Kinetic Chemicals

History

Polytetrafluoroethylene (PTFE) was accidentally discovered in 1938 by Roy J. Plunkett while he was working in Chemours Chambers Works plant in New Jersey for DuPont. On 6 April 1938, while attempting to make a new chlorofluorocarbon refrigerant, Plunkett and his assistant Jack Reebok found that a cylinder of tetrafluoroethylene (TFE) gas contained a white powder: polytetrafluoroethylene. The gas in its pressure bottle stopped flowing before the bottle's weight had dropped to the point signaling "empty". John J. Beall (chemist), noticing a weight differential in his test cylinder, brought it to the attention of Roy Plunkett. The chemists in the lab sawed the bottle apart and found the bottle's interior coated with a waxy white material that was oddly slippery. Analysis showed that it was polymerized perfluoroethylene, with the iron from the inside of the container having acted as a catalyst at high pressure. Kinetic Chemicals patented the new fluorinated plastic (analogous to the already known polyethylene) in 1941, and registered the Teflon trademark in 1945.

An early use was in the Manhattan Project as a material to coat valves and seals in the pipes holding highly reactive uranium hexafluoride at the vast K-25 uranium enrichment plant in Oak Ridge, Tennessee. By 1948, DuPont, which founded Kinetic Chemicals in partnership with General Motors, was producing over 910,000 kilograms (2,000,000 lb) of Teflon-brand polytetrafluoroethylene per year in Parkersburg, West Virginia.

In 1954, Colette Grégoire urged her husband, the French engineer Marc Grégoire, to try the material he had been using on fishing tackle on her cooking pans. He subsequently created the first PTFE-coated non-stick pans under the brand name Tefal (combining "Tef" from "Teflon" and "al" from aluminium). In the United States, Marion A. Trozzolo, who had been using the substance on scientific utensils, marketed the first US-made PTFE-coated pan, "The Happy Pan", in 1961. Non-stick cookware has since become a common household product, now offered by hundreds of manufacturers across the world.

The brand name Zepel was used to promote its stain resistance and water resistance when applied to fabrics.

In the 1990s, it was found that PTFE could be radiation cross-linked above its melting point in an oxygen-free environment. Electron beam processing is one example of radiation processing. Cross-linked PTFE exhibits enhanced high-temperature mechanical properties and improved radiation stability. That was significant because, for many years, irradiation at ambient conditions has been used to break down PTFE for recycling. This radiation-induced chain scission allows it to be more easily reground and reused.