Upcycling End-of-life Polyamide 66 Into Antibacterial Materials

Polyamide 66 (PA66), as a widely utilized non-biodegradable plastic, constitutes a significant source of marine pollution. Current chemical recycling approaches often necessitate monomer purification, excessive use of depolymerization agents, and reliance on metal catalysts, leading to complex procedures and high costs. Therefore, directly converting waste polymers into high-value-added products by using them as raw materials holds substantial significance. Here, we successfully transformed end-of-life PA66 into a high-toughness antibacterial material via a one-pot method. End-of-life PA66 was employed as the polymer feedstock, and melt polycondensation was directly conducted using antibacterial monomers and bio-based long-chain dicarboxylic acids, resulting in the successful synthesis of a series of polyamide-based copolymers. The resultant material demonstrates outstanding mechanical performance, achieving a maximum tensile strength of 34.3 MPa and an elongation at break of up to 457.3% for a 0.5 mm-thick film. Furthermore, antibacterial assays confirmed that the material can exhibit nearly 100% antibacterial activity. Additionally, the material demonstrates excellent spinnability and processability, indicating strong potential for application in fabrics and films. This work proposes a practical strategy for the large-scale upcycling of end-of-life PA66, demonstrating significant potential for application in the polymer industry.