High-performance epoxy covalent adaptable networks enabled by alicyclic anhydride monoesters

[Display omitted] •Two anhydride monoesters from alicyclic five-membered cyclic anhydride and six-membered cyclic anhydride were synthesized to prepare epoxy CANs with dynamic transfer autocatalysis.•The reprocessability, degradability and mechanical properties of epoxy CANs were readily tuned by changing the structure of the anhydride monoester.•The alicyclic anhydride monoester cured epoxy CANs possessed high thermal and mechanical properties.•The conformational transition of the alicyclic anhydride monoester accelerated the rate of network rearrangement and reprocessing. 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.