The effect of thermal aging on xanthan solutions

✍ Scribed by M. Milas; J. L. Linossier; F. Contat

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 404 KB
• Volume: 35
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1988.070350422

✦ Synopsis

The viscosity stability of xanthan solutions is crucial to petroleum recovery processes. The effects of oxygen concentration, pH, and temperature on viscosity during aging up to 6 months were studied. T h e structure modifications of the xanthan (substituent contents, weight-average molecular weights) with aging times were followed and related to viscosity loss. In all cases, the acetyl groups were hydrolyzed. The best stability to thermal aging corresponds to neutral or basic conditions with very low oxygen concentrations. At these conditions the viscosity was stabilized t o about 50% of its initial value after 6 months at 80°C. In these cases the pyruvate groups were not hydrolyzed. The stabilization of main chain breaks in the srdered xanthan conformation improves the stability results.