Plastic is also a polymer like synthetic fibre which can be moulded into desired shape when soft and then hardened to produce a durable article

 

It is used to make many daily use articles like chairs,buckets,toys

Polythene is also an example of plastic which is used to make polythene bags




Different Types of Plastic Arrangements

Some Plastics are linear arrangement,these are called thermoplastics

 

While others are cross linked arrangements,these are called thermosetting plastics

Plastic Arrangements.jpg

 

Different Types of Plastics

Plastics are of two types

Thermoplastics

Those plastics which are deformed on heating and can be reformed into different shapes again are called Thermoplastics

Hence,Thermoplastics can be moulded repeatedly

Example

Polythene, PVC(Polyvinyl Chloride)

PVC Pipes and Polythene Bags.jpg

 

Thermosetting Plastics

Those plastics whch can be moulded only once and do not change shape on heating are called Theromosetting Plastics

They can be moulded only once

Later,they cannot be softened by heating

Example

Melamine resists fire and can tolerate heat better than other plastics. It is used to make microwave safe utensils, firemen clothes

Bakelite is a poor conductor of heat and electricity - It is used to make switches,handles of various cooking utensils

Thermosetting Plastics.jpg

Questions

NCERT Question 6 - Explain the difference between the thermoplastic and thermosetting plastics

View Answer

 

NCERT Question 7 - Explain why the following are made of thermosetting plastics.
(a) Saucepan handles
(b) Electric plugs/switches/plug boards

View Answer

 

  1. Class 8
  2. Chapter 3 Class 8 - Synthetic Fibres And Plastics

About the Author

CA Maninder Singh's photo - Expert in Practical Accounts, Taxation and Efiling
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 9 years and a teacher from the past 16 years. He teaches Spoken English, Written English, Grammar and Vocabulary at Englishtan.