History PTFE was accidentally invented by Roy Plunkett of Kinetic Chemicals in 1938. While Plunkett was attempting to make a new CFC refrigerant, the perfluorethylene polymerized in its pressurized storage container, with the iron from the inside of the container acting as a catalyst. Kinetic Chemicals patented it in 1941 and registered the Teflon trademark in 1945. By 1950, DuPont had acquired interest in Kinetic Chemicals and was producing over a million pounds (450 tons) of Teflon per year in Parkersburg, West Virginia. In 1954, French engineer Marc Grgoire created the first pan coated with Teflon non-stick resin under the brand name of Tefal after his wife urged him to try the material he had been using on fishing tackle on her cooking pans. In the United States, Kansas City, Missouri resident Marion A. Trozzolo, who had been using the substance on scientific utensils, marketed the first US-made Teflon coated frying pan, “The Happy Pan,” in 1961. An early advanced use was in the Manhattan Project as a material to coat valves and seals in the pipes holding highly reactive uranium hexafluoride in the vast uranium enrichment plant at Oak Ridge, Tennessee, when it was known as K-25. Properties PTFE is often used to coat non-stick frying pans as it is hydrophobic and possesses fairly high heat resistance. PTFE is a white solid at room temperature, with a density of about 2.2 g/cm3. According to DuPont its melting point is 327C (621F), but its properties degrade above 260C (500F). PTFE gains its properties from the aggregate effect of carbon-fluorine bonds, as do all fluorocarbons. The coefficient of friction of plastics is usually measured against polished steel. PTFE’s coefficient of friction is 0.1 or less, which is the second lowest of any known solid material (diamond-like carbon being the first). PTFE’s resistance to van der Waals forces means that it is the only known surface to which a gecko cannot stick. PTFE has excellent dielectric properties. This is especially true at high radio frequencies, making it suitable for use as an insulator in cables and connector assemblies and as a material for printed circuit boards used at microwave frequencies. Combined with its high melting temperature, this makes it the material of choice as a high-performance substitute for the weaker and lower melting point polyethylene that is commonly used in low-cost applications. Its extremely high bulk resistivity makes it an ideal material for fabricating long life electrets, useful devices that are the electrostatic analogues of magnets. Because of its chemical inertness, PTFE cannot be cross-linked like an elastomer. Therefore it has no “memory,” and is subject to creep, also known as “cold flow” and “compression set”. A little bit of creep allows PTFE seals to conform to mating surfaces better than most other plastic seals. Too much creep, however, and the seal can be compromised. Compounding fillers control unwanted creep and improve wear, friction, and other properties. Sometimes metal springs apply continuous force to PTFE seals to give good contact, while permitting some creep. Due to its low friction, it is used for applications where sliding action of parts is needed: plain bearings, gears, slide plates, etc. In these applications it performs significantly better than nylon and acetal; it is comparable to ultra high-molecular weight polyethylene (UHMWPE), although UHMWPE is more resistant to wear than Teflon. For these applications, versions of Teflon with mineral oil or molybdenum disulfide embedded as additional lubricants in its matrix are being manufactured. Property Value Density 2200kg/m3 Melting point 327 C Young’s modulus 0.5 GPa Yield strength 23 MPa Coefficient of friction 0.05-0.10 Dielectric constant =2.1,tan()3.0.CO;2-8. ^ Teflon (PTFE) Thermal Decomposition Products. Fluoride Action Network Pesticide Project. ^ a b Teflon offgas studies
