Ethylene tetrafluoroethylene melt viscosity

Fluorinated ethylene-propylene (FEP) is a copolymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP). It has a branched structure containing units of -CF2-CF2- and -CF2-CF (CF3)-. It retains most of the favorable properties of PTFE but its melt viscosity is low enough for conventional melt-processing. The introduction of HFP reduces the melting point of polytetrafluoroethylene from 325°C (617°F) to about 260°C (500°F).26... 

Copolymers. Fluorinated ethylene propylene (FEP) is a copolymer of tetrafluoroethylene and hexafluoropropylene. It has properties similar to PTFE but with a melt viscosity suitable for molding with conventional toermoplastic processing techniques. The improved processabUity is obtained by replacing one of the fluorine groups on PTFE with a trifluoromethyl group as shown in Fig. 2.4. ... 

Several other thermoplastic powders are available based on specialty polymers such as ethylene-chlorotrifluoroethylene [25101-45-5], poly(phenylene sulfide) [25212-74-2], and tetrafluoroethylene-ethylene [68258-85-5] copolymers. Such powders are used in functional applications where resistance to corrosion and elevated temperatures are required. They are usually applied by fluidized-bed coating techniques but can also be applied by electrostatic techniques to a heated substrate (15). Extremely high application temperatures in the range of 250-350°C are required for these polymers because of high melting point and high melt viscosity. 

FEP polymers are fully fluorinated and melt processible. They have chemical resistance comparable to polytetrafluoroethylene (PTFE). Melt viscosity of FEP is over one million times lower than PTFE. Fluorinated ethylene propylene resins are in general copolymers of tetrafluoroethylene with hexafluoropropylene and possibly one or more other comonomers. Commercial examples of the latter include perfluoroalkyl vinyl ether (PAVE), such perfluoroethyl vinyl ether (PEVE). FEP... 

Unlike poly(tetrafluoroethylene), copolymers of tetrafluoro-ethylene with perfluoro comonomers are made as relatively low molecular weight (i.e., low melt viscosity) products that can be processed by conventional melt procedures and stiU have properties in the soUd state that are simUar or superior to those of poly(tetrafluoroethylene). Both PFA, poly[tetrafluoroethylene-co-perfluoro(alkoxy vinyl ether)]. 

General Description Fluorinated ethylene propylene (FEP), a melt-processable fluorocarbon, is a copolymer of tetrafluoroethylene (TFE) and hexafluo-ropropylene. Fluorinated ethylene propylene and TFE yield similar properties, with the exception ofTFE s lowermelt viscosity.fl 1 DuPont s high-performance material Teflon FEP film is a transparent, thermoplastic film.P ... 

ETFE polymers are melt processible. Commercial ETFE is a copolymer of ethylene and tetrafluoroethylene. They have lower chemical resistance and thermal stability than perfiuorinated polymers. ETFE exhibits excellent resistance to radiation and can stand up to 200 megarads of exposure to cobalt 60. It is a tough thermoplastic available in different viscosities, which can be processed by techniques applicable to polyethylene. ETFE resins are specified by ASTM Method D3159, which also provides procedures or references to other ASTM methods for the measurement of resin properties. Commercial FEP resins offered by major manufacturers have been listed in Tables 6.15 through 6.18. 

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