Tailoring the interfacial interaction of collagen fiber/waterborne polyurethane composite via plant polyphenol for mechanically robust and breathable wearable substrate

Collagen fiber-waterborne polyurethane composites possess great potential applications in flexible wearable devices owing to their excellent biocompatibility, flexibility, and biodegradability. However, the weak interfacial interactions which result in poor mechanical strength and breathability, have significantly hindered their practical application. Herein, high-performance collagen fiber-based wearable substrates prepares by constructing a hydrogen-bonded cross-linked network structure using bayberry tannin, a natural plant polyphenol, as a coupling bridge to bind collagen fibers and waterborne polyurethane (WPU). The dynamic rupture and reformation of sacrificial hydrogen bonds on the molecular scale effectively dissipate energy under mechanical stress, endowing these composites with remarkable toughness and ultrahigh water vapor permeability (WVP). The resultant composite’s tensile strength and WVP are 100% and 60 times higher than WPU, respectively. Additionally, this cost-effective strategy enables easy large-scale composite production. This method guides the development of high-performance, multifunctional collagen fiber-based wearable composites while advancing the tannery solid waste circular economy.