Multi-scale dynamic physical networks towards ultra-tough, mechanoresponsive, and rapid autonomic self-healable elastomers

Abstract

Recently, one of the challenges faced by autonomous self-healing materials is how to improve strength and toughness while maintaining rapid self-healing properties at ambient temperature. Herein, by integrating multi-scale dynamic physical networks that are hydrogen bonds, metal-coordination bonds, and dynamic crystalline domains in bio-based long-chain polyamides, a series of multi-scale elastomers (MSEn) were obtained. The multi-scale dynamic physical networks endow elastomers with low initial modulus, outstanding nonlinear “J-shaped” stress-strain mechanoresponsive behavior, high tear-resistance, and good puncture properties. More importantly, the representative elastomers MSE18 exhibit outstanding toughness (strength of 66.3 ± 1.84 MPa, elongation at break of 660 ± 17.28%, and toughness of 155 ± 4.32 MJ/m3) and rapid autonomic self-healing properties (totally healed in 3 h at room temperature). The design concept indicates a promising direction for elastomers with ultra-tough mechanical properties and rapid room temperature self-healing behavior without external stimuli.