| In this paper, modified dyes were obtained by directly using2-methyl-3-butene-2-ol asmonomer to modify CI.Reactive red198and the optimum reacting conditions weredetermined by orthogonal and single factor experiments respectively. UV-visible absorptionspectrum, Fourier Transform Infrared spectroscopy, and Nuclear Magnetic Resonance wereapplied to characterize the chemical structure of the obtained modified dyes. Properties suchas tensile properties, flexibility and surface friction properties of cotton fabrics dyed with themodified dyes via photo-induced grafting were tested. Furthermore, reactive dyes can also bemodified with ethanol amine and acryloyl chloride in two steps. In the first step, ethanolamine was connected to reactive dye molecular structure and in the next step, acryloylchloride was adopted to react with the end group of ethanol amine connected to dye stuff.Dyeing abilities of the final obtained products towards cotton fabric via photo-inducedgrafting were also studied.In modifying reactive dyes with2-methyl-3-butene-2-ol, orthogonal experiments wereconducted and the results showed that the influence of factors on dye modification was in thedescending sequence of reacting temperature, pH value, reacting time and mole ratio ofdye/monomer. The comprehensive results of orthogonal and single factor analysis revealedthat at pH8, dye and monomer ratio1:3and reacting for40min at70℃the experiment canbe well conducted.The strongest absorption peak shifting from515nm to509nm in the UV-visibleabsorption spectrum together with the emerging of peak1621.19cm-1and1141.58cm-1whichwere attributed to C=C and C-O-C bond respectively in FTIR spectra and the peak at5.8724ppm in H proton NMR all showed that the reactive dyes were modified successfully.According to the single factor experiments, the best grafting conditions of modified dyestowards cellulose fabric such as cotton were UV radiation time of3min and photoinitiator of3%on the mass of dye monomer.Adsorption peak at2851.77cm-1which belongs to methyl group appeared in the FTIR spectrum of dyed cotton fabric proved that the dye monomer had been grafted onto fabricsurface. Impurities were found on the surface of untreated cotton fabric. After dip-dyeing, thesurface became smoother. The appearance of photo-grafted polymer was observed on thesurface of photo-graft dyed cotton fabric. In comparison of dip-dyeing method,3%decrementof tensile property,4%enhancement of rigidity,8.1%increment of static friction coefficient,slight increment of dynamic friction coefficient and decreased air permeability were obtained.However, the properties still met the demands of clothing.The best reacting conditions of the two step modification according to the single factorexperiments were: ratio of dyes and ethanol amine1:1, ratio of ethanol amine modified dyesand triethylamine2:3at the temperature of60℃for70min.In the FTIR spectra of modified dyes prepared with ethanol amine and acryloyl chloride,stronger adsorption peaks at3070.97cm-1and2971.43cm-1which corresponded to CH bondand1594cm-1which was attributed to NH bond together with the appearance of C=C bond at1619.35cm-1indicated that the dye stuff was modified successfully. Strengthen of the peak at2893cm-1which corresponds to CH, the disappearance of C=C bond at1619.35cm-1ofmodified dyes at the FTIR spectrum of grafted fabric suggested that modified dyes weregrafted onto fabric. Tensile properties and permeability of the grafted fabric decreased whilerigidity and surface friction properties increased, but still met the demands of clothing.After comparing the effects of dyes modified with two methods, dyes modified with2-methyl-3-butene-2-ol provided a slighter color depth but better wearing properties, while itwas more easier for production. |
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