Mechanically Robust and Self-Healable Polyureas Based on Multiple Dynamic Bonds

The synthesis of polymeric materials that simultaneouslypossessmultiple outstanding mechanical properties and self-healability isalways a great challenge. Herein, we report the synthesis of a robustand self-healing polyurea material, which contains a dual metal coordinationstructure of Zn(II)-urea and Zn(II)-diamidepyridine as well as densehydrogen bonds. Due to the synergistic enhancement of dynamic coordinationbonds and hydrogen bonds in the supramolecular network, the obtainedpolyurea materials possess a combination of excellent mechanical propertiesand high-efficiency self-healing properties, which are adjustableby varying the content of Zn(II) ions. The optimal PU-L/Zn-3 samplehas a tensile strength of & SIM;22.82 MPa, while the elongationat break is & SIM;1312% and the toughness is & SIM;222.68 MJ/m(3). In addition, the fully cut sample exhibits a high healingefficiency of 95.7% based on toughness after treatment at 50 & DEG;Cfor 4 h. Multi-dynamic cross-linked polymers might provide a new wayto obtain robust self-healing materials for protection materials andwearable electronics.