The Legacy of PTFE: From Serendipity to Global Impact – Part 10

During a recent online talk, a physicist explained how elements heavier than uranium are synthesized. These superheavy elements, created in the first nuclear weapons program, become increasingly difficult to produce as their atomic number rises, often yielding only a few atoms that decay rapidly. The practical value of such research is hard to justify to funders, so the speaker drew a comparison to the space program, citing a NASA engineer who argued that, although a moon landing may not seem like a wise investment, it led to inventions such as Teflon. That comparison is historically inaccurate: PTFE was discovered accidentally in 1938, nearly twenty years before the first rockets were launched into orbit and more than three decades before the Apollo 11 landing.

PTFE, or poly(tetrafluoroethylene), shares a structural lineage with polyethylene. Both polymers consist of a carbon backbone, but while polyethylene’s hydrogens remain, PTFE’s hydrogen atoms are replaced with fluorine. This substitution gives PTFE its exceptional chemical inertness, high melting point, and low coefficient of friction. The story of PTFE’s discovery mirrors that of polyethylene: Eric Fawcett and Reginald Gibson inadvertently polymerized ethylene under high pressure, and a similar accidental polymerization of tetrafluoroethylene led to the first PTFE crystals.

Research has shown that PTFE’s low‑friction surface is the only material that a gecko’s feet cannot grip.

Roy Plunkett, the chemist credited with PTFE’s discovery, joined DuPont after completing his Ph.D. at Ohio State. While his contemporary Paul Flory, later Nobel laureate, focused on theoretical polymer science, Plunkett applied chemistry directly to industrial challenges. His first project at DuPont involved developing new refrigerants, a pursuit that led to the synthesis of 100 lb of tetrafluoroethylene. When a storage cylinder was opened, no gas escaped; instead, a white, waxy substance was found. The material, with a high melting point and chemical resistance, turned out to be PTFE, formed by the polymerization of tetrafluoroethylene under pressure.

Although Plunkett did not commercialize PTFE—his work was later spun off into Chemours in 2013—the polymer’s military value became apparent during World War II. PTFE’s resistance to corrosive uranium hexafluoride (UF₆) was critical for handling and processing fissile material at Los Alamos and Oak Ridge National Laboratories. Patents for PTFE were filed in 1941, and the material was officially marketed in 1945.

Plunkett’s career intersected with other pivotal chemical developments. While he was promoted to DuPont’s gasoline‑additive division, General Motors’ chemist Thomas Midgley had earlier discovered tetraethyl lead in 1921, enabling smooth gasoline engines. Midgley also helped synthesize the first chlorofluorocarbon refrigerant, dichlorodifluoromethane (Freon 12), a compound Plunkett was producing when PTFE emerged. These events illustrate how industrial chemistry can spur unforeseen breakthroughs.

Discovery of PTFE eventually led to a family of melt‑processable fluoropolymers suitable for injection, extrusion, and blow molding. (Photo: Performance Plastics Ltd.)

Building on PTFE, manufacturers developed fluoropolymers that can be melt‑processed, such as fluorinated ethylene propylene (FEP), perfluoro‑alkoxy (PFA), and copolymers like ethylene‑tetrafluoroethylene (ETFE) and ethylene‑chlorotrifluoroethylene (ECTFE). Polyvinylidene fluoride (PVDF) offers a lower melting point (~160 °C) and is often molded with minimal additives. These materials range from elastomers to semi‑rigid composites filled with minerals or carbon. Their fluorine content confers chemical resistance, flame retardancy, and low friction, while also providing excellent electrical insulation—making them indispensable in electronics, aerospace, and medical devices.

PTFE’s most celebrated property is its non‑stick surface, which was first applied to cookware in the mid‑1950s. Today, PTFE remains the only known material that prevents geckos from adhering to surfaces, and it holds the record for the most patents filed by DuPont. Although Plunkett did not oversee the commercial rollout, his name is synonymous with PTFE and its derivatives.

Plunkett’s legacy is complex; his later work on leaded gasoline and CFC refrigerants is now viewed critically. Nonetheless, the creation of PTFE and its fluoropolymer family has profoundly shaped modern technology, from aerospace to everyday consumer goods.

In the next installment, we’ll explore the evolution of engineering thermoplastics, focusing on the influential material polycarbonate.

About the author: Michael Sepe is an independent materials and processing consultant based in Sedona, Ariz., serving clients across North America, Europe, and Asia. With over 45 years of experience in the plastics industry, he specializes in material selection, design for manufacturability, process optimization, troubleshooting, and failure analysis. Contact: (928) 203‑0408 • mike@thematerialanalyst.com