What are some general materials in foam, specifically foam cups?

Question

just generally like what are they made of I am not interested in materials of different cups or different brands that the coam cups r made of.

Answer 1

They are typically made of polystyrene.  It's a good insulator because it is filled with tiny pockets of air.  The "dead air" spaces mixed into the foam that makes the product acts exactly like the air trapped in a down coat or in the insulation used in a house to hold heat in.

I disagree that foam cups allow the warm liquid to cool faster than a ceramic cup would.  In a ceramic cup, at least part of the heat from the hot liquid is transferred to the cup, so the glass or ceramic cup feels warmer.  The liquid itself though, is cooler, though the difference may be small and not easily identified unless you are doing a side-by-side comparison.

It might make an interesting quesition for a science project.

Answer 2

polystyrene, which is easily dissolvable in gasoline

Answer 3

Disposable foam cups are generally made of Polystyrene. They cannot be effectively recycled.