Solution property characterization of the copolymer polyacrylamide-co-acrylate

Anionic polyelectrolytes are used as flocculants in the treatment of paper, mining and municipal wastewaters. The solution properties of polyacrylamide-co-acrylate and their effect on the flocculation of aqueous kaolinite suspensions in the presence of simple electrolytes was investigated.; Polyacrylamide-co-acrylate samples ranging in charge density from 0.6 to 65.4 mol% were prepared by hydrolysis of a high molecular weight polyacrylamide. Intrinsic viscosities and flocculation subsidence rates were measured as a function of polyelectrolyte charge density and the type and concentration of added electrolyte. The electrolytes studied included LiCl, NaCl, KCl, MgCl{dollar}sb2{dollar} and CaCl{dollar}sb2{dollar} and ranged in concentration from 0.001 to 0.1M.; The findings indicate that the behavior of polyacrylamide-co-acrylate is sensitive to the charge density and the type and concentration of added electrolyte. The polymer intrinsic viscosities and flocculation subsidence rates were found to increase with decreasing salt concentration independent of salt type. The results show that flocculation performance increases with increasing intrinsic viscosity of the polymer and that it has a maximum at an intermediate charge density. Flocculation effects were particularly enhanced upon the addition of divalent counterions.