Study on preparation of cationic flocculants by grafting binary monomer on cellulose substrate by γ-ray co-irradiation

Carboxymethyl cellulose (CMC) and wood flour cellulose (WFC) graft copolymers were prepared from acrylamide/dimethyl diallyl ammonium chloride (AM/DMDAAC) by γ-ray co-irradiation graft copolymerization method. CMC could obtain an excellent grafting effect at the absorbed dose of 6 kGy and CMC/AM/DMDAAC ratio of 0.2 g:2 g:1 ml, and the grafting rate, grafting efficiency, cationic degree and grafting efficiency of DMDAAC monomer were 790%, 46.01%, 20.17% and 64.56% respectively. Relatively, when the ratio of AM and DMDAAC was 3 g:1 ml and the absorbed dose was 8 kGy, the grafting effect of WFC was the optimum, and the more WFC added, the better graft copolymerization effect. The flocculation effect of the products and cationic polyacrylamide on kaolin wastewater was investigated, and the maximum turbidity removal rate of CMC graft copolymer on kaolin wastewater reached 86.0%, showing an excellent flocculation effect. The flocculation effect under different conditions was WFC graft copolymer＞CMC graft copolymer＞Cationic Polyacrylamide. • The cationic flocculants were prepared by γ-ray co-irradiation method. • The binary monomer was grafted onto cellulose by initiating free radicals. • The optimum graft copolymerization conditions were explored. • These flocculants had an excellent turbidity removal rate for kaolin wastewater.