Experimental researches are carried out for the concentration and temperature dependences of the kinematic viscosity and the density of diluted and semidiluted solutions of polyvinyl alcohols (PVAs) with hydrolysis degrees of 85.2 ± 1.0 mol.% and 98.4 ± 0.4 mol.% in dimethyl sulfoxide and water. Critical concentrations of the transition from the diluted solution to more concentrated regimes are calculated. The results of calculations show that the critical crossover concentrations for PVA solutions in dimethyl sulfoxide are lower than that for PVA aqueous solutions. The obtained temperature dependences of the effective hydrodynamic radii of macromolecules in the diluted PVA solutions testify that this parameter decreases, as the temperature grows.

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Rheological properties of normal aliphatic alcohols and their fluorinated analogs have been studied. The temperature dependences of the density and the kinematic viscosity of fluorinated and normal alcohols are shown to have the same character. The density growth for fluorinated alcohols is revealed, with the shear viscosity growing more pronouncedly, if more hydrogen atoms in the alcohol molecule are substituted by fluorine ones. The calculated thermodynamic properties of a viscous flow testify that fluorinated aliphatic alcohols are more structured in comparison with normal ones. K e y w o r d s: fluorinated aliphatic alcohols, shear viscosity, thermodynamic parameters, viscous flow.

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