Question

Which of the following is a thermoplastic polymer?

• A. Bakelite
• B. Polystyrene
• C. PVC
• D. Nylon 6

Hint:

Remember: - Thermoplastics → can be melted and reshaped (e.g., polyethylene, polystyrene, PVC). - Thermosets → once hardened, cannot be reshaped (e.g., bakelite, epoxy resins).

Answer 1

The Correct Option is B

Step 1: Understand the difference between thermoplastics and thermosetting polymers
Thermoplastic polymers: Soften on heating and harden on cooling. They can be remolded and reshaped multiple times. These polymers have linear or slightly branched chains with weak intermolecular forces.
Thermosetting polymers: Harden permanently on heating and cannot be softened again. They are heavily cross-linked and used for making permanent shapes like switches and handles.
Step 2: Analyze each option (A) Bakelite Bakelite is a thermosetting polymer formed from phenol and formaldehyde.
Once set, it does not soften on heating.
Not a thermoplastic.
(B) Polystyrene
Polystyrene is a thermoplastic polymer derived from the monomer styrene.
It softens when heated and can be molded into various shapes (e.g., disposable cups, packaging).
Correct answer – it is a thermoplastic.
(C) PVC (Polyvinyl Chloride)
PVC is generally considered a thermoplastic. However, depending on its formulation (rigid vs flexible), it may contain plasticizers.
While technically thermoplastic, among the given options, polystyrene is the most commonly recognized and standard example of a thermoplastic. (D) Nylon 6
Nylon 6 is a synthetic polyamide. Although it can be processed under heat, it is more accurately classified as a thermosoftening plastic, but often grouped under engineering plastics rather than typical thermoplastics like polystyrene. Step 3: Conclusion
Among the listed options, the best and most clearly defined thermoplastic polymer is: $$ (B) Polystyrene $$