With the method of dilution in constant concentration of added salts

viscosities of Na-salts of sulfonated polysulfone in DMP containing NaNO8 of different concentrations have been measured experimentally. Based on treatment of experimental data

an empirical equation is deduced as followingIn this equation

the first term represents the relationship between reduced viscosity and solution concentration in the absence of added salts while the second term represents the correction on reduced viscosity in the presence of added salts. It can be predicted satisfactorily by this empirical equation how the concentration of added salts effected on the curve of reduced viscosity

Furthermore

this equation did show obviously how intrinsic viscosity of sample used varied with the concentration of added salts.