Abstract: An object of this invention is to provide an electrolytic membrane excellent in ion conductivity and oxidation resistance, and this invention is directed to an electrolytic membrane formed of a polymer comprising at least one recurring unit selected from the group consisting of a recurring unit of the following formula (A), and a recurring unit of the following formula (B), and having a reduced viscosity, measured in a methanesulfonic acid solution having a concentration of 0.5 g/100 ml at 25° C., of 0.05 to 200 dl/g, and a process for the production thereof.

Abstract: An object of this invention is to provide an electrolytic membrane excellent in ion conductivity and oxidation resistance, and this invention is directed to an electrolytic membrane formed of a polymer comprising at least one recurring unit selected from the group consisting of a recurring unit of the following formula (A), and a recurring unit of the following formula (B), and having a reduced viscosity, measured in a methanesulfonic acid solution having a concentration of 0.5 g/100 ml at 25° C., of 0.05 to 200 dl/g, and a process for the production thereof.

Abstract: A polyether ester elastic fiber comprising a polyether ester elastomer containing polybutylene terephthalate as a hard segment and polyoxyethylene glycol as a soft segment and copolymerized with a specific metal organic sulfonate, having a coefficient of moisture absorption of not less than 5% at 35° C. and at a RH of 95% and a coefficient of water absorption extension of not less than 10%. The above-mentioned polyether ester elastic fiber has a good moisture-absorbing property, and is reversibly largely expanded or contracted by the absorption or release of water. Therefore, a fabric giving excellent comfortableness can be obtained from said elastic fibers, and can be recycled.