Environmental Working Group ^ Zapp JA, Limperos G, Brinker KC (1955-04-26). “Toxicity of pyrolysis products of ‘Teflon’ tetrafluoroethylene resin”. Proceedings of the American Industrial Hygiene Association Annual Meeting. ^ Can Nonstick Make You Sick? ABC News ^ a b DuPont, Key Questions About Teflon, accessed on 3 December 2007. ^ Dale Blumenthal. “Is That Newfangled Cookware Safe?”. Food and Drug Administration. http://www.fda.gov/bbs/topics/CONSUMER/CON00036.html. Retrieved 2006-05-20. ^ http://www.bafu.admin.ch/publikationen/publikation/01066/index.html?lang=en&downloadshop=NHzLpZig7t,lnp6I0NTU042l2Z6ln1ad1IZn4Z2qZpnO2Yuq2Z6gpJCDdIN,f2ym162dpYbUzd,Gpd6emK2Oz9aGodetmqaN19XI2IdvoaCVZ,s-.pdf, pages 4041 ^ Sandy, Martha. “Petition for Expedited CIC Consideration of Perfluorooctanic Acid (PFOA)”. The State of California, Office of Environmental Health Hazard Assessment, Cancer Toxicology and Epidemiology Section, Reproductive and Cancer Hazard Assessment Branch. http://www.oehha.ca.gov/Prop65/public_meetings/pdf/PFOACIC%20Slides121206.pdf. Retrieved 2008-09-27. ^ Lau C, Anitole K, Hodes C, Lai D, Pfahles-Hutchens A, Seed J (October 2007). “Perfluoroalkyl acids: a review of monitoring and toxicological findings”. Toxicol. Sci. 99 (2): 36694. doi:10.1093/toxsci/kfm128. PMID 17519394. http://toxsci.oxfordjournals.org/cgi/reprint/99/2/366.pdf. ^ a b c “PFOA in Norway TA-2354/2007”. Norwegian Pollution Control Authority. 2007. p. 18. http://www.sft.no/publikasjoner/2354/ta2354.pdf. Retrieved 29 August 2009. ^ a b c Guo Z, Liu X, Krebs KA (March 2009). “Perfluorocarboxylic Acid Content in 116 Articles of Commerce” (PDF). USEPA. p. 40. http://www.epa.gov/nrmrl/pubs/600r09033/600r09033.pdf. ^ Begley TH, White K, Honigfort P, Twaroski ML, Neches R, Walker RA (October 2005). “Perfluorochemicals: potential sources of and migration from food packaging”. Food Addit. Contam. 22 (10): 102331. doi:10.1080/02652030500183474. PMID 16227186. ^ Powley CR, Michalczyk MJ, Kaiser MA, Buxton LW (September 2005). “Determination of perfluorooctanoic acid (PFOA) extractable from the surface of commercial cookware under simulated cooking conditions by LC/MS/MS”. Analyst 130 (9): 1299302. doi:10.1039/b505377c. PMID 16096677. ^ “Teflon firm faces fresh lawsuit”. BBC News. 19 July 2005. http://news.bbc.co.uk/2/hi/business/4697939.stm. Retrieved 24 January 2009. ^ “About Teflon”. DuPont. http://web.archive.org/web/20080229143203/http://www2.dupont.com/PFOA/en_US/about_teflon/. Retrieved 2010-02-09. ^ Houde M, Martin JW, Letcher RJ, Solomon KR, Muir DC (June 2006). “Biological monitoring of polyfluoroalkyl substances: A review”. Environ. Sci. Technol. 40 (11): 346373. doi:10.1021/es052580b. PMID 16786681. Supporting Information (PDF). ^ Trudel D, Horowitz L, Wormuth M, Scheringer M, Cousins IT, Hungerbhler K (April 2008). “Estimating consumer exposure to PFOS and PFOA”. Risk Anal. 28 (2): 25169. doi:10.1111/j.1539-6924.2008.01017.x. PMID 18419647. ^ “Nonstick pans: Nonstick coating risks”. Consumer Reports. http://www.consumerreports.org/cro/home-garden/kitchen/cookware-bakeware-cutlery/nonstick-pans-6-07/overview/0607_pans_ov_1.htm. Retrieved 4 July 2009. ^ http://www.rsc.org/chemistryworld/Issues/2005/September/Cooking.asp ^ Ellis DA, Mabury SA, Martin JW, Muir DC (July 2001). “Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment”. Nature 412 (6844): 3214. doi:10.1038/35085548. PMID 11460160. ^ Ellis DA, Martin JW, Muir DC, Mabury SA (June 2003). “The use of 19F NMR and mass spectrometry for the elucidation of novel fluorinated acids and atmospheric fluoroacid precursors evolved in the thermolysis of fluoropolymers”. Analyst 128 (6): 75664. doi:10.1039/b212658c. PMID 12866900. ^ Juliet Eilperin (2006-01-26). “Harmful PTFE chemical to be eliminated by 2015”. Washington Post. http://www.washingtonpost.com/wp-dyn/content/article/2006/01/25/AR2006012502041.html. Retrieved 2006-09-10. ^ Michael McCoy (November 2008). “Dyneon Phasing Out Perfluorooctanoate”. Chemical & Engineering News 86 (46): 26. http://pubs.acs.org/isubscribe/journals/cen/86/i46/html/8646busc7.html. ^ “Learn More About DuPont Teflon”. DuPont. http://www2.dupont.com/Teflon/en_US/keyword/pfoa.html?src=search_us_pfoa. Retrieved 16 May 2009. ^ “Failure to Report Chemical Risks Can Result in Major Fines, EPA Office of Civil Enforcement”. Environmental Protection Agency. 