Polytetramethylene Terephthalate (PTMT)
PTMT is a thermoplastic, further classified as a polyester plastic. The graph bars on the material properties cards below compare PTMT to: polyester 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.
Thermal Properties
Heat Deflection Temperature At 1.82 MPa (264 psi)
50 °C 120 °F
Heat Deflection Temperature At 455 kPa (66 psi)
150 °C 300 °F
Maximum Temperature: Mechanical
130 °C 270 °F
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 Hz
3.2
Dielectric Strength (Breakdown Potential)
17 kV/mm 0.64 V/mil
Other Material Properties
Density
1.3 g/cm3 82 lb/ft3
Impact Strength: Notched Izod
53 J/m 1.0 ft-lb/in
Tensile Strength: Ultimate (UTS)
56 MPa 8.1 x 103 psi
Common Calculations
Strength to Weight: Axial
12 points
Strength to Weight: Bending
25 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