Fluoro-polymers contg. carboxyl gps. or gps. derived. therefrom - by oxidn. of omega-h per:fluoro side chains, at 150-300 deg. C to form cof gps.

摘要

Perfluorinated polymers (I) contg. monomer units of formula (II) (with m = 0-3; n = 2-10; X = COF) are produced by reaction of the corresp. polymer (III) contg. units of formula (II) (with X = CF2H) at 150-300 deg C with a gaseous oxidising agent (IV) which is capable of liberating iodine from acidified aq. KI soln. Pref. (I) also contain monomer units of formula CF2=CF-R (with R= F or 1-10C perfluoroalkyl, pref. F or CF3), and pref. F or CF3), and pref. also units of formula (II) (with m = 0-3; n = 1-10; X = CF3); pref. comonomer units are omega-H-perfluoropropyl perfluorovinyl ether (H-PPVE) and TFE, esp. pref. with perfluoropropyl perfluorovinyl ether (PPVE) as third comonomer; (IV) is a nitrogen oxide, or air, O2, ozone or a mixt.; polymers (I) (with X = COOH or X = CONH2) are produced directly by adding to (IV) an amt. of water vapour or NH3 which is equal to or greater than the mol. wt. of CF2H gps.. USE/ADVANTAGE - (I) (with COOH or carboxy derivs. as functional gps.) are useful for the prodn. of cation exchange membranes for chlor-alkali electrolysis, and for the prodn. of hydrophilic coatings on hydrophobic polymer surfaces. The invention provides a simpler, less expensive process for the prodn. of (I), compared with prior-art processes.