ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Viscosity properties of aqueous-solutions of hydroxyethylcellulose

A. Blažková, J. Hrivíková, and L. Lapčík

Department of Physical Chemistry, Faculty of Chemical Technology, Slovak Technical University, CS-812 37 Bratislava

Abstract: In this paper attention is paid to the influence of varying content of the Li⁺, K⁺ , Cu²⁺, and Mn²⁺ ions bonded to the CI^- ions and of pH of medium on the change in viscosity properties of the aqueous solutions of hydroxy­ethylcellulose (НЕС) which were subjected to low-temperature degradation in air. The change in properties of НЕС solutions was estimated on the basis of the values of limiting viscosity number [η], density of statistical coil ϼ_[η], and Huggins constant k_H under given experimental conditions. It has been found that [η] of the НЕС solutions containing univalent metal cations increases with the content of these cations, while it does not change in the presence of the bivalent Mn²⁺ cations. On the other hand, it slightly de­ creases in the presence of Cu²⁺. In the course of thermal stress the values of [η] usually decrease with increasing temperature in the investigated temperature interval. The influence of the pH value of medium on [η] is most significant in strong acid and strong alkaline medium at higher temperatures and at higher time periods of thermal stress. The НЕС solutions are most stable below 60 °C in the pH region 6—8. The calculated values ofϼ_[η] and k_H change consistently with the value of [η] of the НЕС solutions.

Full paper in Portable Document Format: 443a289.pdf

Chemical Papers 44 (3) 289–301 (1990)