Excluded Volume of Alkali Poly(styrene sulfonates) in Solutions with Added Salt

The intrinsic viscosities of sodium and potassium poly(styrene sulfonates) having different molecular weights were determined in sodium and potassium chloride solutions of various concentrations. The data were analyzed on the basis of the theory of Stockmayer and Fixman and the values of the mutal excluded volume of segments determined. The values obtained have been compared with those calculated using Ptitsyn's theory of excluded volume. To achieve semiquantitative agreement between theory and experiment, the effective and not the nominal charge of polyions has to be used in calculations. From the intrinsic viscosities the molecular expansion was also determined and the values obtained compared with those given by Fixman's theory of polyelectrolytes. Finally, the temperature coefficients of the intrinsic viscosities of some solutions having different ionic strength have also been ascertained.