Polymers, perfluorination

Like perfluorinated polymers, perfluorinated fluids are both chemically and thermally very stable. Originally developed during the Manhattan Project their commercial application dates from the 1960s. There are two major production methods, cobalt(III) fluoride fluorination of hydrocarbons and electrochemical fluorination. The first route involves the fluorination of a stirred or fluidized bed of cobalt(II) fluoride to cobalt(III) fluoride with elemental fluorine at... 

The era of fluoropolymers began with the serendipitous discovery of PTFE by Roy Plunkett of DuPont Companywhile conducting research to find new refrigerants. A number of fluoroplastics have been developed since the discovery of PTFE. They are divided into two classes of perfluorinated and partially fluorinated polymers. Perfluorinated fluoropolymers... 

I, 1980, 76, 2558-2574 L.Y. Levy, A. Jenard and H.D. Hurwitz, Hydration and ion-exchange process in carboxylic membranes. Part 1. Infrared spectroscopic investigation of the acid membranes, J. Chem. Soc. Trans. 1, 1982, 78, 29-36 M. Falk, Infrared spectra of perfluorosulfonated polymer and water in perfluorosulfonate polymer, Perfluorinated Ionomer Membranes, ed. A. Eisenberg, H.L. Yeager, ACS Symposium Series, American Chemical Society, Washington DC, 1982, p. 139 C. Heitner-Wirguin and D. Hall, An infrared study of an anion exchange membrane,... 

It is known that the incorporation of pentafluorothio groups (SFj) (pentafluoro-A -sulfanyl) into molecular systems can bring about significant changes in their physical, chemical, and biological properties. These properties are manifested by various applications, such as solvents for polymers, perfluorinated blood substitutes, surface-active agents (surfactants), and fumigants and as thermally and chemically stable systems. ... 

The serendipitous discovery of polytetrafluoro-ethylene (PTFE) in 1938 by Roy Plunkett, a DuPont Company chemist, [4] began the era of fluoropolymers. PTFE has been used in thousands of applications because of its unique properties. Numerous flu-oroplastics (Fig. 3.1) have been developed since the discovery of FI FE. These plastics are produced by several companies in the US, Europe, Japan, China, India, and Russia. Ruoropolymers are divided into two classes of perfluorinated and partially fluorinated polymers. Perfluorinated fluoropolymers are homopolymers and copolymers of Tre. Some of the comonomers may contain a small amount of elements other than C or F. 

Gangal SV, Brothers PD. Perfluorinated polymers, perfluorinated ethylene-propylene copolymers. Encyclopedia of polymer science and technology. Online ed. New York John Wiley and Sons 2010. 

Gangal, S. V, Fluorine Compounds, Organic (Polymers), Perfluorinated Ethylene-Propylene Copolymers, in Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed., 11 644-656, John Wiley Sons, New York, 1994. 

Recently, a kind of perfluorinated polymer, perfluorinated(alkenylvinylether), has been investigated as an ultimate low-loss polymer. In this case, ultimate loss will be obtained at a 1.3 pm wavelength because there will be small C-F absorption and residual... 

Another approach to the fabrication of LB films from prefonned polymers is to fonn a hydrophobic main chain by reacting monomers tenninated by a vinyl group [102, 103, 104, 105 and 106]. The side groups studied also included perfluorinated hydrocarbon chains, which tilt with respect to the nonnal to the plane of the film, whereas the analogous ordinary hydrocarbon chains do not [105]. 

Chemical Properties. A combination of excellent chemical and mechanical properties at elevated temperatures result in high performance service in the chemical processing industry. Teflon PEA resins have been exposed to a variety of organic and inorganic compounds commonly encountered in chemical service (26). They are not attacked by inorganic acids, bases, halogens, metal salt solutions, organic acids, and anhydrides. Aromatic and ahphatic hydrocarbons, alcohols, aldehydes, ketones, ethers, amines, esters, chlorinated compounds, and other polymer solvents have Httle effect. However, like other perfluorinated polymers,they react with alkah metals and elemental fluorine. 

