Facile synthesis of hemiacetal ester-based dynamic covalent polymer networks combining fast reprocessability and high performance

Abstract

Dynamic covalent polymer networks (DCPNs) can address the recycle or reuse issue of thermosets due to their network rearrangement from the dynamic bond exchange. However, developing DCPNs combining fast reprocessability and high performance through a facile and green method is still a huge challenge. Herein, a facile and green method (in situ polymerization and dynamic cross-linking (ISPDC)) was utilized to produce hemiacetal ester-based DCPNs which exhibited fast reprocessability and high performance. No solvent and no purification were required, and the facile synthesis process also showed readily regulated performance for the DCPNs. The obtained DCPNs could be continuously reprocessed by extrusion as well as compression remolding; meanwhile their solvent resistance, thermo-physical and mechanical properties are excellent on account of their high cross-link density. The small-molecule model reactions and theoretical calculation demonstrated that hemiacetal ester exchange follows a dissociative mechanism without or with an extra carboxyl group. This work studied DCPNs which showed great potential to be efficiently recycled via reprocessing and scaled up. It tallies with sustainable development and contributes to carbon neutrality.