Question

Explain the difference between thermoplastic and thermosetting plastic.

Answer 1

Hint: Thermoplastics are linear or slightly branched chain polymers that harden on cooling and soften on heating. Thermosetting plastics are highly branched that harden on heating and cannot be remoulded after that.

Complete step by step answer:
Let us make a table and list the major differences between thermoplastic and thermosetting plastic.

Thermoplastics	Thermosetting plastics
Their molecular weight is very low.	They have a large molecular weight.
They are flexible.	b. They are brittle in nature.
They are synthesised by addition polymerisation reactions.	c. They are synthesised by condensation polymerisation reactions.
They have low tensile strength	d. They have high tensile strength
They possess a low melting point.	e. They possess a high melting point.
They harden on heating and soften on cooling.	f. They harden on heating and cannot be softened on cooling.
They can be easily remoulded by heating and cooling.	g. They cannot be remoulded by heating and cooling. They form cross-links between chains when heated that cannot be altered.
They are linear or slightly branched.	h. They are highly branched.
They are less durable.	i. They are more durable.
They are soluble in organic solvents.	j. They are insoluble in organic solvents.
They can be recycled.	k. They cannot be recycled.
Examples are polystyrene, nylon, Teflon etc.	l. Examples include vulcanised rubber, vinyl ester resin, epoxy resin etc.

Note:
Thermoplastics are more dangerous than thermosetting plastics because they release toxic fumes.A thermoplastic is a material, usually a plastic polymer, which becomes more soft when heated and hard when cooled. Thermoplastic materials can be cooled and heated several times without any change in their chemical or mechanical properties. When thermoplastics are heated to their melting point, they melt to a liquid.