Atom transfer radical polymerization of styrene initiated by α

α- dibromotoluene and cataIyzed by copper (I) bromide／2

2′-bipyridine was carried out．The produced polymers had narrow molecular weight distributions and controlled molecular weights that were proportional to monomer conversion．In order to show that α

α-dibromotoluene is a bifunctional initiator for atom transfer radical polymerization of styrene

polymerization of styrene using a mixture of 1-phenyl ethyl bromide and α

α-dibromotoluene initiators was also carried out．The GPC trace of obtained polystyrene exhibited bimodal distribution．The peak appearing at lower elution time corresponds to polymer from α

α-dibromotoluene and the other one corresponds to polymer from 1-phenyl ethyl bromide．The ratio of peak molecular weight of the polymer from α

α-dibromotoluene to that from 1-phenyl ethyl bromide was found to be close to two

confirming that the polymer from α

α-dibromotoluene grows from both ends of the polymer chain．Furthermore

the ratio of the two peak surface area changed with the molar ratio of α

α-dibromotoluene to 1-phenyl ethyl bromide.