Versatile Imidazole-Anion-Derived Ionic Liquids with Unparalleled Activity for Alcoholysis of Polyester Wastes under Mild and Green Conditions

Abstract

Polyester wastes have caused a series of environmental issues, and it has became imperative to promote recycling of polyester wastes. Herein, a novel protocol for polyester depolymerization to recover the corresponding monomers or chemicals catalyzed by imidazole-anion-derived ionic liquids (ILs) was developed. The catalytic behavior, catalyst recyclability, and versatility for alcoholysis of polyester were studied in detail under mild and green conditions. A comparison of the activity with the reported catalysts was provided, which indicated the unparalleled activity of [HDBU][Im] for the polyester alcoholysis. An in-depth study of the feasible alcoholysis mechanism was given assisting with in situ analysis technique. The developed protocol realized the highly efficient chemical recycling of polyesters via alcoholysis method with unparalleled activity, avoided the pollution caused by toxic transition metal ions and organic solvents, indicating a green and promising alternative for practical recycling of polyester wastes.