F Chlorotrifluoroethylene

The most chemical-resistant plastic commercially available today is tetrafluoroethylene or TFE (Teflon). This thermoplastic is practically unaffected by all alkahes and acids except fluorine and chlorine gas at elevated temperatures and molten metals. It retains its properties up to 260°C (500°F). Chlorotrifluoroethylene or CTFE (Kel-F, Plaskon) also possesses excellent corrosion resistance to almost all acids and alkalies up to 180°C (350°F). A Teflon derivative has been developed from the copolymerization of tetrafluoroethylene and hexafluoropropylene. This resin, FEP, has similar properties to TFE except that it is not recommended for continuous exposures at temperatures above 200°C (400°F). Also, FEP can be extruded on conventional extrusion equipment, while TFE parts must be made by comphcated powder-metallurgy techniques. Another version is poly-vinylidene fluoride, or PVF2 (Kynar), which has excellent resistance to alkahes and acids to 150°C (300°F). It can be extruded. A more recent development is a copolymer of CTFE and ethylene (Halar). This material has excellent resistance to strong inorganic acids, bases, and salts up to 150°C. It also can be extruded. 

TABLE 16.11 Effect of Surface Treatment on Bondability of Epoxy Adhesive to Teflon (Tetrafluoroethylene) and Kel-F (Chlorotrifluoroethylene)65... 

The elimination of a HX molecule is also typical for a polymer such as poly(ethylene-a/f-chlorotrifluoroethylene). In this case the elimination reaction from the side chain takes place as follows ... 

Another halogenated polyolefin that contains chlorine and fluorine in the molecule is poly(ethylene-a/f-chlorotrifluoroethylene), CAS 25101-45-5. As shown in Section 2.1, the pyrolysis of this polymer takes place with the side chain elimination of FICI and FIF by the following reaction ... 

Mihtary interest in the development of fuel and thermal resistant elastomers for low temperature service created a need for fluorinated elastomers. In the early 1950s, the M. W. Kellogg Co. in a joint project with the U.S. Army Quartermaster Corps, and 3M in a joint project with the U.S. Air Force, developed two commercial fluorocarbon elastomers. The copolymers of vinyUdene fluoride, CF2=CH2, and chlorotrifluoroethylene, CF2=CFC1, became available from Kellogg in 1955 under the trademark of Kel-F (1-3) (see Fluorine compounds, ORGANic-POLYcm.OROTRiFLUOROETHYLENE Poly(vinylidene) fluoride). In 1956, 3M introduced a polymer based on poly(l,l-dihydroperfluorobutyl acrylate) trademarked 3M Brand Fluorombber 1F4 (4). The poor balance of acid, steam, and heat resistance of the latter elastomer limited its commercial use. 

Chemical Designations - Synonyms Chlorotrifluoroethylene Kel F monomer Plascon monomer Trifluoromonochloroethylene Trifluoroevinil chloride Chemical Formula F2C=CFC1. 

Organic Fluorides. Part XIII. The High-temperature Dimerisation of Chlorotrifluoroethylene, M. W. Buxton, D. W. Ingram, F. Smith, M. Stacey, and J. C. Tatlow, /. Chem. Soc., (1952) 3830-3834. 

Ethylene chlorotrifluoroethylene (Halar) (ECTFE) has excellent chemical resistance to most chemicals including caustic. ECTFE can be used from -105°F (-76°C) to 302°F 150°C). To obtain good extrusion characteristics, this polymer is usually compounded with a small amount of extrusion aid. 

The name is used both for the monomer and polymers made horn it. The polymers are usually clear oils at RT and non cracking solids at —65°F(—54°C). The typical fluoro-carhons are chemically inert, thermally stable, and nonflammable. The monomer can be prepd similarly to CFE from tribromotiifluoroethane and zinc. BFE polymers are used as flotation fluids for gyros and accelerometers used in inertial guidance systems. Can also be used as CFE (chlorotrifluoroethylene) polymers, but are more expensive Refs 1) Beil 1, 189 2) CondChemDict... 

Kel-F (copolymer of chlorotrifluoroethylene and vinylidene fluoride) (3 1 ratio) Inert binder for main high explosive compositions... 