2008-08. http://www.epa.gov/compliance/resources/newsletters/civil/enfalert/8e-tsca-0807.pdf. Retrieved 2009-01-19. ^ FEP Detailed Properties Parker-TexLoc, 13 April 2006. Retrieved 10 September 2006. References Ellis, D.A.; Mabury, S.A.; Martin, J.W.; Muir, D.C.G. (2001). “Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment”. Nature 412 (6844): 321324. doi:10.1038/35085548. External links EPA: Compound in Teflon may cause cancer , Tom Costello, NBC News, June 29, 2005 DuPont (2005). Teflon News and Information. Retrieved 7 October 2005. Plasma Processes and Adhesive Bonding of Polytetrafluoroethylene vde Health issues of plastics and Polyhalogenated compounds (PHC)’s Plasticizers: Phthalates DIBP DBP BBP (BBzP) DIHP DEHP (DOP) DIDP DINP Other plasticizers Organophosphates Adipates (DEHA DOA) Monomers Bisphenol A (BPA, in Polycarbonates) Vinyl chloride (in PVC) Other additives incl. PHC’s PBDEs PCBs Organotins PFCs Health issues Teratogen Carcinogen Endocrine disruptor Diabetes Obesity Miscellaneous PVC Plastic recycling Plastic bottle Vinyl chloride Dioxins Polystyrene Styrofoam PTFE (Teflon) California Proposition 65 List of environmental health hazards Persistent organic pollutant European REACH regulation Japan Toxic Substances Law Toxic Substances Control Act vde E.I. du Pont de Nemours and Company (DuPont) Corporate directors Samuel Bodman Richard H. Brown Robert A. Brown Bertrand P. Collomb Curtis J. Crawford Alexander M. Cutler There du Pont John T. Dillon Marillyn Hewson Lois Juliber Ellen J. Kullman William K. Reilly Products Corian FE-13 Hypalon Kalrez Kapton Kevlar Mylar Neoprene Nomex Nylon Sorona Teflon Tyvek Zodiaq Zytel Subsidiaries and joint ventures Pioneer Hi-Bred Solae DuPont Danisco Divisions and facilities DuPont Building DuPont Central Research DuPont Experimental Station Notable people Eleuthre Irne du Pont Alfred I. du Pont Eugene du Pont Francis Gurney du Pont Francis Irne du Pont Lammot du Pont Pierre S. du Pont Norman Borlaug Donaldson Brown Wallace Carothers Uma Chowdhry Thomas M. Connelly Linda Fisher Richard Goodmanson Charles O. Holliday Steven Ittel Stephanie Kwolek Rudolph Pariser George Parshall Roy J. Plunkett John J. Raskob Irving S. Shapiro Joseph Shivers Richard R. Schrock Howard Ensign Simmons, Jr. Charles Stine Nathaniel C. Wyeth History Hagley Museum and Library Eleutherian Mills E. I du Pont de Nemours Company Hercules Powder Company Atlas Chemical Industries B Reactor (Manhattan Project) Remington Arms Savannah River Site Kinetic Chemicals Conoco Inc. Consolidation Coal Company Annual revenue: $27.3 billion USD (1.3% FY 2004) Employees: 60,000 Stock symbol: Preferred stock: NYSE:DDPRA, NYSE:DDPRB Common stock: NYSE:DD Website: www.dupont.com vde Plastics Polyacrylic acid (PAA) Cross-linked polyethylene (PEX or XLPE) Polyethylene (PE) Polyethylene terephthalate (PET or PETE) Polyphenyl ether (PPE) Polyvinyl chloride (PVC) Polyvinylidene chloride (PVDC) Polylactic acid (PLA) Polypropylene (PP) Polybutylene (PB) Polybutylene terephthalate (PBT) Polyamide (PA) Polyimide (PI) Polycarbonate (PC) Polytetrafluoroethylene (PTFE) Polystyrene (PS) Polyurethane (PU) Polyester (PEs) Acrylonitrile butadiene styrene (ABS) Poly(methyl methacrylate) (PMMA) Polyoxymethylene (POM) Polysulfone (PES) Styrene-acrylonitrile (SAN) Ethylene vinyl acetate (EVA) Styrene maleic anhydride (SMA) Categories: Fluorocarbons ns
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