CLASSIFICATION OF POLYMERS

1. ON BASIS OF SOURCES:
1. Natural : Starch, cellulose, protein, nucleic acid, natural rubber,etc.

2. Synthetic: polyethene, polypropylene, polystyrene, polyvinyl chloride (PVC) ,nylon, terylene, bakelite, etc.

ON BASIS OF STRUCTURE:
1.Linear: Monomeric units are joined in the form of long straight chains, such polymers have high densities, high tensile strength and high melting point.

LINEAR CHAIN
e. g. Polyethylene, nylons and polyesters.

2.Branched chain: are mainly linear in nature but also possess some branches along the main chain. E.g. low density polyethene (LDPE)
They have densities, lower tensile strength and low melting point

BRANCHED CHAIN
e. g. Amylopectin and glycogen
3.Crossed Linked polymers : Monomeric unit’s are linked together to constitute a three dimensional network. They are hard, rigid, and brittle.

CROSS LINKED
e. g. Bakelite, Melamine formaldehyde resin, etc,

Based on Interparticle forces:
1. Elastomer: Polymer chain is held up by weakest attractive forces. They are amorphous polymers having high degree of elasticity.
E.g. Synthetic rubber.
2. Fibers : These are the polymer which have quite strong Interparticle forces such as H - bond . They have high tensile strength and high modulus.
E.g. Nylon 6,6
3. Thermoplastic polymer: Interparticle forces of attraction are in between those of elastomer and fibers. They are linear, long chain polymers, they are linear, long chain polymers, which can be softened on heating and hardened on cooling reversibly.
e.g. polyethene ( P E ), Polypropylene( P P ), polyvinyl polyethene ( P V C ), polymers ( P S ), Nylons, Polytetrafluoro ethylene ( P T EE or teflon ), etc.
4. Thermosetting polymers: These are the polymers which become hard and infusible on heating. Once they have solidified, they cannot be softened. Heating results excessive cross linking between the chain forming three dimensional network. They are permanent setting polymers.
E.g. polyester (Terylene), bakelite, melamine.