Perfluorodioxole membranes

Abstract

A selectively permeable membrane for the separation or enrichment of gaseous mixtures may be formed from amorphous polymers of perfluoro-2,2-dimethyl-1,3-dioxole, especially copolymers with a complementary amount of at least one of tetrafluoroethylene, perfluoromethyl vinyl ether, vinylidene fluoride and chlorotrifluoroethylene. Preferably, the polymer is a dipolymer containing 65-99 mole % of perfluoro-2,2-dimethyl-1,3-dioxole and having a glass transition temperature of at least 140.degree. C. The membranes may be used for the separation or enrichment of a wide variety of gaseous mixtures, including oxygen enrichment of air, and separation or enrichment of gaseous organic compounds in admixture with air, including separation or enrichment of the amount of fluorocarbon gases in air. The membranes exhibit a very high flux rate, compared with other glassy organic polymer membranes.

Dependencies are inferred from the claim text.