Mechanically robust, highly adhesive and autonomously low-temperature self-healing elastomer fabricated based on dynamic metal − ligand interactions tailored for functional energetic composites

Self-healing materials are used in various applications because of their capacity to prolong the material's longevity and durability. Several important properties, including high adhesion force to various surfaces and mechanical robustness have the potential to further expand their application in various fields. In this study, we designed an energy-containing and high-adhesion elastomer (3,5-BTP-PDMS-4), which was fabricated via the click polymerization, that could self-heal at −20 °C. The prepared polymer adhesive exhibited prominent mechanical strength with a high Young's modulus of up to 17.91 MPa. The material also showed that it could autonomously and completely self-heal and restore its mechanical properties within 6 h at room temperature when the 3,5-BTP-PDMS-4 sample was cut into two separate pieces. Moreover, this material was found to possess a high adhesion force of up to 1.65 MPa on steel, which increased when the temperature was reduced. Furthermore, we prepared TATB-based PBXs using 3,5-BTP-PDMS-4 as a binder because of its energy-containing property and excellent self-healing properties to heal cracks generated during fabrication, transportation and storage. Surprisingly, the TATB-based PBXs achieved complete self-healing at 0 °C and partial self-healing at −20 °C, although the low plastic explosive crystals were detrimental to the material's self-healing properties. The successful development of a polymer adhesive that has a high-Young's modulus and can autonomously and completely self-heal could help expand its applications with enhanced versatility in several fields, including military and civil applications.