Effective radii of macromolecules in dilute polyvinyl alcohol solutions

Abstract

The temperature and concentration dependences of the effective radii of polyvinyl alcohol (PVA) macromolecules have been studied on the basis of experimental data on the viscosity of dilute PVA solutions in dimethyl sulfoxide (DMSO) and water, as well as using the Malomuzh–Orlov theory of shear viscosity in polymer solutions. The temperature dependences of the effective radii of PVA macromolecules in DMSO are shown to be linear in the temperature interval 293÷353 K. At the same time, those dependences are more complicated for aqueous PVA solutions. Namely, the effective radii of macromolecules remain unchanged at relatively low temperatures and PVA concentrations, but they decrease nonlinearly at higher temperatures and concentrations. The concentration dependences of the effective radii of PVA macromolecules in both solvents are found to decrease nonlinearly in the concentration interval 0.3–3 wt.%.