Homogeneous synthesis and characterization of polyacrylamide-grafted cationic cellulose flocculants

In this work, cationic cellulose (CC) with different degrees of substitution (DS) was successfully synthesized by the reaction between cellulose and 3-chloro-2-hydroxypropyl-trimethylammonium chloride (CHPTAC) in a 7 wt % NaOH and 12 wt % urea aqueous solution. The structure of the CC was characterized by using elemental analysis, H-1-NMR, and FTIR. The DS values of CC ranged between 0.18 and 0.50, which could be obtained by adjusting the reaction temperature, reaction time, and molar ratio of CHPTAC to anhydroglucose unit of cellulose. The cationic cellulose-graft-polyacrylamide flocculant (CC-g-PAM) based on CC and polyacrylamide (PAM) was also synthesized in a homogeneous aqueous solution. The flocculation characteristics of CC and CC-g-PAM were evaluated in a kaolin suspension. The results showed that CC-g-PAM was an effective flocculant for the kaolin suspension under acidic or neutral conditions, and the flocculation efficiency was over 90%, while the CC showed better flocculation performance under alkaline conditions. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43106