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Styrene is regarded as a "known carcinogen", especially in case of eye contact, but also in case of skin contact, of ingestion and of inhalation, according to several sources. [20] [33] [34] [35] Styrene is largely metabolized into styrene oxide in humans, resulting from oxidation by cytochrome P450.
Styrene oxide is an epoxide derived from styrene. It can be prepared by epoxidation of styrene with peroxybenzoic acid, in the Prilezhaev reaction: [1] Styrene oxide is slightly soluble in water. A trace amount of acid in water causes hydrolysis to racemic phenylethyleneglycol via a benzylic cation.
With thousands of tons/year being produced annually, the peroxydisulfates, S 2 O 2− 8, are preeminent members of this class.These salts serve as initiators for polymerization of acrylates and styrene.
The styrene monomer (from which polystyrene is made) is a cancer suspect agent. [109] Styrene is "generally found in such low levels in consumer products that risks aren't substantial". [110] Polystyrene which is used for food contact may not contain more than 1% (0.5% for fatty foods) of styrene by weight. [111]
as the first step of the aerobic styrene degradation pathway. [1] The product 2-phenyloxirane is also known as styrene oxide and can be converted by a styrene oxide isomerase (SOI) to obtain phenylacetaldehyde, which can be transformed into the key-intermediate phenylacetic acid by a phenylacetaldehyde dehydrogenase (PAD).
The systematic name of this enzyme class is styrene-oxide isomerase (epoxide-cleaving). This enzyme is also called SOI. This enzyme participates in styrene degradation and is the second step of the pathway after the epoxidation of styrene by styrene monooxygenase. SOI is an integral membrane protein consisting of four transmembrane helices.
Styrene maleic anhydride (SMA or SMAnh) is a synthetic polymer that is built-up of styrene and maleic anhydride monomers. In one copolymer , the monomers can be almost perfectly alternating. [ 1 ] but (random) copolymerisation with less than 50% maleic anhydride content is also possible. [ 2 ]
Styrene acrylonitrile resin (SAN) is a copolymer plastic consisting of styrene and acrylonitrile. It is widely used in place of polystyrene owing to its greater thermal resistance. The chains of between 70 and 80% by weight styrene and 20 to 30% acrylonitrile. [ 1 ]