Properties of Polyethylene Terephthalate (PET)
Polyethylene terephthalate (PET) is a type of plastic polymer that is widely used in the production of various everyday items, such as plastic bottles for beverages, food containers, and synthetic fibers in textiles. PET is known for its transparency, lightweight, and recyclability.
The following table provides a comprehensive list of polyethylene terephthalate (PET) 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 |
|---|---|
| Category | Thermoplastic |
| Density | 1560 kg/m3 |
| Water Absorption | 0.1 %wt/day |
| Mechanical Properties | Metric |
| Ultimate Tensile Strength | 80 MPa |
| Young’s Modulus (E) | 2.0 - 4.0 GPa |
| Flexural Modulus | 3 GPa |
| Elongation at Break | 70% |
| Rockwell Hardness (M) | 94 - 101 |
| Static Friction Coefficient (µ) | 0.2 - 0.4 |
| Thermal Properties | Metric |
| Melting Point | 255 °C |
| Thermal Conductivity | 0.17 - 0.40 W/m·K |
| Specific Heat Capacity (Cp) | 1200 J/kg·K |
| Coefficient of Thermal Expansion (αL) | 1.5×10-5 - 6.5×10-5 1/°C |
| Glass Transition Temperature (Tg) | 69 °C |
| Vicat Softening Temperature | 235 °C |
| Electrical Properties | Metric |
| Relative Permittivity (@1 MHz) (εr) | 3 |
| Electrical Resistivity | 1014 Ω·cm |
| Dielectric Field Strength (Ed) | 170 kV/cm |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.58 - 1.64 |
| Hazardous Data | Metric |
| Flammability Rating (ANSI/UL 94) | HB |
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) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.