On the Structure of Cellulose Acetate Molecules in Acetone Solution

Abstract

Data obtained from sedimentation velocity and viscosity measurements on a series of cellulose acetate fractions in acetone are interpreted in terms of two models, the impenetrable ellipsoid of rotation and the uniform density random coil. The lack of agreement using the former model is shown to be a real effect, rather than one determined by experimental inaccuracy. As other investigations have revealed, the uniform density random coil is not a satisfactory model for these molecules either. Probably the best hydrodynamical model for these and other extended but not perfectly rigid molecules in solution is a penetrable ellipsoid of rotation.