A high‐performance self‐healing polyurea material based on exchangeable aromatic disulfide

Abstract

AbstractHigh‐performance polyurea materials demonstrate promising applications in the field of aerospace, military, etc. During processing and use, however, the formation of cracks may cause serious degradation of material properties. Self‐healing polyurea should be an effective way to address this issue. Here, an innovative polyurea material, which exhibited excellent mechanical properties and self‐healing abilities, was synthesized from the commercially available poly(propylene glycol) bis(2‐aminopropyl ether), isophorone diisocyanate, and 2‐Aminophenyl disulfide (APD). The rigid benzene ring in APD is beneficial to the mechanical properties of polyureas, simultaneously the irregular structure of APD prevents the hard segments from stacking tightly, which facilitates the exchange of disulfide bonds to achieve the self‐healing function. Furthermore, the microstructure, mechanical properties and self‐healing ability of the polyureas are highly dependent on the amount of APD. The obtained SPU‐4 exhibits robust mechanical strength (tensile stress of 21.2 MPa), outstanding stretchability (strain of 1006%), high rigidity (Young's modulus of 248.1 MPa), and excellent energy absorption (toughness of 139.7 MJ·m−3), besides, with heat stimulation, the self‐healing efficiencies based on strength and elongation could reach 92.7% and 74.5%, respectively. The excellent properties allow the material to show broad potential in the practical applications such as protection, energy absorption, etc.