Realization of dual crosslinked network robust, high toughness self-healing polyurethane elastomers for electronics applications

Currently, research into self-healing polyurethane materials has progressed significantly; however, ensuring that the materials exhibit excellent mechanical properties and good healing efficiency is an urgent problem. In this study, a self-healing polyurethane elastomer exhibiting the synergistic enhancement effect of a double-crosslinked network is prepared by introducing a hydrogen-bond functional monomer and the Diels-Alder reaction. Consequently, the resulting elastomer shows a high fracture strength of 72.5 MPa, an elongation at break of 1241.0 %, an ultrahigh toughness of 235.7 MJ/m3, and a fracture energy of 219.4 KJ/m2. Dynamic covalent crosslinking and reversible hydrogen bonding dual networks endow the elastomers with good self-healing properties and multiple repair capabilities, thus allowing them to achieve up to 86 % self-healing efficiency. In addition, we prepare self-healing capacitive electronic devices using a liquid metal blended and compounded with a dual dynamic bonded polymer system, which exhibit stable electrochemical properties, excellent mechanical properties, excellent self-healing properties, and two-component recyclable properties after mechanical training. The self-repairing device can be reused, thus significantly reducing material waste and pollution, and benefits environmental and resource conservation.