Reactive dyes definitionclassificationproperties and. F rom the year 1856, following perkins discovery of the first synthetic dye, the growth of organic chemical knowledge. These dyes chemically reacted with the fibers with the formation of a covalent bond between the dyes and the fiber. Each class of dye has a very unique chemistry, structure and particular way of bonding. History of reactive dyes reactive dyes first appeared commercially in 1956, after their invention in 1954 by rattee and stephens at the imperial chemical industries dyestuffs division site in blackley, manchester, united kingdom. It can be biodegraded by the laccase enzyme in ganoderma lucidum. Effect of reactive dyes structure on light fastness ijert. The first commercial success was described in the early 1950s. Fiber reactive dyes attach permanently to cellulose fibers using a covalent electronsharing bond. This article is written for high school chemistry teachers who wish to introduce the activity of tie dyeing to show its application to organic chemistry. Perkins discovery of mauveine and a short description of the synthetic dyestuff industry.
For dark colors, reactive dye is expensive but the colors are colorfast and bright. Different types of dyes with chemical structure textile. Reactive dyes are by far the best choice for dyeing cotton and other cellulose fibers at home or. Reactive dyes comprise class of high colored organic substances that find primary application for tinting of textiles. Classification there are several ways for classification of dyes. They derive their name from the fact that they undergo a chemical reaction with cellulose to form a covalent bond. Aspland, school of textiles, clemson university, clemson, s. Dyeing operation is performed by the reaction between fiber and dyes.
These classifications are more suited to a book aimed at the technology of the application of dyes to a substrate rather than one dealing primarily with. Reactive dyes react with fiber molecules to form chemical bonds. Reactive dye is the dye that can react with a fibre to form a covalent link, that is forming a permanent attachment in the fibre and could not be removed by repeated treatment with boiling water under neutral conditions. The molecular structure of the dye 21 is shown in figure 4a. Reactive dyes attach to the cellulose fiber by forming a strong covalent molecular chemical bond.
These dyes chemically reacted with the fibers with the formation of a covalent bond. In dyeing operations, the dye must become closely and evenly associated with a specific material to give level even colouring with some measure of resistance to moisture, heat, and lighti. Reactive black 5 belongs to the class of textile azo dyes. Dyes are compounds that possess the ability to stick to a fabric. These dyes are used in paint, textiles, garments and other industry sectors and are available in different color choices. It discusses the processes and the chemistry involved in the various steps of tie dyeing fabric with procion mx dichlorotriazine, a commonly used fabric reactive dye.
Effects of substituent groups within an azo dye system. Chemical structure of reactive dyes commercial names of. So dyeing depends on both fiber and dyes chemical properties. Emphasis is placed on the properties of the colouring matters themselves rather than on their applications or the system in which they may be applied. Is their any web site which gives the structure of the textile dyes. Reactive dyes are capable of forming chemical covalent bonds with the hydroxyl groups of. Fourth edition click below to download the pdf file download here chapter history of dyeing the early history of dyeing textile materials and the use of dyes derived from natural sources. Understanding effects of chemical structure on azo dye. Electrolyte is must for exhaustion of dyes in the fiber. Covalent bonding is the one of the most basic and strongest types of chemical reactions. Dying the fabric forms strong chemical bonds between dye molecules and the fabric. The preparation of the solutions, the purpose of each chemical, the. The first fibrereactive dyes were designed for cellulose fibres, and they are still used mostly in this way.
Vinyl sulfone dyes are reactive dyes comprising a vinyl sulfone group as reactive group a fiberbonding site of the reactive dye, reactive hook. Dye technology remazol application in cotton, hosiery, viscose dyeing, printing and ink industries. Reactive dyes are commonly used in dyeing of cellulose like cotton, wool and nylon. But the problem in reactive dyeing is the low exhaustion properties due to the. The cibacron f fiber reactive dyes are monofluorotriazines, very similar in structure and reactions to the dichlorotriazines, which are called procion mx dyes. Rattee and stephens at imperial chemical industries popularlized the chlorotriazines as linkers between. In terms of its atomic structure, the nitroso dyes consist on an no 2 group in orthoposition to an electrondonating substituent such as usually nh 2 and an oh group 11. Dyes may also be classified by their method of application to the substrate.
