Studies on chitin. vi. preparation and properties of alkyl-chitin fibers

Abstract

Alkali-chitin was prepared by a simple procedure which included a freezing process in a sodium hydroxide-sodium dodecylsulfate system. Its alkylations were achieved with various alkyl halides of different chain lengths and bulkiness. The affinity toward water or formic acid was remarkably enhanced by the alkylations in spite of the low degree of substitution. The increase in hydrophilicity was considered to be result from the partial destruction of crystalline structure in the chitin molecule. The alkyl-chitin fibers were successfully prepared by spinning the solution of alkyl-chitin in formic acid-dichloroacetic acid mixture into ethyl acetate. The extent of swelling with water was found to correspond both to the chain length and the bulkiness of the alkyl group. The hydroxyl group at the C6 position is considered to be substituted prior to that of C3 position, according to a 13C NMR study. 1H NMR and elemental analysis proved useful in estimting the degree of alkylation even in the case of low degree of substitution. © 1982 The Society of Polymer Science, Japan.