香豆胶流变性的研究

Abdel-Mutaleb M .Khatir University of Zalingi Sudan

研究了香豆胶的流变特性。胶中甘露糖：半乳糖大约为1：1，分子量约为3．12×105。较低浓度时剪切速率范围内剪切速率与粘度无相关性。较高浓度时香豆胶表现剪切变稀现象。由于聚合物水解，粘度随pH的降低而下降。在较高的pH范围，中性聚合物转变为聚电解质，使粘度增加。温度下降，粘度也降低。香豆胶的粘弹性较其它半乳甘露聚糖低，可能是由于较高的半乳糖含量使得内部交联降低，粘度下降。

The rheological properties of the gum from seeds of a member of loguminosae have studied. The samples used had mannose: galactose ratio close to unity and molecular weight of 3. 12 × 105. No shear rate viscosity dependence was obtained in the range of the shear rate used for lower concentration(0. 5% ). For the high concentrations(>1. 0% ) the behavior of the gum solutions became shear-thinning. Viscosinty decreased with decreasing of the PH due to the hydrolysis of the polymers. At high pH the neutral polymers were converted to polyelectrolytes which was caused increasing in viscosity. Temperature viscosity dependence was observed, viscosity decreased when the temperature was decreased. The viscoelastic behavior was lower than that found for Other galactomannans and less severe dependence of the viscosity on the coil overlap parameter is probably due to the lower interaction because of the high galactose content.