Synthesis And Application Of Gardenia Blue Dye With Double Chromophoric Structure

Although natural dyes have a wide range of sources,rich colors,and unique hue.However,natural dyes also have many shortcomings.For example,blue dyes have not only a small number of types but also have limited dyeing limitations.In this paper,genipin and lysine were used as reactive monomers to synthesize gardenia blue dyes with a double chromophoric structure,that is,a new blue natural dye was developed by semi-organic synthesis,and the?dyeing application process was further studied at the same time.The genipin solutions of the same concentration were placed at different temperatures and pH for 6 hours,and then througth measuring the solution's UV spectrum and liquid chromatography to determine the stability of genipin solution.The results show that the genipin solution is stable below 100?;When solution at 100?,genipin is unstable and changed.The genipin solution is relatively stable under acidic and neutral conditions,but self-polymerization will occur under weak alkalinity.The results of liquid chromatography tests have confirmed that as the pH value increases,the degree of reaction is higher,and the product is a self-polymerization product of two molecules of genipin;when the pH is 12,genipin will have hydrolysis reaction and a self-polymerization reaction.The experiment was performed according to n _Genipin:n _lysine=1:1,the single factor and orthogonal experiments were used to optimize the synthesis process.The conclusion is that the reaction pH had the largest effect on the synthesis of gardenia blue dye with single chromophoric structure,and the smaller effect of reaction temperature and time.The best optimize synthesis process is:the reaction pH is 7,the reaction temperature is 70?,and the reaction time is 5h.After the reaction is completed,the purification is performed according to the following process:firstly extract the reaction solution with ethyl acetate multiple times,and then use D-101 macroporous adsorption resin for adsorption.After the adsorption is complete,desorb and collect the 30%ethanol water desorption solution.A single hair color gardenia blue with a purity of up to 95%can be obtained.Based on mass spectrometry and HNMR analysis,the molecular structure and reaction equation of the gardenia blue with single chromophoric structure was deduced.Tested the ultraviolet spectrum and liquid phase spectrum of the solution after the reaction of different ingredients ratios,it was found that when the reactants reacted according to n _genipin:n _lysine=1:1,the product was mainly gardenia blue with single chromophoric structure;According to n _Genipin:n _lysine=1.5:1,the products have two gardenia blue dyes with single chromophoric structure and double chromophoric structure;according to n _genipin:n _lysine=2:1,the product is mainly gardenia blue dye with double chromophoric structure.When the reactants genipin and lysine reacted according to n _genipin:n _lysine=2:1,it is found through each group of single factor experiments that if the reaction temperature is low,the time is short,and the pH value is low,the product will contains a large number of single chromophoric structure gardenia blue,and only under appropriate conditions will the double chromophoric structure gardenia blue be produced.Orthogonal experiments were carried out in the appropriate range,and the optimized process for the synthesis of gardenia blue with double chromophoric structure was obtained:the reaction pH was 8,the reaction temperature was 70?,and the reaction time was4h.After the reaction is completed,purification is performed according to the following process:firstly the reaction solution is extracted multiple times with ethyl acetate,and then adsorbed with D-101 type macroporous adsorption resin,and the non-adsorbed solution is collected and dried,and the dried solution is dissolved with ethanol,and the filtrate is collected and dried to obtain a pure product.Based on mass spectrometry and nuclear magnetic resonance,the molecular structure and reaction equations of gardenia blue with double chromophoric structure were deduced.Using alum as a mordant,double chromophoric structural gardenia blue dye was dyed on wool fabrics by a pre-medium method,and the dyeing method was determined by measuring the K/S value and L.a.b value of the dyed fabric.The effects of dyeing pH,dyeing temperature,mordant concentration,and dyeing time on the dyeing effect were analyzed by single factor and orthogonal experiments.The results showed that the degree of influence of each factor on the dyeing effect was within the appropriate range:dyeing temperature>dyeing time>dyeing pH>mordant concentration.When the amount of gardenia blue dye is 0.5%o.w.f,the dyeing pH is3,the dyeing temperature is 80?,the amount of mordant is 3%o.w.f,and the dyeing time is60 min,the dyeing effect is best.After dyeing the fabric,except for the sun fastness of level 2,all other fastnesses reach level 3.