Determination of intrinsic viscosity and molecular weight of xanthan gum by plots of different equations

الملخص EN

Xanthan gum (XG) is a natural high molecular weight polymer.

It is one of the important polysaccharides, produced by the fermentation process.

This research aims to estimate the intrinsic viscosity of XG.

The intrinsic viscosity [η] was evaluated by various equations, initially by Huggins equation as a reference, then using other equations, it was compared and calculated with the relative percentage of errors.

From the calculations, we note that the Arrhenius-Rother-Hoffmann is the most reliable method for estimating the intrinsic viscosity, while the Fuoss method is very unsuitable for estimating the intrinsic viscosity.

The fundamental importance of intrinsic viscosity lies in the fact that it's the first step to estimating the molecular weight (1043107 g/mol) and hydrodynamic radius (280 nm).

Furthermore, the value of molar mass was calculated by the Mark-Houwink equation for helical conformation with parameters a= 0.74×10-3 cm3 /g and k = 1.35.

where a and k are M-H constants depending upon the type of polymer.