CLASSIFICATION OF POLYMERS
Polymers can be classified in two ways as give below:
- Classification based on source of availability.
- Classification based on method of synthesis.
1. Classification based on source of availability
According to this classification polymers are of two types:
- Natural polymers
- Synthetic polymers
The polymers obtained from nature are called natural polymers. For example, starch, cellulose, natural rubber, proteins and nucleic acids etc. are common examples of natural polymers.
The polymers which are prepared in the laboratories are called synthetic polymers. These are also known as man-made polymers. Examples of synthetic polymers are nylon, teflon, terylene, polyvinyl chloride and synthetic rubber.
2. Classification of polymers on the basis of method of synthesis
On the basis of method of synthesis, the polymers are also of two types:
- Addition polymers
- Condensation polymers
1. Addition Polymers
A polymer formed by direct addition of repeated monomers without the elimination of any molecule is called addition polymer. The addition polymers are generally prepared from unsaturated compounds. For example natural rubber is obtained as latex from rubber trees. The monomer of natural rubber is isoprene. There may be as many as 11000 to 20000 isoprene units in a polymer chain of natural rubber.
2. Condensation Polymers
These polymers are formed by the condensation of two or more monomers with the elimination of simple molecules like water and alcohol. Following are the examples of two important condensation polymers: