Wool Shrinkproofing Studies: Part III: Fiber Modification in Neutral Potassium Permanganate–Salt Treatments

Abstract

Reaction of ivool with potassium permanganate in water is shotvn by electron microscopy to extend into the outer cortes, whercas reaction with potassiuni permanganate in saturated salt solution takes place at the cuticle. Deductions based on relative reaction and clearing rates (in Part I [37]) are therefore confirmed.Attack by the reagent on the fiber is preferential in the region of the scale edges. The most dense deposition of manganese dioxide is found in the outer layer of the esocuticle. Staining of cross sections of wool with pernianganate suggests that the cuticle reacts faster initially than the cortes.Aniino acid analyses of wool fabrics treated with permanganate in water and differcnt concentrations of salt s110~~-no significant wriation and are similar to those obtained after dry chlorination of the same fabric. All treatments produce significant increases in cysteic acid content and decreases in serine, cystine, and tryptophan residues.Treatment with permanganate in high salt concentration appears to reduce the differential friction effect of the fiber by reducing the against-scale friction.

Some New Observations on the Effects of Mild Shrinkproofing Treatments on Wool Fibers

“…It is clear that, even after relaxation of the fiber in the extended condition, the tensile stress in the para-cortex always exceeds that in the ortho-cortex. This observation applies to 1 In the comprehensive study of crimp recovery by Banbaji et al [Textile Res. J.…”

“…The first puzzling feature is that, although treatment causes very little change in the elastic properties of the fiber [27] and its attack on the fiber is almost confined to the cuticle [1,33 ] , it has not been possible to establish with certainty that it acts via the frictional properties. There has been considerable disagreement among experimenters [1,6,9,15,26,27] who have measured the friction.…”

“…There has been considerable disagreement among experimenters [1,6,9,15,26,27] who have measured the friction. Their measurements have been made in various aqueous media at various loads, usually by the &dquo;capstan&dquo; method, the fiber being drawn over a horn rod or a layer of wool.…”

Physical Properties of Surface Oxidized Wool

“…The surface patterns, breaking strength, friction coefficient, and electrical resistance of oxidized and un-oxidized wool are then examined, and the static electricity in two resulting fabrics is investigated. Changes in the wool surface have a significant effect on its physical properties.A number of studies have considered chemical modifications [1][2][3]8] of the wool surface and their effects on felting shrinkage, and these studies have led to a better understanding of the physical properties of wool before surface oxidization [4]. However, little has been reported about the physical properties except for the friction coefficient of surface-oxidized wool.…”

“…A number of studies have considered chemical modifications [1][2][3]8] of the wool surface and their effects on felting shrinkage, and these studies have led to a better understanding of the physical properties of wool before surface oxidization [4]. However, little has been reported about the physical properties except for the friction coefficient of surface-oxidized wool.…”