Instability of aqueous solutions of cationic acrylamide copolymers

Abstract Instability with time in aqueous solutions of cationic acrylamide copolymers has been studied by viscometry. The ageing effect is manifest to a higher degree for solutions of lower concentration and for copolymers with a higher content of acrylamide units. The introduction of NaNO 3 into freshly prepared aqueous solutions of the copolymers stabilizes the viscosity of the system. The absence of change in the viscosity of dilute solutions of the copolymers in 1 m NaNO 3 obtained from aqueous solutions at different stages of ageing excludes the degradation mechanism of their instability.