Poly PTFE, Teflon

Chemically universally stabile is poly-tetrafluoroethylene (PTFE, Teflon ), but it is relatively expensive. A problem is the cold flow , that is, the polymer is slowly deformed under the mechanical stress of the pressure on the gaskets and a leakage of the cell can occur (PTFE compounds, e.g. with glass powder or graphite, show a better behavior.)... [Pg.57]

Membrane materials often employed are hydrophobic polysulfone or hydrophilic regenerated cellulose or cellulose acetate other materials are nylon, polytetrafluoro-ethylene (PTFE, Teflon), polyether ether ketone (PEEK) or poly(divinyl fluoride) (PDVF). [Pg.113]

Injection valves designed for FIA are produced by a number of manufacturers. These valves are often microprocessor controlled (26) and are quite versatile. However, for all of the analyses described later, a simple low-pressure rotary injection valve designed for liquid chromatography is adequate (e.g., Rheodyne Model 50). Pneumatic and electric actuators are available for automated operation. An injection valve that can be machined quite easily from poly(tetrafluoroethylene) (PTFE, Teflon) and Plexiglas is described elsewhere (25, 27). [Pg.14]

Polymeric materials for MF membranes cover a very wide range from relatively hydrophilic to very hydrophobic materials. Typical hydrophilic materials are polysulfone (PS), poly ether sulfone (PES), cellulose (CE) and cellulose acetate (CA), polyamide (PA), polyimide (PI), polyetherimide (PEI), and polycarbonate (PC). Typical hydrophobic materials are polyethylene (PE), polypropylene (PP), polytetra-fluoroethylene (PTFE, Teflon), and polyvinylidene fluoride (PYDF). [Pg.2330]

Polytetrafluoroethylene (PTFE Teflon) was discovered accidently by PlunkettCZ nd commercialized by DuPont in the 1940 s. This polymer has a solubility parameter of about 6H and a high melting point of 327°C and is not readily moldable. Poly-chlorotrifluoroethylene (CTFE, Kel-F), the copolymer of tetrafluoroethylene and hexafluoropropylene (FEP), polyvinylidene fluoride (PVDF, Kynar), the copolymer of tetrafluoroethylene and ethylene (ETFE), the copolymer of vinylidene fluoride and hexafluoroisobutylene (CM-1), perfluoroalkoxyethylene (PFA) and polyvinyl fluoride (PVF, Tedlar) are all more readily processed than PTFE. However, the lubricity and chemical resistance of these fluoropolymers is less than that of PTFE. [Pg.92]

Solid perfluorocarbon surfaces also have extremely low surface energies Thus, poly(tetrafluoroethylene) (PTFE, Teflon) has a y value of 18.5 dyn cm which is the reason for the anti-stick and low-friction properties used for frying pans and other applications. That this effect is directly related to the fluorine content becomes obvious on comparison of the surface energies of poly(difluoro-ethylene) (25 dyn cm ), poly(fluoroethylene) (28 dyn cm ), and polyethylene (31 dyn cm Y If only one fluorine atom in PTFE is replaced by more polarizable chlorine, the surface energy of the resulting poly(chlorotrifluoroethylene) jumps to 31 dyn cm , the same value as for polyethylene [8]. [Pg.11]

PTFE poly(tetrafluoroethylene) (Teflon) TMS trimethylsilyl protecting group... [Pg.321]

Fluoropolymers The different fluoropolymers, poly(tetrafluoroethy-lene) (PTFE, Teflon, Fig. 14.7), ethylene-tetrafluoroethylene copolymers, and poly (vinylidene fluoride) (PVDF), are commercially very important polymers. The most... [Pg.551]

Folythiopherie Polypyrrole (undoped) Nylon - Poly(p-phenylene) (undoped) Folytphcnylcnc sulphide) (undopcd) PVC Folystyrcnc Polyimide (Kapton) PTFE (Teflon) Cu-plillialocyanine Anthracene Diamond Si02... [Pg.467]

