N 10 N-alkylation of chitosan by beta-halopropionic acids in the presence of various acceptors [Text] / A. V. Pestov, Yu. A. Skorik, G. Kogan, Yu. G. Yatluk // Journal of Applied Polymer Science . - 2008. - Vol. 108, № 1. - P119-127 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: N-carboxyethylation of chitosan by -halopropionic acids in the presence of various proton and halogen ion acceptors was investigated. It has been observed that carboxyethylation of chitosan in aqueous medium is accompanied by the by-processes of hydrolysis and dehydrohalogenation of the -halopropionic acids yielding -hydroxypropionic acid, bis(2-carbox-yethyl) ether, and acrylic acid. Degree of carboxyethyl substitution (DS) of chitosan and the relative rates of the by-processes varied significantly depending on the conditions used and nature of the proton or halogen ion acceptor. At carboxyethylation of chitosan with the alkaline -bromopropionates, the DS increased in the order Cs+ Rb- K+ sim; Na+ Li-. |