obtained from http://www.net-master.net/~ptfedave
Teflon (Polytetrafluoroethylene)
How was Teflon discovered?
.
In the 1960's, Dr. Roy Plunkett, a Dupont chemist, was working on a project to find alternate materials for cooling purposes.  He had stored some tetrafluorethylene gas (similar to freon) in a container and left it overnite.  When he returned in the morning, the gas was gone and in its place was a white wax-like substance.  Teflon had been discovered.
.
Properties of Teflon
.
PTFE is an extaordinary material.  Some say that it is the most useful material known to man.  This is because it has a combination of properties that are very hard to find.  Its four great properties are: 1. very low coefficient of friction, 2. highly inert, 3. high melting point, 4. wonderful electrical properties.  These properties are due to its unique molecular structure.
image obtained from http://www.psrc.ums.edu/macrog/ptfe.html
As you can see, PTFE is composed of carbon and fluorine.  Carbon-fluorine and carbon-carbon bonds are among the strongest in single bond organic chemistry.  This accounts for many of its properties.  Because of the strong bonds, much thermal energy must be used to break down the material.  It is also nonpolar; this leads to its chemical inertness, as the diagram demonstrates, and the fact that its electrical resistance is over 1018 .  The low coefficient of friction of Teflon results from low interfacial forces between its surface and another material and the comparatively low force to deform.  A good table of PTFE's properties follows.
obtained fromhttp://www.efni.com/~paradox/feflon/uses.html
Property DIN or ASTM
DIN or Standard
Unit Value
General
Density 53479 g/cm³ 2,14 - 2,19
upper continuous operating temperature without stress ° C 250 - 260
Combustibility non-combustible
Water absorption 53495 % < 0,01
Mechanical
Tear strength at 23° C 53456 N/mm² 29 - 39
Tear strength at 150° C 14 - 20
Yield point at 23° C 53455 N/mm² 10
elongation at break at 23° C 53455 % 200 - 500
Modulos of elasticity in tension at 23° C 53457 N/mm² 400 - 800
Maximum bending stress at 23° C 53452 N/mm² 18 - 20
Modulos of elasticity in bending 53457 N/mm² 600 - 800
Ball indentation hardness 132 / 60 53456 N/mm² 25 - 30
Shore-D hardness 53506 55 - 72
Coefficient of friction, dyn. against steel dry * 0,05 - 02
Thermal
Melt temperature ASTM 2116 ° C 327
Deflection temperature
heat deflection temp. A (18,5) kp/cm²
heat deflection temp. E (4,6) kp/cm²
53461
ISO R 75
° C 50 - 60
130 - 140
coeffizient of linear expansion I/K 1,00 E-5 10 - 16
Thermal conductivity at 23° C 52612 W/K · m 0,23
specific heat at 23° C KJ/Kg · K 1,01
Oxygen index >95
Electrical
Dielectric constant at 10³
Dielectric constant at 1,00 E6
53483 2,0 - 2,1
2,0 - 2,1
Dissipation factor at 10³
Dissipation factor at 1,00 E6
53483 1,00 E-4 0,3 - 0,5
0,7 - 1,0
Volume resistivity 53482 ·cm 1,00 E18
Surface resistance 53482 1,00 E17
Tracking resistance 53480 KA3c
Arc resistance ASTM 495 sec. >360
Dielectric strength 53481 KV/mm 40 - 80
* This test is not standardised. The coefficient of friction ist influenced by several factors. The indicated value is only a rough guideline value.
 This table was obtained from http://www.fietz.de/ptfe_phe.htm.