propylene

Propene
IUPAC name	Propene
Identifiers
CAS number	115-07-1 Y
UN number	1077 In Liquefied petroleum gas: 1075
RTECS number	UC6740000
SMILES	C=CC
Properties
Molecular formula	C3H6
Molar mass	42.08 g/mol
Appearance	colorless gas
Density	1.81 kg/m3, gas (1.013 bar, 15°C) 613.9 kg/m3, liquid
Melting point	− 185.2 °C (88.0 K)
Boiling point	− 47.6 °C (225.5 K)
Solubility in water	0.61 g/m3 (? °C)
Viscosity	8.34 µPa·s at 16.7 °C
Structure
Dipole moment	0.366 D (gas)
Hazards
MSDS	External MSDS
R-phrases	12
S-phrases	9-16-33
NFPA 704	4 1 1
Flash point	−108 °C
Related compounds
Related groups	Allyl, Propenyl
Related compounds	Propane, Propyne Allene, 1-Propanol 2-Propanol
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Propene, also known as propylene, is an unsaturated organic compound having the chemical formula C₃H₆. 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.

Properties

At room temperature, propene is a colorless gas.

Propene has a higher density and boiling point than ethylene due to its greater size. 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 C_s).

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

Synthesis

Propene is produced from non-renewable fossil fuels - petroleum, natural gas and to a much lesser extent coal. Propene is a byproduct of oil refining and natural gas processing. Ethylene, propene, and other compounds are produced by cracking larger hydrocarbon molecules. Propene is separated by fractional distillation from hydrocarbon mixtures obtained from cracking and other refining processes.

Production and Uses

Propene is the raw material for a wide variety of products including polypropylene, a versatile polymer used in packaging and other applications. It is the second highest volume petrochemical feedstock after ethylene.^{[citation needed]} 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.^[1]

Propene production has remained static at around 35 million tonnes (Europe and North America only) from 2000 – 2008 but has been increasing in East Asia, most notably Singapore and China.^[2][3] Total world production of propene is currently about half that of ethylene.

Reactions

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.

References