Research Of Graft Modification And Dyeing Properties On Linen Fibers

The grafted of linen fibers and dyeing mechanism and dyeing properties modified linenfiber were studied in detail in this paper.Theoretical analyze and repeated experiments were finished firstly. The results showedthat sodium periodate as the oxidant and sodium bisulfite as sulfonating agent were fit formodifying linen. Respectively, aldehyde groups of oxidatized linen fibers and breakingstrength loss rate of linen fabric were used as inspection index to investigate oxidation process.And cationic dyes dyestuff exhaustion quantity of linen fibers and breaking strength loss rateof linen fabrics were used as inspection index to investigate sulfonation process. ThroughPreliminary investigation by the single factor experiment and orthogonal optimization testobtained the optimum conditions of linen oxidation and sulfonation process. And throughvalidation tests verified the reliability of optimal process.The characterization of functional group on oxidized linen fabric and sulfonatied linenfabric was carried out by infrared spectrometry, verification the modified groups were graftedsuccessfully. The Micro-structure of grafted linen fibers was analyzed by means of X-raydiffraction, and verified the change of proportion of crystalline regions and amorphousregions on linen fibers. The reaction area of modified reagents in fibers was determined, theessential reason of decrease of linen fibers breaking strength was explained reasonably. Thechange of surface appearance of before and after the modified of linen was carried out byScanning Electron Microscope, in appearance this change showed that the accessibility ofmodified reagent on the linen fibers had a improvement.The thermodynamics principle of dyeing on modified linen fibers has been studied in theaspects of adsorption isotherms, dyeing saturation value and dyeing affinity. The resultsindicate that dyeing of cationic dyes on modified linen fibers belongs to the characteristic ofLangmuir adsorption isotherm.The kinetics mechanism of dyeing of modified linen fabric was investigated from theaspects of relationship of dying speed and pervasion velocity with temperature. The resultsrevealed that modified linen fabric dyeing could be done in a relatively short period of time.The exhaustion almost achieved maximum when the dyeing time was30minuties.The pervasion velocity increased with the temperature namely, the lower temperature was ofbenefit dyeing. And studied the dyeing properties of modified linen fabric,the levelness of modifiedlinen fabrics was better, the results showed that the modified linen fabric had better levelnessand better color fastness or higher dye uptake.