Polyfoams are a number of various materials received in the artificial way and representing cellular frothed structure with gas inside. Polystyrene – one of types of polyfoam which differs in the low cost, rigidity and fragility.
Polyfoam
Polyfoam is produced from plastic which is filled with gas that the structure similar for the solid stiffened foam has turned out. Polyfoam consists of set of the small cells filled with gas. Gas allows material to have low density in comparison with initial raw materials. Heat-insulating properties of frothed plastics are explained by it: at temperature which is not exceeding value of destruction of this substance they remarkably protect from cold.
Polyfoam collapses from fire, but to light up from sparks, the smoldering cigarette or the calcinated wire cannot, more high temperatures are necessary.
Polyfoams are very popular thanks to their lightweight and simplicity in application. They are used generally in construction as thermal insulation materials, also do easy packing for food of polyfoams and other goods which well protects from damages and environmental activities. Polyfoams cheap and convenient, and their only shortcoming – harmful effects on human body when heating. Besides, very much popular belief that harm of these materials is limited not only the increased temperature: allegedly, they emit substances hazardous to health in any conditions. Polyfoam is the whole class of a few materials differing on properties and methods of production. Distinguish such types as polyvinylchloride, polyurethane, formaldehyde and polystyrine polyfoams. Thus, the difference between polyfoam and polystyrene is that the last is one of types of the first.
Polystyrene
Such kind of polyfoam as polystyrene, also often call expanded polystyrene. It is made from styrene – colourless liquid, water-insoluble and having strong specific smell. On the basis of this material do polymers including polystyrene which when foaming becomes expanded polystyrene. As a result cellular moisture resistant granules which for 98% consist of gas turn out.
Polystyrene has very small weight, but excellent heat-insulating properties.
It is easy to work with expanded polystyrene, it is harmless to health, is resistant to influence not only waters, but also various acids and alkalis. Compression almost does not deform this material differing in high strength. This fireproof substance which does not emit substances hazardous to health, according to official data. Polystyrene quite rigid and in comparison with other polyfoams differs in fragility. Expanded polystyrene is used by production of sandwich panels for thermal insulation of buildings, parking of cars, for waterproofing of communications and pipes, for warming of the bases, at construction of pools and building sites. It is applied in chemical production, mechanical engineering.