p-Perfluoro[1-(2-fluorosulfonyl)ethoxy]ethylated poly(alpha-methyl styrene), 3, was synthesized via electron transfer initiated p-perfluoro[1-(2-fluorosulfonyl)ethoxy]ethylation of poly(alpha-methyl styrene), 1, with perfluoro-di[2-(2-fluorosulfonyl)ethoxylpropionyl peroxide, 2, then was converted into p-perfluoro[1-(2-sulfonic)ethoxy]ethylated poly(alpha-methyl styrene), 5, by further hydrolysis of the p-substitution product 3 and acidification of the sulfonate 4. The aromatic p-substitution was proved by FT-IR and F-19 NMR. The desulfonation occured above 128 degrees C was found by TGA. The consistent polydispersity values determined by GPC indicated no degradation of the parent polymer chain occurred during the reaction. The ion exchange capacity(IEC) of ion exchange resin 5 increased with the increase of the reactant molar ratio (2:1). Published by Elsevier B.V.