Study On Ozone Decolorization Of Dyed Polyester And Polyester/Cotton Fabrics

As the most common synthetic fiber used in textiles,polyester and cotton fibers have consistently been in high demand and usage,and the recycling has always been a problem for the textile industry.The decolorization of dyed fabric is the key to expanding recycling use.However,currently,there is no fast and simple decolorization method.In this study,ozone was introduced into decolorization of colored polyester and polyester cotton fabrics based on its significant effect on dye degradation.Based on the analysis of the influence of ozone feed rate,time,water pick-up value,and p H on the decolorization effect,the decolorization technological conditions by ozone alone were as follows:room temperature,ozone feed rate of 130 mg L^–1 min^–1,treatment time of 2 h,water pick-up of 100%,and p H value of 3.Under the conditions,the decolorization rate of polyester fabrics dyed by different processes could reach over 45%.The changes of dye structure during the process of ozone decolorization were analyzed using scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,and the mechanism of ozone decolorization was further analyzed.The results showed that ozone have effect on polyester fabric and dye simultaneously.The aim of entering the fiber was achieved by etching the polyester and decolorization was achieved by oxidizing the chromaticity group.In order to further improve the decolorization effect of colored polyester fabric,the decolorization rate of86.70%and the retention rate of 74.89%were achieved by introducing DMSO based on ozone decolorization.Ozone technology was further introduced into decolorization of waste colored polyester/cotton fabric,and more remarkable decolorization effect was obtained.In the single factor experiment,it was found that the water pick-up value of the fabric was an important factor affecting the decolorization of polyester/cotton fabric,and the decolorization rate could be greatly increased when the fabric was properly pick-up water.The decolorization rate could reach 85.04%and the retention rate of strength can reach 75.61%.SEM and XRD were used to further analyze the fabric before and after ozone decolorization.The result showed that the surface of the fabric was etched obviously after ozonization,and the crystallinity of the fabric was reduced and the crystal shape remained unchanged.The decolorization of colored polyester and polyester cotton fabrics based on ozone technology can achieve significant decolorization effect.Compared with the traditional decolorization process,the decolorization efficiency of ozone technology is higher,and this decolorization technology has obvious advantages of high efficiency,fast,low water consumption and pollution-free emission.In addition,through the study of ozonation kinetics of dyes and colored fabrics and data fitting,it is found that the decolorization of dyes is a first-order reaction,and the decolorization of fabrics is a third-order reaction.The fitted curves could provide theoretical guidance for practical production.