Synthesis Of High Temperature Dispersants And Their Application To Dyeing Dyes

In the process of dyeing polyester fabrics with disperse dyes,the dispersibility and stability of the disperse dyes directly affect a series of quality standards such as level dyeing,dye uptake,gloss,and tinting strength of polyester fabrics.And therefore during the dyeing process of disperse dyes,the addition of a suitable dispersant can reduce disperse dye agglomeration,which is of great significance for improving the quality of dyed fabrics,energy saving and emission reduction.This dissertation designs and synthesizes four dispersants using phthalic anhydride,diethylene glycol,ethylene glycol,maleic anhydride,and sodium bisulfite(dispersant A,dispersant B,dispersant C,dispersant D),and apply it to the high-temperature impregnation dyeing process of disperse dyes.The research ideas of the project are mainly divided into the following four parts:Firstly,to design and synthesize the four different structures of dispersants to optimize the synthesis process;Secondly,to explore the stability of the target dispersant hydrolysis under high temperature conditions;Thirdly,to explore the effect of dispersants with different structures in the process of the dispersion of disperse dyes with` high-temperature and high-pressure dyeing;Fourthly,to study the effect of dispersants with different structures when acting on the dyeing performance of disperse dye-dyed polyester fabrics.Firstly,the influence of reaction time,reaction temperature,molar ratio of reactants and catalyst amount on the esterification rate of the target product was investigated using the control variable method.The synthesis process and sulfonation process of the dispersant were optimized.The acid-base titration method was used to determine the esterification rate of the synthetic target dispersant,in which the dispersant B has an esterification rate of 94.3%.Since disperse dyes were dyed on polyester fabrics under weak acidic conditions at 130°C,the dispersants synthesized were applied to high-temperature and high-pressure dyeing of disperse dyes,and their structural stability at weak acidic conditions at 130°C was analyzed.In this experiment,disperse dyes were treated with disperse dyes and fabrics were treated at a high temperature of 130°C.The four dispersants were treated at a high temperature of 130°C under weak acidic conditions,and the dispersants were treated by acid-base titration.The change of the acid value before and after indirectly indicated its stability under weak acid conditions at 130°C.The results of the investigation showed that the stability of dispersant B is the best,and the stability of dispersant C and dispersant D is poor.Secondly,this article selected four target synthetic products and commercial dispersants to formulate different dyes with four disperse dyes respectively.Under the premise of no fabrics adding,high-temperature and high-pressure dyeing processes are used to determine the disperse dyes in four different colors.The particle size was changed,and the optimal amount of four dispersants was selected,and the dispersibility of disperse dyes was compared with the two commercially available dispersants.The results showed that the optimal amounts of dispersant A,dispersant B,dispersant C,and dispersant D were 5 g/L,7 g/L,5 g/L,and 7 g/L,respectively;and dispersant B disperses of the dyestuff has the best dispersion effect,and it was better than the dispersant effect of some disperse dyes by the commercial dispersant in terms of particle size change.After dispersant B was added at high temperature and pressure,the disperse red dye particle size was maintained in the range of 330 to 400 nm.Finally,four target synthetic products and commercially available dispersants were applied to disperse dyes for high temperature and high pressure dyeing of polyester fabrics.After reduction cleaning and drying,the dye leveling properties of the fabrics were measured using the Data colour color matching colorimeter.The depth of dyeing and the evaluation of the fastness properties of the fabrics,such as soaping fastness and dry/wet rubbing fastness,showed that the polyester fabrics dyed with dispersant A and dispersant B had good levelness.The polyester fabrics dyed with dispersant C and dispersant D were inferior in dyeing level;the dispersant B dyed polyester fabrics had the best soaping fastness and dry/wet rubbing fastness,all of which could reach 4-5.The polyester fabric dyed with dispersant C and dispersant D had lower soaping fastness and dry/wet rubbing fastness,with only 3-4 levels.