Investigation of Structural Characteristics by FTIR Spectroscopy of Chitosan Derivative with N Heterocyclic Compound - COSTEA (NOUR), Iuliana Florina; ȘORCARU, Florentina; CÂRÂC, Geta (The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science, 2022)