Study On Extraction Of Natural Dyestuff From Buddleja Officinalis Maxim And Its Dyeing Performance On Cotton Fabric

Buddleja officinalis Maxim is a commonly used as a raw material for extracting food-grade yellow pigments,which is widely distributed in Guangxi,Yunnan,Guizhou and other places.It is often used to make five-color rice,but its dyeing research and application on textiles are relatively rare.In this paper,a new yellow natural dye was obtained by extracting the dried yellow fragrant flower buds and inflorescences,and the dye properties were studied.The dyeing properties and the color fastness on cotton fabrics also been studied to providing technical theoretical support for the industrial application and promotion of natural dyes.Firstly,the extraction process of Buddleja officinalis Maxim natural dyes was studied.In order to adhering the principle of environmental protection,the deionized water was used as the extractant,and the effects of different material-to-liquid ratios,pH values of the extracts,extraction temperature,and extraction time on the extraction effect of fragrant flower pigments was analyzed in the single factor experiments.The response surface test was used to optimize the extraction process,and the best extraction process parameters were obtained,and then,the stability of the pigment extract was explored.The results show that the extract of yellow fragrant flower pigment has an obvious absorption peak at ?=325nm.The optimized extraction process were determined as: material-to-liquid ratio 1:10,pH=6.2,extraction temperature 95?,extraction time 70 min.Stability of the extracting yellow fragrant flower pigment have shown that the heat stability is well,it is more stable under neutral and weak acid conditions,and the pigment molecules will be hydrolyzed under strong acid and alkaline conditions;The pigment extract will have complexation reaction with metal ions,which can changes the color of the solution;its oxidative resistance is better,and the effect of resistance to reducing agents is poor,as well as the light resistance.Secondly,a combination method of macroporous adsorption resin adsorption and organic solvent extraction was used to purifying the yellow fragrant anthocyanidins,and characterized by Ultraviolet-visible spectrophotometer and high performance liquid chromatography(HPLC)technology.the results show that DM301 type macroporous adsorption resin has the best adsorption performance.When it is used as an adsorbent,the best purification condition is that 80% ethanol aqueous solution was used as the eluent and ethyl acetate was used as the extraction solvent.And then the fabric was dyed with the crude extracted dye and the purified dye respectively,the color characteristic values of the dyed fabric were analyzed,it was found that the dyeing performance of the purified dye was improved significantly,and its dyeing reproducibility was better.The purified dyes powders was prepared by freeze-drying technology.Compared with the direct dyeing method,three mordant dyeing methods such as pre-medium,co-medium and post-medium were selected.Five kinds of mordant such as zinc sulfate,ferrous sulfate,iron sulfate,alum and copper sulfate Metal salt is used as a mordant to exploring the dyeing process of yellow fragrant flower,studying its dyeing performance on cotton fabrics,and analyzing and comparing the color fastness and color characteristics of the dyed fabrics.The result show that the color fastness and K/S value of the mordant dyeing fabric are higher than the direct dyeing fabric,the dyeing effect of the alum used as the mordant with the pre-mordant dyeing method is best.The influence of different pre-medium time,pre-medium temperature,mordant concentration,dyeing time,dyeing temperature,and pH value of dye bath on the dyeing effect of cotton fabrics is discussed by single factor test and response surface test analysis.And then,the optimized dyeing process showed as the mordant concentration is 1.25 g/L,the pre-medium temperature is 70?,the pre-medium time is 41 min,the dyeing pH is 7,the dyeing temperature is 80?,and the dyeing time is 93 min.Finally,the antibacterial properties of the dyed cotton fabrics were tested,and the study showed that the nature dye extracted from the Buddleja officinalis Maxim had a significant inhibitory effect on Escherichia coli,and the dyed fabrics had certain antibacterial properties.