天然茶色素对棉纤维的铁离子媒染染色

 以硫酸亚铁为媒染剂，用绿茶萃取液对棉纤维进行染色，研究了不同媒染方式以及后媒染的染浴pH值、媒染剂用量、染料质量浓度和染色时间对棉纤维染色性能影响。利用傅里叶红外光谱仪分析染色前后纤维的微观结构，并测试了媒染前后纤维的力学性能。结果表明，后媒染对纤维染色效果最好，K/S值最大。天然茶色素对棉纤维的铁离子后媒染染色最佳工艺条件为：染料质量浓度10 g/L，染色温度100 ºC，pH值4，媒染剂用量5 %(o.w.f)。纤维素的羟基与金属离子发生配位反应形成金属络合物。媒染后棉纤维的断裂强力略有下降，断裂伸长率呈现一定幅度的上升趋势。

Natural tea pigment dyeing of cotton fibers with Fe2+ as a mordanting agent

The aqueous tea solution extracted from green tea was used to dye cotton fibers with FeSO4 as mordanting agent. The effect of pre-mordanting, meta-mordanting and post-mordanting on dyeing property of fibers was studied. In the case of the post-mordanting, the effect of dye concentration, dyeing temperature, pH value of dye bath and mordant concentration on the dyeing of fibers were analyzed. FTIR was used to characterize the microstructure of fiber samples, and the strength and elongation of fibers before and after dyeing were also tested. The results showed that post-mordanting method exhibited the best effect of dyeing with the maximum K/S value. The optimum conditions for the post-mordanting dyeing method with natural tea pigment using Fe2+ as mordant were as follows: dye concentration 10 g/L, dyeing temperature 100 ºC, pH = 4, and mordant concentration 5 %(o.w.f). The hydrogen bond of cellulose reacted with Fe2+ to form metal complex. In comparison with the cotton fibers before dyeing, the breaking strength decreased slightly and breaking elongation increased considerably for the dyed fibers.