A new reactive and functionalized polystyrene with a maleimide moiety at the one polymer end was synthesized with N-(4-(1-chloroethyl)pheyl)maleimide (CEPMI)/SnCl4/tetra-butylammonium chloride (TBAC) initiating system. The polymer obtained with the CEPMI/SnCl4/TBAC initiating system under the condition of [TBAC]/[SnCl4] = 1 was to be maleimide-type macromonomer with polystyrene having controlled molecular weight of polystyrene (VI). VI could be polymerized with anionic and radical initiators to give new type graft polymer (poly[N-(4-ethylphenyl)maleimide]-graft-polystyrene) with controlled chain length with respect to side chains. (C) 2011 Elsevier Ltd. All rights reserved.