Synthesis And Dyeing Properties Of Quinoidal Thiophene Disperse Dyes

Quinoidal-thiophene-containing compounds,which usually have extremely high color strength and a pronounced dark color effect,are a class of potentially superior dye chromophores.At present,no report has been found on the application of quinoidal thiophene structure in the molecular design of dye for textiles.In this thesis,two kinds of quinoid thiophene backbones were selected for dye design.According to their hydrophobicity,they were used as disperse dyes to dye polyester fibers.The structural relationship between structure and dyeing properties was studied.Which laying a theoretical foundation for the development of new quinone heterocyclic disperse dyes with excellent dyeing performance.Two bisfluorenyl quinoidal thiophene dyes A1 and A2 were selected and synthesized.Their molecular structures were characterized by ~1H-NMR,IR,MS and elemental analysis.The influence of molecular planarity of quinoidal dyes A1 and A2on their dispersion properties was investigated.The optimum conditions for the dispersion and grinding of the dye were as follows:dispersant NNO,dye/dispersant ratio 1:2,zirconium bead size 0.2 mm.Using high temperature and high pressure dyeing method,dye A1 can be used for producing red polyester fabric.The dyeing rate of dye is 65%,the K/S value of dyed fabric is 9,the color fastness to soaping,rubbing and sublimation can all reach grade 4 or above.However,the dye A2,which has a larger planar molecular structure,is difficult to dye the polyester fiber,and the color depth of the dyed fabric is low.Seven cyano-or ester-substituted quinoidal bithiophene dyes B1-B7 were designed and synthesized.Their structures were characterized by ~1H-NMR,IR,MS and elemental analysis.The effect of alkyl chains on the spectral properties of dyes was investigated.The results showed that the maximum absorption wavelength of dye was mainly determined by quinoidal backbone,and alkyl chain had little effect on it.The dyeing of polyester fabric was carried out by high temperature and high pressure dyeing method,and the effect of alkyl chains on dyeing properties was investigated.The results show that the alkyl chain with proper steric hindrance helps to reduce the intermolecular interaction energy of the quinoidal dyes and makes the dye easy to dye the fibers in a single molecule state in the dyebath.Among them,n-butyl group-containing dye B6 showed the best dyeing performance.When the dye dosage is 1%o.w.f,dye uptake rate of 97%,dyed fabric K/S value of 17,and soaping resistance,abrasion resistance,resistance to sublimation and sun fast degrees of above level 4 are achieved.The results of this dissertation show that the quinoid thiophene structure can be used to disperse dyes and obtain better dyeing results,which provides a useful reference for further design of disperse dye molecules based on quinone structure in the later period.