Yao Yuan, Liu Bo, Xu Ziyang, Yang Jianhai, Liu Wenguang
School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300350, China.
Mater Horiz. 2021 Oct 4;8(10):2742-2749. doi: 10.1039/d1mh01217g.
Self-healing polyurethane elastomers have been extensively studied; however, developing an eco-friendly self-healable waterborne polyurethane (WPU) with exceptional mechanical properties remains a great challenge. Herein, we report healable, and highly tough WPU elastomers with unprecedented crack tolerance by introducing the concerted interactions of strong multiple H-bonds and ionic bonds in the network. The WPU elastomer demonstrated that the microphase separation structure contributes to an ultrahigh tensile strength (≈58 MPa), super toughness (≈456 MJ m), and unprecedented record fracture energy (≈320 kJ m). Due to the dynamic reconstruction of reversible H-bonds and ionic bonds, the WPU elastomer demonstrates a robust self-healability at 50 °C, allowing complete recovery of mechanical properties. Importantly, the thermoplasticity and reprocessability of WPUs enable direct 3D printing of different objects and electrospinning of tubes, showing great potential for expanding their application scope in soft robots and artificial stents.
自修复聚氨酯弹性体已得到广泛研究；然而，开发一种具有优异机械性能的环保型可自修复水性聚氨酯（WPU）仍然是一项巨大挑战。在此，我们报道了通过在网络中引入强多重氢键和离子键的协同相互作用，制备出具有前所未有的抗裂性的可愈合且高韧性的WPU弹性体。该WPU弹性体表明，微相分离结构有助于实现超高拉伸强度（约58 MPa）、超强韧性（约456 MJ/m）以及前所未有的断裂能记录（约320 kJ/m）。由于可逆氢键和离子键的动态重构，WPU弹性体在50℃时表现出强大的自修复能力，能够使机械性能完全恢复。重要的是，WPU的热塑性和可再加工性使得能够直接3D打印不同物体以及静电纺丝制备管材，这在扩大其在软机器人和人造支架中的应用范围方面显示出巨大潜力。
