Styrene

DescriptionStyrene is a certain organic chemical compound having the chemical formula C8H8 and structural formula CH2=CHC6H5, also known as styrol, vinylbenzene, phenylethene,phenylethylene,styrene,styreen and so on. Its chemical structure is made up of a benzene ring bonded onto a vinyl group . At room temperature and pressure, styrene is a clear, colorless liquid. Styrene is an important monomer of synthetic rubber, adhesives and plastics, such as styrene sheet.

UsesStyrene is an important monomer of synthetic rubber, adhesives and plastics. [3,4,5] It is used for the synthesis of styrene butadiene rubber and polystyrene resin, polyester glass fiber reinforced plastics and coatings. It is used for preparing polystyrene, ion exchange resin, and foam polystyrene. It is also used for copolymerization with other monomers to produce various engineering plastics, such as copolymerization of acrylonitrile and butadiene to produce ABS resin, widely used in various household appliances and industries. Copolymerization with acrylonitrile, obtained SAN is a resin with shock resistance and bright color. The SBS produced by copolymerization with butadiene is a thermoplastic rubber, which is widely used as a polyvinyl chloride and acrylic modifier. SBS and SIS thermoplastic elastomers are made with butadiene and isoprene copolymerization, and as a crosslinking monomer, styrene is used in the modification of PVC, polypropylene, and unsaturated polyester. Syrene is used as a hard monomer for the production of styrene acrylic emulsion and solvent pressure sensitive adhesive. Emulsion adhesive and paint can be prepared by copolymerization with vinyl acetate and acrylic ester. Styrene is one of the most commonly used vinyl monomers in the scientific field, used in various modified and composite materials.[6] In addition, a small amount of styrene is also used as perfume and other intermediates. By chloromethylation of styrene, cinnamyl chloride is used as an intermediate for the non anesthetic analgesic strong pain determination, and styrene is also used as an antitussive, expectorant and anticholinergic original medicine in stomach Changning. It can be used to synthesize anthraquinones dye intermediates , pesticide emulsifiers, and styrene phosphonic acids ore dressing agent and copper plating brighteners.[7]

DescriptionStyrene has a characteristic, sweet, balsamic, almost floral odor that is extremely penetrating. Styrene occurs naturally in plants. It was first isolated from a resin called storax obtained from the inner bark of the Oriental sweet gum tree (Liquidambar orientalis) by Bonastre. In 1839, the German apothecary Eduard Simon prepared styrene by distilling it from storax and called it styrol. Simon observed it solidifi ed into a rubbery substance after being stored and believed it had oxidized into styrol oxide. Subsequent analysis showed the solid did not contain oxygen and it was renamed metastyrol. This was the first written record of polymerization in chemistry. In 1845, the English chemist, John Blyth, and the German chemist, August Wilhelm von Hofmann (1818 1892), observed that styrene was converted to polystyrene by sunlight and that styrene could be polymerized to polystyrene by heating in the absence of oxygen. It took another 70 years for the polymerization of styrene to be described by Hermann Staudinger (1881 1965) in the 1920s. This laid the foundation for the commercial polystyrene industry that developed in the 1930s.

OccurrenceReported found in cranberry and bilberry, currants, grape, parsley, milk and dairy products, whiskey, cocoa, coffee, tea, roasted filberts and roasted peanuts. Also reported found in fresh apple, guava fruit, pineapple, vinegar, butter, fish oil, black tea, roasted filbert, roasted peanut, soybean, plum brandy, apple brandy, Brazil nut, rice bran, Bourbon vanilla, grapes, peach, strawberry, onion, peas, bell pepper, cassia leaf, cheeses, parsley, milk, boiled and scrambled egg, lean fish, fish oil, cooked chicken and beef, rum, malt and Scotch whiskey, cider, grape, wine, cocoa, coffee, honey, cloudberry, plum, rose apple, beans, trassi, walnut, buckwheat, soursop, watercress, kiwifruit, wild rice, sapodilla fruit, nectarine, okra, crab, crayfish and pawpaw.

HistoryDuring the early 1940s, the development of cellular polystyrene took place. Styrofoam was discovered accidentally by Ray McIntire (1918 1996), a Dow chemical engineer in 1944. McIntire was trying to make an artificial rubber for electrical insulation. He was combining isobutene with polystyrene when the isobutene formed bubbles in the styrene, resulting in a light cellular structure. Dow registered the trademark Styrofoam in 1954, but the name is now used generically for foam cellular insulation. World demand for styrene monomer in 2006 is approximately 25 million tons. Styrene has numerous uses. The homopolymer, which is hard and clear, is used for plastic eating utensils, CD/DVD cases, and plastic hobby models. The most common forms of polystyrene is expanded polystyrene (EPS) and extruded expanded polystyrene (XEPS). EPS is produced using a mixture of polystyrene beads, pentane, and a blowing agent. The mixture is heated with steam, causing the beads to expand to 10 to 100 times their original volume as the pentane vaporizes. After this, the mixture is injected into a vacuum mold where heat and a partial vacuum cause further expansion. EPS can be molded into a variety of shapes. The pentane in the foam is replaced by air during the curing process. Extruded expanded polystyrene starts with polystyrene crystals. The crystals are mixed with additives and blowing agents in an extruder. In the extruder, the mix is heated under pressure into a plastic melt. This plastic melt expands through a die into foam. Extruded expanded polystyrene cannot be molded but is produced in sheets. At one time chlorofl uorocarbons (CFC) were the preferred blowing agents used to produce expanded polystyrenes, but they have been replaced by hydrochlorofl uorocarbons because of concerns about CFC's impact on the ozone layer (see Dichlorodifl uoromethane). Styrofoam, produced by Dow, is extruded. Coff ee cups and food packaging are technically not Styrofoam because Dow does not produce Styrofoam as molded expanded polystyrene. EPS and XEPS are used extensively for insulation in the construction industry. Polystyrene is used as a co-polymer with a number of other materials. Examples of co-polymers are acrylonitrile-butadiene-styrene, styrene-acrylonitrile, and styrene-butadiene rubber. Polystyrene is used in paints, coatings, adhesives, and resins.

UsesSTYRENE, is the simplest and by far the most important member of a series of aromatic monomers. Also known commercially as styrene monomer (SM), styrene is produced in large quantities for polymerization. It is a versatile monomer extensively used for the manufacture of plastics, including crystalline polystyrene, rubber-modified impact polystyrene, expandable polystyrene, acrylonitrile– butadiene–styrene copolymer (ABS), styrene–acrylonitrile resins (SAN), styrene–butadiene latex, styrene–butadiene rubber (SBR), and unsaturated polyester resins.

UsesStyrene polymers and copolymers are usedextensively in making polystyrene plastics,polyesters, protective coatings, resins, andsynthetic rubber (styrene–butadiene rubber)..

UsesStyrene (monomer) is a viscous, highly flammable liquid that evaporates easily and polymerizes readily to polystyrene unless a stabilizer is added. Styrene is used in multiple industries, especially in reinforced plastics (e.g., fiberglass boats), and is widely used to make plastics and rubber, packaging materials (e.g., packing peanuts ), insulation for buildings, plastic pipes, food containers (e.g., takeout containers), and carpet backing) (ATSDR, 2010).

General DescriptionA clear colorless to dark liquid with an aromatic odor. Flash point 90°F. Density 7.6 lb/gal. Vapors heavier than air and irritating to the eyes and mucous membranes. Subject to polymerization. If the polymerization takes place inside a closed container, the container may rupture violently. Less dense than water and insoluble in water. Used to make plastics, paints, and synthetic rubber.