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

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Science

Background:

• Particulate reinforcement enhances mechanical and degradation properties of bioresorbable polymers for implants.
• Conventional methods like twin-screw extrusion and solvent casting often lead to thermal degradation and particle agglomeration, compromising composite quality.

Purpose of the Study:

• To develop a facile and efficient method for producing polymer-inorganic composites with improved particle dispersion.
• To overcome the limitations of existing techniques, reducing thermal exposure and particle agglomeration time.

Main Methods:

• A novel precipitation method involving adding a glass slurry to a dissolved poly(L-lactic acid) (PLLA) solution.
• Utilizing ethanol to precipitate PLLA onto glass particles, followed by micro-injection molding.
• Characterization of composite precipitate properties, focusing on particle dispersion and mechanical performance.

Main Results:

• Significant reduction in particle agglomeration, with the d0.9 particle size decreasing from 170 μm to 43 μm.
• Drastic improvement in ductility (elongation at break, ɛB) from 7% to 120%.
• Maintenance of material strength and stiffness despite enhanced ductility.

Conclusions:

• The developed precipitation method offers a versatile and effective approach for creating high-performance polymer-inorganic composites.
• This technique minimizes particle agglomeration and thermal degradation, leading to superior mechanical properties, particularly ductility.
• The method is adaptable for various polymer and filler combinations, showing broad applicability in biomaterial development.