On the morning of April 6, 1938, a 27-year-old chemist named Roy J. Plunkett walked into DuPont's Jackson Laboratory in Deepwater, New Jersey, and opened a steel cylinder of tetrafluoroethylene (TFE) gas. He was hunting for a non-toxic refrigerant to replace sulfur dioxide. Nothing came out. The valve worked, the pressure gauge read zero, but the cylinder still weighed exactly what a full one should.

Suspicious, Plunkett sawed the cylinder in half. Inside was a slippery white waxy powder. The TFE gas had spontaneously polymerized against the iron walls into a substance no chemist had ever seen — one that wouldn't dissolve in any solvent, wouldn't burn, wouldn't react with concentrated acids or molten alkali, and had a coefficient of friction lower than wet ice on wet ice.

Plunkett filed for a patent on July 1, 1939. U.S. Patent 2,230,654, "Tetrafluoroethylene Polymers," was granted on February 4, 1941. The compound — polytetrafluoroethylene, or PTFE — would become commercially famous as Teflon after DuPont trademarked the name in 1945.

The Patent's Secret First Customer

Before anyone fried an egg in a non-stick pan, PTFE was a classified Manhattan Project material. Enriching uranium required handling UF₆, uranium hexafluoride — a gas so corrosive it ate through nearly every gasket, seal, and pipe material known. PTFE didn't flinch. The 1941 patent quietly enabled the gaseous diffusion plants at Oak Ridge. The cookware came later.

What the Patent Actually Claims

Plunkett's claims describe a "solid polymer of tetrafluoroethylene" with thermal stability above 250°C and resistance to "all known solvents and corrosive agents." The patent doesn't explain why — the carbon-fluorine bond is one of the strongest in organic chemistry (≈485 kJ/mol), and the fluorine atoms form a tight helical sheath around the carbon backbone, blocking chemical attack and reducing intermolecular friction. Plunkett observed the behavior; the quantum-mechanical explanation came decades later.

Where PTFE Hides in 2026

• Semiconductor fabrication: Every modern fab uses PTFE tubing, valves, and tanks to handle hydrofluoric acid and other ultrapure etchants. No PTFE, no 3 nm logic.
• 5G and mmWave electronics: PTFE laminates (Rogers RO3000-series and equivalents) are the substrate of choice for high-frequency PCBs because of PTFE's extremely low dielectric loss (tan δ ≈ 0.0002).
• Quantum computing: Superconducting qubit packages use PTFE-based dielectrics to minimize microwave loss at millikelvin temperatures.
• Medicine: Expanded PTFE is the "Gore-Tex" in vascular grafts, hernia mesh, and the cuffs of mechanical heart valves. Around 1.5 million ePTFE grafts are implanted globally each year.
• Space: PTFE composites lubricate bearings on Mars rovers and on every cubesat reaction wheel — it's one of the few solid lubricants that survives hard vacuum without outgassing.
• Lithium batteries: PTFE is the binder that holds the cathode of nearly every Li-ion cell together.

The Accident That Patented Itself

Plunkett's filing is unusually honest for the era: it admits the polymer was found "under conditions which were not predicted from prior knowledge." In other words — we don't know why this worked, but it did, and here's how to reproduce it. That single 1941 patent ultimately spawned an entire family of fluoropolymers (FEP, PFA, PVDF) that now sit silently inside roughly every advanced device built since.