Polymethylpentene (PMP)
PMP is an otherwise-unclassified thermoplastic material. It has the lowest density and a fairly low tensile strength among thermoplastics. The graph bars on the material properties cards below compare PMP 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
Elastic (Young's, Tensile) Modulus
1.1 GPa 0.16 x 106 psi
Elongation at Break
30 %
Impact Strength: Notched Izod
130 J/m 2.4 ft-lb/in
Tensile Strength: Ultimate (UTS)
24 MPa 3.5 x 103 psi
Thermal Properties
Glass Transition Temperature
30 °C 86 °F
Maximum Temperature: Mechanical
140 °C 280 °F
Melting Onset (Solidus)
230 °C 450 °F
Specific Heat Capacity
1750 J/kg-K 0.42 BTU/lb-°F
Thermal Conductivity
0.17 W/m-K 0.1 BTU/h-ft-°F
Thermal Expansion
120 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 Hz
2.1
Dielectric Strength (Breakdown Potential)
28 kV/mm 1.1 V/mil
Electrical Resistivity Order of Magnitude
14 10x Ω-m
Otherwise Unclassified Properties
Density
0.83 g/cm3 52 lb/ft3
Refractive Index
1.5
Common Calculations
Stiffness to Weight: Axial
0.74 points
Stiffness to Weight: Bending
41 points
Strength to Weight: Axial
8.0 points
Strength to Weight: Bending
22 points
Thermal Diffusivity
0.12 mm2/s
Thermal Shock Resistance
13 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