Polytetrafluoroethylene
Polytetrafluoroethylene (PTFE), a strong, tough, waxy, nonflammable synthetic resin produced by the polymerization of tetrafluoroethylene. Known by such trademarks as Teflon, Fluon, Hostaflon, and Polyflon, PTFE is distinguished by its slippery surface, high melting point, and resistance to attack by almost all chemicals. These properties have made it familiar to consumers as the coating on nonstick cookware; it is also fabricated into industrial products, including bearings, pipe liners, and parts for valves and pumps.
PTFE was discovered serendipitously in 1938 by Roy Plunkett, an American chemist for E.I. du Pont de Nemours & Company (now DuPont Company), who found that a tank of gaseous tetrafluoroethylene refrigerant had polymerized to a white powder. During World War II it was applied as a corrosion-resistant coating to protect metal equipment used in the handling of radioactive material for the Manhattan Project. For more than a decade after the war, PTFE saw little commercial use, owing to difficulties encountered in devising methods for processing the slippery, high-melting material. DuPont released its trademarked Teflon-coated nonstick cookware in 1960.
PTFE Fine Powders
Chemours is a leading producer of fluoropolymers that include Teflon? PTFE (polytetrafluoroethylene) fine powder resins.
These fine powders may be paste-extruded to create continuous-length PTFE articles such as tubes, tapes, and membranes. PTFE fine powder is the preferred fluoropolymer for many applications, including breathable hydrophobic membranes, aerospace/automotive hoses, and high-performance wires and cables.
Features and Benefits
This family of fine powder fluoropolymer resins offers a wide range of characteristics that include:
Excellent thermal stability
High stress crack resistance
High reduction ratio
Excellent color and clarity
Polytetrafluroethylene ultrafine powder
PTFE ultra-fine powder can be prepared by irradiation at room temperature, followed by ultrafine grinding. Fresh PTFE material, scrap or recycled PTFE waste, etc., can be used to fabricate ultrafine powder. The use of recycled PTFE or waste to produce ultrafine powder can reduce the cost and achieve the recycling of resources. PTFE ultrafine powder is widely used as a functional additive in the fields of engineering plastics, anticorrosion coatings, nonstick coatings, coil coatings, powder coatings, and inks. Shamrock Technologies (the United States), Solvay Company (Italy), Lubrizol Corporation (Germany), Kitamura Company Ltd. (Japan) and many other companies produce PTFE ultrafine powder. In recent years, domestic Chinese enterprises have also made great progress in the technology of manufacturing PTFE ultrafine powder.
The particle size of PTFE powder is usually tens to hundreds of microns, which is suitable for producing PTFE sheet and pipe. PTFE ultrafine powder can be made by polymerization, radiation degradation, and thermal cracking. The irradiated PTFE becomes very brittle, and can be further fabricated into ultrafine powder by grinding or air-jetting. The particle size is closely related to the absorbed dose. The higher the absorbed dose, the lower the relative molecular weight of PTFE, and the smaller the particle size of ultrafine powder. At present, PTFE ultrafine powder is mainly prepared by radiation degradation at home and abroad, since high energy beam can effectively break the molecular chains of PTFE at room temperature. For recycled PTFE, a very high absorbed dose is required for the fabrication of PTFE ultrafine powder. Hence, it is normally irradiated by EB accelerators. PTFE ultrafine powder is mainly used as an additive in lubricating oil and grease, ink, paint, engineering plastics, leather, rubber, etc., in order to improve antifriction and scratch-resistance.