Fluorinated surfactants for making fluoropolymers

A process for producing a fluorinated surfactant, the process comprising:

• carrying out a free radical reaction of a fluorinated olefin of formula
• Rf—(O)t—CF═CF2 (II)
• wherein Rf represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, t is 0 or 1 and n is 0 or 1, Xi+ represents a cation having a valence i and i is 1, 2 or 3
• with a hydrocarbon alcohol;
• and
• oxidizing the resulting reaction product,
• wherein the fluorinated surfactant has the general formula:
• [Rf—(O)t—CHF—(CF2)n—COO−]iXi+ (I)
• wherein t is 1 and wherein Rf is selected from the group consisting of perfluorinated aliphatic groups of 1 to 6 carbon atoms and perfluorinated groups of the formula Rf1—[ORf2]p—[ORf3]q— wherein Rf1 is a perfluorinated aliphatic group of 1 to 6 carbon atoms, Rf2 and Rf3 each independently represents a linear perfluorinated alkylene of 1, 2, 3 or 4 carbon atoms and p and q each independently represent a value of 0 to 4 and wherein the sum of p and q is at least 1, and wherein n is 0 or 1, Xi+ represents a cation having a valence i and i is 1, 2 or 3.