wIn this study, chemical modification of different molecular weight polystyrenes (PS) was researched with various functional group modificators: epichlorohydrin, maleic, and acetic anhydrides, in one stage and in the medium of BF3O(C2H5)(2) cationic catalyst. It was determined that the amounts of the functional groups, bound to the structure of the polymer, have been changed depending on the molecular weight of the PS used and more functional groups have been bonded to the lower molecular weight PS. It is stated that the adhesion properties and corrosion resistance of the modified PS on metal surface have been changed depending on the molecular weight of PS and the amount of the functional groups bound to the aromatic ring of the polymer. Various functional groups bound to the aromatic ring of the PS and their amounts were determined by spectral and chemical analysis methods. (c) 2007 Wiley Periodicals, Inc.