Question

Polymers that can be softened on heating and hardened on cooling are called

• A. Thermosetting polymers
• B. Bakelite
• C. Fibres
• D. Thermoplastic polymers

Hint:

Thermoplastics can be reshaped multiple times through heating and cooling, while thermosetting plastics can only be shaped once.

Answer 1

The Correct Option is D

Polymer Behavior on Heating Analysis

Thermoplastic polymers are materials that can be softened when heated and hardened when cooled. This is due to their molecular structure, which allows the polymer chains to slide past each other when heated, making them moldable. Upon cooling, they solidify into the desired shape. Examples include polythene, polystyrene, and PVC.

In contrast, thermosetting polymers, like Bakelite, harden permanently when heated and cannot be reshaped after that. Fibres are not specific to this property but are a type of polymer used in textiles.

Conclusion:

Therefore, the correct answer is thermoplastic polymers.