Perfluoropolyether

Perfluoropolyether (PFPE) is a type of liquid lubricant that has been used in the aerospace industry for over 30 years.[2] The main properties of PFPE are being temperature resistant between −58 °C (215 K) and 257 °C (530 K) (depending on specific composites), having very low outgassing compared to other fluids (vapour pressure of 6×10−8 Torr) and having a dielectric strength of around 15.7 MV/m.[3]

Perfluoropolyether
Names
Other names
PFPE
Identifiers
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Perfluoropolyether consists of a polymer chain in which monomers consisting of perfluoro-alkyl groups are joined by ether linkages. The bonds between carbon and oxygen or fluorine are strong.[4]

The thermal and chemical stability of PFPE along with a vapor–liquid equilibrium of 230 °C when mixed with the right composites make it a suitable candidate for vapor phase soldering technologies.[5]

History

It's been developed in early 1960s at request of USAF with a requirement to be non-reacting with liquid and gaseous oxygen (O2).[6]

Manufacture

Perfluoropolyether can be synthesized from tetrafluoroethylene or hexafluoropropylene.[4]

Properties

PFPE is chemically inert to many acids and oxidants (like fuming sulfuric acid (oleum, SO3), chlorine gas, oxygen) and solvents, etc..

PFPE is non-toxic under normal conditions, nonflammable, and exhibit unusually high load carry capabilities.[6][1]: 275  PFPE can withstand gamma ray degradation.[6]

Electrical resistivity is 1014 ohm/cm (20 °C (68 °F))[6]

Applications

Generally PFPE may be used as lubricant in all sorts of bearing, plug valves, gaskets, chains, and joint bearing applications, where oxygen inertness of a material is a requirement.[6][1] Examples include aircraft fuel systems, mechanical components of devices used in airspace, deep space or high vacuum and at cryogenic temperatures.[6]

PFPE may be used in mold release agent for plastic injection molding.[6]

As top coating lubricant on computer disc drives and Scanning Electron Microscope[6][1]: 275 

As anti-galling compounds.[6]

As fluid medium in ferrofluidic seals.[6]

Semiconductor industry

In the semiconductor industry, PFPE may be used as a vacuum grease or in plasma etching equipment, or for robots used in semiconductor wafer handling, clean rooms, and other commercial environments.[6]

See also
  • Krytox, a PFPE-based lubricant

References
  1. Ash, Michael (2004). Handbook of green chemicals. Irene Ash (2 ed.). Endicott, NY: Synapse Information Resources. ISBN 978-1-934764-29-9. OCLC 747426845.
  2. Bradley Shogrin (August 1995). "Spontaneous Dewetting of a Perfluoropolyether" (PDF). National Aeronautics and Space Administration. Retrieved November 29, 2017. {{cite journal}}: Cite journal requires |journal= (help)
  3. "Fomblin® PFPE Lubricants".
  4. Fluorochemie. "Brief Introduction of PFPE Synthesis Methods". Fuzhou Topda New Material Co., Ltd. Retrieved June 27, 2022.
  5. "Archived copy" (PDF). Archived from the original (PDF) on 2021-02-27. Retrieved 2020-08-23.{{cite web}}: CS1 maint: archived copy as title (link)
  6. "HUSKEY Specialty lubricants" (PDF). HUSK-ITT Corporation.
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