Fluoroethylene-propylene copolymer

Extrusion-Applied Insulations. The polymers used in extrusion applications can be divided into two classes low-temperature applications and high-temperature applications. Polymers in the first category are poly(vinyl chloride), polyethylene, polypropylene, and their copolymers along with other elastomers. Polymers in the second category are mainly halocarbons such as Teflon polytetrafluoroethylene (which requires special extrusion or application conditions), fluoroethylene-propylene copolymer (FEP), perf luoroalkoxy-modified polytetrafluoroethylene (PFA), poly(ethylene-tetrafluoroethylene) (ETFE), poly(vinylidene fluoride) (PVF2) (borderline temperature of 135 °C), and poly(ethylene-chlorotrifluoroethylene). Extrusion conditions for wire and cable insulations have to be tailored to resin composition, conductor size, and need for cross-linking of the insulating layer. 

All compounds are handled in a dry box. Xenon difluoride (8.5 g, 0.05 mole) is placed in a l(X)-mL stainless steel pressure vessel [Hoke], Seleninyl fluoride (4.4 g, 0.033 mole) is placed into a Kel-F or FEP (fluoroethylene propylene copolymer) test tube-shaped tube and inserted into the reaction vessel in an upright position. The vessel is closed and then cooled to —78° (methanol/Dry Ice) and placed in a horizontal position on a mechanical shaker. After being shaken for 24 hr at room temperature, the vessel is attached to a vacuum line and cooled to — 20°, and the volatile material (Xe) is transferred under dynamic vacuum into a trap cooled to —196°. The vessel is filled with dry argon (or nitrogen) and opened in the dry box. The impure pale yellow liquid is transferred... 

A weighable 10-mL Kel-F or FEP [Zeus] (fluoroethylene propylene copolymer) reaction vessel is best suited for this reaction. The compound HOTeFj is condensed onto XeF (3 g, 17.7 mmol) in about 3-g (12.5-mmol) portions, and the reaction mixture is warmed to a uniform melt. Subsequently, the HF that has formed and the unreacted HOTeF are pumped off at 0° and discarded. Alternatively, the HOTeFj can be freed of HF by trapping at -78° and reused. The above procedure must be repeated about six times, corresponding to a molar excess of HOTeFs of approximately 100%, to shift the equilibrium completely to formation of the product. This displacement is best monitored by weighing until constancy is reached. Yield 10.6 g (96%). 

Synonyms Ethylene/propylene copolymer, fluorinated FEP FEP resin Fluorinated ethylene/propylene resin Fluoroethylene polymer Hexafluoropropylene/tetrafluoroethylene copolymer Petfluoroethylene propylene Tetrafluoroethylene/hexafluoropropylene copolymer TFE/ HFP... 

Seguchi, T., Hayakawa, N., Yoshida, K., and Tamura, N., Fast neutron irradiation effect. II. Crosslinking of polyethylene, ethylene-propylene copolymer, and tetra-fluoroethylene-propylene copolymer, Radiat. Phys. Chem., 26, 221-225 (1985). Keller, A., and Ungar, G., Radiation effects and crystallinity in polyethylene, Radiat. Phys. Chem., 22, 155-181 (1983). 

When polymerization of unsymmetrical monomers such as propylene occurs, addition can occur in a head-to-tail or a head-to-head shion to provide a variety of different structures. If two or more monomers are copolymerized, a variety of monomer sequences ((fyads, triads, tetrads, pentads, etc.) are possible as illustrated by the possible pentad monomer sequences for poly(l-chloro-l-fluoroethylene-co-isobulylene), (PCFEI), shown in Table 1. In general, it is possible to form copolymers having blodcs of monomers, a statistically random distribution of two monomers, and all possible compositional variations between these two extremes. In the example of PCFEI, it is possible to form pentads with five sequential E s, five sequential I s, and all permutations of E s and Fs between those extremes. The relative number of different monomer sequences provides information about the blockiness of the polymer, and is useful for determining the polymer s monomer composition. 

Chlorofluorocarbon resin Chlorofluorohydrocarbon resin Ethylene-chloro-tri-fluoroethylene copolymer Ethylene-tetra-fluoroethylene copolymer Fluorinated ethylene-propylene resin Fluorocarbon resin Fluorohydrocarbon resin Perfluoroalkoxy resin Polychlorotrifluoroethylene Polytetrafluoroethylene Polyvinylidene fluoride... 

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