Dual Cross-linked Vinyl Vitrimer with Efficient Self-Catalysis Achieving Triple-Shape-Memory Properties
Dual Cross-linked Vinyl Vitrimer with Efficient Self-Catalysis Achieving Triple-Shape-Memory Properties
复制标题
双交联乙烯基 Vitrimer 具有高效的自催化作用，可实现三重形状记忆特性
DOI：
10.1002/marc.201900313
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发表时间：
2019
影响因子：
4.6
通讯作者：
Shi An Chang
中科院分区：
文献类型：
--
作者：
Niu Xiling;Wang Fenfen;Kui Xing;Zhang Rongchun;Wang Xiaoliang;Li Xiaohui;Chen Tiehong;Sun Pingchuan;Shi An Chang
作为一类新兴的动态交联网络，玻璃化聚合物由于热固性材料的机械优势和热塑性塑料在高温下的可回收性的结合而引起了人们的广泛关注。特别是，大多数具有多形状记忆特性的玻璃体通常涉及一个以上的热转变或分子开关，这可能对简单的样品制造构成挑战，并可能限制其应用。为了寻求一种更通用、更简单的方法，本文报道了利用市售的廉价试剂从乙烯基单体衍生的预聚物制备具有双交联网络的形状记忆玻璃体。所需乙烯基单体的共聚得到含有羧基和羧酸锌基团的预聚物，其随后通过用双酚A的二缩水甘油醚后固化在单一步骤中转化为玻璃化聚合物。Zn2+离子不仅可以通过离子配位相互作用作为物理交联点，从而提供三重形状记忆性能，而且还可以在动态共价网络中起到催化剂的作用，激活酯交换反应。这种新的自催化的玻璃化聚合物具有优异的酯交换效率，三重形状记忆特性，并且可以在高温下充分愈合和再加工。所提出的自催化材料的分子设计为具有多种形状记忆特性的高性能玻璃体的商业相关制造开辟了新的途径。
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. In particular, most vitrimers with multi‐shape memory properties usually involve 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 is reported here. Copolymerization of desired vinyl monomers gives prepolymers containing carboxyl and zinc carboxylate groups, which are 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 ionic coordination interactions, thus providing the triple‐shape‐memory properties, but also play the role of catalyst to activate transesterification in the dynamic covalent network. This new self‐catalyzed vitrimer has excellent transesterification efficiency, triple‐shape‐memory properties, and can be sufficiently healed and reprocessed at an elevated temperature. The proposed molecular design of self‐catalyzed materials opens a new avenue toward commercially relevant fabrication of high‐performance vitrimers with multiple shape‐memory properties.