Anionic fluorinated surfactants sulfonates

The synthetic method selected for the preparation of an anionic fluorinated surfactant depends on the hydrophile of the surfactant a carboxylate, sulfonate, sul-... 

Partly fluorinated or perfluorinated sulfonic and carboxylic acids are compounds with excellent surface activity combined with an extreme stability against chemical or physico-chemical attacks as also described for non-ionic fluorine containing surfactant compounds. The anionic surfactants are shown with their structural formulae in Fig. 2.11.24(1)—(III). A selected ESI-FIA-MS(-) spectrum of a partly fluorinated surfactant (CF3-(CF2)4-(CH2)8-S03H, m/z 461) is presented in Fig. 2.11.25. The FIA spectrum also contains ions of the by-products CF3-(CF2)2-(CH2)8-S03H (m/z 361) and CF3-(CF2)3-(CH2)8-S03H (m/z 411). 

Perfluoroalkyl compounds have been manufactured since the 1950s.The total production of fluorinated surfactants (anionic, cationic and neutral) was 2001 in 1979, whereas in 2000 the total production of PFOS (perfluorooctane sulfonate) alone was nearly 3000t (Shoeib et al., 2004). Together with PFOA (perfluoroocta-noic acid), PFOS is used in refrigerants, surfactants, fire retardants, stain-resistant coatings for fabrics, carpets and paper and insecticides. Surface treatments, such as protection of clothing and carpets constitute the largest volume of PFOS production (Moriwaki, Takata and Arakawa, 2003). PFOA as well is present in several... 

Amphoteric fluorinated surfactants have at least one anionic and at least one cationic group at about their isoelectric point [181]. The cationic group is usually a quaternary amine or a protonated tertiary or secondary amine. The anionic functionality is a carboxylate, sulfonate, sulfate, or phosphate group. Most widely used fluorinated surfactants are carboxybetaine-type amphoteric surfactants which have, like betaines, a cationic amine functionality and an anionic carboxylate group. Instead of a carboxylate group, the anionic component of sulfatobetaines is a sulfate group and that of sulfobetaines is a sulfonate group. 

Surfactants used as lubricants are added to polymer resins to improve the flow characteristics of the plastic during processing they also stabilise the cells of polyurethane foams during the foaming process. Surfactants are either nonionic (e.g. fatty amides and alcohols), cationic, anionic (dominating class e.g. alkylbenzene sulfonates), zwitterionic, hetero-element or polymeric (e.g. EO-PO block copolymers). Fluorinated anionic surfactants or super surfactants enable a variety of surfaces normally regarded as difficult to wet. These include PE and PP any product required to wet the surface of these polymers will benefit from inclusion of fluorosurfactants. Surfactants are frequently multicomponent formulations, based on petro- or oleochemicals. 

At the end of the 1990s statistics show that the non-ionic surfactants achieved the highest growth in production rates world-wide, though anionic surfactants (anionics) maintained the dominant position in the surfactant market. Today they are produced in a larger variety by the petrochemical industry than all other types of surfactants. Their production spectrum covers alkyl sulfates (ASs), secondary alkane sulfonates (SASs) and aryl sulfonates and carboxylates via derivatives of partly fluorinated or perfluorinated alkyl surfactants to compounds with an alkylpolyglycolether substructure combined with an anionic moiety such as alkylether sulfates (AESs), phosphates, phosphonates or carboxylates. 

Polyfluorinated compounds comprise hundreds of chemicals characterized by hydrophobic linear alkyl chains partially or fully fluorinated (as the perfluorinated compounds [PFCs]) and containing different functional groups. Polyfluorinated compounds include perfluoroalkyl sulfonamides (PFASAs), fluorotelomer alcohols (FTOHs), polyfluorinated alkyl phosphates (PFAPs), fluorotelomer unsaturated carboxylic acids (FTUCAs), perfluoroalkyl acids (PFAAs), and their salts. The most common PFAAs are perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFASs). In particular, PFASs contain one or more fluorinated alkyl chains bonded to a polar head, which at neutral pH can be charged (anionic, cationic, and amphiphilic surfactants) or noncharged (nonionic surfactants). 

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