What is PTFE?
PTFE or Polytetrafluoroethylene has a molecular structure which is based on a chain of carbon atoms. However, unlike some other fluoropolymers each carbon atom in PTFE is linked to two fluorine atoms that form a helical spiral which surrounds the carbon chain and protects it.
The carbon-fluorine bond is one of the strongest in any polymer and it is this structure which accounts for the unique properties of PTFE including excellent chemical resistance.
Key properties
The table below lists a generally accepted summary of properties that we believe to be reliable. Please note that many of these resins are produced in several varieties and property characteristics may vary. Therefore, determination of resin is dependent on the application and this table is only meant to serve as a general guideline.
Properties | ASTM or unit | PTFE |
MECHANICAL PROPERTIES | ||
Specific Gravity | D792 | 2.18 |
Elongation % | D638 | 200 ~ 450 |
Tensile Strength (psi) | D638 | 2,000~7,000 |
Flexural Strength (psi) | D790 | no break |
Compressive Strength | D695 | 3.500 |
Tensile Elastic Modulus (Young’s Modulus) (psi) | D638 | 57.000 |
(psi) Flexural Modulus 103MPa (103kgf/cm2) | D790 D790 |
71,000 ~ 85,000 0.5-0.6 (5.0-6.0) |
FlexLife (MIT cycles) | D2176 | >1,000,000 |
Hardness Durometer Shore D | D636 | D50 ~ 65 |
Coefficient of Friction | On steel | 0.02 |
Abrasion Resistance 1000 revs. | Taber | 12 |
Impact Strength IZOD 73°F/23°C, notched ft/lbs/in | D256 | 3 |
Properties | ASTM or unit | PTFE |
THERMAL PROPERTIES | ||
Melting Point | °C (°F) | 327 (621) |
Upper Service Temperature(20,000h) | °C (°F) | 260 (500) |
Flame Rating** | UL 94 | V-0 |
Thermal Conductivity | BTU/hr/ft2/deg F in cal/sec/cm2,ºC/cm |
1.7 6 x 10-4 |
Linear Coefficient of Thermal Expansion 10-5 °C | D696 | >11.6 |
Heat of Fusion | BTU/LB | 29-37 |
Heat of Combustion | BTU/LB | 2200 |
Low Temperature Embrittlement | °C (°F) | -268 (-450) |
Properties | ASTM or unit | PTFE |
ELECTRICAL PROPERTIES | ||
Dielectric Constant | D150/103Hz D150/106Hz |
2.1 2.1 |
Dielectric Strength 10 mil film | D149 | >1400 |
Volume Resistivity ohm-cm | D257 | >1018 |
Surface Resistivity ohm/sq. | D257 | >1017 |
Properties | ASTM or unit | PTFE |
GENERAL PROPERTIES | ||
Chemical/Solvent Resistance | D543 | Excellent |
Water Absorption, 24h | % | >0.01 |
Deformation Under Load | *D621/100°C **D621/25°C |
5.0 7.0 |
Refractive Index | 1.35 | |
Limiting Oxygen Index | >95 | >95 |
Properties | ASTM or Unit | PTFE |
*6.8 MPa (986 psi),24h **13.7 MPa (1987 psi),24h |