Alpha-Methylstyrene

The methyl styrenes (also vinyltoluenes or methyl vinyl benzenes called ) form a group of substances derived from both the styrene and from toluene in chemistry. The structure consists of a benzene ring with an added ethene (-CH = CH2) and methyl group (- CH3) as substituents. Due to their different arrangement of three structural isomers arise with the molecular formula C9H10. They are mainly to be regarded as methyl-substituted styrenes. There are also with isopropenylbenzene ( α -methylstyrene ) and 1- propenyl ( β -methylstyrene ) two isomeric compounds in which the methyl group at the ethene and not on the benzene ring is attached.

Properties

Methylstyrenes are colorless liquids with unpleasant smell.

Use

2-methyl styrene is used as a modifier of alkyd resins; it is added for example in the Polystyrolpolymerisation to increase the heat resistance of polystyrene. α -methyl styrene is used for the production of plasticizers for plastics, paint, wax, etc., and modified polyester and alkyd resins. By polymerization, poly -alpha -methylstyrene ( CAS: 25014-31-7 ) can be obtained.

Safety

Unstabilized is the danger of the polymerization. The monomers are therefore stabilized and usually marketed as a mixture of isomers in the trade. Upon heating, the stabilizer may (for example 3,5-di -tert- butyl- catechol) are ineffective and form vapors of methyl styrenes, which can form an explosive mixture with air.