preview

Industrial Production of PTFE

Best Essays
PTFE or Telfron is a common commercial organic fluoropolymer which is obtained by the polymerization of tetrafluoroethylene. It was first synthesized by Roy Plunkett accidentally in New Jersey in 1938 (Plunkett, R. J., 1987). It gradually becomes as an important industrial material for its extraordinary properties of high corrosion resistance, good electrical insulation, good heat insulation and low frictional coefficient. Due to those properties it is widely used as seals in chemical processing sector, and tubing or piping for laboratory uses. The low frictional coefficient makes it as a good lubricant as well.

Property of Tetrafluoroethlyene

The PTFE is polymerised from the monomer TFE. The TFE is made up by 2 carbon atoms and 4 fluorine atoms. The atomic orbitals of the two carbon atoms undergo sp2 hybridization individually with the 2 fluorine atoms and overlap with each other to give out a planar structure. As fluorine is a very electronegative element, the TFE has very poor solubility in most solvent. The carbon-fluorine bonds are very stable in the compound, relatively, the pi bonding in the carbon-carbon double bond is weaker and more reactive. The high polarity presenting in the structure also contributes to the value of enthalpy change of polymerization of TFE is 41.12kcal per mole which is very exothermic (Gangal, S. V., 1989).

Principle of Polymerization

In general, the free radical polymerization is favored by TFE which can be divided into 3 steps, namely, initiation, propagation and termination.

1. Initiation:

The common free radical initiator is ammonium persulfate and disuccinic acid peroxide. (F.A. Bovey and F.H Winslow, 1979)

The free radicals are formed due to the deco...

... middle of paper ...

...tember 1952, http://www.freepatentsonline.com/2612484.html

George, Odian. Principles of Polymerization. McGraw Publishing, Canada, 1981, pp319-317 pp194-201

Kapeliouchko, Valery (Alessandria, IT), Marchese, Enrico (Asti, IT), “Fine powders of polytetrafluoroethylene”, U.S. Patent 6479591, November 2002, http://www.freepatentsonline.com/6479591.html

Morgan, Richard A. (Vienna, WV, US), “Directly polymerized low molecular weight granular polytetrafluoroethylene”, U.S. Patent 7176265, February 2007 , http://www.freepatentsonline.com/7176265.html

Plunkett, R. J., “The History of Polytetrafluoroethylene: Discovery and Development,” in: High

Performance Polymers: Their Origin and Development, Proceed. Symp. Hist. High Perf. Polymers at the ACS Meeting in New York, April 1986, (R. B. Seymour and G. S. Kirshenbaum, eds.), Elsevier, New York, 1987.
Get Access