A common strategy to endow carboxyl group containing WPU with antibacterial, self-healing and recyclable functions

Waterborne polyurethanes (WPUs) are known for their eco-friendliness and adaptability in various industries. However, the quest for multifunctional materials has created a demand for WPUs with self-healing, recyclable, and antimicrobial properties. In this study, we introduce a universal approach to doping FeCl3 and poly(acrylic acid) (PAA) into carboxyl group containing WPUs that promotes dynamic coordination bonding between Fe3+ and -COO- groups of PAA and WPUs. WPU/Fe/PAA-5.5 with 5.5 wt % PAA stands out with excellent mechanical properties, strong self-healing capabilities and an impressive >90% antimicrobial rate. Importantly, these supramolecular films proved to be highly recyclable by facile hot-pressing, which can maintain good antimicrobial properties after multiple cycles. This research will shade light on the multifunctionalization of WPU.