Editing Polytetrafluoroethylene (section)

== History ==
[[File:Happy Pan Poster.jpg|left|thumb|upright|Advertisement of the Happy Pan, a Teflon-coated pan from the 1960s]]{{external media |width = 210px [https://www.sciencehistory.org/distillations/podcast/teflon "From stove tops to outer space... Teflon touches every one of us some way almost every day."], Roy Plunkett, [[Science History Institute]]}}
[[File:1963 Zepel advertisement.jpg|thumb|upright|Advertisement for Zepel, the trade name used to market Teflon as a fabric treatment]]
[[File:EL-1994-00019.jpeg|thumb|upright|PTFE thermal cover showing impact craters, from NASA's Ultra Heavy Cosmic Ray Experiment (UHCRE) on the [[Long Duration Exposure Facility]] (LDEF)]]
[[File:Teflon logo.svg|thumb|Logo of Teflon, the commonly known brand name of PTFE-based compositions manufactured by Chemours]]

Polytetrafluoroethylene (PTFE) was accidentally discovered in 1938 by [[Roy J. Plunkett]] while he was working in Chemours Chambers Works plant in New Jersey for [[DuPont]]. A team of Dupont chemists attempted to make a new [[chlorofluorocarbon]] refrigerant, called [[tetrafluoroethylene]]. The gas in its pressure bottle stopped flowing before the bottle's weight had dropped to the point signaling "empty". John J. Beall (chemist), noticing a weight differential in his test cylinder, brought it to the attention of Roy Plunkett.  The chemists in the lab sawed the bottle apart and found the bottle's interior coated with a waxy white material that was oddly slippery. Analysis showed that it was polymerized perfluoroethylene, with the iron from the inside of the container having acted as a catalyst at high pressure.<ref name="Institute">{{cite web |title=Roy J. Plunkett |url=https://www.sciencehistory.org/historical-profile/roy-j-plunkett |website=Science History Institute |date=June 2016 |access-date=10 February 2020}}</ref> Kinetic Chemicals patented the new fluorinated plastic (analogous to the already known [[polyethylene]]) in 1941,<ref>{{Cite patent|inventor-last = Plunkett|inventor-first = Roy J|inventorlink = Roy Plunkett|issue-date = 4 February 1941|title = Tetrafluoroethylene polymers|country-code = US|patent-number = 2230654}}</ref> and registered the Teflon trademark in 1945.<ref name="fluoroboom">{{cite news|title = History Timeline 1930: The Fluorocarbon Boom|url = http://www2.dupont.com/Refrigerants/en_US/sales_support/history_1930.html|access-date = 10 June 2009|publisher = DuPont|archive-date = 3 July 2011|archive-url = https://web.archive.org/web/20110703073623/http://www2.dupont.com/Refrigerants/en_US/sales_support/history_1930.html|url-status = dead}}</ref><ref>{{cite news|title = Roy Plunkett: 1938|url = http://www2.dupont.com/Heritage/en_US/1938_dupont/1938_indepth.html|access-date = 10 June 2009|archive-date = 17 February 2012|archive-url = https://web.archive.org/web/20120217011800/http://www2.dupont.com/Heritage/en_US/1938_dupont/1938_indepth.html|url-status = dead}}</ref>

By 1948, DuPont, which founded Kinetic Chemicals in partnership with [[General Motors]], was producing over {{convert|2,000,000|lb|order=flip}} of Teflon-brand polytetrafluoroethylene per year in [[Parkersburg, West Virginia]].<ref>''[[American Heritage of Invention & Technology]]'', Fall 2010, vol. 25, no. 3, p. 42</ref> An early use was in the [[Manhattan Project]] as a material to coat valves and seals in the pipes holding highly reactive [[uranium hexafluoride]] at the vast [[K-25]] [[enriched uranium|uranium enrichment]] plant in [[Oak Ridge, Tennessee]].<ref name="rhodes">{{cite book |last1=Rhodes |first1=Richard |title=The Making of the Atomic Bomb |date=2012 |publisher=Simon and Schuster |isbn=978-1-4391-2622-6 |page=494 }}</ref>

In 1954, Colette Grégoire urged her husband, the French engineer [[Marc Grégoire]], to try the material he had been using on fishing tackle on her cooking pans. He subsequently created the first PTFE-coated, [[non-stick pans]] under the brand name [[Tefal]] (combining "Tef" from "Teflon" and "al" from aluminium).<ref name="history">{{cite web|archive-date = 14 February 2008|website = Useless Information|url = http://home.nycap.rr.com/useless/teflon/index.html |archive-url=https://web.archive.org/web/20080214150646/http://home.nycap.rr.com/useless/teflon/index.html |title=Teflon |publisher=home.nycap.rr.com}}</ref> In the United States, [[Marion A. Trozzolo]], who had been using the substance on scientific utensils, marketed the first US-made PTFE-coated pan, "The Happy Pan", in 1961.<ref name="intofire">{{cite news |id={{ProQuest|110883381}} |last1=Robbins |first1=William |date=21 December 1986 |url=https://www.nytimes.com/1986/12/21/us/teflon-maker-out-of-frying-pan-into-fame.html |title=Teflon Maker: Out of a Frying Pan Into Fame |newspaper=[[New York Times]] |url-access=subscription }}</ref> Non-stick cookware has since become a common household product, now offered by hundreds of manufacturers across the world.

The brand name Zepel was used for promoting its stain-resistance and water-resistance when applied to fabrics.<ref>{{cite news |last=Fenton |first=Lois |date=1992-01-02 |title=Go, spot, go Teflon enters fashion world as a protective coating |url=https://www.baltimoresun.com/news/bs-xpm-1992-01-02-1992002050-story.html |work=Baltimore Sun |archive-url=https://web.archive.org/web/20210620172022/https://www.baltimoresun.com/news/bs-xpm-1992-01-02-1992002050-story.html|archive-date=2021-06-20}}</ref>

In the 1990s, it was found that PTFE could be radiation [[cross-linked]] above its melting point in an oxygen-free environment.<ref name="autogenerated655">{{cite journal |last1=Sun |first1=Jiazhen |last2=Zhang |first2=Yuefang |last3=Zhong |first3=Xiaoguang |last4=Zhu |first4=Xianglin |title=Modification of polytetrafluoroethylene by radiation—1. Improvement in high temperature properties and radiation stability |journal=Radiation Physics and Chemistry |date=December 1994 |volume=44 |issue=6 |pages=655–659 |doi=10.1016/0969-806X(94)90226-7 |bibcode=1994RaPC...44..655S }}</ref> [[Electron beam processing]] is one example of radiation processing. Cross-linked PTFE has improved high-temperature mechanical properties and radiation stability. That was significant because, for many years, irradiation at ambient conditions has been used to break down PTFE for recycling.<ref>[http://www.e-beamservices.com/chain.htm Electron Beam Processing of PTFE] {{Webarchive|url=https://web.archive.org/web/20130906131658/http://e-beamservices.com/chain.htm |date=6 September 2013 }} E-BEAM Services website. Accessed 21 May 2013</ref> This radiation-induced [[chain scission]] allows it to be more easily reground and reused.

[[Corona treatment|Corona discharge treatment]] of the surface to increase the energy and improve adhesion has been reported.<ref>{{cite book |doi=10.1016/B978-1-895198-85-0.50009-1 |chapter=Degradation by Other Forms of Radiation |title=PVC Degradation and Stabilization |date=2015 |last1=Wypych |first1=George |pages=215–226 |isbn=978-1-895198-85-0 }}</ref>