Synthesis and flocculation characteristics of a novel biodegradable flocculating agent amylopectin-g-poly(acrylamide-co-N-methylacrylamide)

Amylopectin-g-poly(acrylamide-co-N-methylacrlymide) [AP-g-poly(AM-co-NMA)] was prepared in presence of potassium persulfate (K2S2O8) as the initiator by solution polymerization technique. The synthesised graft copolymer was characterized by various characterization techniques like FTIR, H-1 NMR and C-13 NMR spectroscopy, thermal analysis and SEM. Biodegradation of the graft copolymers was carried out by enzyme hydrolysis. Flocculation performance of the graft copolymer was evaluated in 1.0 wt% coal, 1.0 wt% silica, 1.0 wt% kaolin, 0.25 wt% iron ore and 1.0 wt% bentonite clay suspensions. The flocculation efficiency of the graft copolymer was also evaluated by the colour removal capacity from aqueous solution of a synthetic dye, malachite green. A comparative study of the flocculation performance AP-g-poly(AM-co-NMA) was also made with another laboratory synthesised graft copolymer namely amylopectin-g-polyacrylamide (AP-g-PAM) and some commercially available flocculants in the same suspensions and also in the malachite green solution. The results showed that the graft copolymer AP-g-poly(AM-co-NMA) showed better flocculation performance than that of AP-g-PAM as well as to some of the commercial flocculating agents. (C) 2015 Elsevier B.V. All rights reserved.