Krytox is a group of colourless synthetic lubricants (oils and greases) with a variety of applications. Invented by researchers at DuPont, Krytox oils are fluorocarbon ether polymers of polyhexafluoropropylene oxide, with a chemical formula: F−(CF(CF3)−CF2−O)n−CF2CF3, where the degree of polymerization, n, generally lies within the range of 10 to 60. These compounds are collectively known by many names including perfluoropolyether (PFPE), perfluoroalkylether (PFAE) and perfluoropolyalkylether (PFPAE). A unique identifier is their CAS registry number, 60164-51-4.
In addition to PFPE, Krytox grease also contains telomers of PTFE and in fact was designed as a liquid or grease form of PTFE. It is thermally stable, nonflammable (even in liquid oxygen), and insoluble in water, acids, bases, and most organic solvents. It is nonvolatile and useful over a broad temperature range of −75 to 350 °C (−100 to 660 °F) or higher. Its high resistance to ionizing radiation makes it useful for the aerospace and nuclear industries. It can also withstand extreme pressure and high mechanical stress.
The manufacturer states on Krytox tubes, "May cause mild skin and eye irritation. Contact with very hot surfaces (above 500°F/260°C) can generate fumes which can cause coughing or respiratory irritation. Large amounts could lead to lung damage which might not be apparent for several hours. These fumes may also cause flu-like symptoms."
- Günter Siegemund, Werner Schwertfeger, Andrew Feiring, Bruce Smart, Fred Behr, Herward Vogel, Blaine McKusick “Fluorine Compounds, Organic” Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a11_349
- DuPont Krytox Performance Lubricants Product Overview, available online here
- "Krytox® PFPE/PTFE Greases (GPL 20(X) Series) Material Safety Data Sheet" (PDF). Dupont. Retrieved 15 June 2013.
- "Krytox® PFPE Oils Material Safety Data Sheet" (PDF). DuPont. Retrieved 15 June 2013.