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

Abstract

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.

Keywords:

• Carboxymethylation
• dispersion stability
• graphite suspension
• wheat straw alkali lignin

Acknowledgments

The authors are thankful for the financial support of the National Science Foundation for Distinguished Young Scholars of China (20925622), the National Natural Science Foundation of China (21006036, 20976064), the National Basic Research Program of China (2010CB732205), the Natural Science Foundation of Guangdong Province of China (8351064101000002), and the Fundamental Research Funds for the Central Universities.