The copolymer of vinyl ferrocene (VF) and butadiene has also been reported in the literature for use as a binder for composite propellants. It does not require any burn-rate (BR) accelerator because of the presence of iron (Fe) in vinyl ferrocene which is converted to finely divided Fe203 (a well-known BR accelerator) during combustion. A few groups of scientists have also studied fluorocarbon polymers as binders for composite propellants because of their excellent compatibility with oxidizers and fuels coupled with high density. Accordingly, Kel-F elastomer (a copolymer of vinylidene fluoride and chlorotrifluoroethylene, trade name of 3M, USA) and Viton-A (copolymer of hexafluoropropylene and vinylidene fluoride, trade name of Du Pont, USA) have also been reported for this purpose. The structures of Kel-F 800 [Structure (4.13)] and Viton-A [Structure (4.14)] are ... 

For the current study, the source of PCTFE was Kel-F 6061, a solid homopolymer of chlorotrifluoroethylene, produced by the 3M company. Preliminary studies with other forms of PCTFE indicate that its chemistry is by no means unique. We chose this particular polymer for its insolubility and other physical properties. 

D. Fluorocarbon Polymers. Four different fluorocarbons account for the bulk of the laboratory applications polytetrafluoroethylene, Teflon PTFE po-ly(chlorotrifluoroethylene), KEL-F tetrafluoroethylene-hexafluoropropylene copolymer, Teflon FEP and tetrafluoroethylene-perfluorovinyl ether copolymer, PFA. These polymers are inert with most chemicals and solvents at room temperature and exceptionally inert with oxidizing agents. They also have an exceptional resistance to temperature extremes. However, they are decomposed by liquid alkali metals, solutions of these metals in liquid ammonia, and carban-ion reagents such as butyllithium. Teflon retains some of its compliance at liquid hydrogen temperature. The maximum temperature which is recommended for continuous service is 260°C for Teflon PTFE and PFA, and about 200°C for Kel-F and Teflon FEP. 

The apparatus consists of a simple vacuum manifold similar to that shown in Fig. 4. The vacuum manifold should be fabricated from nickel or Monel metal, with silver-soldered or Swagelok connections. Valves should be of Monel metal, and the traps and scrubber, the function of which is to remove hydrogen fluoride vapor from the C103 F product, may be constructed conveniently of poly(chlorotrifluoroethylene) (Kel-F) tubing. A nickel cylinder of 500-ml. or 1-1. capacity serves as a reaction vessel, and a 500-ml. Monel bulb or similar vessel may be used as a product receiver. The scrubber (about 1-in. o.d.) is charged with pellets of sodium fluoride prepared in a separate operation by heating sodium... 

The first commercial fluoroelastomer, Kel-F, was developed by the M. W. Kellog Company in the early to mid-1950s and is a copolymer of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE). Another fluorocarbon elastomer, Viton A, is a copolymer of VDF and hexafluoropropylene (HFP) developed by du Pont was made available commercially in 1955. The products developed thereafter can be divided into two classes VDF-based fluoroelastomers and tetrafluoroethylene (TFE)-based fluoroelastomers (perfluoroelastomers).72 The current products are mostly based on copolymers of VDF and HFP, VDF and MVE, or terpolymers of VDF with HFP and TFE. In the combination of VDF and HFP, the proportion of HFP has to be 19 to 20 mol% or higher to obtain amorphous elastomeric product.73 The ratio of VDF/HFP/TFE has also to be within a certain region to yield elastomers as shown in a triangular diagram (Figure 2.2).74... 

The last method is telomerization, followed by the chemical change of the end-groups. Thus, from telomere of chlorotrifluoroethylene (C.T.F.E.) with Cl3CBr. Barnhart et al. [7] prepared diacids according to the following scheme ... 

Mandelkern, L., G. M. Martin and F. A. Quinn Glassy state transition of Poly-(chlorotrifluoroethylene), Poly-(vinylidene fluoride) and their copolymers. J. Research Nat. Bur. Standards 58, 137—143 (1957). 

Chlorotrifluoroethylene Resins. Polymers of CFE characterized by high degree of chemical inertness. Virtually unaffected by inorg acids, alkalies, oxidizing agents, and most org solvents. Typical commercially available marerials are "Fluorothene , "Halon (Trademark of Allied Chemical Corp, Plastics Div, New York, 10006 and Kel-F (Trademark of Minnesota Mining Mfg Co)... 

CFE (Chlorotrifluoroethylene, Kel-F) 350 Higher cost than TFE. Better chemical resistance than most other gasket materials, although not quite so good as TFE. 

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