Thermoplastic Polyimide (PI)
Thermoplastic PI is a thermoplastic, further classified an an imide plastic. It can have a moderately high tensile strength among the thermoplastics in the database.
The properties of thermoplastic PI include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare thermoplastic PI to: imide plastics (top), all thermoplastics (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
3.7 to 20 GPa 0.54 to 2.9 x 106 psi
Elongation at Break
1.8 to 7.5 %
Flexural Modulus
3.8 to 19 GPa 0.55 to 2.8 x 106 psi
Flexural Strength
170 to 330 MPa 24 to 48 x 103 psi
Tensile Strength: Ultimate (UTS)
110 to 220 MPa 16 to 31 x 103 psi
Thermal Properties
Glass Transition Temperature
260 °C 500 °F
Maximum Temperature: Autoignition
600 °C 1110 °F
Maximum Temperature: Decomposition
530 °C 980 °F
Specific Heat Capacity
970 to 1100 J/kg-K 0.23 to 0.26 BTU/lb-°F
Otherwise Unclassified Properties
Density
1.4 to 1.5 g/cm3 86 to 96 lb/ft3
Limiting Oxygen Index (LOI)
35 %
Common Calculations
Stiffness to Weight: Axial
1.5 to 7.9 points
Stiffness to Weight: Bending
37 to 64 points
Strength to Weight: Axial
22 to 42 points
Strength to Weight: Bending
36 to 57 points
Followup Questions
Further Reading
Reinforced Plastics Durability, Geoffrey Pritchard (editor), 1999
SPI Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., 5th ed., Michael L. Berins (editor), 2000
Modern Plastics Handbook, Charles A. Harper (editor), 1999
Plastics Materials, 7th ed., J. A. Brydson, 1999