Propene


 * Propene **, also known as ** propylene ** or ** methylethylene ** , is an [|unsaturated] [|organic compound] having the [|chemical formula] [|C] 3 [|H] 6 . It has one [|double bond] , and is the second simplest member of the [|alkene] class of [|hydrocarbons] , and it is also second in natural abundance.

At [|room temperature] and [|atmospheric pressure], propene is a gas, and as with many other [|alkenes] , it is also colourless with a weak but unpleasant smell.

Propene has a higher density and boiling point than [|ethylene] due to its greater mass. It has a slightly lower boiling point than propane and is thus more [|volatile]. It lacks strongly [|polar bonds], yet the molecule has a small [|dipole moment] due to its reduced symmetry (its [|point group] is [|Cs] ).

Propene has the same empirical formula as [|cyclopropane] but their atoms are connected in different ways, making these molecules [|structural isomers].

Propene is the second most important starting product in the petrochemical industry after [|ethylene]. It is the raw material for a wide variety of products. Manufacturers of the plastic [|polypropylene] account for nearly two thirds of all demand. Polypropylene is, for example, needed for the production of films, packaging, caps and closures as well as for other applications. In the year 2008 the worldwide sales of propene reached a value of over 90 billion US dollars.

Propene and [|benzene] are converted to [|acetone] and [|phenol] via the [|cumene process]. Propene is also used to produce [|isopropanol] (propan-2-ol), [|acrylonitrile], [|propylene oxide] (epoxypropane) and [|epichlorohydrin].

Propene resembles other alkenes in that it undergoes [|addition] reactions relatively easily at room temperature. The relative weakness of its double bond (which is less strong than two single bonds) explains its tendency to react with substances that can achieve this transformation. Alkene reactions include: 1) [|polymerization], 2) [|oxidation] , 3) [|halogenation] and [|hydrohalogenation] , 4) [|alkylation] , 5) [|hydration] , 6) [|oligomerization] , and 7) [|hydroformylation].