Synthesis of N-(1,2-dicarboxyethyl)chitosan

• Published in: Russian chemical bulletin Vol. 72; no. 12; pp. 2987 - 2993
• Main Authors: Veretennikova, E. A., Koryakova, O. V., Mekhaev, A. V., Bratskaya, S. Yu, Pestov, A. V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2023; Springer Nature B.V
• Subjects: Addition polymerization; Ammonium acetate; Buffer solutions; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Chitosan; Crosslinking; Epichlorohydrin; Full Articles; Functional groups; Inorganic Chemistry; Ion exchange; Ion exchange materials; Organic Chemistry; Polymers; Sodium; chitosan; synthesis in gel; chitosan carboxyalkylation; sorption
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-023-4110-9

In order to prepare new ion-exchange materials, we proposed two methods for the synthesis of N -(1,2-dicarboxyethyl)chitosan from chitosan via polymer-analogous transformations: by nucleophilic addition—elimination with dimethyl ester of 2-oxosuccinic acid followed by reduction with sodium borohydride and by nucleophilic substitution with 2-bromosuccinic acid under the “synthesis in gel” conditions. When chitosan is treated with the 2-oxosuccinic acid derivatives, cross-linking of the polymer with the formation of amide functional groups occurs along with functionalization and leads to insoluble products. When sodium 2-bromosuccinate was used, water-soluble N -(1,2-dicarboxyethyl)-chitosan with the degree of functionalization up to 0.35 was synthesized. The ion-exchange properties were studied for the polymer additionally crosslinked with epichlorohydrin. The total static exchange capacity with respect to an equimolar mixture of Cu II , Ni II , Co II , and Zn II ions in an ammonium acetate buffer solution at pH 6.5 was 2 mmol g −1 . The degree of extraction of the metal ions decreases in the series Cu II (47%) > Ni II (30%) > > Zn II (13%) > Co II (10%).