Abstract: Per(poly)fluorinated polyoxyethylated carbamates of general formula (I) in which R.sub.F represents a perfluorinated group containing between 1 and 18 carbon atoms, W represents an oxo group or nothing, n is an integer from 1 to 10, m is from values 2 to 6, 80 or not defined, R is an alkyl group, R.sub.F W(CH.sub.2).sub.n+1 NHC(O)-- in which R.sub.F and W are as defined above, --(CHCH.sub.3 CH.sub.2 O).sub.30 (CH.sub.2 CH.sub.2).sub.80 C(O)NH(CH.sub.2).sub.n+1 R.sub.F in which R.sub.F is a perfluorinated group containing from 1 to 18 carbon atoms, R' is a hydrogen atom, an alkyl group containing between 1 and 18 carbon atoms which is optionally substituted, an optionally substituted aryl or aralkyl group, an allyl, methallyl or propargyl group or a perfluorinated chain having between 1 and 18 carbon atoms.

Abstract: The use of perfluorinated heterocyclic compounds of the general formula I, ##STR1## wherein n represents 2-8,X and Y represent a --CF.sub.2 OCF.sub.2 -- group, a --CF.sub.2 --CF.sub.2 --CF.sub.2 -- group or a --CF(CF.sub.3)--CF.sub.2 -- group, andY is a --CF.sub.2 --O--CF.sub.2 -- group, a --CF(CF.sub.3)--CF.sub.2 -- group or a --CF.sub.2 --CF.sub.2 --CF.sub.2 -- group,or mixtures thereof, is described as emulsion-stabilizing additives in medically usable aqueous emulsions of perfluorocarbons, optionally containing hetero atoms, suitable for use in blood substitutes. The compounds are obtained by electrochemical perfluorination.