composites that reduces the time at elevated temperature and the time available for particle agglomeration. Glass slurry was added to a dissolved PLLA solution, and ethanol was added to precipitate polymer onto the glass particles. Characterisation of parts formed by subsequent micro-injection moulding of composite precipitate revealed a significant reduction in agglomeration, with d0.9 reduced from 170 to 43 {\mu}m. This drastically improved the ductility ({\epsilon}B) from 7% to 120%, without loss of strength or stiffness. The method is versatile and applicable to a wide range of polymer and filler materials.