The substance that would later be named Teflon was at first shelved, and the scientists returned to their quest for new refrigerants. At the time, the researchers couldn’t envision a profitable use for such an expensive-to-manufacture substance. That all changed just a few years later with the United States’ entry in World War II and the Manhattan Project’s push for atomic weapons. As viewers of 2023’s hit movie Oppenheimer will remember, one of the most critical endeavors in creating the world’s first atomic bomb was refining enough uranium and plutonium, apocryphally represented with scenes of scientists at Los Alamos slowly and dramatically filling a glass bowl with marbles to represent the progress toward explosivity.
According to Gordon Fee, a nuclear engineer and the retired president of Lockheed Martin Energy Systems, scientists and engineers at a government facility in Oak Ridge, Tennessee, stepped up to the task of refining uranium. They settled on a process, called gaseous diffusion, that forced a gas called uranium hexafluoride through miles and miles of pipes containing thousands of filters that sorted out the explosive isotope from the rest of the substance.
The problem for the scientists at Oak Ridge and the general who directed the Manhattan Project, Leslie Groves, was that uranium hexafluoride is highly corrosive. The gas was eating up the gaskets and the valve seals that helped contain and regulate the flow of the rare and crucial material.
What exactly happened next isn’t totally clear, given the secrecy and compartmentalization inherent to the Manhattan Project and the continued classification of documents. But we do know, says Fee, that lots of DuPont employees were working in Oak Ridge, mostly in a separate plant used to refine plutonium.
The DuPont employees knew that Groves had miles of piping he had to seal, says Fee, who began working at the gaseous diffusion plant at Oak Ridge in 1956. “They said, ‘Gee, we have this unique family of materials, we think it would make a good corrosion resistant gasket.’”
From its discovery in 1938 until that moment, likely in 1942, polytetrafluorethylene—it wouldn’t be officially registered as Teflon until after the war—bounced around DuPont as a curious laboratory product.
The nearly unlimited resources of the Manhattan Project gave DuPont its first industrial use for the new material. Scientists and engineers at Oak Ridge, like Fee, used PTFE to protect the facility’s pipes from corrosive gases until the plant was shut down decades later. “There was never a substitute considered as far as I know,” says Fee, “and so it had a lifetime in the Manhattan Project, you might say, until 1985.”