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Polytetrafluorethylene (PTFE) Chandra Heller Michael Mallicote.

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Presentation on theme: "Polytetrafluorethylene (PTFE) Chandra Heller Michael Mallicote."— Presentation transcript:

1 Polytetrafluorethylene (PTFE) Chandra Heller Michael Mallicote

2 Discovery Accidentally discovered on April 6, 1938 by Roy Plunkett.

3 Uses By 1941, PTFE had been patented and had its first brand name Teflon®. By 1946, the resin product was being used to produce machine parts for military and industrial applications. In the 1960s it began its life in the arena of nonstick cookware.

4 Uses (continued) Today it has expanded into a whole family of polymers (resins, films, coatings, moldable forms, powders) and sold under various brand names, including Gore-Tex® and Zylon®. It is used in a wide range of industries from aerospace to pharmaceuticals and is sold in over 40 countries worldwide.

5 Teflon® Monomer CC F F F F tetrafluoroethylene

6 Teflon® Polymer

7 Teflon® Polymer (continued)

8 Emulsion Polymerization Initiation: Free radical formation ROOR + Heat → 2 RO Initiation: Formation of new free radicals by peroxide + TFE in aqueous phase RO + CF 2 =CF 2 → RO(CF 2 –CF 2 ) Propagation: Growth of free radicals by further addition of TFE RO(CF 2 –CF 2 ) + n CF 2 =CF 2 → RO(CF 2 –CF 2 )–(CF 2 –CF 2 ) Free radicals undergo hydrolysis where a hydroxyl group replaces the peroxide RO(CF 2 –CF 2 )–(CF 2 –CF 2 ) + H 2 O → HO(CF 2 –CF 2 ) n –(CF 2 –CF 2 ) + H + + HOR HO(CF 2 =CF 2 ) n –(CF 2 =CF 2 ) + H 2 O → COOHCF 2 –(CF 2 –CF 2 ) n + 2HF Termination: COOH– CF 2 –(CF 2 – CF 2 ) n + COOH– CF 2 –(CF 2 – CF 2 ) m → COOH– CF 2 –(CF 2 – CF 2 ) m+n COOH

9 Toxicity The monomer TFE is a confirmed animal carcinogen with unknown relevance to humans. The finished polymer in solid form is inert under ordinary conditions. There is some indication that the powdered forms of PTFE may be carcinogenic if inhaled.

10 Recycling of PTFE It is easy to recycle since no chemical reaction is necessary. Only the extruded forms are recycled (not the resin or powerdered forms). The uses of recycled PTFE are restricted. It is typically ground up into fine powders and used as additives in such products as inks, paints, and cosmetics.

11 Questions

12 References 1)Inventor of the Week: Archive. http://web.mit.edu/invent/iow/plunkett.html (2000)http://web.mit.edu/invent/iow/plunkett.html 2)Teflon.com - the complete resource on Teflon® products by DuPont. http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/home_page.jsp (2005) http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/home_page.jsp 3)Biomaterials. http://www.abe.msstate.edu/Classes/abe4523_6523/polymers.PDF (2001)http://www.abe.msstate.edu/Classes/abe4523_6523/polymers.PDF 4)Zonyl Packaging: Whistleblower. http://www.mindfully.org/Plastic/Teflon/Zonyl-DuPont-Risk17nov05.htm (2005)http://www.mindfully.org/Plastic/Teflon/Zonyl-DuPont-Risk17nov05.htm 5)Teflon fluorocarbon information. http://www.omega.com/techref/fluoro.html (2001)http://www.omega.com/techref/fluoro.html 6)Polymers. http://www.chemistry.mtu.edu/pages/courses/ch1120-pcharles/Oxtoby_Ch25.pdf (2004)http://www.chemistry.mtu.edu/pages/courses/ch1120-pcharles/Oxtoby_Ch25.pdf 7)Ebnesajjad, S. Non-melt Processible Fluoroplastics : The Definitive User's Guide and Databook. Norwich, N.Y. : Plastics Design Library. (2000) 8)Ebnesajjad, S. Melt Processible Fluoropolymers: The Definitive User's Guide and Databook. Norwich, N.Y. : Plastics Design Library (2003) 9)Chemical Structure. http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/Chemical_Structure.html (2003)http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/Chemical_Structure.html 10)Synthesis. http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/synthesis.html. (2003)http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/synthesis.html 11)Burridge, E. PTFE. Eur. Chem. News. 80, 16 (2004) 12)Bingham, E., Cohrssen, B., Powell, C., Eds. Patty's Toxicology. New York : John Wiley. (2001) 13)Useless Information. http://home.nycap.rr.com/useless/teflon/ (2003)http://home.nycap.rr.com/useless/teflon/ 14)DuPont Electronic Materials Keep Mars Rovers Going. http://www2.dupont.com/Teflon_Industrial/en_US/news_events/article20050120.html (2005) http://www2.dupont.com/Teflon_Industrial/en_US/news_events/article20050120.html 15)National Toxicology Program. http://ntp.niehs.nih.gov/ (2005)http://ntp.niehs.nih.gov/ 16)Learn more about Teflon®. http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/eng/housewares/keyword/teflon_ke yword_birds.html (2005) http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/eng/housewares/keyword/teflon_ke yword_birds.html 17)NIOSH: The National Institute for Occupational Safety and Health. http://www.cdc.gov/niosh/homepage.html (2005)http://www.cdc.gov/niosh/homepage.html 18)Recycling. http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/Recycling.html (2003)http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/Recycling.html


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