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Measurement of critical concentration for mesophase formation of chitosan derivatives in both aqueous and organic solutions
Author(s) -
Dong Yanming,
Mao Wei,
Wang Huiwu,
Zhao Yaqing,
Li Xiaojian,
Bi Danxia,
Yang Liulin,
Ge Qiang,
Fang Xueming
Publication year - 2006
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2099
Subject(s) - mesophase , chitosan , aqueous solution , amphiphile , derivative (finance) , circular dichroism , materials science , chemical engineering , polymer chemistry , chemistry , organic chemistry , crystallography , polymer , phase (matter) , copolymer , economics , financial economics , engineering
Abstract A novel chitosan derivative, acryloyl chitosan (AcCs), and two N ‐maleoyl chitosans, MaCs‐1 and MaCs‐2, with different degrees of substitution were synthesized using completely deacetylated chitosan as raw material under different reaction conditions. AcCs is an amphiphilic chitosan derivative, but MaCs‐1 and MaCs‐2 are soluble in water and organic solvents respectively. The concentrated solutions of AcCs, MaCs‐1 and MaCs‐2 all demonstrated mesophases and were investigated using polarizing optical microscopy (POM). Circular dichroism (CD) was also employed for determining the critical concentration for mesophase formation. A broad peak in the visible light region of CD spectra had its origin in the appearance of the mesophase, and arose from the selective reflection of cholesteric helix pitches. The results of CD measurements agreed with those of POM. The critical concentration values for aqueous solutions were much lower than those for organic solutions, which was explained by the strong interactions between the chitosan derivatives and water. Copyright © 2006 Society of Chemical Industry