Teflon is a name made from parts of a chemical name that almost nobody can say.
The material is polytetrafluoroethylene. Etymonline says Teflon was formed from syllables in that name, with the ending -on added. The word is first recorded in 1945, and DuPont registered it as a trademark. The sources I read disagree slightly on the year: the Hagley Museum says DuPont filed for the trademark in February 1945, while others say 1944.
None of the pages I read says who at DuPont came up with the name.
The substance itself came first and by accident. In April 1938, Roy Plunkett, a DuPont chemist at the Jackson Laboratory in Deepwater, New Jersey, was working on refrigerants. A cylinder of tetrafluoroethylene gas stopped flowing. When he cut it open, he found a slippery white powder. The gas had polymerized.
Plunkett applied for a patent in July 1939. It was assigned to Kinetic Chemicals, a joint venture of General Motors and DuPont, and granted on February 4, 1941. DuPont began selling the polymer in 1944.
The first big customer was the Manhattan Project. Teflon-type seals and coatings resisted the corrosive chemicals used to enrich uranium, including at the plant in Oak Ridge, Tennessee.
Frying pans came later. A French engineer, Marc Grégoire, patented his non-stick pan invention in 1954 and founded Tefal in 1956, according to Wikipedia. Goodfellow's history says he launched PTFE-coated pans under the Tefal brand in 1954. Etymonline dates Teflon as a non-stick pan coating to the 1960s.
The brand also escaped the kitchen. In 1983, Representative Pat Schroeder used it as a figure of speech for Ronald Reagan, according to Etymonline. A trade name for a plastic had become a metaphor for a person that nothing seemed to stick to.
The -on ending was already common in fiber names. Etymonline calls it a common ending in fiber names such as rayon and nylon, and says Dacron was modeled on nylon and similar names.