Bioinspired modified graphene oxide/polyurethane composites with rapid self-healing performance and excellent mechanical properties.

Self-healing efficiency and mechanical strength are always a pair of mechanical contradictions of a polymer. Herein, a series of novel mussel-inspired modified graphene oxide/polyurethane composites were successfully fabricated rational molecular design and introducing hyperbranched polymer-modified graphene oxide. The composites exhibit outstanding self-healing performances with a self-healing efficiency of 87.9%. Especially, their self-healing properties possess exceptional water-insensitivity, which presents a high self-healing efficiency of 92.5% under 60 °C water for 2 h and 74.6% under 25 °C water for 6 h. Furthermore, the tensile strength of the composites increased by 107.7% with a high strain of 2170%. In addition, the composites show a remarkable recovery capability of 76.3% and 83.7% under tensile and compression loading, respectively, after 20 cycles. This strategy shows prominent application potential in high-performance solid propellants, protective coating, electronic skin, soft sensors and other water-insensitive devices.