Study On Extraction And Dyeing Properties Of Pomegranate Peel Pigment

As an important supplement of synthetic dyes,natural dyes have been increasingly promoted in the textile industry with the high demand of consumers for green and healthy textiles products.Pomegranate rind,as a by-product of food industry,is rich in anthocyanins and phenolic substances with biological activities,making it another reliable source of natural dyes.In this thesis,the waste pomegranate rind was used as raw material,and on the basis of ensuring the dye yield and biological activity,the ultrasonic assisted extraction process of natural dye was optimized by response surface methodology,and then the pomegranate rind dye(PRD)was used for dyeing wool fiber and cationic modified Tencel fiber.Compared with traditional aqueous extraction,ultrasonic technology is more suitable for extraction of PRD.Under the optimal extraction conditions of extraction time: 60.00 min,extraction temperature: 65.00°C,liquid-solid ratio: 19.00 m L/g,and ultrasonic power: 132.00 W,the extraction yield of PRD assisted by ultrasound reached17.08%,which was more than 50% higher than that of traditional aqueous extraction under the same conditions.While improving the yield of PRD by ultrasonic assisted extraction,the antioxidant property of PRD increased by more than 10% compared with that of aqueous extraction,and the particle size distribution of aqueous extraction was more uniform and the particle size decreased from 293.23 nm to 34.80 nm.PRD can be used as an excellent natural dye for wool.The wool dyed with PRD has excellent fastness to washing(level 4-5),saliva(level 4)and perspiration(level 4).More than ten kinds of colors with different styles,such as gold,orange,dark green and black,can be realized by a variety of metal mordants with different mordant processes,which not only broadens the color range of dyed wool,but also improves the added value and application prospect of wool fiber.Through the optimization of a variety of modifiers,the low-toxic small-molecule cationic modifier,CHPTAC,was selected to modify Tencel fiber.Under the modification condition of c(CHPTAC)=70 g/L;m(CHPTAC): m(Na OH)= 3:1;T=80°C and t=30 min,Tencel not only has less loss of strength,but also has deeper dyeing depth and better color evenness.The optimal dyeing conditions of the cationic modified Tencel were: PRD concentration(o.w.f): 5%;dyeing temperature: 70°C;the dyeing time: 40 min.Under this condition,the K/S value of the dyed fiber was the maximum,which was 4.91.The dyed Tencel fiber was endowed with excellent antibacterial properties while obtaining high K/S value and color fastness to washing.