Study On The Synthesis Of Formazane Reactive Dyes And Relationship Between Structure And Properties

The application and synthetic methods of formazans reactive dyes materials were reviewed,as well as the relationship between structure of formazan reactive dyes and properties,based on the comprehensive study of related domestic and abroad articles.The synthetic mechanism and procedure were analyzed.The synthetic methods of formazan copper complex reactive dyes and the relationship between structure of formazans reactive dyes and properties were studied respectively.Used as raw material,2-amino-4-sulfobenzoic acid was diazotized,reduced and combined with furfural,then 2-carboxyl-5-sulfophenylhydrazine-furfuralhydrazone was obtained.Afterward, 2-carboxyl-5-sulfophenylhydrazine-furfuralhydrazone reacted with the diazo salt of 3-acetamino-5-amino-4-hydroxybenzenesulfonic-acid, and formazans was obtained.Formazans was then complex with copper ion and hydrolyzed,so the final product formazans-copper complex was produced,which was able to be combined with active groups and the heterlcyclic formazans-copper complex reactive dyes were synthesized.The preferable reaction conditions were achieved as following:the feeding method of diazotization was firstly resolved in alkaline,then precipitated in acid,and the weight ratio between 2-amino-4-sulfobenzoic acid and concentrated chloride acid was 1:2,the reaction temperature was 10℃;in diazotization reduction,the weight ratio between 2-amino-4-sulfobenzoic acid and sodium bisulfite was 2.25:1,and the temperature was 40℃,pH=5.0;in hydrolysis reaction,the concentration of sodium hydroxide was 6～8%;the reaction temperature in the first step of combination with active groups was 0～5℃,and in the second step the reaction temperature was 35℃,pH=6.0.the yield of the intermediate 2-carboxyl-5-sulfophenylhy-drazine-furfuralhy-drazone was 89.7%.Five compounds of formazan reactive dyes were synthesized. The synthetic methods of central carbon atom in copper complex formazan substituted by aromatic ring and aliphatic substitutes were surveyed,as well as effects of different substitutes on their properties.The result showed that as follows:the yields of key intermediates Schiff base derivatives were more than 90%;the effects of different substitutes on central carbon atom in copper complex formazans were positively important and following the rule in which the color was from light to strong according to the sequence of aliphatic substitutes,aromatic substitutes,heterocycle substitutes.The optimized synthetic database of heterocyclic formazan copper complex dyes and the relationship between structure of formazan reactive dyes and properties were confirmed.It provided the theoretic basis and practical database for industrialization of the dyes.