Extraction Of Natural Dyes From Zanthoxylum Bungeanum Shell And Study On Dyeing Of Modified Cotton Fabric

Zanthoxylum bungeanum Maxim（scientific name:Zanthoxylum bungeanum Maxim）is a small deciduous tree of the Rutaceae and Zanthoxylum genus.It has the effects of warming and dispersing cold,removing dampness and pain,killing insects and detoxifying,and is a very widely used food ingredient.After the Chinese prickly ash is made into Chinese prickly ash oil,its residue is directly discarded as waste,not only polluting the environment but also causing resource waste.However,the Chinese prickly ash shell residue also contains a lot of protein,cellulose,and natural dye components,including natural dye components such as tannins,flavonoids,and phenols,which have good dyeing performance.Utilizing it as a natural dye resource with potential application value can not only impart color to fabrics,but also provide them with certain antibacterial and UV resistance properties.Therefore,this article chose to study the extraction process,dye composition,and dyeing performance of natural dyes from Zanthoxylum bungeanum shell,in order to provide scientific basis and technical support for their application in the comprehensive utilization of resources and textile dyeing.This article first explored the optimal extraction process of natural dyes from Zanthoxylum bungeanum shell.Using ethanol/water as the solvent,the effects of ethanol volume fraction,solid-liquid ratio,extraction temperature,pH value,and extraction time on the extraction efficiency of natural dyes from Zanthoxylum bungeanum shell were discussed.The experimental results showed that the highest extraction efficiency was achieved when the volume fraction of ethanol was 40%,the ratio of material to liquid was 1:20,the extraction pH was 7,the extraction time was 90 min,and the extraction temperature was 70℃.Further screening suitable macroporous adsorption resins to separate and purify the extract,and then using Fourier transform infrared spectroscopy,high-performance liquid chromatography,and mass spectrometry to analyze its components.The results showed that the main components in the natural dye of Zanthoxylum bungeanum shell were flavonoids,among which the identifiable components were rutin(C₂₇H₃₀O₁₆),coumarin（C₉H₆O₂）,baicalin(C₂₁H₁₈O₁₁),and quercetin(C₁₅H₁₀O₇).Secondly,the stability of natural dyes from Zanthoxylum bungeanum shell was tested and analyzed.The experimental results show that natural dyes from Zanthoxylum bungeanum shell can react with different metal ions to produce counter color reactions,even precipitates;The natural dye from Zanthoxylum bungeanum shell has a strong stability in pigment resistance,but is poor under strong alkali conditions;It has strong stability in oxidants such as hydrogen peroxide,but is easily reduced in solutions such as sodium sulfite;In addition,environmental conditions such as light and high temperature can also cause dye degradation.Finally,the dyeing properties of Zanthoxyl shell natural dyes on cotton fabrics modified with 3-chloro-2-hydroxypropyl-trimethylammonium chloride were investigated.The experimental results show that the optimal modification process for cotton fabric is as follows:sodium hydroxide concentration of 15 g/L,modifier dosage of 6%,modification temperature of 70℃,and modification time of 100 min.Through further research on factors such as different dyeing pH values,dyeing temperature,and dyeing time,the experimental results show that the optimal dyeing conditions for modified cotton fabrics with Zanthoxylum bungeanum shell natural dyes are:dyeing pH value of 5,dyeing temperature of 95℃,and dyeing time of 40 minutes.The dyeing mechanism of Zanthoxylum bungeanum natural dyes on modified cotton fabrics was investigated.The experimental results showed that the dyeing kinetics fitting results of Zanthoxylum bungeanum natural dyes on modified cotton fabrics conformed to the pseudo second order model,and the dyeing thermodynamics fitting results conformed to the Langmuir model when the dyeing temperature was 65℃;When the dyeing temperature is 95℃,the fitting results of dyeing thermodynamics conform to the Freundlich model.Subsequently,the dyed modified cotton fabric was tested for color fastness.The test results showed that the dyed cotton fabric had a color fastness to rubbing of 4-5 grades,a soaping fastness of 3 grades,and a fastness to sunlight of 3 grades,with a high color saturation.