NOVELTY - A modified polymer, membrane or molded article comprises a metallized polymer in the main chain or side chain prepared by reaction with an alkene with optionally no further polymerization, reaction of the product with an alkene such that anionic polymerization occurs at the newly formed metal center and reaction of the metallized chain of the graft side chain of the polymer with an electrophile.    USE - The modified polymers and membranes are useful for membrane fuel cells and electrolyzers.    ADVANTAGE - The modified polymers, membranes and molded articles have modified hydrophilic, hydrophobic or biochemical properties.    DETAILED DESCRIPTION - A modified polymer, membrane or molded article comprises a metallized polymer in the main chain or side chain prepared by:    (a) reaction with a alkene as shown in formula (1) with optionally no further polymerization;    (b) reaction of the product from (A) with an alkene as shown in formula (1) such that anionic polymerization occurs at the newly formed metal center as shown in formula (2);    (c) reaction of the metallized chain of the graft side chain of the polymer with an electrophile as shown in formula (3) and;    (d) optionally further reaction of the electrophile.    R1-R8 = organic group that does not react with an organometallic reaction center;    M = cation of an organometallic compound that undergoes addition reactions with unsaturated compounds;    EL = electrophile;    Polymer = polymer    INDEPENDENT CLAIMS are included for:    (1) a process for the production of the modified polymers by dissolution or suspension of the polymer in an appropiate solvent, optionally under inert gas and metallization with the organometallic compounds at -80-+80 degreesC by addition of the pure compound, optionally in the same solvent as the polymer by dropwise addition or spraying, addition of the second unsaturated compound when the reaction is complete by addition of the pure compound, optionally in the same solvent as the polymer by dropwise addition or spraying, and addition of the electrophile or mixture of electrophiles to quench the metallized chain end by addition of the pure compound, optionally in the same solvent as the polymer by dropwise addition or spraying, and maintaining the reaction temperature at -80-+80 degreesC with further processing by optionally addition of a 2-10 fold excess of an alkyl alcohol, optionally addition of a 2-10 fold excess of water, precipitation and/or suspension of the reaction mixture in a 2-20 fold excess (with respect to the volume of the reaction mixture or the modified polymer) of an alcohol (methanol, ethanol, i-propanol, n-propanol), water or an aqueous mineral salt solution (NaCl, NaHCO3, Na2SO4) or other conventional precipitating agent (acetone or methylethyl ketone) and filtration, washing of the precipitate, drying at elevated temperature and optionally reduced pressure, optional re-dissolution of the modified polymer and reprocessing as above and optional re-dissolution of the modified polymer and further reaction of the functional groups on the side chain;    (2) a process for the production of surface or bulk modified polymer membranes or molded articles and; forming of the modified polymers to produce membranes for use in membrane processes or optionally membrane fuel cells or membrane electrolyzers.