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®.
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.
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.
Teflon® Monomer
F
F
C
F
C
F
tetrafluoroethylene
Teflon® Polymer
Teflon® Polymer (continued)
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
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.
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.
Questions
References
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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_ke
yword_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)