Solutions and membranes formed therefrom are disclosed with solvents having completely halogenated, saturated, hydrocarbon backbones and solubility parameters within a particular range. Preferred solvent have at least one ether linkage. An exemplary solvent is ##STR1## wherein X is F, Cl, Br, and I; n is 0, 1, and 2; m is 1, 2, and 3; and Y is COOCH.sub.3 and SO.sub.2 F. The solutions include perfluorinated copolymers having high equivalent weight which have been prepared from tetrafluoroethylene and perfluorinated sulfonyl fluoride- or carboxyl-containing vinyl monomers.
本发明揭示了使用具有完全卤代、饱和、碳氢化合物骨架和溶解度参数在特定范围内的溶剂制备的解决方案和膜。首选的溶剂至少具有一个醚键。一个示例性的溶剂是##STR1##其中X为F、Cl、Br和I;n为0、1和2;m为1、2和3;Y为COOCH.sub.3和SO.sub.2 F。这些溶液包括高当量重的
全氟共聚物,该共聚物是从
四氟乙烯和含有
全氟磺酰
氟或羧基的
乙烯单体制备而成的。