Teflon
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Teflon is the brand name of a polymer compound discovered by Roy J. Plunkett (1910-1994) of DuPont in 1938 and introduced as a commercial product in 1946.
Teflon is polytetrafluoroethylene (PTFE).
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Teflon is also used as the trade name for a polymer with similar properties, perfluoroalkoxy polymer resin (PFA):
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PTFE has the lowest coefficient of friction of any solid material. It is used as a non-stick coating for pans and other cookware. PTFE is very unreactive, and so is often used in containers and pipework for reactive chemicals. Its melting point varies between 260 °C (FEP) and 327 °C (PTFE), depending on which specific Teflon polymer is being discussed.
PTFE is sometimes said to be a spin-off from the US space program with more down-to-earth applications; this is an urban legend, as teflon cooking pans were commonplace before Yuri Gagarin's flight in 1961. PTFE was discovered serendipitously by Roy Plunkett of DuPont in 1938, while attempting to make a new CFC refrigerant. DuPont patented it in 1941, and registered the Teflon trademark in 1944.
Its first significant use was in the Manhattan Project, as a material to contain highly-reactive uranium hexafluoride, when it was known as K416.
It was first sold commercially in 1946 and by 1950, DuPont was producing over a million pounds (weight) per year in Virginia.
Teflon has been supplemented with another DuPont product, Silverstone, a three-coat fluoropolymer system that produces a more durable finish than Teflon. Silverstone was released in 1976.
Amongst many other industrial applications, PTFE is used to coat certain types of hardened, armour-piercing bullets, so as to reduce the amount of wear on the firearm's rifling. These are often mistakenly referred to as "cop-killer" bullets on account of PTFE's supposed ability to ease a bullet's passage through bullet-proof armour. Any armour-piercing effect is, however, purely a function of the bullet's velocity and rigidity rather than a property of PTFE.
Teflon exposure has been implicated in cancer, though DuPont denies any association. Non-stick coatings on househould frying pans have also been shown to release toxic gases upon overheating. These gases are lethal to avians, and can cause flu-like symptoms in humans.
PTFE has excellent electrical properties especially at radio frequencies, making it eminently suitable for use as an insulator in cables and connector assemblies. Combined with its high melting temperature this makes it the material of choice as a high performance substitute for the weaker and more meltable polythene that is commonly used in low-cost applications.
External links
- Adams, Cecil (1995). If Teflon is nonsticky, how do they get it to stick to the pan? (http://www.straightdope.com/classics/a4_173.html). Retrieved March 28, 2005.
- DuPont (2005). Teflon News and Information (http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/eng/news/news_list.html). Retrieved March 28, 2005.
- Environmental Working Group (2005). Canaries in the Kitchen - "Teflon Toxicosis" is deadly to pet birds. Are we at risk? (http://www.ewg.org/reports/toxicteflon/). Retrieved March 28, 2005.
- Kopel, Dave (2004). The Return of a legislative Legend (http://www.nationalreview.com/kopel/kopel200403010926.asp). Retrieved March 28, 2005.
- nature publishing group (2001). Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment (http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v412/n6844/abs/412321a0_fs.html). Retrieved March 29, 2005.
- The Chemical Heritage Foundatin (2000). Roy J. Plunkett (http://www.chemheritage.org/EducationalServices/chemach/pop/rjp.html). Retrieved March 28, 2005.de:Polytetrafluorethylen
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