2 edition of reactions of reactive dyes with wool. found in the catalog.
reactions of reactive dyes with wool.
Written in English
Thesis (Ph.D.)--The Queen"s University of Belfast, 1980.
|The Physical Object|
Covalent bonding is the one of the most basic and strongest types of chemical reactions. This reaction happens gradually over time depending on temperature and/or the Ph level of the surrounding environment. Higher pH speeds the reaction, as does heat. But with the cooler water Procion type dyes, too much heat can cause the colors to actually not bond. Reactive dyes current account for about 5 % if the wool dyes market. The largest dye group is the chrome dye class with 31 % of the market but globally there are increasing concerns about the environmental impact of the group of the dyes they have excellent fastness properties however and only the reactive class comes close in the : Ruma Chakrabarti.
Reaction to alkalis: Wool is quickly damaged by strong alkalis. Reaction to acids: 1. Wool is damaged by hot sulphuric acid. 2. The fibre is not affected by other acids. Affinity for dyes: Wool fibre has high affinity for certain types of dyes, i.e. Acid, reactive dyes, Basic dye 5. Fiber reactive dyes such as Procion MX, Cibacron F, and Drimarene K can also be used as acid dyes on wool; see Reactive dyes on protein fibers. Natural dyes. Many natural dyes work very well on protein fibers, such as wool. Most will require a mordant, such as alum, copper, tin, or iron, so they are not necessarily more on-toxic than synthetic.
The effect of urea on formation and cleavage of a covalent bond between a reactive dye and cellulose has been investigated. The evidence presented is consistent with the view that urea increases the bonded dye yield by keeping the reactive dye in solution during the diffusion of the dye to its reaction Cited by: Although Acid dyes are usually recommended for protein fibres, you can also use Procion MX fibre reactive dyes (here is the fibre reactive dye recipe for cellulose fibres). Even old dyes continue to work well on wool. Some of the colours will dye more true to type than others. In particular some blues produce unexpected results.
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Amino–acid analyses of wool dyed to heavy depths with unmetallised and 1: 2 metal–complex acrylamido dyes show that reaction takes place predominantly with the –amino group of lysine residues, there being no evidence of reaction with the thiol group of cysteine nor with histidine by: A novel system, based on the use of trichloroacetic acid, is proposed, which gives improved levelness, especially when dyeing wool with mixtures of reactive dyes.
use of chrome dyes. Reactive dyes Reactive dyes are so named because they chemically react with the wool protein via either nucleophilic substitution or addition reactions.
In this way a covalent bond (a reactions of reactive dyes with wool. book bond) is formed between the reactive dye and the wool fibre.
Reactive dyes. Reactive dyes can also be used to dye wool and nylon, in the latter case they are applied under weakly acidic conditions. The most important characteristic of reactive dyes is the formation of covalent bonds with the substrate to be coloured, i.e. the dye forms a chemical bond with cellulose, which is the main component of cotton fibers.
It is interesting to reflect why reactive dyes based on reactive halogenated heterocycles, which react with wool fibre nucleophiles by a nucleophilic substitution reaction, are less effective in controlling wool damage in dyeing than are the activated carbon-carbon double bond type of reactive dye.
From the above discussions it is clear that. t dyeings on wool. from. dyes con taining chloroacetyl groups and in mids they were placed in the market as supramine orange R.
the first gen uinely reactive dye for wool of the followin,lUUc:tute. During () CIBA chemists. Haller and Hecken dron. File Size: KB. variety of groups that are able to combine with reactive dyes . The most important sites on keratin that are available for reactions with reactive dyes are shown in Table .
There are plenty of evidences that reactive dyes react with the various side-chains of wool . Remazol Brilliant Blue R reacts with the lysine, histidine,File Size: 2MB.
The reactions of wool with sulfamic acid have been investigated and the results show that under the conditions used, the reactions are similar to those of sulfuric acid and wool. project: reaction mechanism of reactive dyes in on cellulose fiber.
(Gokhale and Shah, ). In general, structure of all reactive dyes can be represented as C-B-A. Abstract. Facets of the basic chemistry of the various types of reactive dyes relevant to their use in dye-affinity chromatography are discussed and the wide variety of chromogens used in reactive dyes Cited by: 1.
Dyes containing one or more azo groups (i.e. azo dyes) comprise by far the largest family of organic dyes. Prominent types are 1) acid dyes for polyamide and protein substrates such as nylon, wool, and silk; 2) disperse dyes for hydrophobic substrates such as polyester and acetate, and 3) direct and reactive dyes for cellulosic substrates such asFile Size: KB.
D-SO2-CH2-CH2-OSO3Na + NH2- wool D-SO2-CH2-CH2-NH-Wool + NaHSO3 Here, D= dye part. Wool = wool polymer. Cell = cellulosic polymer. Reasons for so named: Reactive dyes are so called because this is the only type of dye, which has reactive group, and that reactive group reacts chemically with fibre polymer molecules and form covalent bond.
Dye Hydrolysis Exhaustion Fixation N ucleophilic,Reactions Reactive Dyes Washingoff Wetfastness savor to dye research and development, both continued to be directed primarily towards cotton and, to a lesser extent, wool.
It was not until after the second World War, in the early Os, that the rapid growth of nylon and polyester beganFile Size: KB. The launch of the first fibre-reactive dyes for cellulose ina century after the development of the first synthetic dye, enabled new and high fastness properties to be obtained.
Reactive dyes have the unique property that they are designed to bond covalently with the substrate on application. IV. Competitive Reaction with Adsorption and Diffusion V. Use of Reaction Catalysts VI.
Removal of Unfixed Dye from Reactive-Dyed Materials VII. Stability of Dye-Fiber Bonds VIII. Fixation of Reactive Dyes on Wool IX. Novel Approaches to Reactive Dye Fixation II. Leather Dyes I. Introduction II. General Discussion III. Anionic Dyes IV. Cationic Book Edition: 1. In a reactive dye, a chromophore contains a substituent that reacts with the substrate.
Reactive dyes have good fastness properties owing to the covalent bonding that occurs during dyeing. Reactive dyes are most commonly used in dyeing of cellulose like cotton or flax, but also wool is dyeable with reactive dyes.
Reactive dyeing is the most important method for the coloration of cellulosic fibres. Reactive dyes can also be applied on wool. Low brand reactive dyes: This type of dyes has very low reactivity properties with fiber with comparison with medium and high brand reactive dyes.
Dyeing is carried out on 60 degree Celsius. Properties of reactive dyes: Reactive dye is anionic in nature. Reactive dye is a water soluble dye. They have better wash and light fastness properties. Reactive dyes Reactions of cyanuric chloride and the chemistry of reactive dyes.
Evidence supporting the formation of a covalent bond between the dye molecule and cellulose. Application of dichlorotriazinyl dyes at low temperatures and monochlorotriazinyl dyes at.
Reactive dyes are so-called because this is the only type of dye that has a reactive group. This group reacts chemically with the fiber polymer molecules to form covalent bonds. This covalent bond is formed between the reactive group and terminal –OH group of cellulosic fibers and terminal –NH 2 group of polyamide and wool fiber.
It was not until the early s, following the marketing in by Hoechst of two Remalan (HOE) vinylsulphone dyes capable of reacting with wool, that ICI was successful in devising a reactive dyeing process that enabled cellulose to be dyed with a trichromatic mixture of dyes under practical conditions.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.
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. The preparation of the solutions, the purpose of each chemical, the Cited by: 3.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.
The dyestuff thus becomes a part of the fibre and.