Question

Are Polythene and PVC examples of thermosetting plastic?

Answer 1

Hint: Polymers can be defined as a class of molecules which could be natural or synthetic and composes of a large number of repeated units called monomers.The monomers involved are chemically acted upon by either Addition polymerisation or Condensation polymerisation to build a larger unit known as polymers.

Complete answer: When large number of monomers come together and chemically react with each other we get polymers.Depending on the nature of monomers involved,polymers can be classified on the basis of their source as Natural polymers or Synthetic polymers.Polymers which are made up of partially organic or fully synthetic monomers are as Synthetic polymers or Plastic.
On the basis of the molecular force present in them polymers,they can be classified into-Elastomer,Fibre,Thermoplastic and Thermosetting.The polymers which consist of cross-linked structures or heavily branched molecules are termed as Thermosetting polymers.
The characteristics of thermosetting polymers are as follows-
1)Thermosets are insoluble in most of the inorganic solvents.
2)They harden during molding and cannot be modified once they are cooled down.
3)They are quite resistant to high temperatures and have high levels of dimensional stability.
The polymer polythene is made by addition polymerization of monomer Ethene.It’s a thermosetting plastic.It’s one of the most commonly used plastic.Similarly PVC stands for Poly Vinyl Chloride.This polymer is made up of the Vinyl chloride monomer hence the name PVC.It’s a thermosetting plastic and it’s the world’s third highest produced plastic polymer.
Hence polythene and pvc are examples of thermosetting plastic.

Note:
 Due to the presence of strong cross linking bonds and branching in the monomer chains thermosetting polymers have a variety of unique characteristics due to which fit well for a range of applications like packaging,manufacturing and making insulation for wires and cables,toys etc.