Patent ID: 11841302

Abstract:
The invention relates to a method for determining the intrinsic viscosity [η] of an aqueous polymer solution at a temperature T, wherein the aqueous polymer solution comprises at least one acrylamide-based polymer in an aqueous solvent, the aqueous solvent having a salinity of from 6 to 250 g/L, the method comprising the steps of: —providing a single universal relation R1 between (i), the product of polymer concentration and intrinsic viscosity C·[η], and (ii) specific viscosity at zero shear rate ηsp; —performing a measurement of the dynamic viscosity of the aqueous polymer solution at one polymer concentration C1, at temperature T and at various shear rates; —determining from said measurement the zero-shear viscosity η0 of the aqueous polymer solution at polymer concentration C1 and at temperature T; —calculating the specific viscosity at zero shear rate of the aqueous polymer solution at polymer concentration C and at temperature T as ηsp=(η0−ηs)/ηs, where ηs is the zero-shear viscosity of the aqueous solvent; —estimating the intrinsic viscosity [η] of the aqueous polymer solution at temperature T by applying the universal relation R1 to the calculated specific viscosity at zero shear rate ηsp and polymer concentration C1.