| � |
Updated February
23, 2007
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. 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 ( ):
|
2.1 |
Dissipation
factor (tan  ): |
.0004 |
| Temperature
coefficient of : |
ppm/�C |
Bulk resistivity
( ): |
1018
 -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 |
|
|
