Fluorinated-Ethylene Propylene Teflon

FEP Teflon FEP (fluorinated ethylene propylene). Teflon is a Du Pont registered trademark. 

Fluorinated ethylene propylene (Teflon) (FEP) is a fully fluori-nated plastic. This polymer was developed to have a combination of unique properties. It combines the desirable properties of PTFE with advantageous melt processing properties. 

EEP Fluorinated-ethylene propylene Teflon FEP E. I. du Pont de Nemours Co. 

The materials examined were high and low density polyethylene, silvered fluorinated ethylene propylene teflon blanket material, polysulphone matrix resin/graphite fibre reinforced composites, poly(methyl methacrylate) and silicones [326, 450,1326, 2314]. Long term exposed polymeric samples show loss of surface integrity and surface erosion. The radiation combines with atomic oxygen to initiate chain scission and crosslinking, both of which greatly affect the polymers structural properties. 

These materials were first introduced by Du Pont in 1956 and are now known as Teflon FEP resins. (FEP = fluorinated ethylene-propylene.) Subsequently other commercial grades have become available (Neoflon by Daikin Kogyo and Teflex by Niitechim, USSR). These copolymers may be regarded as the first commercial attempt to provide a material with the general properties of PTFE and the melt processability of the more conventional thermoplastics. 

Wire and cable Teflon FEP Neopflon FEP Fluorinated ethylene/ propylene polymer DuPont, USA Daikin, USA... 

Steel [52013-36-2] suture is made from 316-L stainless steel wire. The suture may be monofilament, known as fixation wire, or multifilament twisted wires. The steel is heat-treated to improve ductility. The multifilament strands are either uncoated, or coated with Teflon (polytetrafluoroethylene) or Teflon-fluorinated ethylene—propylene copolymer. 

Teflon FEP (fluorinated ethylene propylene). This material is translucent and flexible, and it feels heavy because of its high density. It resists all known chemicals except molten alkali metals, elemental fluorine, and fluorine precursors at elevated temperatures. It should not be used with concentrated perchloric acid. FEP withstands temperatures from -270°C to + 205°C and may be sterilized repeatedly by all known chemical and thermal methods. It can even be boiled in nitric acid. 

Spacecraft flying in LEO are exposed not only to neutral atomic and molecular species, but also high fluxes of vacuum ultraviolet (VUV) radiation and relatively low fluxes of ions, both of which might contribute to the degradation of materials present on spacecraft surfaces. ° It has been reported that fluorinated ethylene-propylene copolymer (FEP Teflon), which is used as a thermal blanketing material, erodes under the combined exposure of VUV light and atomic oxygen, while the erosion by... 

Apparatus for preparations. All reactions were performed with a stainless steel vacuum line. Preparations were carried out in Teflon reactors assembled especially for each. The reactors were joined to the metal line via flexible fluorinated ethylene propylene (FEP) tubes and a polytetrafluoroethy-lene (PTFE) valve. FEP-tube reactors were prepared by first cutting lengths to —25 cm. These tubes were softened at one end by heating in a flame, then squeezed with broad-nose pliers to seal the end. One-armed reactors consisted of one of these tubes connected directly to a PTFE valve. T-shaped reactors had two of these tubes connected to a PTFE T-joint, which itself was connected via FEP tubing to a PTFE valve. All reactors were made vacuum-tight with PTFE swage connections. 

Substrate materials included poly (dimethyl siloxane) (SR) (Silastic Rubber, medical grade, Dow Corning), fluorinated ethylene/propylene copolymer (FEP) (Teflon FEP, Dupont), and a segmented copolyether-urethane-urea (PEUU) based on poly (propylene glycol), methylene bis-4-phenylisocyanate, and ethylenediamine. This PEUU was provided by D. J. Lyman. 

Storage of water samples to detect trace metals is normally carried out in plastic containers fluorinated plastic materials i.e.. Teflon, fluorinated ethylene propylene (FEP), perfluoroalkoxy polymers (PFA) or polyethylene are used because if opportunely treated and conditioned they guarantee contamination-free samples. However, FEP or Teflon bottles are preferable to those made of polyethylene when speciation studies are carried out. In fact, polyethylene over long periods of storage can release plasticizers (above all phthalates or amines), which behave as ligands and modify the complexation equilibria of the solution. When Hg is to be determined plastic materials must be avoided because they are permeable to gases and vapours glass or quartz are therefore used. 

Teflon [Du Pont], TM for tetrafluoroethyl-ene (TFE) fluorocarbon polymers available as molding and extrusion powders, aqueous dispersion, film, finishes, and multifilament yam or fiber. The name also applies to fluorinated ethylene-propylene (FEP) resins available in the same forms. The no-stick cookware finishes may be of either type. Fibers are monofilaments made from copolymer of TFE and FEP. 

Over the years constmction of the dynamic chamber has been modified. For studies conducted recently, the chamber is generally constmcted as follows. The dynamic flow-through chamber system is cylindrical in nature and built from Plexiglas material. Chamber dimensions may vary but are generally about 23 cm inner diameter (i.d.) and 46 cm. in height. The entire closed system is lined on the inside with 2 mil fluorinated ethylene propylene (FEP) Teflon and stainless steel fittings in order to minimize chemical reactions with sample flow. 

Table 1.2. Hydrogen Permeability vs Temperature and Pressure through DuPont Teflon Fluorinated Ethylene Propylene Copolymer...

Teflon FEP 100 Fluorinated ethylene propylene copolymer (FEP) general purpose, medium viscosity, melt extrusion resin. 

Known in Germany since 1933, polytetrafluoro-ethylene (PTEE) is a semicrystalline resin (92-98% crystallinity), with T = 342°C and melt viscosity of 7 - 10 GPas. Others, more common fluoro-polymers are polychlorotrifluoroethylene (PCTFE), Hostaflon commercialized in 1934, fluorinated ethylene-propylene (FEP), Teflon -FEP introduced in 1972, and numerous copolymers with Tjjj = 260 to 304°C, processable at = 315 to 425°C, and having the degradation temperature, deg 440°C. The fluoropolymers are... 

Copolymers of tetrafluoroethylene were developed in attempts to provide materials with the general properties of PTFE and the melt process-ability of the more conventional thermoplastics. Two such copolymers are tetrafluoroethylene-hexafluoropropylene (TFE-HFP) copolymers (Teflon FEP resins by Du Pont FEP stands for fluorinated ethylene propylene) with a melting point of 290°C and tetrafluoroethylene-ethylene (ETFE) copolymers (Tefzel by Du Pont) with a melting point of 270°C. These products are melt processable. A number of other fluorine containing melt processable polymers have been introduced. 

The best known fluorocarbon polymer is polytetrafluoroethylene (PTFE), commonly known as Teflon (DuPont). Other polymers containing fluorine are polytrifluorochloroethylene (PTFCE), polyvinylfluor-ide (PVF), and fluorinated ethylene propylene (FEP). Only PTFE will be discussed here since the others have rather inferior chemical and physical properties and are rarely used for implant fabrication. 

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