石榴皮染料对桑蚕丝织物的环保染色研究

Study of eco-friendly dyeing on mulberry silk fabrics with pomegranate peel dye

石榴皮染料染色桑蚕丝织物的色牢度较低,故金属媒染剂和化学固色剂常被用于提高植物染料的染色色牢度,但二者会对环境及人体健康产生威胁。本文运用正交试验优化染色工艺,对比三种环保型媒染剂和三种金属媒染剂在不同媒染方式下的染色效果,评估松香固色剂的固色效果,并采用扫描电子显微镜分析固色前后桑蚕丝织物纤维的表面形态。结果表明,优化的直染工艺为温度60℃,染色时间60 min, pH 9;在环保型媒染剂(茶卡盐后媒染)和松香固色剂作用下,其色牢度可提高至5级;固色后纤维表面附着的保护膜提高了染料的牢固性。

With the development of textile industry,wastewater contaminated with synthetic dyes has polluted the environment and threatened human health worldwide.Conversely,natural dyes represent an excellent alternative for the textile industry,as these dyes are considered to be safe,environmentally friendly,and biodegradable.Based on these advantages,natural dyes have been attracting increasing attention over the past decade.Most studies examining the use of natural dyes for textile dyeing have focused on the dyeing of natural fibers,such as silk and others.Compared with cotton and hemp fabric,silk fabrics have better compatibility with human skin.Because silk fabrics have a excellent fineness,bright and beautiful appearance,and the overall vertical characteristics of the fabric,it is also called the"fiber queen".However,natural dyes also have some disadvantages for textile dyeing,such as low color fastness and single shades.These issues have been addressed using chemical fixing agents and metallic mordants.On the one hand,the properties of natural dyeing can be improved using fixing agents,most of which are chemical fixing agents.On the other hand,when metallic mordants contact natural dyes,complexation reactions occur between the metal ions and the dye molecules,forming coordination bonds.Because metallic mordants and chemical fixing agents can pollute the environment and harm human health,silk is important to identify alternative natural fixing agents and mordants to develop cleaner dying processes.Furthermore,natural dyes are more costly than synthetic dyes,and their supplies are limited.If agricultural crop waste,which is continually produced and sustainably supplied,could be used as a source of natural dyes,the value of these remnant materials could be increased by recycling.Pomegranate peel,a by-product of pomegranate production,accounts for 20%-30%of the total fresh weight of pomegranate fruit.And this agricultural waste product could be used to create natural dyes.The purpose of this study is to explore the feasibility of using biomordant and natural fixing agent(gum rosin)instead of metal mordant to dye pomegranate peel dye on mulberry silk fabric.We analyzed the pigment composition of pomegranate peel extract through ultraviolet-visible spectroscopy and FTIR analysis;compared the effects of biomordants(C.speciosa,mineral salt and rare earth)and metallic mordants on fabrics dyed with pomegranate peel by evaluating indicators including K/S value,color characteristics(L^(*),a^(*)and b^(*)),and color fastness;examined the morphology of dyed fabrics before and after color fixing treatment by scanning electron microscopy;and proposed possible mechanisms for the chemical basis of using natural dye-fixing agents for dyed fabrics.In the past ten years,most research on the use of pomegranate peel dye has focused on metallic mordants,the method of dye extraction,and the dyeing process.However,no previous study has evaluated the dyeing properties of pomegranate peel extract using a biomordants and fixing agents or compared the use of metallic vs.biomordants.It was found that the optimum dyeing conditions was pH 9,60℃ for 60 min for silk,as determined in an experiment using an orthogonal array design.The dyeing properties of dyed fabrics were significantly improved using biomordants and natural dye-fixing agent and were similar or even superior to those using metallic mordants.Biomordants and fixing agents generate chemical reaction,and the color fastness can be increased to grade 5 under the action of biomordant(mineral salt in post-mordant)and rosin fixing agent.The fastness of dye was improved by the protective film attached to the fiber surface.Pomegranate peel,a form of agricultural crop waste,could be used to create an eco-friendly dye using natural mordants and dye-fixing agents.The use of these renewable materials would accelerate the ecological recycling of agricultural by-products.Further research is needed to improve the functions of natural mordants and fixing agents to achieve wider ranges of color with greater color fastness for cleaner textile production.This study provides scientific evidence for the research of other eco-friendly color fixing agent and mordant,and provides research basis for the dyeing application of other crop waste products.Meanwhile,it promotes the sustainable utilization of plant dyes and the development of eco-friendly dyeing and finishing industry.