A cephalopod-inspired multi-environmental adaptive self-healing polyurethanes

Self-healing polymers often encounter harsh and variable environmental conditions during prolonged use, with their internal dynamic cross-linking structures posing limitations to stability under such circumstances. Drawing inspiration from the self-healing capabilities and environmental adaptability of cephalopods, this study presents a polyurethane material exhibiting outstanding mechanical properties, self-healing efficiency, and robust environmental resistance. Dynamic disulfide bonds were incorporated using 4,4-dithiodianiline (AFD) to enhance self-healing ability, while isophorone diamine (IPDA) reinforced the hard segment structure. Further, free isophorone diisocyanate (IPDI) facilitated the formation of dynamic biphasic hard-segmented structures in the polyurethane matrix. As a result, the material demonstrated exceptional mechanical performance, including a tensile strength of 21.81 MPa, elongation at break of 1125.91 %, and toughness of 107.07 MJ/m³. After 24h of self-healing at 60 °C, the material achieved an impressive self-healing efficiency of 88.91 %. When combined with a hydrophobic component, the composite effectively erased surface scratches after 24h at 80 °C, with a water contact angle reaching 150.3°. This innovative design provides a promising approach for developing self-healing polymers with enhanced durability and environmental adaptability.