Synthesis and combined properties of novel fluorinated cationic surfactants derived from hexafluoropropylene dimer

Three novel fluorinated cationic surfactants were prepared by adopting perfluoro-2-methyl-2-pentene as raw substrate. The as-obtained fluorinated cationic surfactants exhibited excellent surface properties, all of them can reduce the surface tension of water to below 20.00 mN/m at the critical micelle concentrations (CMC). The incorporation of SDS, AOS, APG or LAB into 2-(4-(3,3,4,4,5,5,5-heptafluoro-2,2-bis(trifluoromethyl)pentyl)benzamido)-N,N-dimethylethana-mine oxide 4a could generate much lower CMC and surface tension value at the CMC than individual 4a. Especially, the surface tension values of that combined APG/4a can be reduced to 17.31 mN/m. The excellent surface activities and their remarkable compatibility to various types of hydrocarbon surfactants make them as sustainable alternatives to PFOA (perfluorooctanoic acid, C₇F₁₅CO₂H) and PFOS (perfluorooctane sulphonate, C₈F₁₇SO₃X, with X = K, Na, H).