RHEOLOGICAL PROPERTIES OF POLY(ETHYLENE OXIDE) AQUEOUS-SOLUTIONS

This article describes the rheological properties of certain poly(ethy lene oxide)s dissolved in water-based solvents. The experimental resul ts show that the rheological properties in aqueous solutions are signi ficantly affected by the solvent properties, which have been changed b y the use of ethanol-water mixtures and electrolyte solutions and by t he variation of the ambient pressure and temperature. The variation of the temperature and pressure is seen to change the polymer chain conf iguration and also the interactions of polymer segments with the solve nt molecules. This gives rise to distinctive and apparently unusual rh eological properties for these systems with the variation of the ambie nt temperature and pressure. The study generally illustrates that the rheology of these systems are, to a large degree, influenced by the hy drogen bonding in the solvent and between the solvent as well as the p olymer. At a first-order level, the increase of the pressure and the t emperature and also the addition of electrolytes, and the inclusion of an aqueous diluent, produce comparable effects. In essence, these cha nges seem to disrupt the hydrogen bonding structure in the solutions a nd, hence, the solvent quality in a comparable fashion. (C) 1998 John Wiley & Sons, Inc.