Five questions: Teflon

While cooking, many of us use Teflon and swear by its nonstick properties. If you have ever wondered where it came from and how the science behind Teflon works, we answer five questions about the unique cookware material.

What?
Teflon is the trademarked name for the molecule polytetrafluoroethylene, or PTFE. It is believed to be the slipperiest molecule in existence, as well as one of the largest. Its molecular weight can be over 30,000,000 - to provide some perspective, the molecular weight of water is about 18.

The best-known use of Teflon is in the non-stick coating on frying pans and other cookware. Teflon is effective because of its slipperiness, but also because it's very stable, durable, and non-corrosive. PTFE is a long chain polymer made of carbon atoms connected to each other and to fluorine atoms. Fluorine, when bonded, is extremely chemically stable -- meaning it doesn't react easily with the substances around it; it repels other substances, which is what makes PTFE so slippery. Teflon is also stable because the bonds between the carbons and the fluorine atoms are so strong that other substances can't break them in order to react.

So if Teflon is so stable and slippery, how does it stick to pots and pans? According to Discovery Online, this was a major issue in Teflon's early days. Originally, to apply the substance, the pan was given a rough finish (by sandblasting, for example) and then the Teflon was poured over it. It would then stick because it got caught in all the nooks and crannies of the metal pan. But it wasn't the most permanent solution -- early Teflon pans would scratch and chip with even the slightest abrasion. So the folks at DuPont went back to the drawing board and came up with a stronger multi-step application process. This procedure still involves sandblasting, but it uses a primer, mid-coat and top-coat, all of which contain Teflon, but in varying amounts and with different additives.

Why?
Teflon's unusual qualities make it useful for a lot more than cookware. It has dozens of other industrial and residential applications including non-stain carpeting and fabrics, in semi-conductors, wire insulation and auto parts, as a strengthener for inks and paints or as a coating for weather-resistant graphics. It's likely that Teflon is at work somewhere in almost every home in America.

Who?
Roy Plunkett was the inventor of Teflon and a scientist employed by DuPont. He was a recent graduate of Ohio State University's organic chemistry PhD program and only 27-year-old when he made the discovery.

How?
Back in the 1930s, Frigidaire called in the science whizzes at GM to help them develop a safer alternative to the refrigerants currently in use, which included dangerous ingredients like ammonia and propane. GM came up with Freon, but turned the project over to DuPont to refine the process and develop the refrigerant. In his work for DuPont, Plunkett decided to try developing a refrigerant with tetrafluoroethylene (TFE), which he stored in tanks on dry ice. When Plunkett attempted to use the tanks, they were full but, inexplicably, no TFE would come out. It turned out the TFE had polymerized resulting in a white, waxy coating inside the tank. Plunkett performed a few experiments on the substance and discovered its amazing properties -- it was practically insoluble, did not melt or burn easily nor did it mildew or rot. He may not have created a new refrigerant, but Plunkett had discovered Teflon, the non-stick coating that would over-joy chefs and housewives alike for decades to come!

When?
All this year the U.S. is celebrating the 50^th anniversary of Teflon, though it was actually invented back in 1938. DuPont patented the molecule in 1941 and registered the trademark "Teflon" in 1945, but it wasn't until 1961 that the first U.S.-made Teflon coated frying pan reached the market. It was made by LPF Plastics Corporation and dubbed "The Happy Pan."

For more information on nonstick Teflon, visit our reports on skillets and cookware.

Editor's Note: Fifty years later, another subject of much debate among health researchers and environmental activists are the poential hazards of Teflon.  Read our blog, "The Dangers of Teflon" for more details.