Thermocole (expanded foam) identification: this spongy, porous, rigid or flexible foamed plastic is obtained by foaming which base polymer?

Introduction / Context:
Thermocole (common name in some regions) refers to expanded polystyrene (EPS), a lightweight cellular plastic used for packaging, insulation, and disposable items.

Given Data / Assumptions:

• EPS is produced by expanding polystyrene beads with blowing agents (e.g., pentane, steam expansion).
• Polyurethane foams also exist but are not called thermocole.
• Saturated polyester foams are not the typical material for this application.

Concept / Approach:
Identify the colloquial term “thermocole” with EPS. The base polymer is polystyrene; expansion creates the cellular structure while the chemistry remains polystyrene.

Step-by-Step Solution:
Associate “thermocole” with EPS.EPS derives from polystyrene beads → select polystyrene.

Verification / Alternative check:
Industry practice and packaging standards list thermocole as EPS, not polyurethane.

Why Other Options Are Wrong:
Polyurethane foams are widely used but are distinct and not termed thermocole; saturated polyester is not the standard base for this product.

Common Pitfalls:
Equating any foam with thermocole; the term is specifically linked to polystyrene.

Final Answer:
Polystyrene