Synthesis and surface activity of sodium salts of branched perfluorocarboxylic acids and their analogs containing one chlorine atom

Individual sodium salts of branched perfluorocarboxylic acids, (CF₃)₂CF(CF₂CF₂)_nCOONa, and their analogs containing one chlorine atom, CF₃CF(CF₂CI)(CF₂CF₂)_nCOONa, were synthesized by telomerization of 2-iodoheptafluoropropane and l-chloro-2-iodohexafluoropropane with tetrafluoroethene, the addition of ethylene to both types of iodides considered, HI elimination and the oxidation of perfluoroalkylethylenes with potassium bichromate. The surface tension measurements demonstrated the high surface activity of sodium salts containing 9 and 11 carbon atoms in the hydrophobe. Perfluorocompounds were more surface active than their analogs having one chlorine atom but the differences were not great.