Surface activity of perfluoropolyalkylether N,N-diphenylamide (PFPEA)

A functional derivative of perfluoropolyalkylether, perfluoropolyalkylether N,N-diphenylamide (PFPEA) was synthesized and characterized by FT-IR, ¹H and ¹⁹F NMR, and the thermo stability was determined by TG analysis. The surface activity of PFPEA was characterized by the determination of surface tension of organic solvents and the adsorption behavior on the surfaces of solids such as Fe, Al, Cu plates. PFPEA reduced the surface tension of organic solvents greatly such as benzene, toluene, hexane, and cyclohexane. PFPEA was adsorbed on surfaces of solids to form molecular thin films through the end groups. Surface properties of thin films of PFPEA formed by adsorption in organic solutions were characterized using contact angle measurements and X-ray Photoelectron Spectrum (XPS) analysis. The anti-wear performances of adsorbed thin films of PFPEA were determined on a four-ball tribo-tester under the lubrication of liquid lubricants. Films preadsorbed on the substrate surfaces could improve the anti-wear properties of liquid lubricants.