Methanesulfonic acid method was used to prepare five acylated chitins. Exceptheptanoyl chitin

four of them

i.e.acetyl chitin

propionyl chitin

butyryl chitin andhexanoyl chitin

had high degree of substitution(from 1.5 to 2.0)and exhibited lyotropicliquid crystalline behavior and cholesteric phase . Asthelength oftheside chain increased thecritical concentration (W/ W)somewhat increased from 0.21 to 0.26 because the chainrigidity dropped . The criticalconcentration valuesofallthefour derivatives were much higher than that of chitin (0.12) due to the decrease of intramolecular hydrogen bonds. The four acylated chitin can form typical banded texture after being sheared. There minimum concentrations to form banded texture of them were evidently different

varied from 0.25 (for acetyl chitin)to 0.37 (for hexanoyl chitin).These results further indicated that liquid crystallinity decreased while the length of flexible side substituents increased.