1. FIBRE CHEMISTRY
Ms. Mohaddesa Dehghani
Assistant Professor
Amity School of Fashion Design and Technology
Amity University Mumbai
2. ELEMENT, MOLECULE & COMPOUN
ELEMENT: An element is a simplest pure substance, it cannot
be broken down further. The actual physical particles of
elements are atoms or molecules eg. Na, H.
MOLECULE: Is the smallest particle of a pure substance
(element) that can exist independently and retain all the
properties of the substance. Eg. O2, H2
COMPOUND: When different elements combine in a definite
mass, a compound is formed. NaCl, H2O
3. MONOMER & POLYMERMONOMER
Is a single unit
of a polymer.
Basic unit of an
atom or a small
macromolecule
that combine
together to form
a polymer. POLYMER
Is a long chain
molecule or a
macromolecule
made up of many
units of monomers.
It is technically a
polymolecule i.e.
any molecule
composed of 1 or
more monomer or a
single molecule.
4.
5. POLYMERIZATION
The formation of
polymers from monomers
can be done by joining
them together by
covalent bonds. This
process is known as
polymerization.
6. BONDING
A chemical bond is a lasting attraction
between atoms that enables the formation
of chemical compounds.
The bond may result from the electrostatic
force of attraction between atoms with
opposite charges, or through the sharing of
electrons as in the covalent bonds.
10. IONIC COMPOUNDS
In chemistry, an ionic compound is a
chemical compound comprising ions held
together by electrostatic forces termed
ionic bonding.
The compound is neutral overall, but
consists of positively charged ions called
cations and negatively charged ions
called anions.
11. IONIC COMPOUNDS
Ionic compounds containing hydrogen
ions (H+) are classified as acids, and
those containing basic ions hydroxide
(OH−) or oxide (O2−) are classified as
bases.
Ionic compounds without these ions
are also known as salts and can be
formed by acid–base reactions.
12. Covalent bonds
A covalent bond, also called a
molecular bond, is a chemical bond
that involves the sharing of electron
pairs between atoms.
These electron pairs are known as
shared pairs or bonding pairs, and the
stable balance of attractive and
repulsive forces between atoms, when
they share electrons, is known as
covalent bonding.
13. BENZENE RING
Benzene is an important organic
chemical compound with the chemical
formula C6H6.
The benzene molecule is composed of
6 carbon atoms joined in a ring with 1
hydrogen atom attached to each.
Because it contains only carbon and
hydrogen atoms, benzene is classed
as a hydrocarbon.
15. VANDER WAAL FORCES
Formed between atoms along the length of
adjacent polymer when these are less than
0.3Nm apart but no closer than 0.2Nm.
They are the only inter-polymer forces of
attraction existing in the polymer system.
They are considered to be predominant
inter-polymer force of attraction in the
polymer system of acryllic, mod acryllic and
polyester fibre.
17. CRYSTALLINITY
Crystallinity refers to the degree of
structural order in a fibre/any solid.
In a fibre, the atoms or molecules are
arranged in a regular, periodic manner.
The degree of crystallinity has a big
influence on hardness, density,
transparency and diffusion of the fibre.
18. AMORPHOUS REGIONS
The term amorphous means to have
no defined shape, or an easily altered
shape, like a liquid or a rubber.
19. DIFFERENCE
The amorphous nature of polymers is
analogous to a plateful of spaghetti ---
loose and randomly coiled.
While the crystalline state is more like
the uncooked spaghetti in the box ---
the chains are all tightly bundled and
ordered in the same direction.
20. WATER AFFINITY
Hydrophilic means having a tendency to mix
with, dissolve in, or be wetted by water.
Hygroscopy is the ability of a substance to
attract and hold water molecules from the
surrounding environment.
Hygroscopic substances include fibers
such as cotton and rayon.
Hydrophobic means ending to repel or fail to
mix with water. Eg. most synthetic fiber
such as polyester and polypropylene
21. SOLUBILITY
The solubility of a fibre in a particular
chemical agent is a means of
identification.
The fibre can be placed in a chemical at
a particular temperature and the
solubility will confirm the type of fibre.
FIBRE NAME – CHEMICAL NAME
Cotton – 75% Sulphuric Acid
Wool & Silk – 5% Sodium
Hydrochlorite,5% NaOH at boil
22. OXIDATION & REDUCTION
Oxidation is the loss of electrons or an
increase in oxidation state by a molecule,
atom, or ion. Presence of Oxygen atom.
Reduction is the gain of electrons or a
decrease in oxidation state by a molecule,
atom, or ion. Presence of a Hydrogen atom.
23.
24. STRUCTURE & PROPERTIES OF COTTON
Comfortable Soft hand.
Good absorbency.
Color retention.
Prints well.
Machine-washable.
Dry-cleanable.
Good strength.
Drapes well.
25. STRUCTURE & PROPERTIES OF WOOL
Resists wrinkles: wool springs back quickly
Resists soiling
Is durable
Repels moisture
Retains shape: resilient fibers return to size
Resists flames: fibers will not support combustion
Is comfortable in all seasons: keeps layer of air next to skin
26. STRUCTURE & PROPERTIES OF
SILKSilk has a smooth, soft texture that
is not slippery, unlike many synthetic
fibers.
Silk is one of the strongest natural
fibers.
It has a good moisture regain .
Its elasticity is moderate to poor:
if elongated even a small amount, it
remains stretched.
27. STRUCTURE & PROPERTIES OF
NYLON
Variation of luster: nylon has the ability to be very
lustrous, semilustrous or dull.
Durability: its high tenacity fibers are used for seatbelts,
tire cords, ballistic cloth and other uses.
High elongation.
Excellent abrasion resistance.
Highly resilient (nylon fabrics are heat-set)
Paved the way for easy-care garments.
28. STRUCTURE & PROPERTIES OF
POLYESTER
Polyester is very durable, resistant to most chemicals,
stretching and shrinking, wrinkle resistant, mildew and
abrasion resistant.
Polyester is hydrophobic in nature and ensures quick
drying.
