Quaternized lignin-based dye dispersant: Characterization and performance research

Lignin-based dye dispersants have aroused an increasing interest due to their environment-friendly properties. In this research, the quaternized lignin-based dye dispersant (QLD) was prepared using alkali lignin from masson pine sulfate pulping liquor as raw materials by chemical modification, that is, sulfonation and quaternization. The structure and performance characterization of alkali lignin and QLD were studied. The analyses indicated that the structural unit of alkali lignin contained more G type and S type. Additionally, it was also proved that QLD contained quaternary ammonium group, amine group, and sulfonic group, which could improve the dispersion performance and thermostability of QLD. The results of thermogravimetric (TG) concluded that the dispersion performance and thermostability of QLD prevailed over alkali lignin. Compared with the contact angle of water, alkali lignin, and QLD with dye, the contact angle of QLD was much better than water and alkali lignin, indicating that the hydrophilicity and dispersion performance of QLD were superior to water and alkali lignin in Vat Olive T.