Supertough spontaneously self-healing polymer based on septuple dynamic bonds integrated in one chemical group

The development of spontaneously self-healing materials with excellent mechanical properties remains a formidable challenge despite the extensive interest in such materials. This is because the self-healing and mechanical properties of a material are usually optimized via contradictory routes. The present study demonstrated a supertough spontaneously self-healing polymer, Fe-(2,6-diacetylpyridine dioxime)-urethane-based polyurethane (Fe-PPOU) based on septuple dynamic bonds integrated in one chemical group. A synergistic effect was induced by the presence of multiple dynamic crosslinking points, which comprised the integrated dynamic interactions, and the hidden lengths of the folded polymeric chains in Fe-PPOU. Thus, the mechanical and self-healing properties of the polymer were simultaneously optimized. Fe-PPOU demonstrated the highest reported toughness (139.8 MJm−3) among all the room-temperature spontaneously self-healing polymers with a nearly 100% healing rate. Fe-PPOU exhibited instant (30 s) self-healing to reach a strength of 1.6 MPa that was higher than the original strength of numerous recently reported self-healing polymers.