Unfilled PSU
Unfilled PSU is a grade of PSU. It has the lowest strength and highest ductility compared to the other variants of PSU. The graph bars on the material properties cards below compare unfilled PSU to: sulfone 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
180 MPa 26 x 103 psi
Elastic (Young's, Tensile) Modulus
2.5 GPa 0.37 x 106 psi
Elongation at Break
52 %
Flexural Modulus
2.7 GPa 0.39 x 106 psi
Flexural Strength
110 MPa 15 x 103 psi
Impact Strength: Notched Izod
65 J/m 1.2 ft-lb/in
Rockwell M Hardness
69
Tensile Strength: Ultimate (UTS)
70 MPa 10 x 103 psi
Thermal Properties
Glass Transition Temperature
190 °C 370 °F
Heat Deflection Temperature At 1.82 MPa (264 psi)
180 °C 360 °F
Heat Deflection Temperature At 455 kPa (66 psi)
180 °C 360 °F
Maximum Temperature: Autoignition
510 °C 950 °F
Maximum Temperature: Decomposition
480 °C 900 °F
Maximum Temperature: Mechanical
170 °C 340 °F
Specific Heat Capacity
1000 J/kg-K 0.24 BTU/lb-°F
Thermal Conductivity
0.25 W/m-K 0.14 BTU/h-ft-°F
Thermal Expansion
57 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 Hz
3.1
Dielectric Constant (Relative Permittivity) At 1 MHz
3.1
Dielectric Strength (Breakdown Potential)
17 kV/mm 0.66 V/mil
Electrical Dissipation At 1 Hz
0.00080
Electrical Dissipation At 1 MHz
0.0034
Electrical Resistivity Order of Magnitude
15 10x Ω-m
Otherwise Unclassified Properties
Density
1.2 g/cm3 78 lb/ft3
Limiting Oxygen Index (LOI)
30 %
Water Absorption After 24 Hours
0.26 %
Common Calculations
Stiffness to Weight: Axial
1.1 points
Stiffness to Weight: Bending
37 points
Strength to Weight: Axial
16 points
Strength to Weight: Bending
30 points
Thermal Diffusivity
0.2 mm2/s
Thermal Shock Resistance
35 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