Synthesis and investigation of chitosan derivatives formed by reaction with acyl chlorides

Chitosan is a linear polysaccharide obtained from chitin deacetylation. Several applications of chitosan have been proposed in specialized literature: water treatment, cosmetic, food additives, development of biomaterials, and mainly drug delivery. In the present paper chitosan was hydrophobized by esterification reaction with acyl chlorides; its derivatives were swelling in water and characterized by C-13- and H-1-NMR and infrared spectroscopy. The main scope of this result was to generate hydrophobic derivatives through reactions on hydroxyl and amine groups of polysaccharides by incorporation of long alkyl chains. In accordance with the results, the exponential growing of degree of substitution (DS) with TEA concentration shows the necessity of higher concentrations to obtain good results. In the presence of acyl chloride the DS achieved higher values for lower concentrations of this, due to the presence of a favorable amount of TEA.