structure of fibre and dye

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MY PRESENTATION

Submitted by:Name: Md. Ashraful Alam ID: 11121107013Intake: 4thProgram: B.sc. in Textile Engineering

Submitted to: Md. Mahabub Hasan Lecturer in Textile Department of Textile Engineering BUBT

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Fibre structure with functional group:

Cotton fibre:

Functional group:Hydroxyl group (-OH)Identification:Cotton fibre formed by long molecular chain of celluboise and contains hydroxyl group (-OH) in the molecular structure.

Wool fibre:

Functional group: Carboxylic acid group (-COOH) and amino group (-NH2) presents as peptide group (-CONH-) Carbonyl group (=CO) Imino group (-NH-)Identification:Wool is a natural fibre (protein), carboxylic acid group (-COOH) and amino group(-NH2) present as peptide group in wool. Also carbonyl group and imino group presentsin wool.

Silk fibre:

Functional group: Carboxylic acid group (-COOH) and amino group (-NH2) presents as peptide group (-CONH-) Carbonyl group (=CO) Imino group (-NH-)Identification:Silk is a natural fibre (protein), carboxylic acid group (-COOH) and amino group (-NH2) present as peptide group in silk. Also carbonyl group and imino grouppresents in silk.

Polyester fibre:

Functional group: Methylene group (-CH2-) Carbonyl group (=CO) Ester group (-COOR)Identification: Polyesters are formed by combining of terephthalic acid and ethylene glycol.It contains methylene, carbonyl and ester group in their structure.

Nylon 6:

Functional group: Amide group (-CONH-)Identification:Nylon 6 consists by polymerization of Caprolactam. It contains amide group intheir structure.

Nylon 6,6:

[-OC-( CH2)4-CO-NH-(CH2)6-NH-] n

Functional group: Amide group (-CONH-)Identification:Nylon 6,6 consists by polymerization of hexamethylene adipamide and contains amidein their structure.

Acrylic fibre:

Functional group: Methylene groupIdentification:Acrylic fibre formed from any long chain synthetic polymer composed of at least 85%by weight of an acrylonitrile unit.

Acetate fibre:

Functional group: Acetyl group (CH3-CO)

Identification :Acetate fibre consists of long polymer chain of celluboise and contains two acetylgroup (-CH3-CO) instead of two hydroxyl group (-OH) in the structure.

Tri-acetate fibre:

Functional group: Acetyl group (CH3-CO)

Identification :Acetate fibre consists of long polymer chain of celluboise and contains two acetylgroup (-CH3-CO) instead of two hydroxyl group (-OH) in the structure.

Polyurethane fibre:

Functional group: Urethane group (-NH-C=O)Identification: Polyuretehane is generally formed by the reaction of a polyol with a diisocyante andcontains significant number of urethane group in the molecular chain.

Kevlar fibre:

Kevlar is the registered trademark for a para-aramid synthetic fiber, related toother aramids such as Nomex and Technora. Kevlar is synthesized in solution from themonomers 1,4-phenylene-diamine (para-phenylenediamine) and terephthalic acid.

Nomex fibre:

Nomex and related aramid polymers are related to nylon, but have aromatic backbones, and hence are more rigid and more durable. Nomex is the premierexample of a meta variant of the aramids (Kevlar is a para aramid). Unlike Kevlar,Nomex cannot align during filament formation and has poorer strength.However, it has excellent thermal, chemical, and radiation resistance for a polymer material.

Dye structure with functional group:1) According to chemical structure:Nitro dyes:

Group: Nitro group (-NO2)Nitro dyes are poly nitro derivative of phenols containing at least one nitro grouportho or para to the hydroxyl group (-OH).

Azo dyes:

Group: Azo group (-N=N-)

They are characterized by the presence of one or more azo groups (-N=N-), whichform bridges between two or more aromatic group.

Dipheneylmethane dye:Auramine O :

It is obtained by heating Michler’s ketone with ammonium chloride and zinc chlorideat 160 °C.

Triphenylmethane dye:Melachite green:

The central carbon atom of triphenylmethane dye is joined to two benzene rings andto ρ-quinoid group.

Xanthane dyes: Rhodamine B:

They are obtained by condensing phenols with phthalic anhydride in the presence of zinc chloride, Sulphuric acid, or anhydrous oxalic acid.

Phtahaleins:

Phenolphthaleins:

They are obtained by condensing phenols with phthalic anhydride in the presence of zinc chloride, Sulphuric acid, or anhydrous oxalic acid.

Indigoid:

Indigo was originally obtained from plants or indigofera group. Enzymes present in theplants brought about fermentation , as a result of which the β-glucose of indoxylgroup (known as indican) in the leaves was converted into indoxyl and glucose. Uponexposure to air the indoxyl group was oxidised to indigo.

Anthroquionoid dyes:

Anthroquionoid dyes are used for dyeing wool, silk, nylon, cotton, leather and paper.The most important dye in this group is alizarin.Alizarin: It is 1,2-dihydroxyanthrquinone. Alizarin, its name from the fact that was firstobtained from the roots of the modder plant (Fr. Alizarin, modder).

According to method of application:

Reactive dye:

Here the dye contains a reactive group and this reactive group makescovalent bond with the fibre polymer and act as an integral part of fibre.This covalent bond is formed between the dye molecules and theterminal –OH (hydroxyl) group of cellulosic fibres on between the dyemolecules and the terminal –NH2 (amino) group of polyamide or woolfibres.

Direct dyes:

Direct dye contains acidic and basic groups and combined with the polar groups in thefibre. Such dyes color a fabric directly when the fibre is immersed in a hot aqueoussolution of the dye.

Disperse dyes:

These are insoluble in water, but they are capable of dissolving certain synthetic fibres.Disperse dyes are usually applied in the form of a dispersion of finely divided dye in aSoap solution in the presence of some solublising agent such as phenol, cresol, or benzoic acid. The absorption into the fibre is carried out at high temperature and Pressures.

Acid dye:

An acid dye is a dye which is a salt of a sulfuric, carboxylic or phenolic organicacid. The salts are often sodium or ammonium salts. Acid dyes are typically soluble in water and possesses affinity for amphoteric fibers while lacking direct dye'affinity for cellulose fibers. When dyeing, ionic bonding with fiber cationic sites accounts for fixation of colored anions in the dyed material. Acids are added to dyeing baths to increase the number of protonated amino-groups in fibers.

Basic dyes:

Basic dyes, these dyes are also known as cationic dyes. This is a class of synthetic dyes , that act as bases and when made soluble in water , they form a colored cationic salt , which can react with the anionic sites on the surface of the

Substrate.

Vat dyes:

Vat dyes are a class of dyes that are classified as such because of the method by which they are applied. Vat dyeing is a process that refers to dyeing that takes place in a bucket or vat. Vat dyes are insoluble in water but it becomes in soluble form by vatting process. The process of converting insoluble vat dyes into soluble form is called vatting.

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