Polystyrene
Polystyrene is slow to biodegrade and is therefore a focus of
controversy among environmentalists. It is a synthetic aromatic hydrocarbon polymer
made from the monomer styrene. Polystyrene can be
naturally transparent, but can be colored with colorants and can be solid or
foamed. General-purpose polystyrene is clear, hard, and rather brittle. It is
an inexpensive resin per unit weight. It has low melting point and poor barrier
to oxygen and water vapor. It is one of the most widely used plastics. The
scale of its production being several million tons per year. As a thermoplastic
polymer, polystyrene is in a solid (glassy) state at room temperature but flows
if heated above about 100 °C, its glass transition temperature. It becomes
rigid again when cooled. This temperature behavior is exploited for extrusion
(as in Styrofoam) and also for molding and vacuum forming, since it can be cast
into molds with fine detail. Yoghurt pots, refrigerator linings, vending cups,
bathroom cabinets, toilet seats and tanks, closures, instrument control knobs, protective
packaging (such as packing peanuts and CD and DVD cases), containers, lids,
bottles, trays, tumblers, disposable cutlery and in the making of models. It is
increasingly abundant as a form of litter in the outdoor environment, particularly
along shores and waterways, especially in its foam form, and also in increasing
quantities in the Pacific Ocean.
Chemical Formula of polystyrene is (C8H8)n
and IUPAC name is Poly(1-phenylethene).
Density:
0.96–1.04 g/cm3
Melting
Point: ~ 240 °C (464 °F; 513 K) For
Isotactic Polystyrene
Solubility
in water is insoluble and Solubility in acetone is soluble.
Thermal
conductivity : 0.033
W/(m·K) (foam, ρ 0.05 g/cm3)
Refractive
Index(nD): 1.6; dielectric constant 2.6 (1 kHz – 1 GHz)
Related
Compound: Styrene
