活性染料与纤维素替代品的化学反应

Chemical reaction of reactive dyestuffs with cellulose substitutes

活性染料的共价化学固色是整个反应性纤维素染色过程中极其重要的部分。应用选定的替代品取代纤维素以简化染色操作。在均质的水性介质中,一些简单的脂肪醇可在常规纺织条件下与活性染料发生反应。研究表明,相较于仲醇—OH基化合物,伯醇—OH基化合物能更好地与所有类型的活性染料发生反应。由此可获得纤维素最高反应性位置。此外,研究还发现,多元醇化合物可提高反应活性。这主要是基于染料π电子体系与相应的纤维素替代品中—OH基间的缔合。除染料自身发生水解外,活性染料还可能与水解产物及表面活性剂与防尘剂发生其他非期望的共价化学副反应。其中,一些副反应发生在所有类型的活性染料中,而另一些副反应仅发生在乙烯砜型活性染料中。

The covalent-chemical fixation of a reactive dye is coloristically the most important partial step within the full dramaturgy of a reactive cellulose dyeing process.The target of this investigation was a simplified consideration of the dyeing operation by utilization of selected substitutes instead of cellulose.In a physically homogenous aqueous medium some simple aliphatic alcohols were reacted under usual textile conditions with reactive dyes.It was found that primary alcoholic OH-compounds react with all reactive anchor types much better than secondary ones.This may lead to conclusions concerning the most reactive places of cellulose.It was additionally found that polyalcoholic compounds lead to another increase of reactivity.This may be based on the building of association equilibria formed over π-electron system of a dyestuff and OH-groups of respective cellulose substitues.Another result was：besides the dye hydrolysis,other undesired side reactions may happen as a covalent-chemical reaction of fresh,reactive dye with dye-hydrolysate as well as with surfactants and anti-dusting agents.Some of these side reactions happen with all anchor types,other ones just with vinylsulfone-types.