Poly(tetrafluoro ethylene) (PTFE) TEFLON Dupont Replace urinary tissues, vascular graft, guided tissue regenerations, orbital reconstruction, facial reconstruction, rhinoplasty... [Pg.302]

PP it-poly(propylene), HOPE conventional fibers made of high-density poly(ethylene), PTFE poly(tetrafluoroethylene) (Teflon), PVC poly(vinyl chloride), PS atactic poly(styrene), PVAL poly (vinyl alcohol)... [Pg.152]

PTFE Poly tetrafluoroethylene (Teflon) (relatively inert chemical polymer)... [Pg.317]

The ultimate product of the polymerization of the CF, unit is the solid known as poly(tetrafluoroethene) or PTFE (Teflon), used in non-stick surface coverings. In the polymer there are C-C linkages between the tetrafluoroethene monomer units. All the atoms obey the octet rule, all the carbon atoms are four-valent, and each of the fluorine atoms participate in one single bond. That the oxidation state of the carbon is +2 is very misleading. [Pg.145]

CF2=CF2 Tetrafluoroethylene Poly(tetrafluoroethylene), PTFE, Teflon nonstick coatings... [Pg.1224]

Poly(chlorotrifluoroethylene) (PCTFE, Kel-F fluoropolymer) is a thermoplastic semicrystalline polymer with (-CF2CCIF-) repeating units [49], Typically, PCTFE is synthesized via a free radical polymerization using bulk, suspension, or emulsion techniques [50]. Compared with PTFE (Teflon fluoropolymer), which has similar chemical properties, there is asymmetry in the CTFE monomer unit due to the presence of the chlorine atom in CFCl groups. Consequently, the NMR features of PCTFE are more complicated due to the possible monomer- and stereo-sequence variations. Since PCTFE has various distinguished properties, including thermal, chemical, and radiation resistance, low vapor permeability, and electrical insulation [51,52], it has... [Pg.587]

PS Polyslyrane PTFE (Teflon ) Pdy(telialuofoeltiylene) PVA Poly(vinyl alcohol) PVC Poly(vinyl chlonda)... [Pg.216]

PTFE An abbreviation for the polymer poly(tetrafluoroethylene). Teflon is a trademark for tetrafluoroethylene (TEE). [Pg.243]

Polytetrafluoroethylene (PTFE, Teflon) 18.5 Poly(ethylene terephthalate) (PET) 43... [Pg.123]

Figure 8. Transmission electron micrograph of [dried] commercial aqueous dispersion of as-polymerized poly(tetrafluoroethylene) [Teflon, Du Pont]. PTFE is formed as near-spherical particles of 0.2 pm diameter.

Poly(tetrafluoroethylene) (PTFE), which is also known by DuPont s trade-name Teflon, is a solid at room temperature and has a dielectric constant in the range of 2.00-2.08, while its monomer, tetrafluoroethylene, is a gas at room temperature. PTFE is exceptionally chemically inert, has excellent electrical properties and outstanding stability, and retains its mechanical properties at high temperatures. The problem with PTFE is that it is not processable. A family of commercial polymeric materials known as Teflon AF is believed to be a... [Pg.168]

Trade names and abbreviations are frequently used in the literature and in oral communication, e.g. nylon 66 for poly(hexamethylene adipamide), Teflon or PTFE for poly(tetrafluoroethylene) and Lucite or PMMA for poly(methyl methacrylate). Other common abbreviations are listed below ... [Pg.113]

A study has been conducted on PBXs based on TATB using various binders such as polyurethane (Estane 5703-Goodrich), Viton-A (copolymer of vinylidene fluoride and hexafluoropropylene Du Pont), silicone resin (Chemlok), Kel-F800 [copolymer (3 1) of chlorotrifluoroethylene and vinylidene fluoride 3M Company] and Teflon [poly (tetrafluoroethylene), PTFE Du Pont] etc. and it was concluded that... [Pg.120]

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