Wu Haitao, Jin Biqiang, Wang Hao, Wu Wenqiang, Cao Zhenxing, Wu Jinrong, Huang Guangsu
State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu, China.
Front Chem. 2020 Oct 16;8:585569. doi: 10.3389/fchem.2020.585569. eCollection 2020.
Developing degradable and self-healable elastomers composed of reusable resources is of great value but is rarely reported because of the undegradable molecular chains. Herein, we report a class of degradable and self-healable vitrimers based on non-isocyanate polyurethane elastomer. Such vitrimers are fabricated by copolymerizing (6-membered cyclic carbonate) and amino-terminated liquid nitrile rubber. The networks topologies can rearrange by transcarbonation exchange reactions between hydroxyl and carbonate groups at elevated temperatures; as such, vitrimers after reprocessing can recover 82.9-95.6% of initial tensile strength and 59-131% of initial storage modulus. Interestingly, the networks can be hydrolyzed and decarbonated in the strong acid solution to recover 75% of the pure di(trimethylolpropane) monomer. Additionally, the elastomer exhibits excellent self-healing efficiency (88%) and fracture strain (1,200%) by tuning the monomer feeding ratio. Therefore, this work provides a novel strategy to fabricate the sustainable elastomers with minimum environmental impact.
开发由可重复利用资源组成的可降解且可自愈的弹性体具有重要价值，但由于分子链不可降解，相关报道很少。在此，我们报道了一类基于非异氰酸酯聚氨酯弹性体的可降解且可自愈的玻璃态网络聚合物。此类玻璃态网络聚合物通过（六元环状碳酸酯）与端氨基液体丁腈橡胶共聚制备而成。在高温下，网络拓扑结构可通过羟基和碳酸酯基团之间的碳酸酯交换反应进行重排；因此，再加工后的玻璃态网络聚合物可恢复初始拉伸强度的82.9 - 95.6%以及初始储能模量的59 - 131%。有趣的是，该网络在强酸溶液中可水解并脱碳酸，以回收75%的纯二（三羟甲基丙烷）单体。此外，通过调节单体进料比，该弹性体表现出优异的自愈效率（约88%）和断裂应变（约1200%）。因此，这项工作为制备对环境影响最小的可持续弹性体提供了一种新策略。
