(EP932213-A1)      A new polymer electrolyte for fuel cells is made of a sulphonated polymer consisting of units of formula -[Ph-SO2-Ph-O-SO2-Ph-O]- (I) and units of formula -[Ar-O-Ph-SO2-Ph-O]- (II), where only the structure unit of formula (II) is sulphonated. The polymer has an equivalent weight of ion exchanging gp. of 500-2,500 (550-1,500) g/mol. In formulae, Ar = -Phn (n = 1,2,3), -Phn-Ph- (n =1,2), -Ph-O-Ph-, -Ph-S-Ph-, -Ph-CH2-Ph-, -NaPh- or -Ph-Ph- (Ph = phenyl and NaPh = naphthyl). Further claimed are: (1) a polymer electrolyte membrane for fuel cell, (2) the prodn. of the polymer electrolyte membrane, where the new polymer electrolyte is moulded by liq. casting, melt pressing or melt extrusion, and (3) a fuel cell using the new polymer electrolyte membrane.    USE -   Used for polymer electrolyte membrane fuel cells.    ADVANTAGE -   The new polymer electrolyte is produced in a simple, cost effective manner. It has a higher water resistance providing a fuel cell with a higher current-voltage performance.    (US5985477-A)      A new polymer electrolyte for fuel cells is made of a sulphonated polymer consisting of units of formula -[Ph-SO2-Ph-O-SO2-Ph-O]- (I) and units of formula -[Ar-O-Ph-SO2-Ph-O]- (II), where only the structure unit of formula (II) is sulphonated. The polymer has an equivalent weight of ion exchanging gp. of 500-2,500 (550-1,500) g/mol. In formulae, Ar = -Phn (n = 1,2,3), -Phn-Ph- (n =1,2), -Ph-O-Ph-, -Ph-S-Ph-, -Ph-CH2-Ph-, -NaPh- or -Ph-Ph- (Ph = phenyl and NaPh = naphthyl). Further claimed are: (1) a polymer electrolyte membrane for fuel cell, (2) the prodn. of the polymer electrolyte membrane, where the new polymer electrolyte is moulded by liq. casting, melt pressing or melt extrusion, and (3) a fuel cell using the new polymer electrolyte membrane.    USE -   Used for polymer electrolyte membrane fuel cells.    ADVANTAGE -   The new polymer electrolyte is produced in a simple, cost effective manner. It has a higher water resistance providing a fuel cell with a higher current-voltage performance.