Preparation and Evaluation of Carboxymethylated Lignin as Dispersant for Aqueous Graphite Suspension Using Turbiscan Lab Analyzer

Carboxymethylated lignin (CML) was prepared from wheat straw alkali lignin (WAL) via carboxymethylation modification. The characterizations using FTIR, 13C NMR, and 1H–13C HSQC NMR suggest that carboxyl groups are introduced into WAL structure successfully and there are two different active sites substituted by carboxymethyl groups. Moreover, the dispersion efficiency of CML was evaluated using the Turbiscan Lab analyzer. Effects of CML dosage and suspension pH on the dispersion stability of aqueous graphite suspension were investigated. The result shows that the dispersion stability of aqueous graphite suspension prepared with CML of 1.0% dosage at suspension pH 6.7 is obviously improved.