NOVELTY - Alkylated bisphenol-based compounds (I) are new.    USE - (I) are useful in preparation of sulfonated polyarylene sulfone which is useful in fuel cell.    ADVANTAGE - (I) provide: the fuel cell with high performance, with improved output and lifetime; sulfonated polyarylene sulfone with high ionic conductivity, excellent mechanical properties, solvent resistance, brittleness and ionic conductivity.    DETAILED DESCRIPTION - Alkylated bisphenol-based compounds of formula (I) are new.    R1 = 1-30C alkyl (preferably undecyl (-(CH2)10CH3), pentadecyl (-(CH2) 14CH3), heneicosyl (-(CH2)20CH3) or tricosyl (-(CH2)22CH3)); and    R2 = H or 1-5C alkyl.    INDEPENDENT CLAIMS are also included for:    (1) a sulfonated polyarylene sulfone comprising a first repeating unit i.e. substituted 4-(4-(4-benzenesulfonyl-phenoxy)-benzyl)-phenol compounds of formula (III) and a second repeating unit i.e. substituted 4-(4-(2-hydrosulfonyl-4-(3-hydrosulfonylphenylsulfonyl)phenoxy)benzyl)phenol compounds of formula (IV);    (2) preparation of (I);    (3) preparing sulfonated polyarylene sulfone comprising performing polymerization of (I), substituted sulfonyldibenzene compounds of formula (VII) and substituted 3,3'-sulfonylbis(hydrosulfonylbenzene) compounds of formula (VIII);    (4) a fuel cell (1) comprising a cathode, an anode and an electrolyte membrane (100) comprising sulfonated polyarylene sulfone and disposed between the cathode and the anode; and    (5) an electrolyte membrane for a fuel cell comprising sulfonated polyarylene sulfone.    R3 = is 1-10C alkyl, 2-10C alkenyl, phenyl or NO2;    R4 = 1-30C alkyl (preferably undecyl (-(CH2)13CH3), pentadecyl (-(CH2)14CH3), heneicosyl (-(CH2)20CH3) or tricosyl (-(CH2)22CH3));    Y1 = Cl, F, Br or I;    p = 0-4;    M = Na, K or H; and    m, n = 0.01-0.99.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a membrane electrode assembly of a fuel cell.    Fuel cell (1)    Membrane-electrode assembly (10)    Electrolyte membrane (100)    Catalytic layer (110)    Gas diffusion layer (120)