Polystyrene

Polystyrene is a synthetic aromatic hydrocarbon polymer made from the monomer known as styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and rather brittle. It is an inexpensive resin per unit weight.

Chemical Structure

Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year. Polystyrene can be naturally transparent, but can be colored with colorants. Uses include protective packaging (such as packing peanuts and CD and DVD cases), containers, lids, bottles, trays, tumblers, and disposable cutlery.

Production

Polystyrene is produced by polymerization of styrene which is an inexpensive and abundantly available petrochemical. The process of polymerization, initiated with heat, light or a chemical initiator, involves creating a chain of styrene monomers by forming a chemical bond between the carbon atoms.

Properties

Polystyrene's properties are determined by short-range van der Waals attractions between polymers chains. Since the molecules consist of a long hydrocarbon chain, they are non-polar and have a low solubility in water. The material's properties are characterized by a relatively low melting point.

Environmental Impact

Polystyrene foam is a major environmental problem. Non-biodegradable polystyrene is one of the main components of marine debris, and it can also be found on roadsides, in parks, and in other public places.

Health Effects

Polystyrene is generally considered safe for use in food contact items, but there are some health concerns. Styrene can leach from polystyrene containers into food and drink, and chronic exposure to styrene can have adverse health effects.

See Also

• Plastic
• Styrene
• Polymerization
• Aromatic hydrocarbon

Polystyrene

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  Man carrying polystyrene boxes in Guiyang, China
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  Polystyrene formation