Synthesis Of Cationic Reactive Dyes And Study On Their Dyeing

In this thesis,two cationic reactive dyes,low molecular weight reactive dye and polymeric reactive dye,containing reactive groups and quaternary ammonium groups were designed and prepared.4-nitro-4’-aminoazobenzene was prepared from p-nitroaniline via diazotization and coupling reaction.A model cationic reactive dye based on a 4-nitro-4’-aminoazobenzene chromophore was prepared.The synthesis of low molecular weight reactive dye was achieved by the modification of a free amino group of an 4-nitro-4’-aminoazobenzene-based dye,reacting first with cyanuric chloride and then with N-（2-aminoethyl）pyridinium.The effects of temperature,reactant,pH value and time on the yield of this dye were discussed.Their structures are confirmed by IR,¹H NMR.The maximum wave length(λ_max) was 385nm.The polymeric reactive dye（QXPEI） was prepared from polymeric dye synthesized with use of 2,7-Naphthalenedisulfonic acid,5-[（4,6-dichloro-1,3,5-triazin-2-yl）amino]-4-hydroxy-3-（phenyla -zo）-,disodium salt and polyethyleneimine through nucleophilic substitution.The effects of various reaction conditions on the reactions were discussed.The chemical structures of the products were characterized with IR.The maximum wave length(λ_max) was 528nm.The amination degree of polyethyleneimine was 34.8%determined by electroconductibity titration.The substitution degree of XPEI was 51.2%determined by spectrophotometry.The tertiary amination degree of TXPEI and the quaternary degree of QXPEI were determined by titration.With salt-free dyeing,the dyeing characteristics of two cationic reactive dyes on cotton fabric are studied.From the experiments,we could arrive a conclusion that the fixation rate on cotton of the low molecular weight reactive reached 73%when the dyeing temperature was 85℃,the dyes dosages were 2%and the fixation time was 45 minutes.On wool,it reached 70%when the dyeing temperature was 90℃,the dyes dosages were 2%and the keeping time was 60 minutes.On nylon, it reached 60%when the dyeing temperature 95℃,the dyes dosages 2%and the keeping time 60 minutes.The rub-fastness of this dye to cotton and nylon reached 4～5 grade.For the polymeric reactive dye with a quaternary ammonium group,the fixation rate on cotton reached 85%when the dyeing temperature 85℃,the dyes dosages 2%and the fixation time 50 minutes.And the fixation rate on wool reached 73%as the dyeing temperature 90℃,the dyes dosages 2%and the keeping time 60 minutes.The rub-fastness of this dye to cotton reached 3.The antimicrobial property of this polymeric quaternary ammonium salt was researched using Escherichia Coli.The effects of cotton fabrics dyed in different concentration of QXPEI solution on the antimicrobial property were examined with the method of plate counting live bacterium. The experiment results indicated that QXPEI possessed very strong antimicrobial ability,and the antimicrobial ratio of cotton fabrics dyed in 1g/L QXPEI reached 90%.