壳聚糖浓溶液流变学性质研究——溶剂性质的依赖性

Rheological Properties for Concentrated Solution of Chitosan——Dependence of Solvents

用不同pH值的HCOOH,CH_3C000H,HCl,0.lmol·dm^(-3)CH_3COONa+0.2mol·dm^(-3)CH_3COOH水溶液为溶剂,进行了壳聚糖浓溶液的流变学性质研究.实验结果表明,溶剂pH值相同时,壳聚糖在各种酸中的溶解性和溶液粘度差别较大.同一种酸中,在可溶范围内,pH值增加,溶剂变劣,粘度-浓度的幂律方程指数α增大.外加盐使溶剂变劣程度增加.在任何一种酸中,浓溶液粘度都随存放时间的延长而下降,流动指数n减小,流动活化能基本不变.

Rheological properties for concentrated solution of chitosan were investigated in different solvents, such as HCOOH, CH3COOH, HOI and 0.2mol·dM-3 CH3COOH+ 0.1mol·dm-3 CH3COONa aqueous solutions. It was shown that viscosities and flow behavior of the solutions of chitosan were dependent on the kinds of acids and the pH value of solvents. And the exponent of concentration a in viscosity-concentration power law, nc-K·ca, increased with increasing of pH value, and it was largely higher in 0.2mol·dm-3 CH3COOH+0.1mol·dm-3 CH3COONa, because the solvent changed from good to poor. In addition, the stability of rheologcal properties was studied.