Characterization of Antimicrobial Poly(Lactic Acid)- and Polyurethane-Based Materials Enduring Closed-Loop Recycling...

Area of Science:

• Materials Science
• Biomedical Engineering
• Space Health

Background:

• Astronauts exhibit altered immune responses in space, increasing illness risk.
• Longer space missions necessitate in situ resource utilization for medical supplies.
• Additive manufacturing (3D printing) offers potential for on-demand medical device production.

Purpose of the Study:

• To test and validate recyclable antimicrobial materials for additive manufacturing.
• To assess the antimicrobial, mechanical, and chemical properties of materials before and after recycling.

Main Methods:

• Developed and tested antimicrobial poly(lactic acid) and polyurethane materials.
• Evaluated material properties through antimicrobial assays, mechanical testing, and chemical analysis.
• Assessed material performance after one closed-loop recycling cycle and accelerated aging.

Main Results:

• Both poly(lactic acid) and polyurethane materials demonstrated high biocidal efficacy (>90%).
• Antimicrobial efficacy was retained post-recycling, except for polyurethane after accelerated aging (0% efficacy).
• Recycling caused significant changes in tensile and compression properties, but not in functional chemical groups.

Conclusions:

• Antimicrobial 3D-printable materials can be recycled, maintaining efficacy for potential use in spaceflight.
• On-demand manufacturing of medical devices using these materials could serve as preventative health countermeasures.
• Further research is needed to address the degradation of recycled polyurethane for long-term space applications.