Properties of Propylene Glycol (C3H8O2)
Propylene glycol is a synthetic organic compound with a chemical formula C3H8O2. It is a colorless, odorless, and tasteless liquid that is commonly used in various industrial and consumer products.
The following table provides a comprehensive list of propylene glycol properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the icon to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Molar Mass | 76.09 g/mol |
| Density | 1040 kg/m3 |
| Dynamic Viscosity | 54.65 mPa·s |
| Surface Tension | 36.51 mN/m |
| Thermal Properties | Metric |
| Melting Point | -60 °C |
| Boiling Point | 188.2 °C |
| Thermal Conductivity (25°C) | 0.2 W/m·K |
| Specific Heat Capacity (Cp) | 2533 J/kg·K |
| Coefficient of Thermal Expansion (αV) | 6.95×10-4 1/°C |
| Vapor Pressure | 0.01 kPa |
| Critical Constants | Metric |
| Critical Temperature (Tc) | 403 °C |
| Critical Pressure (Pc) | 5.9 MPa |
| Critical Molar Volume (Vc) | 237 cm3/mol |
| Electrical Properties | Metric |
| Relative Permittivity (εr) (30°C) | 27.5 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.431 |
| Hazardous Data | Metric |
| Flash Point | 99 °C |
| Autoignition Temperature | 371 °C |
| Lower Flammability Limit | 2.6% |
| Upper Flammability Limit | 12.5% |
| NFPA Rating (Health) | 0 |
| NFPA Rating (Fire) | 1 |
| NFPA Rating (Reactivity) | 0 |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) Yaws, Carl L. The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals. Netherlands: Elsevier Science, 2015. 4) Fire Protection Guide to Hazardous Materials, 14th Edition. United States: National Fire Protection Association, 2010.