A large variety of newer poly(ether imide)s has been described. Included among these are perfluorinated polymers (96), poly(ester ether imide)s (97), poly(ether imide)s derived from A/,Ar-diamino-l,4,5,8-naphthalenetetracarboxyHcbisimide (98), and poly(arylene ether imide ketone)s (99). In addition, many other heterocyHc groups have been introduced into polyether systems, eg, poly(pyrazole ether)s (100) and poly(aryl ether phenylquinoxaLine)s (101) poly(aryl ether oxazole)s with trifluoromethyl groups (102) and polyethers with other heterolinkages, eg, poly(arylether azine)s (103). 

Because of its high crystallinity and incapability of specific interaction, there are no solvents at room temperature. At temperatures approaehing the melting point certain fluorinated liquids such as perfluorinated kerosenes will dissolve the polymer. 

Other SSIMS studies of polymer surfaces have included perfluorinated polyether [3.21], low-density polyethylene [3.22], poly(ethylene terephthalate) [3.23], and the oxidation of polyetheretherketone [3.24]. 

This material was first synthesized in the middle 1960s by E.I. Du Pont de Nemours and Co., and was soon recognized as an outstanding ion conductor for laboratory as well as for industrial electrochemistry. The perfluorinated polymeric backbone is responsible for the good chemical and thermal stability of the polymer. Nation membrane swollen with an electrolyte solution shows high cation conductivity, whereas the transport of anions is almost entirely suppressed. This so-called permselectivity (cf. Section 6.2.1) is a characteristic advantage of Nation in comparison with classical ion-exchange polymers, in which the selective ion transport is usually not so pronounced. 

Materials similar to Nation containing immobilized —COO- or —NR3+ groups on a perfluorinated skeleton were also synthesized. These are available in the form of solid membranes or solutions in organic solvents the former can readily be used as solid electrolytes in the so called solid polymer electrolyte (SPE) cells, the latter are suitable for preparing ion-exchange polymeric films on electrodes simply by evaporating the polymer solution in a suitable solvent. 

In spite of the high effort focused on the carbon electrochemistry, very little is known about the electrochemical preparation of carbon itself. This challenging idea appeared in the early 1970s in connection with the cathodic reduction of poly(tetrafluoroethylene) (PTFE) and some other perfluorin-ated polymers. The standard potential of the hypothetical reduction of PTFE to elemental carbon ... 

Table 10.49 Oil and water repellency of cotton fabrics treated with perfluorinated acrylic polymers [502]...

Nafion, a perfluorinated sulfonated polymer, is a typical example of an ion-exchangeable resin with high promise as a catalyst support. Its properties are significantly different from those of common polymers (stability towards strong bases, and strong oxidizing and reducing acids and thermal stability up to at least 120 °C if the counter ion is a proton, and up to 200-235 °C if it is a... 

Nafion-H, a perfluorinated sulfonic acid resin, is another strongly acidic solid that has been explored as alkylation catalyst. Rprvik et al. (204) examined unsupported Nafion-H with a nominal surface area of 0.2 m2/g (surface area of a swellable polymer is difficult to define) in isobutane/2-butene alkylation at 353 K and compared it with a CeY zeolite. The zeolite gave a better alkylate and higher conversion than Nafion-H, which produced significant amounts of octenes and heavy-end products. The low surface area of the resin and questions about the accessibility of the sulfonic acid groups probably make the comparison inadequate. 

The membrane, made from a perfluorinated polymer bearing sul-phonic acid groups, is known in the trade as Nafion . 

A very different route to soluble PPP derivatives was demonstrated by Yoshino and coworkers [586], who introduced perfluorinated alkyl substituents into PPP 471 by reaction with perfluorobutanoyl peroxide. The resulting modified polymer 475 was soluble in common organic solvents and a solution-fabricated PLED ITO/475/Mg In emitted blue to green light (depending on voltage) with band half-width of over 200 nm. 

M. Jang, S. Song, and H. Shim, Efficient green light-emitting polymer by balanced injection of electron and holes new electron accepting perfluorinated substituent, Polymer, 41 5675-5679, 2000. 

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