Study On Encapsulation And Dyeing Behavior Of Natural Turmeric Pigment Based On Environmental Protection Mordant

Curcumin is one of the main natural pigments for wool fabric dyeing.At present,due to the lack of stability,water solubility and other properties of natural curcumin as well as the use of metal ion mordant,there are still environmental problems in the research of natural curcumin dyeing wool fabric,and the dyeing fastness needs to be further improved.This paper focuses on the packaging process of the stable and environmentally friendly color material coated with oil-soluble natural curcumin by zeolite imidazolate skeleton material（ZIF-8）,regulates the packaging behavior parameters,and characterizes the properties of the color material.At the same time,the screening of environmental mordant was studied,and the dyeing behavior of stable environmental color prepared by oil-soluble natural turmeric was explored with the intervention of the best environmental mordant,and the dyeing behavior was compared with that of water-soluble turmeric stable environmental color packaged by ZIF-8.Optimized packaging process parameters of oil-soluble natural turmeric stable color material and low-temperature environmentally friendly dyeing process are obtained.The expected goal is to form a dyeing method of natural pigment packaging color material of wool fabric with the intervention of environmental friendly mordant,which will provide the theoretical basis for the accumulation of natural pigment packaging and dyeing technology.The main conclusions are as follows:（1）By comparing the metal ion mordant,the post mordant method was adopted to apply several common representative environmental mordant to the natural turmeric dyeing process of wool fabric,analyze and discuss the color obtaining situation of dyeing wool fabric under the action of different mordant,test the comprehensive index of dyeing wastewater,and screen the environmental mordant with the best color fixing effect.The results showed that the color difference of dyed wool fabric under the effect of citric acid was 26.951.The COD_Crvalue of the dyeing wastewater is 1.43×10³ mg/L,the ammonia nitrogen content is 5.39 mg/L,and the hexavient chromium content is 0.004 mg/L.The color yield of the dyed fabric is the best and the comprehensive index of the dyeing wastewater is the best.The soap fastness of dyed wool fabric meets the requirements of daily use.The best environmental mordant was citric acid.（2）ZIF-8 material was synthesized by conventional solvent method,and ZIF-8 material was used to carry out oscillatory encapsulation test on oil-soluble curcumin.The influence of ZIF-8 material quality on encapsulation rate was explored according to different process parameters,and oil-soluble natural curcumin stable environmental color was obtained.The results showed that the ZIF-8 material with high crystallinity,good appearance and high thermal stability was prepared.Under the conditions of p H 7,temperature 25℃and oscillating rate 150 rpm/min,the optimized process parameters for the encapsulation of oil-soluble natural curcumin in ZIF-8 material were as follows:the dosage of ZIF-8 was 200mg,the adsorption time was 10 h,and the concentration of curcumin solution was 1.0 g/L.Under these conditions,the encapsulation rate was 76.0%.The packaged oil soluble natural curcumin stable color material has the common characteristics of ZIF-8 material and oil soluble curcumin.The excellent physical and chemical properties of ZIF-8 material improve the stability of oil soluble natural curcumin.At the same time,using the previous research results of the research group,the preparation of water soluble turmeric pigment stable environmental protection color for the next step of research.（3）Design-Expert.v8.0.6.1 software was used to Design the single factor test and response surface optimization test scheme.The color difference value of dyed wool fabric was taken as the consideration index.With the intervention of the screened environmental mordant citric acid,The influence factors and dyeing process of water soluble and oil soluble natural turmeric stable dyes for wool fabric were studied.The results showed that the optimized dyeing process of water-soluble natural turmeric pigment stable environmental color material was:The dyeing time was 76 min,the dyeing temperature was 82℃,the dyeing p H 2.7,the dyeing method was post-dyeing,the fixed dyeing bath ratio was 1:50,and the amount of mordant citric acid was 5%.Under these conditions,the color difference of dyed wool fabric was 10.178 and the K/S value was 11.27.The optimized process of oil soluble natural turmeric stable and environmentally friendly color material was as follows:dyeing time 70min,dyeing temperature 70℃,mordant dosage 2%,post-dyeing mode,fixed dyeing bath ratio 1:50,dyeing p H 2.7.Under these conditions,the color difference of dyed wool fabric was 36.471,and K/S value was 35.22.The rubbing fastness and soap-washing fastness of wool fabrics dyed with two kinds of color materials meet the requirements of daily use,but the fastness to sunlight is not up to the standard,which needs to be further improved in the follow-up study.The appearance of wool fibers before and after dyeing showed that the two low temperature dyeing processes had no adverse effects on wool fibers.（4）Compared with the optimized water-soluble natural curcumin stable color dyeing process,the optimized oil-soluble natural curcumin stable color dyeing process showed lower dyeing temperature under the condition of the same dyeing time,dyeing p H,mordant and dyeing method,which reduced energy consumption and the influence on the physical and mechanical properties of wool fabric.In terms of color difference and K/S,the optimized dyeing process of oil-soluble natural curcumin stable color material showed excellent color yield and depth（color difference value was 26.293 higher,K/S value was 23.95 higher）than that of water-soluble natural curcumin stable color material.In terms of dyeing fastness,wool fabrics dyed by the optimized oil-soluble natural curcumin stable dyeing process showed a lower half grade in terms of wet-rubbing fastness and soap-washing color fastness.It was analyzed that wool fabrics dyed by oil-soluble natural curcumin stable dyeing process had deep color concentration,which affected the stability of wet processing fastness.