Chitosan is the product when partially deacetylated chitin dissolves in dilute acetic acid. As such, depending on the degree of deacetylation, the carbonyl, C=O-NHR band can be observed at similar to1670 cm(-1) and the amine, NH2 band at 1590 cm(-1). When lithium triflate is added to chitosan to form a film of chitosan acetate-salt complex, the bands assigned to chitosan in the complex and the spectrum as a whole shift to lower wavenumbers. The carbonyl. band is observed to shift to as low as 1645 cm and the amine band to as low as 1560 cm(-1). These indicate chitosan-salt interactions. Also present are the bands due to lithium triflate i.e. similar to761, 1033, 1182 and 1263 cm(-1). When chitosan and ethylene carbonate (EC) are dissolved in acetic acid to form a film of plasticized chitosan acetate, the bands in the infrared spectrum of the films do not show any significant shift indicating that EC does not interact with chitosan. EC-LiCF3SO3 interactions are indicated by the shifting of the C=O bending band from 718 cm(-1) in the spectrum of EC to 725 cm(-1) in the EC-salt spectrum. The Li+-EC is also evident in the ring breathing region at 893 cm(-1) in the pure EC spectrum. This band has shifted to 898 cm(-1) in the EC-salt spectrum. C=O stretching in the doublet observed at 1774 and 1803 cm(-1) in the spectrum of pure EC has shifted to 1777 and 1808 cm(-1) in the EC-salt spectrum.