A tri-functional polyhedral oligomeric silsesquioxane (POSS) based silane precursor R(x)R(y)R(z)(SiO(3/2))(n) (x+y+z = n = 6, 8, 10, .... ) bearing 3-(N-(3-triethoxysilylpropyl)ureido)propyl, isooctyl and perfluoropropyl groups was synthesized and investigated as corrosion protective coating for AA 2024 alloy. Infrared reflection-absorption (IR RA) combined with X-ray photoelectron spectroscopy and atomic force microscopy provided information about partial self-assembling of coatings having a fluorine enriched upper layer with a low surface energy (gamma(tot) = 12.37 mN/m). The structural changes that accompanied corrosion produced under chronocoulometrical conditions were assessed from ex-situ IR RA spectra. A new band at 1690-1700 cm(-1) appeared above the corrosion potential, and was assigned to the formation of amidonium ions and consequent relaxation of urea-urea associations. (C) 2009 Published by Elsevier B.V.