Polymers Monomer Polymerization Classification of Polymers

1. Polymer
Know polymers and its different classification

2. What is Polymer?
A polymer is a large molecule or a
macromolecule which essentially is a
combination of many subunits.
The term polymer comes from the Greek word
poly means ‘Many’ and meros meaning
‘parts’.

3. Monomer
The small individual repeating units/ molecules
are known as monomers (means single part)
Imagine that a monomer can be represented
by the letter a, then a polymer made of that
monomer would have the structure.
-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a

4. polymerization
The process by which the monomer
molecules are linked to form a big polymer
molecule is called ‘polymerization’
Polymerization is a process of bonding
monomer, or ”single units” together through a
variety of reaction mechanisms to form longer
chains named polymer
As important as polymers are, they exist with

5. Classification of polymers
 By origin
 By monomer
 By thermal
response
 By mode of
formation
 By structure
 By application &
physical properties
 By tacticity

6. Therearethree types of
classificationunderthis category,
namely,Natural,Synthetic,andSemi-
syntheticPolymers.
By Origin

7. Natural Polymers
Polymers which are
isolated from natural
materials are called
natural polymers
Example : Silk, wool,
natural rubber,
cellulose, starches,
proteins, etc,

8. Semi synthetic polymers
The polymers obtained by
simple chemical treatment of
natural polymers to improve
their physical properties like
lustrous nature, tensile strength
are called semi synthetic
polymers.
Example: Cellulose acetate ,
cellulose nitrate.

9. synthetic polymers
Polymers synthesized in
laboratory from low molecular
weight compounds, are called
as, synthetic polymers.
Example : nylon, terylene,
polyethlene, polystyrene,
synthetic rubber, pvc, bakelite,
teflon, etc

10. By monomer

11. Homo Polymers
A polymer consist of
identical monomers is
called homo polymer
Example : Polyethylene,
pvc, polypropylene, nylon
6

12. Co polymers
A polymer consist of
monomers of different
chemical structure are
called copolymers
Example : Nylon 6,6

13. By thermal response

14. Thermoplastic polymers
They are easily molded in
desired shapes by heating and
subsequent cooling at room
temperature
They are soft in hot and hard
on coding
They may be linear or
branched chain polymers
Example : Nylon 6,6

15. ThermoSETTING polymers
this polymer is hard and infusible
on heating.
these are not soft on heating
under pressure and they are not
remolded.
these are cross linked polymers
and are not reused.
example : bakelite

16. BY MODE OF
FORMATION

17. ADDITIONPOLYMERS
the polymers formed by the addition of
monomers repeatedly without removal
of products are called addition
polymers.
these polymers contains allthe atoms
of monomers hence their molecular
weight are integral multiple of monomer
unit
example :: teflon, polyethylene,
polypropylene, pvc.

18. CONDENSATION POLYMERS
they are formed bY the combination of
two monomers by removal of small
molecules like h2o, alcohol, or nh3. their
molecular mass is not the integral
multiple of monomer units.
they have ester and amide linkage in
their molecules,
example polyamides (nylons),
polyesters (pet)

19. BY structure

20. Linear polymers
In these polymers monomers
are linked with each other and
form a long straight chain
These chains has no any side
chains
Their molecules are closely
packed and have high density,
tensile strength and melting
point.
Example : hpde, nylons

21. Cross-linked polymer
In these monomeric units are
linked together to constitute a 3d
network
The involved are called cross
links
They are hard, rigid and brittle
due to their network structure.
Example : Bakelite, melamine,
formaldehyde resins, vulcanized

22. By applications &
physical properties

23. Fibers
If polymer is drawn into long filament
like a material whose length is at least
100 times it’s diameter, are said to be
converted into fiber
They have high tensile strength
because of high intermolecular
attractive force like hydrogen bonding
Highly crystalline
Example nylon, terylene

24. plastics
Polymer is shaped into hard and
tough utility articles by application of
heat and pressure, is known as
plastics.
Here the intermolecular force
between polymeric chains are
intermediate between elastomeric
and fibers.
They are partially cryystalline
Example : polystyrene, pvc, pmma

25. elastomers
They are solids with rubber like
elastic properties.
Here the polymeric chains are held
together by the weakest
intermolecular forces so they are
amorphous in nature
These weak binding forces permit
them to be stretched.
Example natural rubber, una-s,
buna-n, vulcanized rubber

26. Resins
Low molecular weight
Polymers which are used as
adhesives, sealants etc,, in a
liquid form are described as
liquid resins.
Example ; Epoxy adhesives and
polysulphides sealants.

27. By tacticity

28. Tacticity simply means deposition of sides
groups in space
The head to tail configuration in which
the functional groups are all deposited on
the same side of the chain, is called
isotactic polymers.
If the deposition of side group is in
alternating fashion, it is called synditactic
polymers.

29. Tacticity simply means deposition of
sides groups in space
If the deposition of side groups
are at random around the main,
it is called atactic polymers

30. Other parameters of
classification

31. ByCrystalinity
1. Crystalline – monomers arranged
in ordered way.
2. Amorphous- monomers arranged
in random way

32. Thank you!