1 / 12

Polytetrafluorethylene (PTFE)

Polytetrafluorethylene (PTFE). Chandra Heller Michael Mallicote. Discovery. Accidentally discovered on April 6, 1938 by Roy Plunkett. Uses. By 1941, PTFE had been patented and had its first brand name Teflon®.

adamdaniel
Download Presentation

Polytetrafluorethylene (PTFE)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

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 F F C C 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 + CF2=CF2 → RO(CF2–CF2) Propagation: Growth of free radicals by further addition of TFE RO(CF2–CF2) + n CF2=CF2 → RO(CF2–CF2)–(CF2–CF2) Free radicals undergo hydrolysis where a hydroxyl group replaces the peroxide RO(CF2–CF2)–(CF2–CF2) + H2O → HO(CF2–CF2)n–(CF2–CF2) + H+ + HOR HO(CF2=CF2)n–(CF2=CF2) + H2O → COOHCF2–(CF2–CF2) n + 2HF Termination: COOH– CF2–(CF2– CF2) n + COOH– CF2–(CF2– CF2) m → COOH– CF2–(CF2– CF2) 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 • Inventor of the Week: Archive. http://web.mit.edu/invent/iow/plunkett.html (2000) • Teflon.com - the complete resource on Teflon® products by DuPont. http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/home_page.jsp (2005) • Biomaterials. http://www.abe.msstate.edu/Classes/abe4523_6523/polymers.PDF (2001) • Zonyl Packaging: Whistleblower. http://www.mindfully.org/Plastic/Teflon/Zonyl-DuPont-Risk17nov05.htm (2005) • Teflon fluorocarbon information. http://www.omega.com/techref/fluoro.html (2001) • Polymers. http://www.chemistry.mtu.edu/pages/courses/ch1120-pcharles/Oxtoby_Ch25.pdf (2004) • Ebnesajjad, S. Non-melt Processible Fluoroplastics : The Definitive User's Guide and Databook. Norwich, N.Y. : Plastics Design Library. (2000) • Ebnesajjad, S. Melt Processible Fluoropolymers: The Definitive User's Guide and Databook.Norwich, N.Y. : Plastics Design Library (2003) • Chemical Structure. http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/Chemical_Structure.html (2003) • Synthesis. http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/synthesis.html. (2003) • Burridge, E. PTFE. Eur. Chem. News. 80, 16 (2004) • Bingham, E., Cohrssen, B., Powell, C., Eds. Patty's Toxicology. New York : John Wiley. (2001) • Useless Information. http://home.nycap.rr.com/useless/teflon/ (2003) • DuPont Electronic Materials Keep Mars Rovers Going. http://www2.dupont.com/Teflon_Industrial/en_US/news_events/article20050120.html (2005) • National Toxicology Program. http://ntp.niehs.nih.gov/ (2005) • Learn more about Teflon®. http://www.teflon.com/NASApp/Teflon/TeflonPageServlet?pageId=/consumer/na/eng/housewares/keyword/teflon_keyword_birds.html (2005) • NIOSH: The National Institute for Occupational Safety and Health. http://www.cdc.gov/niosh/homepage.html (2005) • Recycling. http://www.eng.utah.edu/~nairn/mse/students/MSE3410/Teflon/Recycling.html (2003)

More Related