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Influence of degree of deacetylation on critical concentration of chitosan/dichloroacetic acid liquid‐crystalline solution
Author(s) -
Dong Yanming,
Xu Congyi,
Wang Jianwei,
Wu Yusong,
Wang Mian,
Ruan Yonghong
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.2286
Subject(s) - dichloroacetic acid , chitosan , absorbance , acetic anhydride , acetic acid , polymer chemistry , copolymer , comonomer , chemistry , materials science , nuclear chemistry , organic chemistry , chromatography , polymer , catalysis
We prepared chitosans with various degrees of deacetylation (DDAs) by mixing completely deacetylated chitosan and acetic anhydride at room temperature without serious degradation and O‐substitution. We obtained a standard curve to measure DDA by plotting the IR absorbance ratio of A 1560 /A 2880 against the known DDAs (from 1–100%) of 10 specimens. The effect of DDA on the critical concentration ( C *) of chitosan/dichloroacetic acid solutions required to form mesophase was investigated by optical methods. A maximum C * value of 23 wt % appeared at a relative medium DDA (∼20%). The effect was explained by the disordering of chains with medium composition ratios of the copolymer of glucosamine and N ‐acetyl glucosamine. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1204–1208, 2002