Modification And Application Of Hydrolyzed Reactive Dyes

Reactive dyes have the advantages of bright color,complete chromatography,low cost,and wide application.However,the biggest drawback of reactive dyes was easily hydrolyzed in storage and application.Therefore,it is worth to study on that recovery and reuse hydrolyzed reactive dyes.In this project,two kinds of cationic additives prepared in self-made were applied to modified hydrolyzed reactive dyes to study the dyeing performance of modified hydrolyzed reactive dyes.The purpose was to improve the performance of hydrolyzed reactive dyes,effectively utilize waste dyes and waste resources,and reuse hydrolyzed reactive dyes.This study explored the process of modifying the hydrolyzed reactive dyes by the self-made cationic modifier WLS agent and optimized the best modification process:hydrolyzed reactive dye: WLS agent(mass ratio)was 1:10,the amount of sodium hydroxide was 2.5% of the mass of WLS agent,and the treatment was modified at 50? for60 min.At the same time,the process of modifying the hydrolyzed reactive dyes with cationic gelatin protein additives was investigated,and the best modification process was optimized: Hydrolyzed reactive dyes: cationic gelatin protein additives(mass ratio)was1:10,the amount of sodium hydroxide was positive Gelatin mass of 4.0%,it was modified at 60? for 150 min.The process of modifying purified hydrolyzed reactive dyes with cationic gelatin protein agent was also investigated.The process was as follows: Purified hydrolyzed reactive dyes: cationic gelatin protein agent(mass ratio)was 1:10,the amount of sodium hydroxide was 2.0% of the mass of cationic gelatin protein agent,and the modification was performed at 50? for 60 min.The structure and properties of the modified hydrolyzed reactive dyes prepared were analyzed and characterized by infrared spectroscopy and UV-visible absorption spectra.The results showed that the hydrolyzed reactive dyes were successfully modified by cationic modifiers WLS agent and cationic gelatin protein agent;The UV-visible absorption spectrum of the hydrolyzed reactive dyes differs from cationic gelatin protein agent and hydrolyzed reactive dyes,indicating that the cationic gelatin protein agent modified hydrolyzed reactive dyes.The modified hydrolyzed reactive dyes were applied to the dyeing of cotton fabrics.The impregnation dyeing process,rolling baking dyeing process and piling dyeing process were discussed respectively,and the optimal dyeing process for dyeing cotton fabrics with modified hydrolyzed reactive dyes was optimized.The impregnation process is: the cottonfabric is put into a dyeing bath at 90?,heat-treated for 10 minutes,1.0 g/L sodium hydroxide is added,and the heat-retaining treatment is continued for 60 min.The rolling baking process is: padding dyeing liquor(two dip two rolling: liquid pick-up rate 80%;1.0g/L sodium hydroxide)?drying(temperature 90°C,time 3min)?baking(temperature165-170?,time 3min).The piling process: padding dyeing liquor(two dip Second rolling:liquid pick-up rate 80%;1.0g/L sodium hydroxide)? wrapped with plastic wrap ?dyeing machine rotating stacking(temperature 90?,time 60min).The dyeing effect of different types of hydrolyzed reactive dyes modified by cationic gelatin protein agent was evaluated.The K/S value of the modified hydrolyzed reactive dyes dyed cotton fibers was significantly higher than that of hydrolyzed reactive dyes,indicating that the modified hydrolyzed reactive dyes had a good dyeing performance on cotton fibers.At the same time,the modified dye's lifting power,initial dyeing,transferability,level dyeing and wettability of the modified dye-dyed fabrics were also evaluated.The results showed that the dyeing fabrics with the modified hydrolyzed reactive dyes have lower wetting.The dyeing kinetics and thermodynamic properties of cotton fabrics modified with modified dyes were studied.Using the pseudo-first-order kinetics model and the pseudo-second-order kinetics model to simulate the experimental data,the dyeing process conforms to the pseudo-second-order kinetics model.The three adsorption isotherms of cotton fabrics modified with modified dyes were fitted and analyzed.The results showed that the process of cotton fabric dyed with modified dyes was more suitable for Langmuir type adsorption,and also had Langmuir-type and Freundlid type complex adsorption characteristics,indicating that modified dye structures were different from hydrolyzed reactive dyes and traditional reactive dyes.In the structure,the adsorption mechanism of the dyed fibers has changed,from the non-positional adsorption of Freundlich type to the Langmuir type chemical localization adsorption or composite adsorption,and the dyeing process conditions have also changed.