State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University , 38 Zheda Road, Hangzhou 310027, P. R. China.
ACS Appl Mater Interfaces. 2017 Jul 12;9(27):22077-22082. doi: 10.1021/acsami.7b05713. Epub 2017 Jun 26.
The unique capability of topological rearrangement for dynamic covalent polymer networks has enabled various unusual properties (self-healing, solid-state plasticity, and reprocessability) that are not found in conventional thermosets. Achieving these properties in one network in a synergetic fashion can open up new opportunities for shape memory polymer. To accomplish such a goal, the freedom to tune topological rearrangement kinetics is critical. This is, however, challenging to achieve. In this work, two sets of dynamic bonds (urethane and hindered urea) are incorporated into a hybrid network for synthesizing shape memory poly(urea-urethane). By changing the bond ratio, networks with highly tunable topological rearrangement kinetics are obtained. Combining self-healing, solid-state plasticity, and reprocessability in one such shape memory network leads to unusual versatility in its shape-shifting performance.
拓扑重排对于动态共价聚合物网络的独特能力使各种不寻常的性能（自修复、固态塑性和可再加工性）成为可能，而这些性能在传统热固性塑料中是找不到的。以协同的方式在一个网络中实现这些性能，可以为形状记忆聚合物开辟新的机会。要实现这一目标，自由调整拓扑重排动力学是至关重要的。然而，这是具有挑战性的。在这项工作中，两组动态键（氨基甲酸酯和受阻脲）被引入到混合网络中，以合成形状记忆聚（脲-氨基甲酸酯）。通过改变键的比例，可以得到具有高度可调拓扑重排动力学的网络。在一个这样的形状记忆网络中结合自修复、固态塑性和可再加工性，导致其形状变换性能具有异常的多功能性。
