| Abstract: | Using three series of sodium carboxymethylcellulose (NaCMC) in the range of the degree of substitution (the average number of carboxymethyl groups/glucose unit) from 0.5 to 1.3, weight-average molecular weight Mw was determined by light scattering in solution of triethylenediamine cadmium hydroxide (cadoxene). It was found that the relation between Mw and the limiting viscosity number η] in 0.1 N sodium chloride (NaCl) aqueous solution can be represented by Staudinger's equation. Dynamic viscoelasticity of aqueous disperse systems of NaCMC with various added salts was measured by means of a cone-and-plate rheometer. If the concentration of added salt is less than the concentration at which polymer begins to salt out, frequency dependence curves of the dynamic modulus, which is measured at various salt concentrations, can be superposed into a master curve by horizontal shift only. The shift factor depends on the salt concentration and the kind of salt. |
