Properties of Polyimide (PI)
Polyimide (PI) is a high-performance polymer recognized for its outstanding thermal stability, chemical resistance, and electrical insulation capabilities. Due to these properties, it is frequently used in demanding environments, including aerospace, electronics, and industrial applications.
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The following table provides a comprehensive list of polyimide (PI) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the button to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Category | Thermoplastic |
| Density | 1420 kg/m3 |
| Water Absorption | 0.2 - 2.9 %wt/day |
| Mechanical Properties | Metric |
| Ultimate Tensile Strength | 70 -150 MPa |
| Young’s Modulus (E) | 2.0 - 3.0 GPa |
| Flexural Modulus | 3.1 - 3.45 GPa |
| Elongation at Break | 8 - 70% |
| Rockwell Hardness (E) | 52 - 99 |
| Static Friction Coefficient (µ) | 0.42 |
| Thermal Properties | Metric |
| Melting Point | 365 °C |
| Thermal Conductivity | 0.10 - 0.36 W/m·K |
| Specific Heat Capacity (Cp) | 1090 J/kg·K |
| Coefficient of Thermal Expansion (αL) | 3×10-5 - 6×10-5 1/°C |
| Glass Transition Temperature (Tg) | 280 - 330 °C |
| Electrical Properties | Metric |
| Relative Permittivity (@1 MHz) (εr) | 3.4 |
| Electrical Resistivity | 1018 Ω·cm |
| Dielectric Field Strength (Ed) | 220 kV/cm |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.42 |
| Hazardous Data | Metric |
| Flammability Rating (ANSI/UL 94) | V-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)
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.