Polystyrene (PS) chains functionalized with pendant 1,2-bis(trimethylsilyloxy)tetraphenylethane (TPSE) groups are used as macroinitiators to initiate the polymerization of n-butyl acrylate (BuA) to synthesize PS-g-poly(BuA) (PS-g-PBuA) copolymers at 130 degreesC. The TPSE groups are known to function as initers in the polymerization of several vinyl monomers, The homolytic decomposition of TPSE results in a diphenylmethyl (DPM) radical attached to the main chain and a free DPM radical. The former is responsible for the polymerization initiation and the latter momentarily stops the growth of the growing grafts by the formation of a dormant species. Unfortunately, side reactions like the combination between growing grafts take place and the polymerization can only be controlled in a limited range of conversion. The most appropriate conditions for the synthesis of PS-g-PBuA are reported to present their potential use as thermoplastic elastomers with relatively controlled structures. (C) 2002 John Wiley & Sons, Inc.