Propylene (C3H6) is a colorless gas. It is obtained by thermal cracking of ethylene. At low concentration it forms an explosive and flammable mixture with air, while at high concentrations it can cause asphyxiation and skin burns. It is used in the petrochemical industry as a fuel and alkylate and in the chemical industry for the production of polypropylene, isopropyl alcohol, propylene oxide and other chemicals.
| Molecular weight: 42.08 | Critical temperature: 365.57 K |
| Melting point: 87.9 K | Critical pressure:4.6646 MPa |
| Normal boiling point:225.46 K | Critical density: 223.4 kg/m3 |
| Normal vapor density:1.91 kg/m3 | (@ 273.15K; 1.0135MPa) |
Note. The values of thermodynamic properties have been obtained from S. Angus, B. Armstrong, K. M. deReuck—International Thermodynamic Tables of the Fluid State—7, Propylene, Pergamon Press, Oxford, 1980, while the values of transport properties and the surface tension have been obtained from C. F. Beaton, G. F. Hewitt—Physical Property Data for the Design Engineer, Hemisphere Publishing Corporation, New York, 1989.