N,N-bis-aminoalkylamides of polyoxaperfluoroalkandioic acids, derivatives thereof and process for preparing same

Surface active agents having anti-corrosion or oil-repellent properties, the chain of which, having the structure of bis-alkyl-amides of polyoxaperfluoroalkandioic acids, corresponds to the general formula:

• Z--(CH.sub.2).sub.p --NH--CO--CF.sub.2 O(C.sub.2 F.sub.4 O).sub.1 (CF.sub.2 O).sub.n --CF.sub.2 --CO--NH--(CH.sub.2).sub.p -Z
• wherein Z is a ##EQU9## group, a salified quaternary ammonium group or a ##EQU10## group, --C.sub.2 F.sub.4 O-- and --CF.sub.2 O-- are oxyperfluoroalkylene units distributed randomly along the chain, 1 and n are integers the sum of which is from 2 to 50 inclusive and the 1/n ratio is from 0.2 to 1.5, inclusive, p is an integer from 1 to 20, inclusive, R' and R" are alkyl radicals either the same or different and having from 1 to 6 carbon atoms or form, together with the adjacent nitrogen atom, a ring with 5 or 6 atoms, the remaining atoms of the ring consisting of atoms of carbon or of carbon and one oxygen atom, and O is an oxygen atom.