A cascade strategy towards the direct synthesis of green polyesters with versatile functional groups

The synthesis of polyesters with desired functional groups without additional protection and deprotection steps remains a worthwhile challenge to polymer chemists. Herein, we put forward a solution for the direct preparation of green copolyesters with versatile functionality via the cascade polycondensation-coupling ring-opening polymerization (PROP) using a biobased cyclic diester ethylene brassylate as monomer and functional diols/polyether diols as initiator. The combination of two polymerization processes in one system enables the facile synthesis of biodegradable polyesters with versatile functionality, including alkane, alkene, alkyne, aromatic, halides, ether, amide functional groups, and poly(ether ester) multiblock copolymers, together with high functional group content (50% molar ratio to brassylate) and relatively high molecular weights (up to 6 × 104 Da). The cascade strategy provides a feasible method for the synthesis of high functional group content polyesters with tailor-made properties, highly effective for post-modifications that are suitable for a variety of applications.