Molecular-level swelling behaviors of poly (ethylene terephthalate) glycolysis using ionic liquids as catalyst

Ionic liquids (ILs) are considered as the high-efficiency catalysts for PET glycolysis. However, insight into the swelling behaviors for PET glycolysis with IL still remains seldom. Hence, temperature-dependent interfacial properties and catalytic performance for PET glycolysis with [Cho][OAc] catalysts were investigated using molecular dynamic (MD) simulation and experiments. MD results indicate that [Cho][OAc] can enhance the PET swelling in ethylene glycol (EG), especially at high temperature, contributing to the enhanced conversion of PET. Strong interaction between EG and [OAc](-) as well as PET and [Cho](+) can intensify the access of reaction sites between PET and EG, important to the high-efficiency PET glycolysis. Furthermore, experimental results confirm that the PET conversion catalyzed by [Cho][OAc] increases with elevated temperature with almost 100 % PET conversion and 66.7 % BHET yield at 180 degrees C, which strongly supports MD results. The information provides an essential understanding about the swelling for PET glycolysis with IL catalysts. (C) 2022 Elsevier Ltd. All rights reserved.