A study of color fixation agents in secondary alcohol ethoxylate-based reverse micellar cotton dyeing system with reactive dyes

Abstract

Influence of color fixation agent (CFA) and dyebath pH in secondary alcohol ethoxylate (SAE)-based reverse micellar dyeing system of cotton with reactive dyes was investigated and compared with water-based dyeing system using different alkali (i.e. CFA) such as: (i) sodium bicarbonate (NaHCO3), (ii) sodium carbonate (Na2CO3) and (iii) sodium hydroxide (NaOH). The color, tensile strength, fastness and surface morphological properties of dyed samples were examined. Experimental results showed that samples dyed with Na2CO3 can achieve the highest color yield, followed by NaHCO3 and NaOH in both water-based and reverse micellar dyeing system. The color yield and reflectance percentage of the dyed cotton samples were found to be closely related to the dyebath pH value. Relative unlevelness indices (RUI) also reflected that cotton samples dyed with NaOH in reverse micellar dyeing system have a higher chance of color unlevelness when compared with NaHCO3 and Na2CO3. Tensile strength results affirm that higher alkalinity of dyebath could cause higher strength loss to the colored cotton samples. Both cotton samples dyed by water and SAE approach showed good to excellent color fastness properties while scanning electron microscopic (SEM) images exhibit that the use of different alkalis may cause some damage to the cotton fiber. 研究了固色剂（CFA）和染浴pH值对基于仲醇乙氧基化物（SAE）的棉活性染料反胶束染色体系的影响，并与使用不同碱（即CFA）的水性染色体系进行了比较，例如:（i） 碳酸氢钠（NaHCO3），（ii）碳酸钠（Na2CO3）和（iii）氢氧化钠（NaOH）. 对染色样品的颜色、拉伸强度、牢度和表面形态特性进行了检测. 实验结果表明，在水性和反胶束染色体系中，用Na2CO3染色的样品可以获得最高的显色率，其次是NaHCO3和NaOH. 染色棉样品的显色率和反射率与染浴pH值密切相关. 相对不平度指数（RUI）也反映出，与NaHCO3和Na2CO3相比，在反胶束染色系统中用NaOH染色的棉花样品有更高的颜色不平度机会. 拉伸强度结果证实，染浴碱度越高，有色棉样品的强度损失越大. 用水和SAE方法染色的棉花样品都显示出良好到优异的色牢度性能，而扫描电镜（SEM）图像显示，使用不同的碱可能会对棉纤维造成一些损伤.