Reversible addition fragmentation chain transfer (RAFT) bulk polymerizations of 3-[tris(trimethylsilyloxy)silyl] propyl methacrylate (TRIS) have been carried out at 60degreesC, employing cumyl dithiobenzoate (CDB) and 2-cyanoprop-2-yl dithiobenzoate (CPDB) as mediating agents at concentrations ranging from 5.0 X 10(-3) to 2.0 X 10(-2) mol l(-1). The monomer conversion vs. time evolution was followed via dilatometry and H-1 NMR spectroscopy. The CDB mediated polymerization displays RAFT agent concentration dependent inhibition and rate retardation phenomena, whereas the CPDB mediated polymerization process is less susceptible to rate retardation and inhibition effects. The different behavior of CDB and CPDB in TRIS polymerization is most likely due to the increased stability of the intermediate macroRAFF radicals in the CDB mediated process. The generated RAFT polymers were analyzed via size exclusion chromatography indicating linear macromolecular growth with respect to monomer conversion and low polydispersities (PDI < 1.15) up to high monomer to polymer conversion (> 90%). (C) 2003 Elsevier Ltd. All rights reserved.