Functionalized and Chemically Recyclable “Polyethylene-like” Polyesters from Selective Ring-Opening Polymerization of Bifunctional Macrocycles

Abstract

Developing polyethylene-like (PE-like) materials with built-in chemical recyclability provides a promising strategy for addressing the end-of-life challenges of persistent polyolefins. Entropy-driven ring-opening polymerization (ROP) of macrolactones offers an attractive route to floor-temperature (Tf)-regulated long-chain polyesters that combine PE-like performance, thermal stability, processability, and chemical recyclability. However, achieving functional PE-like polyesters remains challenging, as it requires balancing efficient polymerization, retention of reactive functional groups, tunable material properties, and selective chemical recycling. Here, we designed and synthesized ambrettolide-derived 17-membered macrolactones bearing an internal double bond, epoxide, or five-membered cyclic carbonate group and achieved their selective ROP using a Lewis pair catalytic system. The resulting long-chain polyesters exhibited well-defined structures, high molecular weights, and preserved functional groups. These polyesters exhibited PE-like tensile behavior, melt reprocessability, tunable surface wettability, excellent gas barrier properties, and stable melt processability. Moreover, bulk melt depolymerization enabled recovery of the corresponding macrocyclic monomers, and the recovery yields were governed by the stability of the fused functional moieties. The purified recovered monomers retained their repolymerizability. This work establishes functional Tf-regulated long-chain polyesters as versatile platforms with tunable performance, processability, and recyclability.