writer：Yanlin Liu, Zhen Yu, Binbo Wang, Xiwei Xu, Hongzhi Feng, Pengyun Li, Jin Zhu, Songqi Ma*
keywords：环氧热固性树脂，动态共价交联高分子，酯交换，动态转移自催化，脂环酸酐单酯
source：期刊
specific source：European Polymer Journal
Issue time：2022年

Transesterification-based covalent adaptable networks (CANs) exhibit malleability and reprocessability, yet are highly dependent on the addition of a large amount of catalysts to accelerate transesterification reactions. A strategy of dynamic transfer auto-catalysis has been proposed by pending dynamically transferable anhydride monoesters at the network, which will greatly enhance the auto-catalytic efficiency. Here two trifunctional acids from alicyclic five-membered cyclic anhydride and six-membered cyclic anhydride, were synthesized and cured with bisphenol A epoxy monomer, respectively. The reprocessability, degradability and mechanical properties of the obtained epoxy CANs can be readily tuned by changing the structure of the trifunctional acid. The conformational transition of the non-planar ring accelerated network rearrangement and the large steric hindrance slowed down the degradation rate and the rigid feature endowed high thermal and mechanical properties of the epoxy CANs. In addition, the kinetically slow formation of six-membered cyclic anhydride than that of five-membered cyclic anhydride, led to the lower dynamic transfer auto-catalytic efficiency of its monoester. However, its good solubility in water gave it a fast degradation rate.

全文链接：https://doi.org/10.1016/j.eurpolymj.2022.111272