Xanthan is a natural polymer generated by the bacteria Xanthamonas campestris and produced commercially by a fermentation process. It is composed of three monosaccharides – mannose, glucose and glucuronic acid, arranged in a highly branched structure with an estimated molecular weight of 5 million.
Xanthan’s polar side chains provides sites for 1) extensive hydrogen bonding with water and
2) interactions between polymer chains that give rise to a helical structure in solution.
This type of structure allows for a significant increase in solution viscosity especially at low shear rates.
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 high viscosity while at rest. Because of this highviscosity, a certain amount of stress on the fluid isrequired to initiate flow. The amount of stress required to initiate flow is known as the yield point.
|Xanthan Gum Grades|
|D.Col -XCD||1800 cps min.||6.0- 7.0||9% max||Dispersible , brine tolerant , drilling mud additive.|
|D.Col -XC||1500 cps max.||5.5- 6.5||9% max.||Xanthan gum for Drilling Applications|
|D.Col -XG-GG||5500 cps max.||5.5- 7.0||10% max.||Xanthan Gum & Guar Gum Blend.|
|D.Col -XG-Kar||1200 cps min.||5.0- 7.0||10% max.||Standard Xanthan Gum, could be used in Food/Personal care products.|
|D.Col -XG-Co||6000 cps min.||6.5- 7.0||10% max.||Coarse particles. Xanthan based guar substitute|