Intrinsically self-healing super-tough poly(urea-acrylic acid) elastomer

The production of high-quality self-healing materials with ultra-high tensile strength and super-high toughness remains a formidable challenge due to the inherently conflicting nature of these properties. Herein, a novel type of puncture-resistant crosslinked poly (urea-acrylic acid) (CPUA) elastomers with self-healing capabilities and toughness were developed through a photo-induced copolymerization method, incorporating dynamic urea bonds and abundant hydrogen bonds. The unique structure of CPUA provides exceptional mechanical properties, including strain-stiffening behavior, enhanced tensile strength of up to 44.8 MPa, super-high toughness of 143.1 MJ m–3, and stretchability of 645 %. These superior mechanical properties are attributed to multiple hydrogen bonds and a three-dimensional network. It is found that hydrogen interactions act as sacrificial bonds that dissipate energy during stretching. Furthermore, CPUA can self-heal rapidly at mild temperatures, restoring mechanical properties with a self-healing efficiency of up to 89.29 %. The self-healing properties of CPUA are attributed to dynamic bond exchange reactions, allowing for the reprogramming of the topological network. The potential applications of CPUA are in smart protective coatings and durable wearable bracelets. [Display omitted]