1. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201600, China
2. Zhejiang Hexin Science and Technology Co., Ltd., Jiaxing 314000, China
In this study, we employed a two-step approach to synthesize self-healing polyurethane elastomers (BQDU-LPU) containing dynamic oxime-urethane bonds (BQDU) by reacting p-benzoquinone dioxime (BQDO),polytetramethylene ether glycol (PTMG) and isophorone diisocyanate (IPDI). Subsequently, a series of Cu-BQDU-LPUs elastomers possessing triple dynamic bonds, including hydrogen bonds, oxime-amide bonds and metal coordination bonds were constructed by introducing copper ions. The structure of elastomers was characterized by nuclear magnetic resonance spectroscopy and Fourier-transform infrared spectroscopy, while their thermal, mechanical and self-healing properties were evaluated using thermogravimetric analysis,dynamic mechanical analysis and electronic universal material testing machine, respectively. The influence of copper ions on the properties of elastomers was systematically investigated. The results demonstrated that the introduction of copper ions simultaneously enhance the thermal stability and mechanical properties of the elastomers. Among the series of Cu-BQDU-LPUs,the 5% Cu-BQDU-LPU exhibited optimal mechanical properties,characterized by a tensile strength of (15.8±2.7) MPa, toughness of (92.7±31.5) MJ/m3 and Young’s modulus of (5.0±0.4) MPa. When subjected to heating at 70 ℃ for 2 h, this particular composition displayed a healing efficiency up to (90.9±2.9)%.