اصلاح سطح پشم با استفاده از تابش اشعه ماوراي بنفش به همراه گاز اوزن جهت رنگرزي آن در دماي پايين

چكيده انگليسي :

The use of UV Ozone Treatments in Surface Modification of Wool for Low Temperature Dyeing Parisa Davari parisa davari@gmail com Date of Submission February 21 2012 Department of Textile Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiAkbar Khoddami Khoddami@cc iut ac irAbstract Due to the presence of a high degree of disulphide cross linkage in the A layer of exocuticle and thefatty acids on the fibre surface wool surface fiber has hydrophobic nature This property accompanied bycompact scale layer on the surface of wool fibre led to some problems on its processing In order to obtainacceptable dimensional stability good color yields levelness and brightness in dyeing and printing of woolfabric it is essential to modify the fibre surface using a suitable treatment Because of increasingenvironmental legislation relating to adsorbable organohalogens AOX many chemical methods such aschlorination were limited and recent work has been focused on development of dry treatments with low orzero effluent In this work the effects of UV O3 irradiation on the surface characteristics and dyeing properties ofwool fabric have been investigated Also the influence of UV O3 irradiation on kinetic rate of dyeing thermodynamic properties standard affinity heat of dyeing and entropy of dyeing and the possibility oflow temperature dyeing of the wool fabric was examined In addition to UV O 3 the effects of ozone UVand UV O2 treatments on the wettability shrink resistance solubility in alkali yellowness index andtensile strength of wool fabric were evaluated The results indicated that the wool fabric treated by UV O 3for twenty minutes showed the best surface modification with instant wetting time along with minimumphysical and chemical damages on the bulk fibres properties This improvement in wettability could be dueto the removing of the lipid layer on the fibres surface Furthermore because of the effects of surfacemodification the remarkable enhancement in dimensional stability was obtained As a result of shortexposure time and the nature of irradiation process the finishing process did not show any adverse effect onthe substrate tensile characteristics While the UV irradiation increased the fabric yellowness index combining ozone in the process reduced the sample photoyellowing as a subsequent of the bleaching effectof the ozone Moreover the comparison of dyeing properties of the untreated wool sample with the UV O3 irradiated one revealed an increase in the dyeing rate of both leveling and milling acid dyes due to the fibre surface modification by the degradation of the surface diffusion barrier The photo decomposition of surface lipid layer resulted in quicker wetting and swelling of wool thus facilitating the diffusion of dyes by the intercellular route Meanwhile the photo oxidation of cross linked disulphide bonds resulted in opening the transcellular route for dye diffusion Similar results are obtained in low temperature dyeing of the milling acid dye The thermodynamics examination of the samples illustrated a decrease in heat and entropy of dyeing for UV O3 irradiated wool dyed with leveling acid dye while the standard affinity did not change This means that more dye can be retained in the irradiated fibre that is the interaction between dye and the irradiated fibre is increased Key words wool surface modification UV O3 dyeing properties low temperature dyeing aciddyes

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اصلاح سطح پشم با استفاده از تابش اشعه ماوراي بنفش به همراه گاز اوزن جهت رنگرزي آن در دماي پايين

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