Reactive dyes used in materials like cotton, rayon, nylons. Pdf the chemistry of reactive dyes and their application. A fibrereactive dye will form a covalent bond with the appropriate textile functionality. Direct dyes can color fabric directly with one operation and without the aid of an affixing agent.
Dye general features of dyes and dyeing britannica. While the quality of dyes varies with the manufacturer, the dyes which take less time to colour the fabric and are chemically stable are most preferable. Pro mx reactive dyes procion are designed to permanently dye cellulose fibers, plant based fibers like cotton, linen, ramie, hemp, viscose rayon, bamboo, tencel, paper, wood, basket reed, even silk at room temperature, and protein fibers like wool. The chemistry of reactive dyes and their application processes article pdf available in coloration technology 6 december 2014 with 8,281 reads how we measure reads. While some dyes can react chemically with the substrates forming strong bonds in the process, others can be held by physical forces. The introduction of reactive dyes by ici in 1956 is an important landmark in the history of synthetic dyes. Cotton, rayon, and some nylons are dyed by this relatively simple dye. This dye class is used to dye polyester, nylon, acetate and triacetate fibers. In dyeing cellulose fibres with reactive dyes the following chemicals and. Effect of reactive dyes structure on light fastness 1. Chemical structure of the textile dye and use of textile dyes. The principal chemical classes of reactive dyes are azo, triphendioxazine, phthalocyanine, formazan, and anthraquinone. Reactive dyeing is a well accepted method for the coloration of cellulose fibre as it attaches itself to their substrates by a chemical reaction to form a covalent bond between the molecules of the dye and the fibre. The fibres most readily coloured with reactive dyes are natural and man made cellulosic fibres, natural protein.
For example, they may be classified by fiber type, such as dyes for nylon, dyes for cotton, dyes for polyester, and so on. Reactive dyes are a class of highly coloured organic substances, primarily used for tinting textiles, that attach themselves to their substrates by a chemical reaction that forms a covalent bond between the molecule of dye and that of the fibre. Reactive dyes had been tested in the late 1800s involving both adding functionalized dyes to the substrate and then activating the substrate first followed by fixation of the dye. Each year, nearly 140 000 tons of synthetic dyes are lost into the environment because of the dyeing process 11,12. Reactive dyes, reactive cold dyes, reactive he dyes. Reactive dyes textile reactive dyes and reactive dyes. What is the chemical structure of these dyes reactive blue 160, reactive blue 140, reactive red 141, reactive blue 171, reactive yellow 84h. Dyes and pigments covers the scientific and technical aspects of the chemistry and physics of dyes, pigments and their intermediates. Classification of dyes by chemical structure springerlink. Structure of a commercial acid and cationic basic dye. Classification of colorants by their chemical structure. The final class of suitable colourants for cellulosic fibres is known as reactive dyes cf. The functional group of the dye forms a covalent link with substrate. Dyeing is normally done in a special solution containing dyes and particular chemical material.
Reactive dyes is devoted solely to the reactive dyes, emphasizing their outstanding technical importance and development. Pdf classifications, properties and applications of. Cold reactive dyes, such as procion mx, cibacron f, and drimarene k, are very easy to use because the dye can be applied at room temperature. These molecules carry a chromophore which absorb varying spectrums of the light, allowing only certain spectrums to reflect. The primary classification of dyes is based on the fibers to which they can be applied and the chemical nature of each dye. These factors involve both chemical and physical interactions between the dye and the fabric. Some dyes are water soluble and some are water insoluble. Pdf the chemistry of reactive dyes and their application processes.
