Synthesis of well-defined and recyclable polyester from ring opening polymerization of 1,5-dioxepan-2-one catalyzed by Lewis acid-base pair

Abstract

The ring opening polymerization (ROP) of 1,5-dioxepan-2-one (DXO) at mild conditions to give well-defined poly(1,5-dioxepan-2-one) (PDXO) remains a challenge. Herein, we reported the ROP of DXO at room temperature by using Lewis pair of diethyl zinc/4-dimethylaminopyridine (ZnEt2/DMAP) as catalyst system. The “living” ROP in presence of ZnEt2/DMAP showed obviously improved polymerization rate, and can produce linear PDXO with designed molecular weights and well-defined chain ends. Benefiting from the fidelity of “living” terminal groups, a series of block copolymers could be synthesized through the sequential ROP of DXO with δ-valerolactone or L-lactide. Remarkably, the obtained PDXO can be chemically recycled back to its DXO monomer, thus successfully realizing a closed-loop life cycle.