This presentation discusses the functional groups present in various natural and synthetic fibers as well as different types of dyes. It begins by identifying the functional groups in common natural fibers like cotton, wool, and silk, which contain groups like hydroxyl, carboxylic acid, and amino groups. It then examines the functional groups in several synthetic fibers such as polyester, nylon, acrylic, polyurethane and Kevlar. The presentation also categorizes dyes based on their chemical structure and functional groups like nitro, azo, and anthraquinone groups. Finally, it describes different methods of dye application including reactive, direct, disperse, acid, basic, and vat dyes.

1. WELCOME
TO
MY PRESENTATION

2. Submitted by:
Name: Md. Ashraful Alam
ID: 11121107013
Intake: 4th
Program: B.sc. in Textile Engineering
Submitted to:
Md. Mahabub Hasan
Lecturer in Textile
Department of Textile Engineering
BUBT

3. 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.

4. 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 presents
in wool.

5. 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 group
presents in silk.

6. 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.

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

8. 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 amide
in their structure.

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

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

11. Tri-acetate fibre:
Functional group:
 Acetyl group (CH3-CO)
Identification :
Acetate fibre consists of long polymer chain of celluboise and contains two acetyl
group (-CH3-CO) instead of two hydroxyl group (-OH) in the structure.

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

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

14. 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 premier
example 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.

15. 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 group
ortho or para to the hydroxyl group (-OH).

16. Azo dyes:
Group:
 Azo group (-N=N-)
They are characterized by the presence of one or more azo groups (-N=N-), which
form bridges between two or more aromatic group.

17. Dipheneylmethane dye:
Auramine O :
It is obtained by heating Michler’s ketone with ammonium chloride and zinc chloride
at 160 °C.

18. Triphenylmethane dye:
Melachite green:
The central carbon atom of triphenylmethane dye is joined to two benzene rings and
to ρ-quinoid group.

19. 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.

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

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

22. 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 first
obtained from the roots of the modder plant (Fr. Alizarin, modder).

23. According to method of application:
Reactive dye:
Here the dye contains a reactive group and this reactive group makes
covalent bond with the fibre polymer and act as an integral part of fibre.
This covalent bond is formed between the dye molecules and the
terminal –OH (hydroxyl) group of cellulosic fibres on between the dye
molecules and the terminal –NH2 (amino) group of polyamide or wool
fibres.

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

25. 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 a
Soap 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.

26. Acid dye:
An acid dye is a dye which is a salt of a sulfuric, carboxylic or phenolic organic
acid. 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.

27. 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.

28. 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.

29. Thank You Everybody