Caracterisation physico-chimique de polyacrylamides utilises comme agents floculants—I. Etude en solution

The physicochemical behaviour of flocculating agents (polyacrylamide and copolymers with acrylic acid) has been investigated. In aqueous solution after elimination of insoluble fractions by ultracentrifugation, light scattering shows the presence of molecular aggregates. The more important is the ionic character of macromolecules in solution, the more numerous are aggregates. By submitting polymer solutions to mechanical stress, the molecular weight decreases; the mechanism of chain-breaking is radical.