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).

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Table of Polyimide Properties
Physical Properties
Metric
CategoryThermoplastic
Density1420 kg/m3
Water Absorption0.2 - 2.9 %wt/day
Mechanical PropertiesMetric
Ultimate Tensile Strength70 -150 MPa
Young’s Modulus (E)2.0 - 3.0 GPa
Flexural Modulus3.1 - 3.45 GPa
Elongation at Break8 - 70%
Rockwell Hardness (E)52 - 99
Static Friction Coefficient (µ)0.42
Thermal PropertiesMetric
Melting Point365 °C
Thermal Conductivity0.10 - 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 PropertiesMetric
Relative Permittivity (@1 MHz) (εr)3.4
Electrical Resistivity1018 Ω·cm
Dielectric Field Strength (Ed)220 kV/cm
Optical PropertiesMetric
Refractive Index (589 nm)1.42
Hazardous DataMetric
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)

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.