RHEOLOGICAL PROPERTIES FOR CONCENTRATED-S OLUTION OF CHITOSAN - DEPENDENCE OF SOLVENTS

Rheological properties for concentrated solution of chitosan were inve stigated in different solvents, such as HCOOH, CH3COOH, HCl and 0.2 mo l.dm-3 CH3COOH+ 0.l mol.dm-3 CH3COONa aqueous solutions. It was shown that viscosities and flow behavior of the solutions of chitosan were d ependent on the kinds of acids and the pH value of solvents. And the e xponent of concentration alpha in viscosity-concentration power law, e ta0 = K . c(alpha), increased with increasing of pH value, and it was largely higher in 0.2 mol.dm-3 CH3COOH + 0.1 mol.dm-3 CH3COONa, becaus e the solvent changed from good-to poor. In addition, the stability of rheologcal properties was studied.