Fluorine-containing plastics

The high thermal stability of the carbon-fluorine bond has led to considerable interest in fluorine-containing polymers as heat-resistant plastics and rubbers. The first patents, taken out by IG Farben in 1934, related to polychlorotri-fluoroethylene (PCTFE) (Figure 13.1 (a)), these materials being subsequently manufactured in Germany and the United States. PCTFE has been of limited application and it was the discovery of polytetrafluoroethylene (PTFE) (Figure... 

The inability to process PTFE by conventional thermoplastics techniques has nevertheless led to an extensive search for a melt-processable polymer but with similar chemical, electrical, non-stick and low-friction properties. This has resulted in several useful materials being marketed, including tetrafluoro-ethylene-hexafluoropropylene copolymer, poly(vinylidene fluoride) (Figure 13.1(d)), and, most promisingly, the copolymer of tetrafluoroethylene and perfluoropropyl vinyl ether. Other fluorine-containing plastics include poly(vinyl fluoride) and polymers and copolymers based on CTFE. 

Table 13.2 Consumption of fluorine-containing plastics for Western Europe 1991...

Some indication of the relative importance of the various applications is given by the consumption breakdown for fluorine-containing plastics in Western Europe in 1991 is Table 13.2). 

Other fluorine-containing plastics These materials, in general, attempt to compromise between the exceptional end-use properties of p.t.f.e. and the processability of ordinary thermoplastics. Examples include polychlor-trifluorethylene, tetrafluorethylene-hexafluorpropylene copolymers (FEP resins) and polyvinylidene fluoride. Polyvinyl fluoride is available in film form (Tedlar) with excellent weathering resistance. 

Stannous fluoride, a compound of tin and fluorine, is much less dangerous. It is added to drinking water and toothpaste to strengthen the enamel in the teeth of the user. Another compound of fluorine is teflon, a plastic made of carbon and fluorine, which is used in kitchenware. The fluorine-containing compound freon is used in air-conditioners and refrigerators, and is harmless. 

Industrial use of fluorine gas treatment started at the end of the 1980s. Surface modifications with fluorine offer improved reactivity for subsequent demands. One of the major advantages of fluorine gas treatment is the fact that modifications can be carried out under standard pressure and temperature (Figure 17.1), so that it can be used for on-line processes at low cost. Areas of application include, plastic fuel containers, gluing, dyeing or printing preparations on plastics.1-3... 

Although the technological basis of all fluorine-containing plastics and most elastomers continues to be the free radical polymerization of fluoroolefins, which themselves are based on the vastly greater fluorocarbon refrigerant industry, important advances have been made in the past two decades These include primarily the production of polymers that are more resistant to degradation by heat, oxidation, bases, and solvents, as well as polymers that are more easily processable, that is, able to be converted mto their final forms for use, whether by thermoplastic or thermoset processes [1,2,3,4]... 

The polymerization of unsaturated halohydrocarbons has been studied most extensively in the case of vinyl chloride and closely related compounds. Kainer 1S6) published a book recently on polyvinyl chloride and mixed polymers of vinyl chloride. In addition to chlorovinyl polymers, Schildknecht includes fluorovinyl polymers in his book Hl). Books covering plastics generally include material on the halohydrocarbon polymers (14, 144)- Several papers ISS, IS, 135,143) have been published in the last couple of years dealing with the polymerization of fluorine-containing compounds. Articles on polymerization of chloroprene 14 ), fluoroprene 1S8), chlorotrifluoroethylene 140), tetrafluoroethylene 1S9), vinylidene fluoride (157), and dichlorodifluoroethylene 1S7) have appeared in recent years. 

A severe type of toxicity which does not involve AChase is shown by the triaryl phosphates such as tricresyl phosphate, formerly much used as a plasticizer, and also by some fluorine-containing organophosphates. These cause delayed and persistent (up to 2 years) neurotoxicity characterized by swollen neurons. For this condition, oximes are no remedy. 

The product ETFE was first marketed in 1970 by the DuPont company under the name Tefzel . According to DIN 7728, ETFE or E/l FE is the international abbreviation for ethylene-tetra-fluorine-ethylene. Figure 6.24 shows the plastic pyramid containing a few weU-known thermoplastics. The pyramid classifies thermoplastics depending on their temperature resistance and costs. ETFE is among the high-performance thermoplastics. 

The above groups contain plasticizers which have several representatives of similar chemical structure. There still are plasticizers in common use or that were invented for specific purposes. These can be grouped as follows biphenyl derivatives,calcium stearate,carbon dioxide, difurans, " fluorine-containing plasticizers, " hydroxyben-zoic acid esters, " isocyanate adducts, " " malonates, " multi-ring aromatic... 

B. K Mandal, R. Eftler, J. Eluor. Chem. 2005, 126, 845-848. New fluorine-containing plasticized low lattice energy lithium salt for plastic batteries. 

Fluoroplastic (fluoropolymer) n. A plastic based on polymers made from monomers containing one or more atoms of fluorine, or copolymers of such monomers with other monomers, the fluorine-containing monomer(s) being in the greatest amount by mass (ASTM D 883). This is a broad family including ... 

Fluoroplastics n. Plastics, which contain the monomer of fluorine. 

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