Journal of Applied Polymer Science, Vol.62, No.5, 785-788, 1996
Properties of Aqueous Salt-Solutions of Polyvinylpyrrolidone .I. Viscosity Characteristics
The properties of dilute solutions of polyvinylpyrrolidone (PVP) in aqueous salt solutions have been studied by measurements of intrinsic viscosity [eta] in theta and nontheta solvents. Intrinsic viscosities of the polymer solutions were observed to decrease upon addition of a variety of inorganic salts (phosphates, monohydrogen phosphates, carbonates, sulfates, and dihydrogen phosphates). Values of the Huggins constant, k(H), were found to be higher than 0.35 for PVP in pure water at 298 K, whereas in salt solutions they varied from 0.85 to 1.28 in nontheta solvents. Kraemer’s constant, k(K), was also determined and k(H) - k(K) was calculated as 0.78 for PVP in pure water and for aqueous salt solutions of PVP, k(H) - k(K) = 0.61 at 298 K. k(H) values were also higher than the predicted range of 0.5-0.7, and k(H) - k(K) values were noted to be 0.73 in theta solvents.