Conversion of Chitosan to Facilitate Preparation of Chitosan Carboxylic Salt with Moisture Absorption-Retention Abilities

Different chitosan carboxylic salts were successfully prepared via a simple way using chitosan and oxalic, fumaric, salicylic acid for the first time. The characterizations of the salts were evaluated by FT-IR, 13C NMR, 1H NMR, elemental analysis, XRD. The solution properties and moisture absorption-retention abilities of the salts were compared with chitosan. The result indicated that chitosan and carboxylic acid were combined with salt bond. The properties of the salts were related to the type of carboxylic acid added and the formation of salt bond. The water-solubility, wetting effect and moisture-retention absorption abilities of the salts were better than chitosan. They therefore have the potential to substitute for chitosan for easy use as coating in food preservation.