摘要
Dynamic ester bonds are widely employed to build covalent adaptable networks (CANs) and prepare the corresponding vitrimers. Conventional carboxylic anhydride/acid-epoxy chemistry facilitates the formation of dynamic ester bonds and generation of catalytic -OH groups; however, it provides low flexibility for molecular designs and property adjustments pertaining to vitrimers. This study demonstrates Meldrum's acid-mediated ketene chemistry as an effective method for building CANs and preparing the corresponding vitrimers. Through the employment of a newly synthesized AB 2 -type (A, Meldrum's acid group; B, phenol group) monomer (MADV), crosslinked MADV (CR-MADV) with dynamic ester linkages and free -OH groups is obtained through MADV self-polymerization. The prepared CR-MADV exhibits not only features of vitrimers but also favorable properties comparable to those of conventional thermosetting resins, including a thermal stability of 345 °C, a char yield of 53 wt% at 800 °C, a storage modulus of 3.2 GPa at 50 °C, and a T g of 213 °C (observed from the tan δ peak during dynamic mechanical analysis). The prepared CR-MADV vitrimer has a higher T g compared to those reported in other studies and still exhibits mendable and recycling features. This study contributes substantially to the development of synthetic methods and the enhancement of vitrimer properties.