Lyotropic liquid crystalline behavior of five chitosan derivatives

Five chitosan derivatives, i.e. O-butyryl chitosan, O-benzoyl chitosan, N-p hthaloyl chitosan, N-maleoyl chitosan and O-cyanoethyl chitosan, were prepa red from chitosan. All of them had better solubility than chitosan, and dem onstrated lyotropic liquid crystalline behavior in various solvents. The cr itical liquid crystalline behavior of three O-substituted chitosan derivati ves was evidently different from two N-substituted analogues. Typical finge rprint textures of cholesteric phase were only observed in three O-substitu ted derivatives. The critical concentration (v/v%) of three O-substituted d erivatives does not depend on the acidity of acidic solvents.