Polyphthalamide (PPA)
PPA is a thermoplastic, further classified as a polyamide (or Nylon) plastic.
The properties of PPA include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare PPA to: polyamide 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
2.1 to 2.2 GPa 0.3 to 0.32 x 106 psi
Elongation at Break
30 %
Flexural Modulus
2.3 to 2.4 GPa 0.33 to 0.35 x 106 psi
Flexural Strength
95 to 110 MPa 14 to 17 x 103 psi
Poisson's Ratio
0.4
Tensile Strength: Ultimate (UTS)
57 to 69 MPa 8.3 to 10 x 103 psi
Thermal Properties
Glass Transition Temperature
92 to 130 °C 200 to 260 °F
Heat Deflection Temperature At 1.82 MPa (264 psi)
120 °C 250 °F
Maximum Temperature: Decomposition
450 °C 830 °F
Melting Onset (Solidus)
310 °C 590 °F
Specific Heat Capacity
1400 J/kg-K 0.33 BTU/lb-°F
Thermal Conductivity
0.15 W/m-K 0.087 BTU/h-ft-°F
Otherwise Unclassified Properties
Density
1.1 g/cm3 71 lb/ft3
Water Absorption After 24 Hours
0.7 %
Common Calculations
Stiffness to Weight: Axial
1.0 to 1.1 points
Stiffness to Weight: Bending
38 points
Strength to Weight: Axial
14 to 17 points
Strength to Weight: Bending
29 to 33 points
Thermal Diffusivity
0.095 mm2/s
Followup Questions
Further Reading
ASTM D883: Standard Terminology Relating to Plastics
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