Physical Properties of Surface Oxidized Wool

Abstract

A wool surface is oxidized with potassium permanganate in saturated salt solutions. 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. In this paper, we investigate changes in the physical properties of surfaceoxidized wool, in particular the effect of relative humidity (RH) on the electrical conductivity of wool after surface oxidation.:, , .. ExperimentalA 66s merino worsted top of 20.6 micron average diameter was used in the experiments. Two resulting fabrics (un-oxidized wool and oxidized wool doeskins) with the same specification were produced in equal finishing processes, except that the oxidized wool doeskin was blended with 1 S% un-oxidized wool.In terms of McPhee's method for wool oxidization [7], processing parameters such as pH, temperature, and treatment time were altered for industry production. Worsted top was oxidized with potassium permanganate (KMn04) in a saturated salt (NACI) solution, then treated with sodium bisulfite (NaHS03) to remove the Mno2 on the fibers, and finally washed in very dilute hydrochloric acid (HCI) or water. °U n-oxidized and oxidized wool samples were fixed on a sample stand with conductive glue and then vacuum coated in an IB-3 ion coater. The surface patterns of the wools were examined under the scanning electric microscope (SEM).The testing atmosphere was RH 65% ± 2%, 20°C ± 2°C. The friction coefficient of the wool surface before or after oxidation was measured using a fixed load of 200 mg. Breaking strength was tested in an Instron 1122 universal tensile tester.The method described by Hersh and Montgomery [6] was used to measure the electrical resistance of individual fibers in different humidities; the experimental apparatus consisted of a high-resistance meter and a conditioning jar. Figure 1 shows the measuring circuit in the high resistance meter. FIGURE I. Circuit to measure high resistance [6].In the figure, a variable high-voltage supply puts a known voltage V., across the unknown resistance R.~.. The voltage Vs is adjusted until the electrometer reads zero potential difference across its terminals. Provided the current through R,r is equal to the current through a standard resistance R_~, R_r is given by To condition the specimens, samples with various moisture contents were obtained by placing them in a 2 L wide-mouthed bottle over suitable solutions (see Table I) to control relative humidity. As shown in Figure 2, the leads A 'and B from the resistanc...

Reducing Photoyellowing of Wool Using Nano TiO2

“…Martel et al observed that usage of sodium hypophosphite (SHP) can catalyze the reaction between citric acid and wool (18). KMnO 4 consumed by the wool increases with time, temperature and concentration of treating bath (19,20). The treatment produced some bleaching effects on the wool (19,20).…”

“…KMnO 4 consumed by the wool increases with time, temperature and concentration of treating bath (19,20). The treatment produced some bleaching effects on the wool (19,20). Acid cross‐linking agents used for durable press finishing have been actively investigated in recent years.…”

“…Amino acids cystine, tyrosine and tryptophan were greatly affected by KMnO 4 treatment (20). Nitrogen and sulfur contents decreased with an increased extent of KMnO 4 treatment (20). The brown color of oxidized wool was caused by MnO 2 ions.…”

Novel feature of nano‐titanium dioxide on textiles: Antifelting and antibacterial wool

“…Numerous studies have been carried out to better understand the impacts of diverse surface modification methods on wool shrinkage. 36 McPhee has reported that reducing the oxidized samples by sodium bisulfite has two distinct effects: first, precipitated MnO 2 is removed from the wool, and second, the reduction of the oxidized wool causes an increased shrink resistance. In addition, it has been demonstrated that through the oxidation process, the sharp edges of wool scales are fully removed.…”

“…In addition, it has been demonstrated that through the oxidation process, the sharp edges of wool scales are fully removed. 36 Kantouch et al 16 illustrated that the oxidation process in an acidic solution gave better antishrink properties in comparison with those of in alkali solutions. Also, they declared that the amino acids cystine, tyrosine, and tryptophan were greatly affected by the KMnO 4 treatment.…”