Study On The Synthesis And Application Properties Of Acid Dye Based On Difluorenylidene Quinoidal Thiophene Moiety

Deep dyeing is a common problem in the current printing and dyeing industry,the fundamental reason is that the lower coloring intensity of commodity dyes.Although the amount of dye can be used to make up for lack of this problem,but also will lead to a substantial reduction in dye utilization,color fastness,waste water treatment more difficult,rising costs and other issues.Therefore,the development of new high coloring intensity dye is of great significance.Quinoidal thiophene compounds are a new class of compounds that have excellent optical absorption in the visible region and have the potential to become excellent dye color bodies.In this paper,bisfluorenyl quinone thiophene compounds were selected as the color body of dye,and sulfonic acid groups were introduced by sulfonation to design and synthesize acid dye based on difluorenylidene quinoidal thiophene moiety with excellent coloring intensity.Using concentrated sulfuric acid as sulfonating agent and fluorenylidene as reaction sites,two red acid dyes based on difluorenylidene quinoidal thiophene moiety,named S2 and S4,were successfully synthesized by controlling the sulfonation reaction temperature to introduce different numbers of sulfonic acid groups.Its molecular structure was confirmed by Mass Spectrum,FT-IR and ~1H NMR.The results of UV-Vis absorption spectra showed that the maximum absorption wavelengths of S2 and S4 were 539 nm and 551 nm,respectively,and the molar extinction coefficients were 76710 L/(mol?cm)and 24380L/(mol?cm),respectively.The effects of dying temperature,pH value of dying bath,and the amount of Glauber's salt on the dyeing efficiency of wool,silk and nylon fabric and the dye uptake of the two dyes were discussed respectively by using acid dye dyeing method and get the best six kinds of dyeing process eventually.Under these conditions,the two dyes have better dye uptake percentage,color yield,enhancing property and fastness to three kinds of fabrics.Among them,the dye S2 on the wool,silk,nylon dyed fabric K/S value higher than the three selected goods dyed fabric K/S value of about double,with excellent coloring intensity.The two dyes dyed fabrics have good rubbing fastness and stained fastness to the original fabric when soaping,but the light fastness and stained fastness to cotton fabric are not ideal and need improvement in the future.In summary,the acid dye based on difluorenylidene quinoidal thiophene moiety designed and synthesized in this paper have excellent coloring intensity and can be applied to the dyeing of wool,silk and nylon fabrics.The dyed fabrics have good application performance.It provides development of novel heterocyclic dyes with a new way of thinking and method.