Learn about the stories behind 10 extraordinary inventions. In this video, you'll learn about Teflon.
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Male Speaker: In 1938, a Dupont scientist was researching refrigerants, when he unknowingly created a bizarre new material. It took an adventurous young chemist named Roy Plunkett to make the bold decision that gave us Teflon. In the early 1930s GM was looking for a safer refrigerant to use for their Frigidaire line of refrigerators. They needed to find a replacement for ammonia, sulfur dioxide, and propane, the refrigerants used at the time, because they were too dangerous for use in homes. Ultimately they discovered two chlorofluorocarbons or CFCs. GM called their new refrigerants Freon 112 and Freon 113. GM had made the discovery, but their expertise was in making machinery, cars and refrigerators, not chemicals. To refine and mass-produce Freon, GM looked to DuPont. The two companies formed a joint venture called Kinetic Chemicals. While testing the new refrigerants, they actually developed a more efficient version, Freon 114. Unfortunately, Kinetic's entire output of Freon 114 was earmarked for GM, so DuPont started looking for its own refrigerant. One of the scientists assigned to this task was a 27-year old Ohio State chemistry PhD named Roy J. Plunkett. Plunkett hypothesized that a new refrigerant could be made by combining tetrafluoroethylene or TFE with hydrochloric acid. During experiments Plunkett and his assistant Jack Rebok used tanks filled with compressed TFE. They stored these tanks in dry ice to keep the gas inside from expanding too much and exploding. On the morning of April 6, 1938, Plunkett and Rebok set up for an experiment. Rebok connected a TFE tank and opened the valve but to both of their surprise, nothing came out. Plunkett and Rebok weighed the tank to see if the gas had leaked out. Another surprise, the tanks were still full. They unsuccessfully tried to unclog the valve using a wire. Out of frustration, Plunkett took the valve off of the tank and shook it. White flakes fell out. L. Phillip Silverman: The gas was actually in the tank, they weigh the tanks to figure out how much material is left. The next day the scientist went out or came back into the lab, opened the tank, there was no pressure in the tank and yet the tank weighed exactly the same. What have happened is that this material the polytetrafluoroethylene had formed from the tetrafluoroethylene. The polymer had polymerization it happened. Male Speaker: Plunkett immediately sawed the tank in half. Inside they found a white, waxy coating. Plunkett wrote in his lab book that. Speaker: A white solid material was obtained, which was supposed to be a polymerized product. Male Speaker: It was commonly believed that TFE could not be polymerized, but that didn't deter Plunkett. He experimented with the new compound, discovering in two days that. Speaker: It is thermoplastic, melts at a temperature approaching red heat, and boils away. It is insoluble in just about everything, cold water, hot water, acetone, ethers, acids, and alcohols. It doesn't char or melt under a soldering iron, it doesn't rot, swell, mildew, mold, or degrade in sunlight. Male Speaker: Teflon's first use was in gasket seals for the Manhattan project. L. Phillip Silverman: Uranium 235 and uranium 238 as solids are hard to separate. As gases taking advantage of a simple old chemistry laws can check this out in your textbooks called Graham's law dealt with diffusion but one of the problems when you are trying taking these gases of the different isotopes of uranium and trying to diffuse them is this stuff is murderously corrosive. So, they came out with some additional materials specifically the highly corrosion resistant material in Teflon formed really good gaskets and interestingly enough wouldn't have any chemical reactivity whatsoever with the uranium hexafluoride as it was passing through the system. Male Speaker: Teflon also found a home as the nosecone material on proximity bombs. It was resistant to electricity and transparent to radar, making it interference-free to
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