Perfluoro alkane carboxylic acid purifcn. - by extn. of potassium salt from aq. soln. using water miscible organic solvent

摘要

Perfluoro alkene carboxylic acids are sepd. from aq. soln. by extracting K salt from conc. aq. soln. using an organic solvent which is (partially) water-miscible. Acid salts are very water-soluble and easily contaminated with inorganic salts if aq. soln. is evaporated. Extn. or distn. of free acid causes corrosion. Method gives high purity, yields. Solvent is pref. 3-5C alcohol, esp. isopropanol, 3-7C ketone, dimethyl formamide or sulphoxide.