Rheological properties of water-soluble cross-linked xanthan gum

Water-soluble crossslinked xanthan gum (CXG) was prepared from xanthan gum (XG) and epichlorohydrin under alkaline condition by ethanol solvent method. Rheological properties and heat resistance performance of different concentrations of aqueous XG and CXG solutions were investigated. The results showed that the apparent viscosity of 4g center dot L-1 CXG solution was 2.57 times that of 4g center dot L-1 XG solution. The storage modulus G and the loss modulus G of CXG solutions were greater than those of XG solutions, and viscoelastic and thixotropic properties were more significant in CXG solutions. At 80 degrees C, these two solutions were sheared at 170s(-1) for 90 minutes, the reserved viscosity was 32.30 and 62.15 mPa center dot s for XG and CXG solutions, respectively. The heat resistance performance of CXG solution was better than that of XG solution. Nonlinear co-rotational Jeffreys model could be applied to describe the flow curves of XG and CXG solutions correctly, and the calculated values were in good agreement with the experimental data.