THE EFFECT OF UREA ON VOLUMETRIC AND VISCOMETRIC PROPERTIES OF AQUEOUS-SOLUTIONS OF POLY(ETHYLENE OXIDE)

The density and the viscosity of aqueous PEO solutions are observed wi th the several concentrations of PEO at 20 degrees C. The effects of u rea on them are also observed. The apparent and the partial specific v olumes of PEO are calculated from the density data, which result that the polymer-polymer interaction is dominating in the binary aqueous PE O solutions, while the polymer-solvent interaction is dominating in th e ternary aqueous urea-PEO solutions. It is explaind by the urea induc ed breakage of the structured water originated from the hydrophobic in teractions and the binding of the urea to the PEO chain. The concentra tion dependence of relative viscosity and the density dependence of fl uidity is also discussed with the concept of the polymer-solvent and t he polymer-polymer interactions of aqueous urea-PEO solutions.