Pdf technical facts of reactive dyes asad ali academia. Such reactive dyes serve as colorants for many industries including paper. A certain amount of dyes are hydrolyzed during application. Reactive dye contains reactive group and this reactive group makes covalent bonds with the fibers and becomes part of the fiber. Reactive dye, any of a class of highly coloured organic substances, primarily used for tinting textiles, that attach themselves to their substrates by a chemical reaction that forms a covalent bond between the molecule of dye and that of the fibre. They have better wash and light fastness properties. Structure, preparation and chemistry of reactive dyes. Ii must he pointed out that in this context chemical reac. In the dye bath, a suspension of the dye particle dispersion produces a very dilute solution of the dyes, which are then absorbed by the fibers. Effect of reactive dyes structure on light fastness written by p. Solvent dyes waterinsoluble, soluble in alcohols, chlorinated hydrocarbons, or liquid ammonia.
Reactive dyes opened the door to bright wetfast shades on cellulosic fibres that were not previously attainable. Reactive dyes and their application semantic scholar. Egeerton and morgan1 stated that the structure of the. The dyeing of pc fibre blended fabrics is usually carried out by using a twostage dyeing process to dye the individual fibres, with disperse dyes used for polyester and reactive, vat or direct dyes for the cellulosic component. Finding the chemical structure of two reactive dyes. Printing is generally carried out by a pigment printing process. Facets of the basic chemistry of the various types of reactive dyes relevant to their use in dyeaffinity chromatography are discussed and the wide variety of. Reactive black 5 is a reactive dye belonging to vinyl sulphone type. Download free textile books pdf dyeing and chemical. Due to the relatively high reactivity of the vinyl sulfone group with water residual moisture, air humidity, it is present in many commercial products in a protected form.
Sulfur dyes waterinsoluble, low cost, good fastness dyes. All the colorants in the list have been classified by their chemical structure and by their method of application. They were awarded gold medal from the society of dyes and colorists for the year 1960. The colour index assigns dyes of known structure to one of 25 structural classes according to chemical type.
Chemical structure of reactive dyes commercial names of reactive dye. Fiberreactive dyes these dyes react with the cellulosic fiber to form a covalent bond. This is of great interest, since, once attached, they are very difficult to remove 2. Direct dyes are the simplest dyes to apply and the cheapest in their initial and application costs although there are tradeoffs in the dyes shade range and wet fastness corbman, 1975. Different types of dyes with chemical structure meghmani. Types of dyes classification based on chemical structure.
The covalent bonds that attach reactive dye to natural fibers make them among the most permanent of dyes. Mordant dyes used to improve the fastness of the dye against. The dye is retained by means of a chemical reaction between the dye and the fibre. Inevitably, the residual azo dyes in wastewater from the dyestuff or textile industry would be a significant threat to public and environmental health. Nalankilli published on 20140301 download full article with reference data and citations.
A dye is a coloured compound,normally used in solution,which is capable of being fixed to a fabric. Such a classification would include direct dyes, reactive dyes, vat dyes, disperse dyes, azoic dyes, and several more types. Dyeing property and adsorption kinetics of reactive dyes. Basics reactive dyes free download as powerpoint presentation.
Hence, the chemical structure of a protein fiber can be written as 3. Generally, the synthesis of azo dyes involves two steps. Effect of reactive dyes structure on light fastness. They are reduced by another chemical and converted to a soluble form. Table 6 lists the major dye classes, fixation rates, and the types of fibers for which they have an. Azo dyes are the largest chemical class of synthetic dyes, and widely used as colorants in textile dyeing, leather, plastics, food, cosmetics, paper printing, with the textile industry as the largest consumer. This produces dyed fiber with extremely high wash fastness properties. Here, d dye part or chromogen color producing part dyes may be direct, acid, disperse, premetallised dye etc. They form strong covalent bond with the cellulosic fiber. The dye must be fastor chemically stable so that the colour will not wash with soap and water, fade on exposure to sunlight etc. A study of physicochemical properties, exhaust dyeing of. Amino groups or carboxylic groups exist either as terminal groups on the polymer chain or in side chains.
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