The method of formation of well-defined polymer brushes based on the nitroxide mediated polymerization (NMP) of n-butyl acrylate (BA) initiated from a self-assembled mono-layers (SAMs) of an azoic initiator in the presence of a stable nitroxide radical is described. After preliminary qualitative characterization by X-ray photoelectron spectroscopy, the samples were studied by ellipsometry in order to determine the dry film thickness (initiator and polymer) and the grafting density of macromolecular chains. It is demonstrated, that in the presence of stable counter radical SG1, acting as chain growth moderator, the surface initiated NMP exhibits a living/controlled character permitting to control architectural parameters (e.g. degree of polymerization) of elastomer grafted polymer chains. The possibility to use the living control character of this type of polymerization to re-initiate grafted chains in order to increase the thickness of an elastomer thin film with conservation of the brushes regime has been demonstrated. (c) 2006 Elsevier Ltd. All rights reserved.