Teflon®, chemically known as Polytetrafluoroethylene or PTFE for short, was the first fluoropolymer introduced. It was discovered by accident in 1938 when DuPont chemist Dr. Roy Plunket, who was working with fluorocarbon refrigerant gasses, opened the valve to one gas cylinder, and no gas came out of the valve. The cylinder, when cut open, was filled with a white waxy solid that did not melt and did not dissolve – this was PTFE.
Today, PTFE is sold in three different forms that allow fabricators to make parts even though it is not melt processable: granular, fine powder, and dispersion. Fine powder combined with a lubricant liquid into a paste is the most common processing format used in the medical industry.
While PTFE is probably the most well-known fluoropolymer don't forget about these other materials. Each one has its own characteristics that make it desirable for certain applications but the quick overview of features and benefits below can help you decide if a fluoropolymer is the direction to go.
Types of Fluoropolymers
- PTFE (Polytetrafluoroethylene)
- PFA (perfluoroalkoxy alkane)
- FEP (fluorinated ethylene propylene)
- ETFE (ethylene tetrafluoroethylene)
- PVDF (polyvinylidene fluoride)
- ECTFE (ethylene chlorotrifluoroethylene)
Features and Benefits of Fluoropolymers
- Fluoropolymers are semi-crystalline materials. This more organized arrangement of molecules makes fluoropolymers harder and less permeable than elastomers.
- Fluoropolymers can be fully fluorinated or partially fluorinated. Material properties between these groups will differ. PTFE, PFA, and FEP offer higher melt points and lower coefficients of friction while ETFE, PVDF, and ECTFE have higher tensile strengths and are more abrasion resistant.
- Fluoropolymers have a low coefficient of friction. PTFE has the lowest coefficient of any material but overall all of these materials offer good lubricity but will require special surface preparation if bonding is required.
- Fluoropolymers are very chemically resistant. These materials are resistant to a large array of chemicals. It is easier to list what they don’t resist although this will vary depending on the specific material.
- Fluoropolymers are very pure. Leachables and extractables are extraordinarily low compared to other polymers because the thermal and chemical stability of the carbon-fluoride bonds allow them to be processed without any stabilizers or processing aids. This is a great quality for the medical and pharmaceutical industries.
For material data and properties, see our list of available fluoropolymers here. If you want to learn more or have questions on this family of materials, take a look at our Fluoropolymer Extrusion page.