Final answer:
Polypropylene and polycarbonate are the most suitable polymers for fabricating cups to contain hot coffee due to their higher heat resistance, with polycarbonate being known for high strength and polypropylene commonly used for kettles and food containers.
Step-by-step explanation:
When selecting a polymer for fabricating cups designed to contain hot coffee, it's essential to consider the material's thermal properties, such as heat resistance. Among the polymers listed - polyethylene, polypropylene, polystyrene, PET polyester, and polycarbonate - the most suitable choices for this application would be polypropylene and polycarbonate.
Polyethylene, while commonly used for plastic bottles and bags, doesn't have a high enough heat resistance to safely hold hot coffee. Polystyrene, used in foam cups, offers some insulation but can deform if the liquid is too hot and may release harmful chemicals into the beverage. PET polyester is typically used for cold drink and food containers and may not withstand the temperature of hot coffee without deforming.
Polycarbonate is known for its high heat resistance and strength, making it an excellent choice for hot liquid containers. Similarly, polypropylene is commonly used for food containers and kettles due to its higher melting point, making it suitable for a coffee cup that needs to withstand high temperatures.