Polymers

1. CLASSIFICATION OF
POLYMERS
Presented by:
Ujjwal Acharjee
B.Tech (Food Technology) 2nd semester
A20412622018

2. What are Polymers?
A polymer is a large molecule or a macromolecule
which essentially is a combination of many subunits.
The term polymer in Greek means ‘many parts’.
Polymers can be found all around us. From the strand
of our DNA, which is a naturally occurring biopolymer,
to polypropylene which is used throughout the world
as plastic.

3. Classification on the basis of structure

4. Linear Polymer
Branched Polymer
Cross-Linked Polymer
In these polymers monomers are linked with each other
and form a long straight chain. These chains has no any
side chains. Ex. Polyethene, PVC, Nylons, polyesters etc.
Their molecules are closely packed and have high
density, tensile strength, and melting point.
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.
Ex. polypropylene (side chain —CH3), amylopectin
and glycogen.
In these monomeric units are linked together to
constitute a three dimensional network. The links
involved are called cross links. They are hard, rigid
.and brittle due to their network structure.
Ex. Bakelite, melamine, formaldehyde resins,
vulcanised rubber etc.

5. Classification on the basis of source

6. NATURAL
POLYMER
SEMI-
SYNTHETIC
POLYMER
SYNTHETIC
POLYMER
Polymers either obtained from plants or animal are called natural
polymers. They are called plant and animal polymers. Ex. Cellulose,
Jute, Lichen, Silk, Wool, Leather, RNA, DNA, Natural rubber.
The polymers obtained by simple chemical treatment of natural fibers
to improve their physical properties like lastrus nature, tensile
strength are called semisynthetic fibers. Ex. Acetate rayon,
cuprammonium silk, viscous rayon.
The fibres obtained by polymerization of simple chemical molecules in
laboratory are synthetic fibres. Ex. Nylon, erylene, polyethene,
polystyrene, synthetic rubber, nylon, PVC, backlite, Teflon, Orion etc.

7. Classification on the basis of number of monomers

8. Polymer is made from all
identical monomer
molecules e.g., Polyethylene,
Polystyrene,
Polyvinylchloride etc.
Polymer made from two
different type of monomer
units e.g.. Styrene butadiene
rubber, Styrene acrylonitrile
rubber etc.

9. Classification on the basis of arrangement of
monomers in the chain

10. RANDOM
COPOLYMER
ALTERNATING
COPOLYMER
BLOCK
COPOLYMER
Alternating copolymer contains a alternate
arrangement of the monomer. E.g.
ABABABABABABABABA
Random copolymer contains a random
arrangement of the monomers. E.g.
ABCBCBABCBCACBABCBCAC
Block copolymer contains blocks of
monomers of the same type. E.g.
AAAAAAABBBBBBBA

11. Classification on the basis of configuration

12. Isotactic polymer: The head-to-tail configuration, in which functional groups all on the
same side of the chain, is called isotactic polymer.
Atatic polymer: The arrangement of functional groups are random around the main
chain, it is called atatic polymer.
Syndiotactic: The arrangement of the side groups is in alternating fashion, it is called
syndiotactic polymer.

13. Classification on the basis of intramolecular
forces

14. Elastomers
These are rubber like solids with elastic
properties. In these elastomeric polymers, the
polymer chains are held together by the
weakest intermolecular forces. E.g. Buna-S,
Buna-N, Neoprene, etc.
Fibres
Fibres are the thread forming solids which
possess high tensile strength and high
modulus. These characteristics can be
attributed to the strong intermolecular forces
like hydrogen bonding. E.g. Polyamides(nylon
6,6), Polyesters(terylene), etc.
Thermoplastic polymers
These polymers possess intermolecular forces
of attraction intermediate between elastomers
and fibres. E.g. Polythene, Polystyrene,
Polyvinyls, etc.
Thermosetting polymers
These polymers are cross-linked or heavily
branched molecules, which on heating
undergo extensive cross-linking in moulds and
again become infusible. These cannot be
reused. E.g. UreaFormaldehyde resins,
Bakelite, etc.

15. Classification on the basis of type of
polymerisation

16. ADDITION POLYMER
CONDENSATION POLYMER
An addition polymer is a polymer formed by simply linking the monomers with no co-generation of other
products.
These polymers are generally made from molecules having carbon-carbon double bonds which means
addition polymers are prepared from alkenes.
They are also called chain growth polymers.
Generally, these reactions occur in presence of catalyst. Main catalyst used in the polymer industry is the
Ziegler Natta catalyst.
Examples- Polyethylene, Polyvinyl Chloride, Teflon, Rubbers (Buna-N, Buna-S), Polyacrylonitrile.
Condensation polymers are formed when the small monomeric units react with each other to form the
larger polymeric units with a loss of water molecule. Condensation polymers form slowly as compared to the
additional polymers because condensation polymer requires heat. It is a step-growth polymerization. The
condensation polymers contain functional groups like amine, alcohol, carboxylic acid.
Example: Terylene, Nylon and polyesters.

17. THANK YOU