Chemical Modification of Chitosan, 17

Abstract

The Michael reaction of chitosan with acrylic acid was carried out successfully, even in water alone as the reaction medium. As a consequence of its good solubility in water, the reaction product, N‐carboxyethylchitosan, showed excellent biodegradable properties with standard activated sludge.

A Facile Route for Regioselective Conjugation of Organo‐Soluble Polymers onto Chitosan

“…The assignment of the peak at 2.85 ppm to the H-2 of the unsubstituted glucosamine residue in chitosan has been frequently reported previously. [15,[18][19][20][21] When stoichiometric SCC was used as an intermediate, the integration area ratios of A 1.85 /A 2.85 in all of the SCC-g-PEG were found to be almost the same as those in SCC. These results suggest that the amino groups remained intact and PEG was conjugated to SCC through hydroxyl groups.…”

Photo-polymeriable chitosan derivative prepared by Michael reaction of chitosan and polyethylene glycol diacrylate (PEGDA)

“…The Michael type reaction is a well-known process to add various amines onto ␣,␤-unsaturated carbonyl compounds. Recently, many papers have reported the chemical modification of chitosan with double bond monomer by Michael reaction under mild reaction conditions [21][22][23][24]. Photopolymerization is of great interest in many industrial applications: the formulations are solvent-free, the production rates are high, and the required energy is much less than that in thermal curing [25].…”

Aggregation behavior of N-carboxyethylchitosan in aqueous solution: effects of pH, polymer concentration, and presence of a gemini surfactant

“…Acrylic acid (Shanghai LinFeng Reagent Co. Ltd) was distilled under reduced pressure before use. CECh was prepared by a Michael addition reaction as described by Sashiwa et al, 11 and the degree of substitution (DS) of CECh was 0.21, based on 1 H NMR analysis referred to relevant literature. 35 The CECh product was precipitated in anhydrous EtOH and was rinsed three times to remove the low-molecular-weight component.…”

“…These modified chitosans are synthesized with carboxylate or sulfo groups on the reactive functional groups along the polymer backbone. [9][10][11] Among the numerous water-soluble derivatives, N-carboxyethylchitosan (CECh), synthesized by adding the acrylic acid (AA) onto -NH 2 groups by Michael addition, is one of the most attractive derivatives. Due to the modification of COO-, CECh presents some significant properties, such as improved water solubility, higher biocompatibility, and better biodegradability in comparison with chitosan.…”