Review on Research Progress on Bio-Based Self-Healing Polyurethane

Self-healing polyurethane (SHPU) shows great potential in enhancing materials’ durability and sustainability, yet balancing robust mechanical properties with efficient self-healing under mild conditions remains challenging. Conventional approaches often sacrifice strength or healing ability. This Review focuses on the key role of biomass-derived materials, including lignin, cellulose, chitosan, and vegetable oils, in resolving this conflict. Acting as dynamic network modifiers, multifunctional enhancers, and microstructural regulators, they enable sacrificial bonding, microphase separation, and improved chain mobility. Biomass-based SHPUs can achieve over 90% self-healing efficiency at room temperature while maintaining strength and toughness and even incorporate additional functions like flame retardancy or conductivity. Moreover, biomass enhances sustainability by reducing fossil resource dependence and promoting recyclability. Despite challenges in performance consistency and raw material variability, molecular engineering offers a promising path toward high-performance, sustainable SHPUs for advanced manufacturing and a circular economy.