Properties of Partially Methylated Cotton Fabrics

Cotton fabrics were partially methylated by several methods and cross-linked with a commercial finishing agent. Methylation with diazomethane to a degree of substitution (DS) of 0.25 or higher enhanced fabric tensile strength, tear strength, and resistance to flex abrasion, compared with nonmethylated fabrics with comparable crease recovery angles. X-Ray diffraction studies showed that almost no decrystallization of cotton accompanied methylation with diazomethane, but that appreciable decrystallization accompanied methylation with other agents or alkylation with larger alkyl groups. The improved fabric properties resulting from treatment with diazomethane apparently require the preservation of crystallinity in the cotton as well as the deposition of polymethylene deep within the fibers. Methylation with dimethyl sulfate or methyl chloride did not enhance fabric properties, nor did substitution with ethyl, allyl, isopropyl, or benzyl groups