| Polyester fiber is the most widely used synthetic fiber in the textile industry,but its dyeing has some problems of large water consumption and energy consumption,and the usage of a large number of dispersants to pollute the environment.In recent years,in order to save water and protect environment,the non-aqueous medium dyeing of polyester has been widely concerned and valued.As a new non-aqueous medium dyeing method,disperse dye / decamethylcyclopentasiloxane(D5)medium dyeing of polyester does not need dispersant in the dyeing process,and the dyeing water is greatly reduced,which can effectively solve the problem existed in traditional water bath dyeing.However,polyester disperse dye / D5 non-aqueous medium dyeing also has the problems of lower dye uptake rate than water bath dyeing and poor evenness.Moreover,D5 has recently been listed as a highly concerned substance by the European Union,and there is a certain risk for its promotion and application.In view of the problems existing in the dyeing of polyester with disperse dyes / D5 in nonaqueous mediim,this paper focuses on the dyeing performance of polyester with disperse dyes /liquid paraffin system on the basis of the previous development of reactive dyes / liquid paraffin non-aqueous medium dyeing technology by our research group,and studies the related dyeing theory,and makes multi-angle comparisons with D5 non-aqueous medium and water medium.The main research work includes the following three aspects:(1)Ball milling modification of disperse dyes.The effects of dispersant types and ball milling process on the stability of high concentration dye paste were studied,and the structure-activity relationship of surfactants was discussed.(2)Optimization of non-aqueous medium dyeing process polyester fabric.The effects of process parameters on the dyeing properties of polyester fabric in non-aqueous media were investigated by changing dyeing temperature and time,dyeing p H value and different amount of water addition,and the dyeing process was optimized.(3)Study on the dyeing theory related to non-aqueous dyeing of polyester.The solubility,aggregation and charge properties of dyes in different media and the basic properties of fiber swelling and Zeta potential which are closely related to dyeing were studied.The thermodynamic and kinetic properties of polyester dyeing with disperse dyes in different media were further studied.The results show that:(1)Dispersant L is beneficial to the dispersion stability of dye paste in D5 medium.Dispersant GA is beneficial to the dispersion stability of dye paste in liquid paraffin medium.One end of dispersant L contains benzene ring structure that can be compatible with dye,and the other end contains short chain alkane structure that can be compatible with D5 medium.One end of dispersant GA contains benzene ring structure that can be compatible with dye,and the other end contains long chain alkane structure that can be compatible with liquid paraffin medium.Therefore,it can play a ' bridge ' role between dye and medium,and improve the dispersion stability and dyeing uniformity of dye in non-aqueous medium.(2)The addition of trace water(50 %,owf)into the chromosome system could significantly improve the color yield of dyeing,indicating that water played a certain plasticizing effect on polyester fiber and effectively reduced the Tg of fiber.The optimal dyeing process was as follows : dyeing temperature 125 ?,dyeing time 1 h,water addition 50 %(owf).Nonaqueous medium has no effect on dye color,and the rubbing fastness and soaping fastness of nonaqueous medium dyed fabric are consistent with those of conventional water bath dyed fabric.(3)The performance characteristics of polyester fiber and disperse dyes in different media are as follows: D5 medium and liquid paraffin medium have weak swelling ability on polyester fiber,which can only make the fiber surface swell to a certain extent,and will not enter into the fiber during the dyeing process,which is conducive to the washing of dyed fabric and the recovery of medium.The solubility of dyes in non-aqueous medium is higher,and the solubility of dyes in liquid paraffin is higher than that in D5 medium.The higher the solubility of dyes in dyeing process,the lower the color yield.Therefore,the color yield of disperse dyes in D5 medium is higher than that in liquid paraffin medium.(4)The dyeing thermodynamics and kinetics characteristics of polyester disperse dyes in different non-aqueous media are as follows: the adsorption isotherm model of three dyes on polyester fabric in different media conforms to the Nernst adsorption model.With the increase of temperature,the dyeing affinity of D5 medium was higher than that of liquid wax medium.With the increase of temperature,the dyeing affinity decreased.The dyeing heat is negative and the dyeing entropy is negative.With the increase of temperature,the solubility of three dyes in different non-aqueous media systems increases greatly.The dye molecules adsorbed on the diffusion boundary layer of the fiber tend to desorb from the surface of the fiber reversely into the medium,and the diffusion coefficient decreases. |
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