Fluorocarbon polymers, synthesis

Hydrocarbon Polymers. It is difficult to produce perfluorocarbon polymers by the usual methods. Many monomers, such as hexafluoropropylene, polymerize only slowly because of the steric hindrance of fluorine. Furthermore, some monomers are not very stable and are difficult to synthesize. Direct fluorination can be used for the direct synthesis of fluorocarbon polymers (68—70) and for producing fluorocarbon coatings on the surfaces of hydrocarbon polymers (8,29,44—47,49,68—71). 

A/-Chloro fatty acid amides have been synthesized from the direct halogenation of the amide in boiling water (28). They are useful as reactive intermediates for further synthesis. Fluorination has also been reported by treating the fatty amide with fluorine-containing acid reagents at 200 °C to reach a fluorinated amide with less reactivity toward fluorocarbon polymers (29). 

Synthesis and Properties of Imide and Isocyanurate-Linked Fluorocarbon Polymers... 

Applications other than the use in synthesis also have been noted. Fluorocarbon polymer moldings have improved blocking and friction resistance when the surface is modified by the addition of [ (Ph2PhCH2) jPjjN X (X=C1, OH) . Fungicidal activity without concomitant plant damage has been noted for Ph2P(E)N=P(R)Ph2 (E=0 , s ) and (XC HJ2 )2 (X=H, halo, alkyl R=alkyl, substituted benzyl, Y=NOj, halide,... 

The reactions of elemental fluorine with finely powdered hydrocarbon polymers and paraffins have been carefully controlled so that the products of the reactions are perf1uorocarbon polymers. Potentially, this direct fluorination process is a new approach to the synthesis of fluorocarbon polymers. Polyethylene, polypropylene, polystyrene, polyacrylon itr ile, polyacrylamide,... 

Potentially, this direct fluorination process is a new approach to the synthesis of fluorocarbon polymers. Polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyacrylamide, resor phenol formaldehyde resin, and ethylene propylene copolymer have been fluorinated to produce perf1uorocarbon polymers which are structurally similar to the hydrocarbon starting materials and have physical properties similar to known structurally related fluorocarbon polymers obtained by polymerization of fluorocarbon monomers. High yield of fluorocarbon polymers approaching 100 have been obtained. This direct technique used for fluorination of hydrocarbons and polymers is called the LaMar process and has been previously described in connection with the direct fluorination of Lt ver molecular weight species ". ... 

Acrylic pol niiers of linear and of cross-linked varieties are important classes of materials, and the fluorocarbon polymers are likewise important for substantially different reasons. The broad resistance of fluorocarbons to physical and chemical attack suggests that acrylics could be enhanced by the introduction into the molecules of substantial amounts of fluorine, provided such an addition did not compromise the characteristic acrylic properties. Fluorocarbons also possess a range of unusual surface chemical properties which could make for greater versatility in the acrylics if imparted thereto. For example, a fluoroacrylic resin in the liquid, precured state is expected to be of low surface tension and excellent wetting capability for difficult-to-wet fillers, such as powdered Teflon, whereas the cured fluoracrylic can be expected to be relatively non-wetting and non-absorptive of most liquid systems, particularly those that are water based. In order to attempt such an enhancement of acrylic properties, the synthesis of a series of fluorine-bearing acrylics of various functionalities was undertaken. 

There is considerable promise for the synthesis of useful functionalized fluorocarbon materials using other direct fluorination techniques (46), such as the fluorination of pendant polyesters and polymers containing pendant acyl fluoride units. 

Liquid fluorocarbon was used as continuous phase by Perez-Moral and Mayes [19] as well. They proposed a new method for rapid synthesis of MIP beads, in that they prepared 36 polymers imprinted for propranolol and morphine with different amounts of EDMA as a cross-linker and different functional monomers (MAA, acrylic acid, hydroxyethyl methacrylate, 4-vinylpyridine) directly in SPE cartridges. The properties of MIP microspheres prepared by this method were very similar in terms of size, morphology and extent of rebinding to microspheres prepared by conventional suspension polymerisation in perfluorocarbons as well as to bulk polymers prepared in the same solvent. The most notable advantages of this method are no waste production (no transfer of beads during washing steps) and possible direct use for a variety of screening, evaluation and optimisation experiments. 

Chloroform is used to make one specific HCFC known as HCFC-22. HCFC-22 is also known as Freon 22, halocarbon 22, fluorocarbon 22, or R22. By 2003, an estimated 600 million metric tons (660 million short tons) of chloroform were being used in the United States for all commercial purposes. Of the HCFC-22 produced, about 70 percent was being used as a refrigerant, while the remaining 30 percent went for the synthesis of polymers. 

Association of Textile Chemists and Colorists recently [3] described the incorporation of small amoimts of fluorocarbon derivative in a polymeric material normally used to treat textiles for water repellency. They observed that the fluorocarbon preferentially adsorbed at the interfaces and decreased the values to 16 to 18 dynes per cm. Their films clearly showed the ability to self-heal, for when the initially adsorbed layer was deliberately scraped off, additional molecules quickly adsorbed at the interface when the polymer matrix was recured at an elevated temperature. The usefulness of adsorbed films of surface active molecules is thus apparent, and one may expect wide application of this technique to specific problems. The present study, in combination with previous investigations of wettability and surface activity in organic liquids, forms an excellent guide for the design and synthesis of further surface active agents for polymeric systems. 

Fluorocarbon-Modified Water Soluble Polymers Table 7-2. Synthesis and properties of RFM (5) containing copolymers ... 

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