Per- and Poly- Fluorinated Ethers

Per- and poly-fluorinated ether surfactants are the newest commercially available substances in this rapidly expanding group of fluorinated surfactants [33-35]. For example, the phosphate shown in Fig. 4 is used as a grease repellent for food contact paper [36]. Per- and poly-fluorinated polyether carboxylates [37-41] are also used as processing aids in the synthesis of fluoropolymers. Per- and poly-fluorinated polyether silanes are used as surface treatments [42-45]. 

Phosphate surfactant Fig. 4 Synthesis of perfluoropolyether-based intermediates and surfactants 

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Subsequently, additional conunercial processes were developed for synthesis of a range of per- and poly-fluorinated surfactants whose unique properties make them largely irreplaceable in many applications. The widespread use and disposal and the high stability of the perfluoroalkyl acids, which do not breakdown readily either abiotically or biotically in the environment, has resulted in widespread presence of PFAAs in the environment. This caused commercial production to shift toward short chain alternatives and new fluorinated moieties such as the per- and poly-fluorinated ethers. Clearly, there remains a need for fluorinated surfactants in many industries to obtain the beneficial performance properties of these substances that cannot be achieved with other types of surfactants. 

Furthermore, Banerjee and group prepared sulfonated fluorinated poly(arylene ether sulfone) (IBQSH-XX) copolymers (where XX=20, 30, 40, 50, and 60 and DS=0.16, 0.26, 0.39, 0.47, 0.56, respectively) based on imidoaryl biphenol, namely, 3,8-few(4-hydroxyphenyl)-A -phenyl-l,2-naph-thaUmide (IB), by direct copolymerization with SDCDPS as the sulfonated monomer and QBF as the fluorinated monomer [160]. Sulfonated copolymers were obtained with M values in the range 41,200-60,200g/mol with D values in the range 0.96-1.89 the trend increased with an increase in the DS (0.16-0.56 as per H-NMR spectra). Scheme 2.36 shows a representative structure of sulfonated fluorinated poly(arylene ether sulfone) containing IB... 

The high thermal and chemical stability of fluorocarbons, combined with their very weak intermolecular interactions, makes them ideal stationary phases for the separation of a wide variety of organic compounds, including both hydrocarbons and fluorine-containing molecules Fluonnated stationary phases include per-fluoroalkanes, fluorocarbon surfactants, poly(chlorotrifluoroethylene), polyfper-fluoroalkyl) ethers, and other functionalized perfluoro compounds The applications of fluonnated compounds as stationary phases in gas-liquid chroma... 

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