Diffusion, viscosity and sedimentation of poly(ethylene oxide) in water

Abstract

Results are reported for measurements of the diffusion coefficients of poly(ethylene oxide) fractions in aqueous solution and of the viscosities and sedimentation coefficients at temperatures between 8 and 35°C, for molecular weights from 1000 to 6000. These show that the polymers behave in water as non-free-draining coiled molecules having dimensions which become less perturbed by the solvent as the temperature is lowered, the θ-temperature is estimated at 5°C. The unperturbed dimensions are seen to decrease with increasing temperature due possibly to greater freedom of rotation of the atoms around the bonds joining them. The entropy parameter, ψ, is about 0.36, coming within the range of geometrically good solvents.