A High Strength but Fast Fracture‐Self‐Healing Thermoplastic Elastomer

Abstract

Abstract Herein, a new type of healable thermoplastic poly(urethane‐urea) (PUU) elastomer with a unique dual dynamic network structure consisting of multi‐strength hydrogen bonds and aromatic disulfide bonds, is designed and synthesized. The resultant PUU elastomer exhibits high tensile strength (41 MPa), great toughness (104 MJ m −3 ), and excellent self‐healing capability (completely severes, heals at 60 ℃ for just 1 h, and recovers more than 80% of the original tensile strength). Although the PUU possesses high‐density hydrogen bonds, it is completely homogeneous without micro‐phase separation. The unique dual dynamic network structure alleviates the adverse effects of strong molecular interactions on self‐healing process, simultaneously endowing the polymer with outstanding mechanical properties and excellent self‐healing capability at mild temperature. In addition, the underlying mechanism between performance and structure is revealed. The PUU has potential applications in soft robots and wearable electronics.