Fluorinated repellents polymeric

A unique polymer is formed by the radical polymerization of tetrafluoroethylene and is called PTFE or Teflon. The outside of the polymer consists of a layer of fluorine atoms which repel all other molecules. It is used as the coating in nonstick pans and as a bearing that needs no lubrication. Two F pieces of Teflon slide across one another almost without friction. 

Of a large number of possible fluorinated acrylates, the homopolymers and copolymers of fluoroalkyl acrylates and methacrylates are the most suitable for practical applications. They are used in the manufacture of plastic lightguides (optical fibers) resists water-, oil-, and dirt-repellent coatings and other advanced applications [14]. Several rather complex methods to prepare the a-fluoroalkyl monomers (e.g., a-phenyl fluoroacrylates, a-(trifluoromethyl) acrylic and its esters, esters of perfluoromethacrylic acid) exist and are discussed in some detail in [14]. Generally, a-fluoroacrylates polymerize more readily than corresponding nonfluorinated acrylates and methacrylates, mostly by free radical mechanism [15], Copolymerization of fluoroacrylates has been carried out in bulk, solution, or emulsion initiated with peroxides, azobisisobutyronitrile, or y-irradiation [16]. Fluoroalkyl methacrylates and acrylates also polymerize by anionic mechanism, but the polymerization rates are considerably slower than those of radical polymerization [17]. 

FluorinatGd MethacrylatGS. Fluorinated polymers are very important materials because of their water- and oil-repellent properties. The synthesis of fluoropolymers is one case in which special polymerization techniques are required eg, emulsion polymerization with added fluorinated surfactant, and... 

Fluorinated surfactants function as oil and solvent repellents on paper and paperboard [195,236-239]. Monomeric fluorinated surfactants, their chromium or zirconium complexes, and polymeric fluorocheraicals are used for repellent treatments. 

Most polymeric fluorine-containing repellents in commercial use are vinyl polymers of the acrylic or methacrylic type, although polymers of vinyl esters, vinyl ethers, allyl esters, and thiomethacrylates also have been patented (Table 12.1). The vinyl polymers can be visualized as consisting of the perfluoroalkyl group, the polymer backbone, and the nonfluorinated linkage between the two. Many... 

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