Ozone Oxidative Decolorization Process And Fiber Properties Of Yilun Fiber

Yilon is a modified polyester fiber.This fiber consists of polyethylene terephthalate and fatty polyamide,which combines the excellent properties of natural fiber and synthetic fiber.However,due to the pale yellow appearance of the fiber,which makes it a light color and bleaching products limited,as this article selects O3 bleaching agent.The conventional bleaching agent has poor bleaching effect on Yilon,which affects the popularization and application of the product.Therefore,it is necessary to study the bleaching process suitable for Yilon.This paper studied the decolorization process of the Yilon,the physical properties of the fiber after decolorization,the decoloration mechanism of ozone and so on,and analyzed its yellowing reason.The research results have theoretical reference value and practical significance for the further study of the fiber and the development of ozone bleaching technology.In this paper,three kinds of combination methods are studied—ozone,hydrogen peroxide,ozone + hydrogen peroxide,The results showed that ozone+hydrogen peroxide on the fiber has a good decolorization effect.The effects of pretreatment acid auxiliaries,pH and hydrogen peroxide concentration on decolorization were studied.And the effects of ozone concentration,decolorization time,decolorization temperature and liquid ratio on ozone decolorization efficiency were studied by single factor experiments and orthogonal experiments.The results showed that the Hunter whiteness of the fiber was up to about 90 after ozone oxidation bleaching,and the breaking rate of the fiber was within 15%.The optimized process was as follows:the pH value was 3,the concentration of hydrogen peroxide was 11Og/L,the ozone concentration was III file,decolorization temperature 65 ?,time 30min,with liquid rate of 80%.The physical and chemical properties before and after bleaching of Yilon were analyzed.The results showed that the hygroscopicity and dyeing properties of Yilon after bleaching were improved,but the spinnability of Yilon was affected.The moisture regain,friction coefficient and K/S value of Yilon increased with the increase of ozone concentration.However,the tensile properties,curling rate,curly elastic recovery rate and specific resistance value of fiber showed a decreasing trend.No significant change in fiber fineness.The paper studied the changes of fiber surface appearance,fiber structure,functional groups,crystallinity,elemental content and viscosity average molecular weight of fiber macromolecules before and after decolorization.The results show:The surface roughness of fiber becomes smaller after ozone bleaching,and grooves and obvious ring-shaped etching appear on the surface;Raman test results showed that the position of the carbonyl peak "blue shift",From 1728.4cm-1 to 1709cm-1,which indicat the oxidation of C-O-C to O-C = O;The results of XRD showed that the change of fiber peak position before and after decolorization was small,the crystal form of polyesteramide did not change significantly,the amorphous area of fiber macromolecule increased and the crystallinity decreased.Elemental analysis showed that the content of C decreased and the content of O increased.The results of viscosity test showed that the viscosity-average molecular weight of cellulose fiber macromolecules decreased obviously after ozone bleaching,which was caused by the breakage of fiber macromolecule chains.The conjugation system of the colored material in the fiber is damaged,which may be the reason for the increase of the whiteness of Yilon after bleaching by ozone.