Polyarylate (PAR)
PAR is an otherwise-unclassified thermoplastic material. The graph bars on the material properties cards below compare PAR to: otherwise unclassified thermoplastics (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
93 MPa 13 x 103 psi
Elastic (Young's, Tensile) Modulus
2.0 GPa 0.29 x 106 psi
Elongation at Break
50 %
Flexural Modulus
2.1 GPa 0.3 x 106 psi
Flexural Strength
75 MPa 11 x 103 psi
Impact Strength: Notched Izod
220 J/m 4.1 ft-lb/in
Rockwell R Hardness
130
Tensile Strength: Ultimate (UTS)
67 MPa 9.7 x 103 psi
Thermal Properties
Glass Transition Temperature
190 °C 370 °F
Heat Deflection Temperature At 1.82 MPa (264 psi)
170 °C 350 °F
Heat Deflection Temperature At 455 kPa (66 psi)
180 °C 360 °F
Maximum Temperature: Decomposition
470 °C 880 °F
Specific Heat Capacity
1200 J/kg-K 0.29 BTU/lb-°F
Thermal Conductivity
0.18 W/m-K 0.1 BTU/h-ft-°F
Thermal Expansion
88 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 Hz
3.0
Dielectric Strength (Breakdown Potential)
16 kV/mm 0.63 V/mil
Electrical Resistivity Order of Magnitude
12 10x Ω-m
Otherwise Unclassified Properties
Density
1.2 g/cm3 75 lb/ft3
Limiting Oxygen Index (LOI)
35 %
Water Absorption After 24 Hours
0.26 %
Common Calculations
Stiffness to Weight: Axial
0.93 points
Stiffness to Weight: Bending
35 points
Strength to Weight: Axial
16 points
Strength to Weight: Bending
31 points
Thermal Diffusivity
0.13 mm2/s
Thermal Shock Resistance
27 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