polystyrol

Polystyrol, or polystyrene, is a synthetic aromatic polymer produced by polymerizing the monomer styrene. It exists mainly in several forms: general-purpose polystyrene (GPPS), which is clear and rigid; impact-modified polystyrene (HIPS), which incorporates elastomeric modifiers to improve toughness; and foamed forms such as expanded polystyrene (EPS) for packaging and insulation, and extruded polystyrene (XPS) for insulating boards.

Polystyrene is a thermoplastic with a glass transition temperature around 95–105 °C. In its amorphous state it is transparent and rigid but can be brittle unless modified. It processes easily by common molding and forming methods, including injection molding, extrusion, and thermoforming, and has low water absorption. It provides good electrical insulation, though chemical resistance varies and certain solvents can swell or damage it.

Common applications include packaging materials, food-service containers and disposable utensils, and CD/DVD cases; foam polystyrene is widely used for cushioning and packaging, while EPS and XPS are favored for building insulation. It also appears in automotive interiors and various electronics housings.

Environmental and safety notes: polystyrene is not readily biodegradable, and waste handling poses challenges. Recycling exists for clean, separated material but overall rates are relatively low; EPS recycling is particularly difficult, and energy recovery via incineration is used in some regions. Residual styrene monomer can off-gas during processing, presenting occupational exposure concerns, though finished consumer products are generally considered safe under normal use. Historically, styrene polymerization was demonstrated in the 1830s, with commercial production beginning in the mid-20th century by major chemical companies.