Properties of Mixed Aqueous Solutions of Polyethylene Oxide and Carboxymethyl Cellulose with Different Degrees of Ionization and of Composite Films Prepared from Them

Rheological properties of mixtures of dilute and moderately concentrated aqueous solutions of carboxymethyl cellulose with various degrees of ionization and polyethylene oxide were studied. The range of compositions in which the viscosity of dilute solutions of the polymer blends shows negative deviation from the calculated additive values becomes broader in going from carboxymethyl cellulose sodium salt to partially ionized carboxymethyl cellulose. In concentrated mixed polymer solutions, the deviation of the viscosity from the additive values is always positive. Film composite materials were prepared, and their structural organization and compatibility of the polymers in the solid state were studied by dynamic mechanical analysis and X-ray diffraction analysis. Carboxymethyl cellulose with various degrees of ionization is incompatible with polyethylene oxide in the composite films obtained, and no new mixed structures are formed. Polyethylene oxide behaves as an interstructural plasticizer of the cellulose ether.