Changes in Fibrillate Structures of Cottons on Hydrolysis and Oxidation

Abstract

Four modified cottons—mercerized sliver, a partially acetylated fabric, and two cross- linked fabries—were exposed to hydrochloric and sulfuric acids, sodium periodate, nitro gen tetroxide, hydrogen peroxide, ozone, and heat for intervals selected to illustrate early and late stages of fiber degradation. Electron micrographs were made in order to observe changes in tihrillate structure. Parallel changes in moisture regain, crystallinity indices. copper number, carboxyl content, and, in some samples, degree of polymerization were measured. Changes in fibrillate structure and other properties were found to be related to the type of modification and the resistance of substituent groups to the degrad ing agents, the activity of these, agents, and to duration of exposure. In general, where substituents were not removed, degradation decreased with increase in content of sub stituent groups in the chemically modified cottons. Mercerization. without further modi fication, caused an increase in rate of degradation.