Fluorinated sulfonate surfactants

New classes of fluorinated sulfonate surfactants were synthesized in which a perfluoroalkyl chain is interrupted either by an ether oxygen (–O–), or by methylene (–CH2–) units. Both classes of molecules involve multi-step syntheses. The fluoroether sulfonates (RfOCF2CF2CH2CH2SO3H, Rf = C2F5, C3F7) were achieved in four steps including fluoroiodonation of perfluorovinyl ethers (RfCF = CF2), ethylation, chlorination and hydrolysis. The methylene interrupted fluorosulfonates (RfCH2CF2CH2CH2SO3H, Rf = C4F9, C6F13) were also prepared in four steps involving vinylidene fluoride insertion of fluoroalkyl iodides, ethylene insertion, chlorination and hydrolysis. All intermediates and final products were well characterized by 1H and 19F NMR. These new fluorinated surfactants were compared to a commercially available fluorosulfonate (C6F13CH2CH2SO3H) for surface activity. These materials match the surface tensions of commercial fluorosurfactant yet are more efficient because they have lower fluorine content.

Graphical abstractSynthesis of polyfluorinated sulfonate surfactants containing vinyldene fluoride (VDF, –CH2CF2–) units or ether (–O–) groups.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Novel polyfluorinated sulfonate surfactants are reported. ► The fluorinated surfactant chains are interrupted by –CH2– or –O– groups. ► These surfactants performed as well as perfluorinated ethyl sulfonate surfactant.