Mussel-inspired and aromatic disulfide-mediated polyurea-urethane with rapid self-healing performance and water-resistance

Abstract

Although lots of methods have been developed for self-healing materials, it remains a formidable challenge to achieve a thermosetting material with water-insensitive and self-healing properties at room temperature. Nature always provides intelligent strategies for developing advanced materials with superior properties. Herein, a novel self-healable polyurea-urethane was rationally designed by combining mussel adhesive protein-mimetic structure and dynamic aromatic disulfide bonds. It achieves high self-healing efficiency of 98.4% at room temperature for only 6 h and 90% at 60℃ for only 30 min without any external stimuli. Impressively, this self-healing capability possesses exceptional water-resistance, which presents high self-healing efficiency of 98.1% for 2 h and 82.1% for 6 h in 60℃ and 25℃ water, respectively. Besides, the designed polyurea-urethane exhibits excellent mechanical properties such as high elongation at break of 2400%, notch-insensitive stretching elongation of 1500% and notable recovery capability. This strategy shows promising application potential in solid propellants, protective coating, electronic skin, soft sensors and other water-resistant devices.