Classification of polymers based on composition:
(1) Homo-polymer
(2) Co-polymer
(1) Homo-polymer:
When a polymer is obtained from a single monomer unit, it is called homo-polymer. Example: polystyrene, polyethylene, polypropylene, etc.
(2) Co-polymer:
When a polymer contains two or more monomer units in the chain then it is known as a co-polymer. Example: nylon 6.6
**Tar-polymer:
When a co-polymer has three monomers in the chain it is referred to as tar-polymer.
Co-polymer has the following sub-division:
(a) Random co-polymer:
A random co-polymer is a polymer comprised of two or more different repeating units attached in a random order.
- A - A - B - A - B - B - A - B - B - A -
(b) Alternative co-polymer:
An alternative co-polymer is a type of polymer consisting of two different repeating units in which the units alternate position with the chain of molecule.
- A - B - A - B - A - B - A - B - A - B -
(c) Block co-polymer:
comprised two or more homo-polymer sub-units linked by co-valent bond.
- A - A - A - B - B - B - B - A - A - A -
(d) Graft co-polymer:
A special type of branch co-polymer in which the side chains are structurally distinct from the main chain.
- A - A - A - A - A - A -
। ৷
B B
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B B
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B B
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B B
(where A & B are two different monomers)