作者：Niu,X; Wang, FF*; Kui, X; Zha.ng, RC; Wang, XL; Li, XH; Chen,TH; Sun, PC*; Shi AC
关键字：Vitrimer, Cross-link, Self-Catalysis, Shape-Memory
论文来源：期刊
具体来源：Macromolecular Rapid Communications, 2019, in press
发表时间：2019年

As an emerging class of dynamic cross-linked network, vitrimers have attracted much attention due to the combination of mechanical advantages of thermosets and recyclability of thermoplastics at an elevated temperature. Particularly, most vitrimers with multi-shape memory properties usually involved more than one thermal transition or molecular switch, which might pose a challenge for facile sample fabrication and potentially limits their applications. In pursuit of a more universal and simple route, utilizing commercially available and inexpensive reagents to prepare shape-memory vitrimers with dual cross-linked network from vinyl monomer-derived prepolymers was reported here. Copolymerization of desired vinyl monomers gave prepolymers containing carboxyl and zinc carboxylate groups, which were later converted into vitrimers in a single step by post-curing with diglycidylether of bisphenol A. The Zn²⁺ ions can not only act as physical crosslinking points through zinc-carboxylic acid coordination interactions thus provides the triple-shape-memory properties, but also play the role of catalyst to increase the rate of transesterification in the dynamic covalent network. This new self-catalyzed vinyl vitrimer has excellent transesterification efficiency, unique triple-shape-memory properties and can be sufficiently healed and reprocessed at an elevated temperature. Our proposed molecular design of self-catalyzed materials opens a new avenue towards commercially relevant fabrication of high performance self-catalyzed vitrimers with multiple shape-memory properties.