Synthesis And Properties Of N-alkyl Perfluorooctylsulfonamides And Their Derivatives

Fluorosurfactant is one of the most effective special surfactants,its particular properties are usually concluded as high surface activity,high heat resistance and high chemical stability;it is hydrophobic and oleophobic.In this thesis,the recent research progress,characteristics,and uses of fluorosurfactants are reviewed.Ten N-alkyl perfluorooctanesulfonamides were synthesized by the reaction of perfluorooctanesulfonyl fluoride with an excess of amines.Their structures were testified by IR and ¹H NMR.The influences of reactants ratio,solvent,reaction temperature and time on the productivity were discussed.The prefer condition determined by test was isopropyl ether,ether,chlorobenzene or acetone as solvent,the ratio of reactants 1:1～2, the temperature 40～80℃,and the time 3～8h.Two new compounds:N-(3-polyether-3-dimethyl aminopropyl)perfluorooctylsulfonamide and N-(3-oxadimethyl aminopropyl)perfluorooctylsulfonamide were synthesized from N-(3-dimethyl aminopropyl)perfluorooctylsulfonamide,they have high surface activity.The lowest surface tension of their aqueous solution are 18.8 mN/m and 16.7mN/m,the critical micelle concentration are 5.4×10^-4mol/L and 3.0×10^-6mol/L respectively.They often have more unique properties and potential applications than other common fluorosurfactants.The applied properties of these fluorosurfactants such as emulsification,washing, decentralization,foaming,wetting etc.were measured.The results showed that Perfluorooctanesulfonic acid tetraethylammonium salt had good foaming property, N-(3-polyether-3-dimethyl aminopropyl)perfluorooctylsulfonamide had good emulsifing capability,N-(3-oxadimethyl aminopropyl)perfluorooctyl sulfonamide had poor washing capability,but excellent result was found when it mixed with SDS.So the fluorosurfactants display a bright application future.