The document by Devansh Gupta presents a detailed classification of polymers, defining key terms such as polymers, monomers, and polymerization, alongside various classification criteria including origin, monomer type, thermal response, mode of formation, structure, application, physical properties, and tacticity. Natural, semisynthetic, and synthetic polymers are discussed, as well as different types such as homopolymers and copolymers. The document also emphasizes the importance of polymers in applications like fibers, plastics, elastomers, and resins, along with references for further reading.

1. Classification Of Polymers
Presented by
Devansh Gupta
M.ScPolymer Science
Semester 1

2. Contents
 Some Basic Definitions
 Classification Of Polymers
1. By Origin
2. By Monomer
3. By Thermal Response
4. By Mode Of Formation
5. By Structure
6. By Application & Physical Properties
7. By Tacticity
 Reference

3. Definition
The word ‘polymer’ comes from the Greek
words poly (meaning ‘many’) and meros
(meaning ‘parts’).
Example: POLYETHYLENE =
(ETHYLENE+ ETHYLENE+......)n
Where n = 4,000
Polymers are very large molecules made when hundreds of
monomers join together to form long chains.

4. 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-

5. 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
monomers, which are small, single molecules
such as hydrocarbons and amino acids.

6. Classification Of Polymers
1. By Origin
2. By Monomer
3. By Thermal Response
4. By Mode Of Formation
5. By Structure
6. By Application & Physical Properties
7. By Tacticity

7. By Origin
Natural Polymers
Polymers which are isolated from natural
materials are called as natural polymers.
E.g. Silk, Wool, Natural rubber, Cellulose,
Starch, Proteins etc.

8. Natural Rubber
Hevea Brasiilensis

9. Semisynthetic Polymers
The polymers obtained by simple chemical
treatment of natural polymers to improve
their physical properties like lustrous nature,
tensile strength are called semisynthetic
polymers
E.g. Cellulose acetate, Cellulose nitrate

10. Synthetic Polymers
Polymers synthesized in laboratory from low
molecular weight compounds, are called as,
synthetic polymers.
E.g. Nylon, Terylene, Polyethylene, Polystyrene,
Synthetic rubber, Nylon, PVC, Bakelite, Teflon etc.

11. By Monomer
Homo Polymers
A polymer consist of identical monomers is
called homo polymer.
E.g. Polyethylene, PVC, Polypropylene, Nylon 6
Co Polymers
A polymer consist of monomers of different
chemical structure are called copolymers.
E.g. Nylon 6,6

12. By Thermal Response
Thermoplastic Polymers
 They are easily moulded in desired shapes by heating
and subsequent cooling at room temperature.
 They are soft in hot and hard on coding.
 They my be linear or branched chain polymers.
E.g. PE, PVC, PS, PP

13. 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.
E.g. Bakelite

14. By Mode Of Formation
Addition Polymers
The polymers formed by the addition of
monomers repeatedly without removal of by
products are called addition polymers.
These polymers contains all the atoms of
monomers hence their molecular weight are
integral multiple of monomer unit.
E.g. Teflon, Polyethylene, Polypropylene, PVC.

15. 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.
E.g. Polyamides(Nylons), Polyesters(PET)

16. By Structure
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.
E.g. HDPE, Nylons

17. Branched Polymers
They have a straight long chain with different
side chains.
Their molecules are irregularly packed hence
they have low density, Tensile strength and
melting point.
E.g. LDPE, LLDPE

18. Cross-linked Polymer
In these monomeric units are linked together to
constitute a 3D network.
The links involved are called cross links.
They are hard, rigid .and brittle due to their
network structure.
E.g. Bakelite, Melamine, Formaldehyde resins,
Vulcanized rubber

20. By Applications & Physical Properties
Fibers
If polymer is drawn into long filament like
materiel 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.
E.g. Nylon, Terylene.

21. 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
elastomers and fibers.
They are partially crystalline.
E.g. Polystyrene, PVC, PMMA

22. Elastomers
They are solids with rubber like elastic
properties.
Here the polymeric chains are held together by
the weakest intermolecular forces so they are
highly amorphous in nature.
These weak binding forces permit them to be
stretched.
E.g. Natural rubber, BUNA-S, BUNA-N,
Vulcanised rubber

24. Resins
Low molecular weight.
Polymers which are used as adhesives, sealants
etc., in a liquid form are described as liquid
resins.
E.g. Epoxy adhesives and polysulphides sealants.

25. ByTacticity
Tacticity simply means deposition of
side 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 groups is in alternating fashion, it is called
synditactic polymers.
 If the deposition of side groups are at random around the main, it
is called atactic polymers.

26. Other Parameters Of Classification
By Crystallinity
1. Crystalline – Monomers arranged in ordered way.
2. Amorphous – Monomers arranged in random way.
By Backbone Atom
1. Organic – Polymer Backbone is made-up of carbon atom.
2. Inorganic – Polymer Backbone is made-up of other atoms

27. References
Polymer Science - Gowariker V. R., New age
International Publishers
Textbook of Polymer Science - Billmeyer F. W,
Wiley India Publishers
Advanced Polymer Chemistry – Manas Chanda
Marcel Dekker INC.