Family Friendly & Specialty Dentists in London, UK
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History and Production
- PTFE was accidentally discovered in 1938 by Roy J. Plunkett while working for DuPont.
- Kinetic Chemicals patented the new fluorinated plastic in 1941 and registered the Teflon trademark in 1945.
- DuPont started producing over 2,000,000 pounds of Teflon per year in 1948.
- PTFE was used in the Manhattan Project to coat valves and seals.
- Non-stick cookware was created in 1954 by Marc Grégoire and Marion A. Trozzolo.
- PTFE is produced by free-radical polymerization of tetrafluoroethylene.
- Special apparatus is required to prevent explosive decomposition of tetrafluoroethylene.
- Granular PTFE is produced via suspension polymerization or emulsion polymerization.
- Toxic surfactants like PFOA and PFOS were previously used, but alternative surfactants are now being used.
- The production process involves hydrolyzing sulfate ester groups to give OH end-groups.
Properties
- PTFE is a white solid with a density of about 2200kg/m and a melting point of 600K.
- It maintains high strength, toughness, and self-lubrication at low temperatures.
- PTFE gains its properties from carbon-fluorine bonds.
- Highly reactive metals and fluorinating agents can affect these bonds.
- PTFE undergoes depolymerization at temperatures above 650–700°C.
Applications
- PTFE is used as a non-stick coating for pans and other cookware.
- It is used in containers and pipework for reactive and corrosive chemicals.
- PTFE reduces friction, wear, and energy consumption in machinery.
- It is used as a graft material in surgery and as a coating on catheters.
- PTFE is widely applied in various industries and products.
Environmental Impact
- PTFE is a PFAS and a persistent organic pollutant.
- The environmental impact and toxicity to human and mammalian life have been studied since the 21st century.
- DuPont used PFOA during PTFE production, leading to legal actions and discontinuation of its use.
- Chemours now manufactures PTFE using an alternative chemical called GenX.
- PFAS, including PTFE, have raised concerns due to their persistence and potential health effects.
Additional Applications
- PTFE is commonly used for wire insulation in aerospace and computer applications due to its excellent dielectric properties.
- PTFE is used for plain bearings, gears, seals, gaskets, and other applications with sliding action of parts.
- PTFE is an ideal material for fabricating long-life electrets, which are electrostatic analogues of permanent magnets.
- PTFE film is widely used in the production of carbon fiber composites and fiberglass composites in the aerospace industry.
- PTFE is commonly used as a chemically inert liner in hose assemblies, expansion joints, and industrial pipelines.
