Thermal modification of chitosan films in the form of salts with various acids

Potentiometry and IR spectroscopy are used to study the process of amidation in films consisting of chitosan salts with formic, acetic, and propionic acids during the thermal treatment of these films in the air at 120°C. The highest degree of amidation (up to 50%) is shown to be reached in chitosan formates. The amidation leads to significant strengthening of the films and reduces their solubility in aqueous media.