Fluorotelomer

Ellis DA, JW Martin, AO De Silva, SA Mabury, MD Hurley, MPS Andersen, TJ Wallington (2004) Degradation of fluorotelomer alcohols a likely atmospheric source of perfluorinated carboxylic acids. Environ Sci Technol 38 3316-3321. 

These considerations apply also to the fluorotelomer alcohol CF3(CF2)7-CH2CH20H that was degraded in a mixed cnltnre obtained by enrichment with ethanol. Terminal dehydrogenation followed by elimination of flnoride, hydration and further loss of fluoride produced perfluorooctanoate (Dinglasan et al. 2004). 

PFOA emissions PFOA emissions arise from direct and indirect sources. The term direct sources refers to PFOA released to the environment during the manufacturing and use of PFCAs. Degradation from precursor substances, like fluorotelomer-... 

Wallington TJ, Hurley MD, Xia J, Wuebbles DJ, Sillman S, Ito A, Penner JE, Ellis DA, Martin J, Mabury SA, Nielsen OJ, Andersen MPS (2006) Formation of C7F15COOH (PFOA) and other perfluorocarboxylic acids during the atmospheric oxidation of 8 2 Fluorotelomer Alcohol. Environ Sci Technol 40 924-930... 

Under the agreement, companies will reduce emissions of these compounds from their facilities and consumer products by 95 per cent by 2010, and work towards eliminating the sources of PFOA by no later than 2015. Furthermore, PFOS and PFOA as well as other perfluorocarboxylic acids (PFCAs) are stable degradation products and/or metabolites of neutral PFCs such as fluorotelomer alcohols (PFTOHs), perfluorinated sulphonamides (PFASAs) and perfluorinated sulphonamide ethanols (PFASEs) [22]. Therefore, the largest global manufacturer and supplier of fluorotelomers such as Capstone, DuPont have adapted its entire product line to utilise short-chain chemistry because short-chain molecules cannot break down to PFOA in the environment. 

Phillips, M.M., Dinglasan-Panlilio, M.J.A., Mabury, S.A., Solomon, K.R. and Sibley, P.K. (2007) Fluorotelomer acids are more toxic than perfluorinated acids. Environ Sci Technol, 41, 7159-7163. 

These types of reactions have been used extensively to prepare fluorotelomers For example, Zonyl products, manufactured by E I du Pont de Nemours Co, Inc, are based on materials prepared from perfluoroethyl iodide and tetrafluoroethylene [2] (equation 1)... 

Fluorotelomer alcohols Bioaccumulation Food web Surface waters Toxicity ... 

Perfluoroalkyl acids (PFAs) are synthetic, perfluorinated, straight- or bran-ched-chain organic acids characterized by a carboxylate or sulfonate moiety [1]. PFAs are manufactured directly but can also be formed through transformation of many precursor molecules containing a perfluoroalkyl moiety [2], These include fluorotelomer alcohols (FTOHs) and perfluoroalkyl-sulfonamides (Table 1, Fig. 1), however, others likely exist. Collectively, this family of chemicals including PFAs and their polyfluorinated precursors will be referred to in this document as perfluoroalkyl substances (PFSs). 

Fig. 2 a Overall metabolic scheme for the perfluoroalkylsulfonamide alcohols based on rat and fish studies. Presumably the conversion of the alcohol to the corresponding acetates (e.g., N-EtFOSAA and FOSAA) proceed via the aldehyde intermediate though this has yet to be identified. Secondary metabolites for the alcohols (e.g., glucoronide and sulfate) and the carboxylic acids have been omitted, b Overall metabolic scheme for fluorotelomer alcohols (FTOH) derived from published work from microbial and rat studies [52-54,85]... 

Fig. 3 Overall scheme for the atmospheric processing of fluorotelomer alcohols (FTOHs) [26]...

This article outlines the important number of investigations performed on the telomerisation of well-known fluorinated alkenes. These fluorotelomers allow to synthesise novel fluoropolymers regarded as high value added materials with usually exceptional properties. 

Hence, such systems should induce interesting consequences on the structures and on the properties of materials thus obtained. For example, in the case of fluoroacrylic monomers, it is well-known that the crystallisation of perfluori-nated chains insures improvement of surface properties. In addition, by introducing well-defined fluorotelomers in the backbone or in the side chains, building block silicones can be synthesised with monitored thermal properties especially at low temperatures. 

The general structure of fluorotelomer alcohols is F(CF2) CH2CH20H, where usually = 4, 6, 8, 10 or 12 (Table 3.1). FTOHs are named based on the ratio of fluorinated carbons to... 

Fluorotelomer sulfonamidoethanol 4 2 fluorotelomer alcohol 4 2 FTOH CH2CH20H F(CF2)4CH2CH20H... 

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