Cyclic Polyesters with Closed‐Loop Recyclability from A New Chemically Reversible Alternating Copolymerization

Abstract

Polyesters with both cyclic topology and chemical recyclability are attractive. Here, the alternating copolymerization of cyclic anhydride and o‐phthalaldehyde to synthesize a series of cyclic and recyclable polyesters are reported for the first time. Besides readily available monomers, the copolymerization is carried out at 25 °C, uses common Lewis/Brønsted acids as catalysts, and achieves high yields within 1 h. The resulting polyesters possess well‐defined alternating sequences, high‐purity cyclic topology, and tunable structures using distinct two monomer sets. Of interest, the copolymerization manifests obvious chemical reversibility as revealed by kinetic and thermodynamic studies, making the unprecedented polyesters easy to recycle to their distinct two monomers in a closed loop at high temperatures. This work furnishes a facile and efficient method to synthesize cyclic polyesters with closed‐loop recyclability.

Fluoride recovery in degradable fluorinated polyesters

“…In the general context of moving towards a more circular polymer economy, an increasingly popular approach is the incorporation of ester bonds into the polymer main chain which facilitates degradation and enables chemical recycling methods. 18–24 However fluorinated polyesters remain rare. 25–27 One approach to synthesise polyesters is the ring-opening copolymerisation (ROCOP) of an epoxide and a cyclic anhydride which has yet to be applied to the synthesis of degradable fluorinated polymers.…”