Crosslinking Reactions of Oxidized Cellulose Fiber. II. Reactions Between Dialdehyde Cellulose and Chito-Oligosaccharides on Lyocell Fabric

摘要

Antimicrobial nonfibrillated lyocell fibers were developed by crosslinking reactions between dialdehyde cellulose and chito-oligosaccharides. Partially oxidized lyocell fibers with sodium metaperiodate were successfully crosslinked with two water-soluble chito-oligosaccharides with different molecular weights by Schiff base formation and were reduced with sodium borohydride. Infrared spectroscopy measurements showed the characteristic absorption bands caused by the functional groups of each reaction product. The surface chemical compositions of the modified fibers were analyzed with electron spectroscopy. O1s intensities decreased with the oxidation and crosslinking reaction, whereas N1s intensities increased with the crosslinking reaction. According to the curve fittings, C1s spectra were divided into ACH, ACOA/ACNA, AC_O, and ACOOA peaks, and their relative peak areas confirmed the reaction results. The degree of fibrillation of the crosslinked fibers decreased with the oxidation levels and chito-oligosaccharide concentrations and increased with the molecular weight of the chito-oligosaccharide. Furthermore, the chito-oligosaccharide-treated lyocell fibers exhibited antimicrobial activity, especially when treated with a chitooligosaccharide of a low weight-average molecular weight.