Rheological behaviour of chitin in NaOH/urea aqueous solution

The theological behaviour of chitin in 8 wt% NaOH/4 wt% urea aqueous medium was evaluated by steady shear and dynamic oscillatory tests, in which the effects of concentration, temperature and time on the rheological behaviour of chitin aqueous solution were investigated in detail. It suggested that chitin aqueous solution is sensitive to temperature, which will transform to a gel when temperature increases to physiological conditions. And the higher the concentration is, the lower the gelation temperature is. The comparison on theological behaviour of chitin aqueous solution at different time reveals that 8 wt% NaOH/4 wt% urea solvent at low temperature has little effect on chitin structure. It is interesting that the chitin gel has reversibility and it will transit to solution after being treated at low temperature again. The comparison on rheological behaviour between the original chitin aqueous solution and the chitin aqueous solution after gelation reveals that gelation has a little effects on solution properties. (C) 2010 Elsevier Ltd. All rights reserved.