Mechanically and thermo-driven self-healing polyurethane elastomeric composites using inorganic–organic hybrid material as crosslinker

Intrinsic healing materials based on reversible bonds possessing the unique adaptive properties of self-healing and recyclability have attracted considerable attention. One of the major challenges in intrinsic healing materials that remains is how to reinforce the mechanical property without sacrificing healing efficiency. Here, furfuryl-modified silica particles (furan@SiO2) with high functional group grafting ratio and dispersibility, formed by sol–gel process, were introduced into the maleimide-terminated polyurethane (mPU) elastomer to establish a thermo-reversible organic–inorganic network based on Diels–Alder reaction between furan@SiO2 and mPU. The modulus and strength of the elastomeric composites were significantly enhanced compared to neat mPU. Due to the reversible crosslinking points and organic–inorganic network, the thermo-reversible polyurethane elastomeric composites maintained favourable mechanical properties with excellent thermo-driven self-healing efficiency. Moreover, the corresponding elastomeric composites retained high repair efficiency after multiple healing processes. Furthermore, the thermo-reversible polyurethane elastomeric composites could be recycled via solution casting and hot-pressing due to the thermally reversible cross-linking point. Such excellent combination of mechanical and self-healing performance reveals the potential of this new approach in designing self-healing hybrid materials with tunable structures and mechanical properties.