977diffusion in wool would he worthwhile, not least for the reason, implicit in Figure 0. that the diffusion at c-unstant regain deviates grossly from Fickian behavior in the latter part of the change. However, other techniques should he better adapted to this work, the present ii.iii.r. absorption method being too indirect and too limited in the avowed size of the relative humidity step to be real1y satisfactory. AbstractThe influence of inorganic salts on reaction and clearing rates for treatment of wool in neutral solution with potassium permanganate has been studied.In addition to the manganese dioxide deposited on the fiber, reaction in distilled water produces a manganese dioxide sol, which makes qualitative observation of permanganate exhaustion difficult. No sol forms in salt solutions.Permanganate exhaustion is fastest at low salt concentration and slowest in zero and saturated salt solutions. Above 1 molar added salt concentration, the permanganate exhaustion rates are in the order: NaNO 3 > NaCl > Na 2 SO 4 . The nature of the salt has no effect on exhaustion rates below 1 molar. The variation in reaction rate with salt concentration may be explained in terms of either fiber or solution properties. However, activation energy for the reaction is in the range 5,500 to 8,000 cal/mole, which suggests that the rate-controlling step is diffusion through surface solution rather than diffusion through the fiber.Rates of bisulfite clearing of manganese dioxide deposited on the fiber increase for permanganate treatments in increasing salt concentrations and reflect the depth of deposition of manganese dioxide. This is confirmed by optical microscopy.Treatment of wool with aqueous permanganate, followed by bisulfite clearing, results in a wool weight decrease, which is greatest for treatments in saturated salt solutions.

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.

The simplified Conti and Tassinari model describing the kinetic mechanism of pilling was adopted for knitted wool fabrics, and the theory extended to compare the relative masses of pill able and nonpillable fiber being removed during the attrition process. Wool treated with potassium permanganate in saturated sodium sulphate forms fewer and smaller pills than untreated. Kinetic parameters were derived for random tumble and ICI pill box pilling, and pill build-up and decay rates were established. Application of the extended model shows that pillable fuzz is less than 4% of the total wool fiber removed in random tumble tests, and treatment with 5% permanganate decreases pilling by 90%. ICI pill box pilling is slow, and pill removal was incomplete after 140 hours. Similar proportions of fiber were involved in pill formation, but the extent of pilling and fuzz removal was greater than for random tumble pilling.

No abstract

Techniques for the removal of dieldrin from wool are compared and methods of analysis are described. A culorimetric method [19] is satisfactory, when proceeded by prior cleanup of the extract. Gas chromatography on a silicone oil column, without any preliminary cleanup, gives an excellent separation of dietdrin. This method has been used to measure fastness properties of dieldrin-treated wool, and data obtained earlier with radioactive dieldrin [28] have been confirmed.' The gas chromatographic procedure may also be used for the determination of other chlorinated mothproofing agents in wool, and the fastness properties of DDT and Dilene (TDE) on wool have been determined by this method. The washfastness of dieldrin, Dilene and DDT on wool are all similar, but fastness to dry cleaning is in the order dieldrin>Dilene>DDT.