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

Abstract

The synthesis of polymeric materials that simultaneously possess multiple outstanding mechanical properties and self-healability is always a great challenge. Herein, we report the synthesis of a robust and self-healing polyurea material, which contains a dual metal coordination structure of Zn(II)-urea and Zn(II)-diamidepyridine as well as dense hydrogen bonds. Due to the synergistic enhancement of dynamic coordination bonds and hydrogen bonds in the supramolecular network, the obtained polyurea materials possess a combination of excellent mechanical properties and high-efficiency self-healing properties, which are adjustable by varying the content of Zn(II) ions. The optimal PU-L/Zn-3 sample has a tensile strength of ∼22.82 MPa, while the elongation at break is ∼1312% and the toughness is ∼222.68 MJ/m3. In addition, the fully cut sample exhibits a high healing efficiency of 95.7% based on toughness after treatment at 50 °C for 4 h. Multi-dynamic cross-linked polymers might provide a new way to obtain robust self-healing materials for protection materials and wearable electronics.