Industrial ethylene-vinyl alcohol copolymer (EVOH) is mainly prepared by alcoholysis of ethylenevinyl acetate copolymer (EVA) up to now. However

a large amount of wastewater will be produced during the preparation of EVOH

which inevitably results in a series of environmental problems. Herein

a series of alkaline deep eutectic solvents (DESs) were synthesized and used as eco-friendly catalysts for alcoholysis of EVA copolymer. The structure and catalytic performance relationship of DESs and the effects of the reaction parameters

EVA composition

and nitrogen flow on the alcoholysis were systematically investigated. The DESs with higher basicity were more efficient for the methanolysis of EVA

and among them

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8-diazabicyclo[5.4.0]undec-7-ene/benzylalcohol (DBU-BA) exhibited excellent catalytic activity and afforded EVOH with nearly 100% of alcoholysis degree at very low catalyst loadings. Moreover

DBU-BA could be reused at least five times without the decrease of catalytic activity

showing excellent reusability. On the basis of proton nuclear magnetic resonance (

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H-NMR) and Fourier transform infrared spectroscopy (FTIR) analyses

the plausible mechanism of DESs catalyzed alcoholysis of EVA was proposed.