polistyrenie

Polystyrene is a synthetic aromatic hydrocarbon polymer produced by polymerizing the monomer styrene, which is derived from petroleum. In its solid form, polystyrene is a clear, stiff thermoplastic that can be brittle, with a glass transition temperature around 95–105°C. It can be produced as rigid general-purpose polystyrene (GPPS) or as high-impact polystyrene (HIPS), the latter by adding polybutadiene to improve toughness. In addition to solid forms, polystyrene can be foamed to produce expanded polystyrene (EPS) or extruded polystyrene (XPS), both widely used for insulation and packaging.

Production and properties: Polystyrene is made by free-radical polymerization of styrene monomer in bulk, suspension, or emulsion processes. The polymer chain consists of repeating styrene units bearing phenyl side groups, which provides chemical resistance, clarity in its unfilled form, and relatively low density. Additives, colorants, or blends with other polymers can tailor mechanical and thermal properties.

Applications: GPPS and HIPS are commonly used in food packaging, disposable tableware, toys, and consumer electronics housings. EPS foam provides lightweight cushioning and insulation for packaging and shipping, while XPS offers higher insulation performance for building envelopes and coolers.

Environment and safety: Polystyrene is not readily biodegradable. EPS waste can be difficult to recycle, though mechanical recycling and, increasingly, chemical recycling that depolymerizes back to styrene are pursued where feasible. Styrene monomer exposure is a health consideration during processing, so proper ventilation and handling are important throughout manufacturing and use.

History: The substance was first prepared by Eduard Simon in 1839. Industrial production expanded in the mid-20th century, leading to widespread use in packaging, insulation, and consumer goods.