Polytetrafluoroethylene PIPE Teflon

Polytetrafluoroethylene (PIPE, Teflon) Resistant, smooth solid Heart pumps, reinforcement of artery and blood vessels ... 

Since the discovery of Teflon by Roy Plunkett in 1937 a number of fluorinated plastics have reached commercial status. These plastics, exemplified by polytetrafluoroethylene (PIPE), have outstanding electrical, chemical, and thermal properties. AU these commercial materials are either crystaUine or semicrystalline. Teflon AF is a family of amorphous copolymers that retain the desirable electrical, chemical, and thermal properties of semicrystalline fluorinated plastics and also have such properties associated with amorphous materials as optical clarity, improved physical properties, and solubility in selected fluorinated solvents. 

New materials also emerged. Nylon, developed brilliantly by W. H. Carothers and his team of research workers for Du Pont as a fibre in the mid-1930s, was first used as a moulding material in 1941. Also in 1941 a patent taken out by Kinetic Chemical Inc. described how R. J. Plunkett had first discovered polytetrafluoroethylene. This happened when, on one occasion, it was found that on opening the valve of a supposedly full cylinder of the gas tetrafluoroethylene no gas issued out. On subsequently cutting up the cylinder it was found that a white solid, polytetrafluoroethylene (PIPE), had been deposited on the inner walls of the cylinder. The process was developed by Du Pont and, in 1943, a pilot plant to produce their product Teflon came on stream. 

PIPE Teflon , Fluon Polytetrafluoroethylene Poly(1,1,2,2-tetrafluoroethylene)... 

The development of most polymers have occurred at large chemical companies. One of the leaders in polymer development has been DuPont In the United States many polymers are known generally by their DuPont trade names. Perhaps the best example of this is polytetrafluoroethylene (PIPE) known to the public as Teflon. A historical timeline of polymer development is shown in Table 1.1. The Nobel Prizes related to polymers are shown in Table 1.2. ... 

All rubbers, glasses, and plastics are polymers. You are probably familiar with natural polymers like cellulose (the building block of plant fibers) and synthetic polymers like polyethylene (plastic milk cartons), polyisoprene (automobile tires), polyethylene terephthalate (soft drink bottles), polymethyl methacrylate (Plexiglas ), polyvinylidene chloride (transparent plastic wrap), polytetrafluoroethylene (Teflon ), and various polyesters (fabrics). Polyvinyl chloride, the polymer shown earlier, is used to make rigid pipes, house siding, and protective coverings for automobile seals and dashboards, among many other applications. 

An important example of a polymer is that of polyvinylchloride, shown in Figure 9.15. This polymer is synthesized in large quantities for the manufacture of water and sewer pipe, water-repellant liners, and other plastic materials. Other major polymers include polyethylene (plastic bags and milk cartons), polypropylene (impact-resistant plastics and indoor-outdoor carpeting), polyacrylonitrile (Orion and carpets), polystyrene (foam insulation), and polytetrafluoroethylene (Teflon coatings and bearings) the monomers from which these substances are made are shown in Figure 9.16. 

Polytetrafluoroethylene, more commonly known as the trademarked brand name Teflon, is formed from the addition polymerization of tetrafluoroethylene. Tetrafluoroethylene, shown in Figure 25.4(c), is an analogue of ethylene in which fluorine atoms have replaced all four of the hydrogen atoms. Teflon is a very good electrical insulator, so it is commonly used to coat wires. It is probably best known, though, as a nonstick substance used to coat bakeware, frying pans, and pots. It is also used in films that can be inserted into threaded joints between metal pipes to make it easier to unscrew the connection when necessary. Because Teflon is chemically inert, it is not possible to cross-link the chains like an elastomer. The structures of some addition polymers, including the structures of their respective monomers and what they are typically used for, are summarized in Table 25.1. 

PIPE polytetrafluoroethylene. Teflon VLDPE very low-density polyethylene... 

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