5-(二甲氨基)-2-甲基-5-氧戊酸甲酯在超临界二氧化碳流体染色中的应用

Application of methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate in supercritical carbon dioxide fluid dyeing with disperse dyes

为提高部分分散染料在超临界二氧化碳流体(ScCO 2)中上染率,补全ScCO 2分散染料染色色谱,以5-(二甲氨基)-2-甲基-5-氧戊酸甲酯作为分散染料ScCO 2染色助溶剂,通过实验探究了染料与助溶剂质量比、染色温度、染色压力对分散染料上染率的影响,并对染色后涤纶纱线的力学性能、耐摩擦色牢度、耐日晒色牢度以及耐皂洗色牢度进行表征。结果表明:纱线得色深度明显提高,且未对纱线色相、饱和度产生明显影响;分散黄163、分散蓝60染料滤饼上染率分别为21.61%、34.25%;加入助溶剂后,分散黄163、分散蓝60的ScCO 2染色上染率分别可达57.62%、70.97%;染色纱线得色深度显著提高,染色后纱线的K/S值分别由4.5、5.9提升至12.0、12.2;最佳染色工艺为:染料与助溶剂质量比1∶20,染色温度130℃,染色压力27 MPa;加入助溶剂后染色纱线的力学性能、色牢度符合生产需求。

Objective Supercritical carbon dioxide fluid(ScCO 2)dyeing of disperse dyes with low energy consumption and no effluent discharge in the dyeing process is an advanced industrial technology in line with sustainable development.However,some problems associated with the disperse dyes in this process,such as low dye uptake and incomplete dye chromatography caused by low solubility,greatly limit their further development.In view of these problems,this paper proposed to add appropriate cosolvent to the ScCO 2 to improve itssolubility,so as to reduce the impact of these problems on the dyeing process.Method Based on the interaction forces between disperse dye molecules and cosolvent molecules,a green cosolvent(methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate)with high solubility for disperse dyes,high boiling point and non-volatile and non-toxic was selected as a dyeing auxiliary.Disperse yellow 163 and Disperse Blue 60 were selected as experimental dyes.The dyeing rates and K/S values of disperse dye filter cakes and disperse dye filter cakes with cosolvent blends were tested under different process conditions to evaluate their dyeing effects.The mechanical properties and color fastness of the dyed yarns were characterized to assess the effect of the cosolvent addition on the yarn properties.Results The influence of cosolvent on the fabric was studied through the reflectance curve of the dyed fabric.The resultsshowed that the selected cosolvent has a significant influence on the brightness of the fabric,but it will not change the color and saturation of the fabric.With the addition of cosolvent,the K/S value of fabric dyed by Disperse Yellow 163 increased from 4.5 to 12.0,and that of fabric dyed by Disperse Blue 60 increased from 5.9 to 12.2,indicating that this cosolvent could be used in supercritical carbon dioxide fluid dyeing with disperse dyes.By changing the mass ratio of disperse dyes to liquid cosolvent,dyeing temperature and pressure,the influence of process conditions on the dye uptake of disperse dyes was investigated.The dye uptake of disperse dyes increased significantly after adding the cosolvent.When the mass ratio of dye and cosolvent was 1∶20,the dyeing rate of Disperse Yellow 163 and Disperse Blue 60 reached 57.62%and 70.97%,respectively.With the increase of temperature,the dye uptake increased first and then decreased after adding cosolvent,reaching the maximum at 130℃.With the increase of pressure,the dye uptake of disperse dyes increased slightly.The dye uptake did not change significantly with the dyeing pressure above 27 MPa,and the optimum dyeing pressure was 27 MPa.The mechanical properties and color fastness of four different yarns were characterized.The breaking strength and the elongation at break did not change significantly,and the breaking strength of yarns is all about 250 cN and elongation at break is all about 20%.Color fastness to rubbing,color fastness to sunlight and color fastness to soaping of the yarn were all above 4 levels.Properties of yarns dyed with cosolvent met the production requirements.Conclusion In this study,methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate was used as a dyeing cosolvent to effectively improve the dyeing rate of Disperse Yellow 163 and Disperse Blue 60 in the supercritical CO 2 fluid dyeing process from a practical production problem.Meanwhile,the addition of the cosolvent only affected the brightness of the dyed yarn,and had no significant effect on the color phase and saturation.A suitable dyeing process was determined by the subsequent experiment conditions,i.e.,the mass ratio of dye to co-solvent was 1:20,the dyeing temperature was 130℃,and the dyeing pressure was 27 MPa.After the addition of cosolvent,the resulting fabric with increased color depth,no significant loss of mechanical properties,and excellent color fastness performance met the requirementsof national standards.In summary,the addition of cosolvent caused no significant effect on yarn properties while improving the dyeing rate of disperse dyes with good application prospectsin the field of ScCO 2 dyeing.