葡甘聚糖/凹凸棒土共混溶液的流变性质

摘要

Konjac glucomannan(KGM) was modified by blending with attapulgite (AT). The dynamic rheological tester was used to study the effect of different AT loadings on the rheological behavior of the blended solutions at 20℃. The results show that the complex viscosity and storage modulus as well as loss modulus of the blended solutions are lowered than those of pure KGM solution in most cases. When AT content is low, the individual AT nano-rod can rotate freely under external force, which induces the orientation of KGM molecules, and the liquid-like behavior of the blended solution becomes more pronounced; when AT content is high, since the volume effect confines the motion of KGM molecules, the blended solutions display the solid-like behavior. Besides, it was found that local percolation network structure might be formed in the case of mass ratio of AT/KGM =2% . With the increase of AT loading, the blended solutions are seemed to be less frequency dependent compared with pure KGM solution, but more heterogeneous in internal structure.%采用凹凸棒土(AT)对魔芋葡甘聚糖( KGM)进行共混改性,通过动态流变测试研究了20℃时不同纳米AT添加量对共混溶液流变性质的影响.结果表明:AT的加入使得共混溶液的复数黏度、储能模量和损耗模量均比原溶液低.当AT添加量较低时,在外力的作用下AT能够自由旋转,并且诱导KGM分子取向,复合溶液的似液体行为更为明显；当AT添加量较高时,由于体积效应限制了KGM分子的运动,使共混溶液呈现似固体行为；当AT与KGM质量比为2％时,溶液中可能形成了局部的逾渗网络结构.随着AT添加量的增多,共混溶液对频率的依赖性减小,溶液内部结构呈现非均相的趋势愈加明显.