文献类型：期刊文献

英文题名：Catalyst-Free Dynamic Covalent C=C/C=N Metathesis Reaction for Associative Covalent Adaptable Networks

作者：Li, Pengyun[1,2];Jiang, Xin[1,2];Gu, Ruirui[1,2];Tian, He[1,2];Qu, Da-Hui[1,2]

机构：[1]East China Univ Sci & Technol, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Inst Fine Chem,Sch Chem & Mol Engn,Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Inst Fine Chem,Sch Chem & Mol Engn,Joint Int Res L, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2024

卷号：63

期号：33

外文期刊名：ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

收录：;EI(收录号：20242916716286);WOS:【SCI-EXPANDED(收录号:WOS:001271135500001)】；

基金：This work is supported by the National Natural Science Foundation of China (grant No. 22025503, 22205064, 22220102004), Shanghai Municipal Science and Technology Major Project (grant No. 2018SHZDZX03), the Innovation Program of Shanghai Municipal Education Commission (2023ZKZD40), the Fundamental Research Funds for the Central Universities, the Programme of Introducing Talents of Discipline to Universities (grant No. B16017), Science and Technology Commission of Shanghai Municipality (grant No. 21JC1401700), the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study (grant No. SN-ZJU-SIAS-006), and Shanghai Pujiang Program (grant No. 22PJ1402200).

语种：英文

外文关键词：covalent adaptable networks; associative; C=C/C=N metathesis; reprocessability; shape memory polymer

摘要：Covalent adaptable networks (CANs), leveraging the dynamic exchange of covalent bonds, emerge as a promising material to address the challenge of irreversible cross-linking in thermosetting polymers. In this work, we explore the introduction of a catalyst-free and associative C=C/C=N metathesis reaction into thermosetting polyurethanes, creating CANs with superior stability, solvent resistance, and thermal/mechanical properties. By incorporating this dynamic exchange reaction, stress-relaxation is significantly accelerated compared to imine-bond-only networks, with the rate adjustable by modifying substituents in the ortho position of the dynamic double bonds. The obtained plasticity enables recycle without altering the chemical structure or mechanical properties, and is also found to be vital for achieving shape memory functions with complex spatial structures. This metathesis reaction as a new dynamic crosslinker of polymer networks has the potential to accelerate the ongoing exploration of malleable and functional thermoset polymers. By introducing the C=C/C=N metathesis reaction, we have successfully incorporated tunable plasticity into thermosetting polyurethanes, creating catalyst-free and associative covalent adaptable networks with superior thermal and mechanical properties. The rapid exchange of C=C/C=N bonds significantly accelerates stress relaxation, enhancing malleability and enabling recovery under mild conditions. This plasticity also led to advanced shape memory properties with complex 3D permanent shapes. image