Question

Why can't thermosetting polymers be reused after getting moulded?

• A. They become soft at high temperatures and melt.
• B. They form crosslinks at high temperatures which make them hard and strong
• C. They become brittle at high temperatures
• D. They cannot be heated as they are very good conductors of heat.

Answer 1

The correct option is B They form crosslinks at high temperatures which make them hard and strong

Thermosetting polymers are soft and malleable at low temperatures but become hard at higher temperatures.

This is because these polymers tend to form crosslinks between their polymer chains when heated and become hard and strong as a result.
The bonds are very strong.This is why they can't be remoulded by heating them again. They would only get charred and would not soften.

Examples of thermosetting polymers are bakelite and melamine resin.