Dual Cross-linked Vinyl Vitrimer with Efficient Self-Catalysis Achieving Triple-Shape-Memory Properties
作者：Niu,X; Wang, FF*; Kui, X; Zha.ng, RC; Wang, XL; Li, XH; Chen,TH; Sun, PC*; Shi AC
關鍵字：Vitrimer, Cross-link, Self-Catalysis, Shape-Memory
論文來源：期刊
具體來源：Macromolecular Rapid Communications, 2019, in press
發表時間：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.