| 초록 |
The use of trifluoroacetic anhydride as a promoter for the preparation of chitosan. Efficient acylation in a homogeneous solution is attained when the carboxylic acid of interest and trifluoroacetic anhydride are added, the latter in at least twice molar excess to the hydroxyl groups of the residues. The reaction necessitates prior heating of chitosan in acetic acid before the acylation reagent is added. Complete dissolutin is achieved whithin 1~2 h when powdered chitosan is heated at 70℃ in a mixed solution of carboxylic acid(s) and trifluoroacetic anhydride. Chitosan esters prepared are chitosan acetate, chitosan propionate, chitosan butylate, chitosan valerate, each from a solution of the respective reactants. |
