The Influence Of KMnO₄Treating On The Structure And Properties Of Wool And Cashmere Fibers

Both wool and cashmere belong to natural protein fiber and their chemicalcomposition and organization structure are very similar. They have some propertycharacteristics in common such as the absorption of moisture, luster, warmth retentionand so on.According to the environmental friendly concept, KMnO4was chosen asantioxidant in this paper. The difference degree on the structure and properties ofwool and cashmere were investigated by changing the concentration of KMnO4, theprocessing time and the processing temperature so as to further understand thestructure and properties of wool and cashmere and investigate the shrink-proof ofcashmere fibers.Wool and cashmere fibers were treated respectively by changing the concent-ration of KMnO4, the processing time and the processing temperature. And the weightloss rate, breaking strength loss rate, breaking elongation loss rate, fiber feltingvolume and whiteness value of the treated fibers were tested and investigated.Meanwhile, scanning electron microscope(SEM) can be used to analyse the scalechanges of treated fibers. Infrared spectral can be used to analyse the change ofchemical structure of treated fibers. Moreover, the crystallization index of treatedfibers were tested by X-ray diffraction(XRD). And changes of element content oftreated fibers were tested by X-ray photoelectron spectroscopy(XPS).It concluded that cashmere fiber was more sensitive than wool under the sameprocessing conditions of KMnO4by contrasting the two treated fibers. The scale ofcashmere was damaged, but the scale of wool was clearly visible when theconcentration of KMnO4was3%. The scale of wool was visible while the scale ofcashmere was striped out when the concentration of KMnO4was9%. The scales ofthe two fibers were visible when the treating time was20min. The scale of the woolwas still visible while the scale of the cashmere was striped out basically when thetreating time was60min. The scale of cashmere was damaged seriously while thescale of wool was visible when the treating temperature was60℃. The breakingstrength loss rate of cashmere fibers was larger than that of wool fibers under thesame treating conditions. The breaking strength loss rate of cashmere fibers increased with the treating temperature increasing. But the breaking strength loss rate of woolhad a small change with treating temperature increasing.The structures of wool and cashmere fibers before and after treating were testedrespectively. It concluded that crystallization index of cashmere had a seriousdecrease compared with wool fibers. C element content of wool fiber treateddecreased, while N, O, S element content increased. The content of C-C decreasedand the contents of C-O, C=O increased. The C content of cashmere treated decreased,the content of O had little changes, the contents of N, S increased, the content of C-Creduced seriously, and the contents of C-O, C=O increased.