Transparent, colourless, ultra-fast room-temperature self-healing polyurethane with potential for self-repairable electrode

Abstract

This work presents a novel self-healing polyurethane (Upy-PU) that strikes a remarkable balance between ultra-fast room-temperature self-healing and excellent mechanical properties. The representative material, Upy-PU1 after healing at room temperature, exhibits impressive tensile stress (7.8 MPa), extraordinary tensile strain (2379%), and excellent toughness (67.1 MJ/m3) by incorporating the rarely reported Upy-diols into the polyurethane backbone. The healing process can complete in just 30 min with the help of a minimal quantity of solvent. Intriguingly, beverages like beer, wine and Chinese baijiu can also accelerate the room temperature self-healing process, making it more feasible in practical applications. Furthermore, a thin film electrode based on Upy-PU1 demonstrates the ability to maintain electrical conductivity under 300% elongation and restores stable low electric resistance within 200% elongation after 1 h self-healing at room temperature. Notably, at 4.5 V, a conductive circuit can recover the conductivity from cutting within 5 min. These findings highlight the immense potential of Upy-PUs for applications in wearable electronics and soft robotics.