CHEMICAL MODIFICATION OF AQUATIC POLYSACCHARIDES - A REVIEW

The effect of activating treatments (grinding and inclusion with organic solvents with acid or basic reagents) on the physical structure and reactivity of chitin and chitosan in esterification and alkylation reactions was investigated. Improved methods for preparation of water-soluble highly substituted chitosan sulfates (degree of substitution (DS) of up to 1.6) and carboxymethylated derivatives of chitin and chitosan (DS = 0.6-1.3) were proposed. The chemical and physical inhomogeneity of samples with different DS was evaluated. The solubility, acid-base properties of ionogenic groups, and viscosity properties of solutions of the derivatives were analyzed with respect to their polyampholytic nature. The pronounced biological activity of chitosan sulfates and the complexing and film-forming power of carboxymethylated products were used to determine promising areas of their practical use.