Polytetraflouroethelene, a long-chain molecule, one form of it is registered under the Dupont trademark "Teflon". Invented by Dr. Roy J. Plunkett of Dupont in 1930, he's in our Microwave Hall of Fame! PTFE is one of the miracle materials of microwave engineering, and is used in almost all coax cables and soft substrates! The history of PTFE can be found on this web site (updated February 2023 thanks to Vincent). Low water absorption. Properties vary by source. Often combined with other materials to increase dielectric constant or improve temperature stability. Can be exposed to -260°C to +260°C.

Formula or composition: CF2-CF2, repeated
Dielectric constant (PTFE): 2.1
Dissipation factor (tan PTFE): .0004
Temperature coefficient of PTFE: ppm/°C
Bulk resistivity (PTFE): 1018PTFE-cm
Temperature coefficient of resistivity (TCR): PPM/°C
Mass density 2.17 gr/cc
Specific heat (c): 1.01 J/g/°C
Thermal conductivity (k): 0.25 W/m°C
Temperature coefficient of expansion (TCE) at 25 °C: 110 ppm/°C
Melting point, °C: 327
Melting point, °F: 621

Author : Unknown Editor