Preparation mechanism and performance evaluation of deep eutectic solvent-lignin/ZnO composites by one-pot

Lignin, as the aromatic polymer in the world, has attracted more attention because of rich functional groups. In this study, lignin/ZnO composites was prepared by a simple one-pot method rely on urea and ZnCl₂-deep eutectic solvent (U/ZnCl₂-DES) as solvent and raw material. Through molecular dynamics simulation, the interaction mechanism between lignin functional groups and DES was clarified, and it was blended with waterborne polyurethane (WPU) to form a film, while the feasibility of its application in ultraviolet shielding was evaluated. The results showed that lignin /ZnO composites with excellent ultraviolet shielding properties were successfully prepared. Compared with lignosulfonate (SL), enzymatic hydrolysis lignin (EHL) was easier to combine with ZnO, which was benefit to prepare lignin/ZnO composites. When the addition of EHL/ZnO-N_12.5 complex was 1.5 %, the WPU film prepared has good mechanical properties (elongation at break was 25.53 %, tensile strength was 1422 kPa), good light transmission and ultraviolet shielding.