The physical properties of Xanthan have lead to its use in a variety of applications. It is readily soluble in hot and cold water and brines over a wide pH range. In aqueous solutions, the polymer is highly pseudoplastic and shows stability to moderate temperatures and pH changes. Xanthan has unique resistance to thermal degradation at moderate temperatures, but is susceptible to degradation by enzymatic and oxidizing agents. Xanthan may be crosslinked using chromic ions. Xanthan’s major use in the petroleum industry is as a drilling fluid additive. Its “scaffolding” structure makes xanthan an excellent suspending agent to carry cuttings from drilling operations. Xanthan’s rheological properties are particularly well suited to this application in that it is pseudoplastic and has high viscosity while at rest. Because of this high viscosity, a certain amount of stress on the fluid is required to initiate flow. The amount of stress required to initiate flow is known as the yield point.

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