Abstract

PUENTE-CORDOVA, Jesús Gabino et al. Rheological behavior of polymer solutions of carboxymethyl cellulose. Ing. invest. y tecnol. [online]. 2022, vol.23, n.2, e1921.  Epub Nov 04, 2022. ISSN 2594-0732.  https://doi.org/10.22201/fi.25940732e.2022.23.2.012.

Carboxymethyl cellulose is a biocompatible polymer whose synthesis process consists of chemically modifying the macrostructure of cellulose. This cellulose derivative is traditionally used in both the food and pharmaceutical industries. Optimizing these applications is directly related to understanding and manipulating the rheology of aqueous CMC solutions. In this work, CMC solutions of different concentrations were studied by interpreting their experimental viscosity curves as a function of shear rate, concentration level, and temperature. The experimental viscosity curves for the solutions studied showed a shear-thinning rheological behavior that is less evident for the more dilute solutions. It was identified that the viscosity of the solutions increases with increasing concentration but decreases with increasing temperature. The experimental results were adjusted to the Ostwald model or power law and the Cross model, both models showing a good correlation, but they show discrepancies with the experimental curves at shear rates lower than 200 s-1. Finally, two empirical models are proposed, which are an extension of the Ostwald model, one to predict the magnitude of the viscosity as a function of the shear rate and the concentration of CMC, and another that describes the viscosity as a function of temperature and the shear rate. These results constitute a systematic methodology for the evaluation of polymeric solutions of CMC and cellulose derivatives.

Keywords : Carboxymethyl cellulose; viscosity; rheological model; power law; shear-thinning.

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