A deep eutectic solvent with bifunctional acid sites treatment to upgrade a bamboo kraft pulp into a cellulose-acetate grade dissolving pulp.

Valorization of non-wood pulp, such as bamboo bleached kraft pulp into high-purity cellulose acetate (CA)-grade dissolving pulp is crucial but challenging in China. Herein, a series of metal salt-based deep eutectic solvents (MSDESs) involving various ZnCl-urea (U), ZnCl-glycerol (G), and ZnCl-lactic acid (LA) are comparatively investigated for this purpose. Thanks to the bifunctional acid sites of Lewis acid ZnCl and Brønsted acid LA, the ZnCl-LA MSDES has the highest acidity (2.