“Unbreakable” crockery and dinnerware (hard, durable tableware) are typically made from which polymeric material?

Introduction / Context:
So-called “unbreakable” crockery refers to hard, scratch-resistant, heat-tolerant tableware widely used in homes and institutions. These products are molded from melamine–formaldehyde resins, a class of thermosetting aminoplasts valued for surface hardness, stain resistance, and dimensional stability.

Given Data / Assumptions:

• Tableware must withstand hot foods/liquids, repeated washing, and moderate impacts.
• Melamine resins cure to a crosslinked network with excellent surface properties.
• Commodity thermoplastics like polystyrene can be brittle and scratch easily; PVC and PU are not typical for rigid, high-heat tableware.

Concept / Approach:
Melamine–formaldehyde offers high hardness and gloss with good heat resistance, making it suitable for durable crockery. While no polymer is literally “unbreakable,” melamine tableware is far more durable than PS or brittle clear plastics in everyday service.

Step-by-Step Solution:
Identify required properties: hardness, thermal tolerance, cleanliness.Match these to polymer families: aminoplast thermosets fit best.Select melamine–formaldehyde resin.

Verification / Alternative check:
Product specifications and regulatory standards for melamine tableware confirm the typical resin system and performance requirements.

Why Other Options Are Wrong:
Polystyrene: prone to brittleness and stress cracking.PVC: plasticised grades are flexible; rigid PVC lacks the desired heat resistance for crockery.Polyurethane: used for foams or elastomers, not rigid dinnerware.Acrylic (PMMA): good clarity but can crack/chip; used for tumblers, not typical for “unbreakable” plates.

Common Pitfalls:
Assuming toughness equals thermoplastic; many durable dinnerware items are thermoset because of their superior surface hardness and heat resistance.

Final Answer:
Melamine (melamine–formaldehyde resin)