活性染料与甲壳胺纤维的成键稳定性研究

甲壳胺纤维用乙烯砜型活性染料染色,在中性条件下,其染料 纤维键的耐碱性明显好于碱性条件 下形成的染料 纤维键;成键的稳定性远高于纤维素纤维。其固着机理为:在中性条件下,活性染料与甲壳胺 纤维上的氨基形成共价键结合;在碱性条件下,还会与纤维上的羟基形成共价键结合,但耐碱性较差。双活 性基染料可在甲壳胺纤维大分子间形成交联,其中双侧型双活性基染料空间效应小,交联程度相对较高。

Bond stability and fixation mechanism between reactive dyes and chitosan fiber

Chitosan fiber was dyed using reactive dyes with vinylsulfone group, it was found that the bond formed in the neutral dyebath was more stable to alkali than that in alkaline dyebath. The bond stability of reactive dye-chitosan fiber is superior to that of reactive dye-cellulose fiber. Fixation mechanism showed that in neutral bath, the reactive dyes mainly reacted with hydroxyl group, while in alkaline bath, reactive dyes reacted with not only the hydroxyl group, but also with amino group, which had poor stability to alkali. Bi-functional reactive dyes can form crosslinkage among the chitosan fibers, especially the two functional groups located at different end owing to small steric hindrance.