Unfilled PAI
Unfilled PAI is a grade of PAI. It has the highest ductility compared to the other variants of PAI. The graph bars on the material properties cards below compare unfilled PAI 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
Compressive (Crushing) Strength
260 MPa 37 x 103 psi
Elastic (Young's, Tensile) Modulus
4.0 GPa 0.58 x 106 psi
Elongation at Break
12 %
Flexural Modulus
4.0 GPa 0.58 x 106 psi
Flexural Strength
190 MPa 27 x 103 psi
Impact Strength: Notched Izod
140 J/m 2.5 ft-lb/in
Shear Strength
110 MPa 16 x 103 psi
Tensile Strength: Ultimate (UTS)
150 MPa 21 x 103 psi
Thermal Properties
Glass Transition Temperature
280 °C 530 °F
Heat Deflection Temperature At 1.82 MPa (264 psi)
280 °C 530 °F
Maximum Temperature: Autoignition
530 °C 980 °F
Maximum Temperature: Decomposition
490 °C 910 °F
Maximum Temperature: Mechanical
260 °C 500 °F
Specific Heat Capacity
1000 J/kg-K 0.24 BTU/lb-°F
Thermal Conductivity
0.26 W/m-K 0.15 BTU/h-ft-°F
Thermal Expansion
34 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
4.2
Dielectric Strength (Breakdown Potential)
23 kV/mm 0.9 V/mil
Otherwise Unclassified Properties
Density
1.4 g/cm3 87 lb/ft3
Limiting Oxygen Index (LOI)
45 %
Water Absorption After 24 Hours
0.4 %
Water Absorption At Saturation
1.7 %
Common Calculations
Stiffness to Weight: Axial
1.6 points
Stiffness to Weight: Bending
38 points
Strength to Weight: Axial
29 points
Strength to Weight: Bending
44 points
Thermal Diffusivity
0.19 mm2/s
Thermal Shock Resistance
77 points
Followup Questions
Further Reading
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