What is the Difference Between Polystyrene and Styrofoam?

Polystyrene and Styrofoam are often used interchangeably, but they are not exactly the same material. Here are the main differences between the two:

1. Origin: Polystyrene is a versatile plastic polymer made from styrene monomers, which are derived from petroleum. Styrofoam, on the other hand, is a brand of expanded polystyrene (EPS) foam. Styrofoam is a trademarked term owned by The Dow Chemical Company.
2. Structure: Polystyrene is a hard, brittle plastic that can be easily molded into different products, shapes, and foam materials. EPS foam, often mistakenly referred to as Styrofoam, is a lightweight, rigid, and closed-cell foam made from polystyrene beads that are heated and expanded with steam.
3. Usage: Polystyrene is used for a wide range of applications, including packaging, electronics, toys, and food service items. Styrofoam, or more accurately, EPS foam, is primarily used for insulation and packaging. It is commonly used in construction applications and for products like disposable coffee cups and coolers.
4. Permeability: Styrofoam has a higher permeability rating than EPS foam, making it more optimal for water and mold resistance.
5. Recyclability: Unlike Styrofoam, EPS foam is recyclable and considered environmentally friendly due to its organic components and lack of toxic elements.

In summary, polystyrene is a plastic polymer used for various applications, while Styrofoam (EPS foam) is a specific type of foam made from polystyrene beads. They have different properties, uses, and production processes.

Comparative Table: Polystyrene vs Styrofoam

The main difference between polystyrene and Styrofoam lies in their composition and applications. Here is a table summarizing the differences:

It is important not to confuse Styrofoam with expanded polystyrene (EPS) foam products, as they are different materials with distinct applications and properties.