What is Plastic?
Plastic is a polymer in which monomers are arranged in
linear or cross linked chains.
Alexander Parkes is the creator of first plastic known as
“Parkesine”.
Types of Plastics:
a) Thermoplastic
This is the plastic which gets deformed
easily by heating. Some of the thermoplastics are polythene and PVC. This is a
plastic which will soften when heated and harden when cooled. Thermoplastic is
a polymer that turns into a liquid when heated and freezes to a glassy state
when cooled sufficiently.
b) Thermosetting Plastics
Properties of Plastics
1. Plastics are easily mouldable into different shapes.
2. Plastics could be recycled.
3. Plastics could be melted.
4. Plastics could be rolled into sheets.
5. Plastic could be drawn into wires
6. Plastics are nonreactive to chemicals and atmosphere.
7. Plastics are light in weight
8. Plastics are cheaper than metals.
9. Plastics are poor electric conductors and could be used as insulators.
10. Plastics are poor thermal(heat) conductors and hence could be used for cooking utensils etc.
Biodegradable and non-biodegradable Plastics
Plastics, which are decomposed by natural process through
bacteria in the presence of water, sunlight and oxygen are called
bio-degradable plastics. Plastics which
cannot be decomposed by natural processes are called non-biodegradable
plastics.
Plastics take long time for decomposition which causes
pollution of environment. Burning of plastics causes poisonous fumes into air.