Polystyrene (also called polystyrene, and SAGEX in Switzerland with reference only to its expanded form ) is the styrene polymer.
It is a thermoplastic aromatic polymer with a linear structure. It is a glassy solid at room temperature; above its glass transition temperature, about 100°C, it acquires plasticity and is able to flow; it begins to decompose at a temperature of 270 °C.
Polystyrene foam is in the form of lightweight white foam, often moulded into pellets or chips, and is used for packaging and insulation.
Chemically inert to many corrosive agents, it is soluble in chlorinated organic solvents (such as dichloromethane and chloroform), in trichlorethylene, in acetone and in some aromatic solvents such as benzene and toluene.
It is mainly used in the stationery, packaging, automotive, construction and clothing sectors.