Synthesis and characterization of a cationic polyacrylamide flocculant

A cationic polyacrylamide flocculant has been prepared by copolymerization of acrylamide(AM) and dimethyl diallyl ammonium chloride(DMDAAC).The effects of varying the reaction temperature,concentration of initiator,and monomer mass fraction on the final polymer were investigated.The optimal conditions were found to be as follows:a reaction temperature of 55 ℃,total mass fraction of(NH4)2S2O8 and NaHSO3·CH2O·2H2O of 0.0125%,mass ratio of(NH4)2S2O8/NaHSO3·CH2O·2H2O of 7∶3,mass fraction of 2,2′-azobis(2-methylpropionamide)dihydrochloride(V-50) of 0.0125%,monomer concentration of 35%,and cationic degree of 35%.The resulting cationic polyacrylamide(CPAM) with a molecular weight of 2.5×106 had a strong flocculation capability.The chemical structure and thermal behavior of CPAM were characterized by FT-IR and TG respectively.The TG results showed that the thermal stability of CPAM was much better than that of AM.