Efficient dissolution of lignin in novel ternary deep eutectic solvents and its application in polyurethane.

Novel ternary deep eutectic solvents (DESs) were designed to efficiently dissolve the lignin for synthesizing the lignin-containing rigid polyurethane foam (LRPUF). These ternary DESs were constituted by choline chloride (ChCl), two hydrogen bond donors - glycerol (Gly) and polyethylene glycol (PEG-400). The maximum solubility of lignin in the sample DES-2 (ChCl:Gly:PEG-400 = 1:2:2) could up to 66.