Scalable Fabrication of Collagen Fiber-Waterborne Polyurethane Foams with Enhanced Toughness and Thermal Insulation by Constructing Energy Dissipation Networks

Natural fiber-based foams demonstrate outstanding potential for energy-efficient building and personal protective equipment applications due to their lightweight, high porosity, and sustainability. However, the weak interfacial interaction among fibers, functional additives, and the matrix hampers effective stress dissipation, largely affecting the material performance. Herein, this paper demonstrates a facile strategy for fabricating high-performance collagen fiber-based foams by constructing efficient energy dissipation networks using tannin-modified leather collagen fibers (T-LCF) and waterborne polyurethane (WPU). Tannin acts as a coupling bridge, linking the fiber and polyurethane to create a hydrogen-bonded network, enhancing energy dissipation and imparting excellent mechanical properties. Compared to WPU foam (WPUF), the T-LCF-based foam (WPUF/T-LCF) showed 65%, 34 times, and 35% improvements in tensile strength, compressive strength, and ultimate oxygen index, respectively. This study provides new insights into the cleaner production of high-performance natural fiber-based foam composites and a new way for the high-value utilization of collagen solid waste.