Elaboration and characterization of hybrid films siloxane-PMMA prepared by solgel process on tin plates: influence of pH sol

The siloxane-PMMA hybrid materials possess stability, transparency and enable the application of these materials in coating of containers such as tin plates in order to increase the corrosion resistance, the tensile strength and decrease the brittleness of these products. These composites exhibit a good chemical stability due to the presence of covalent siloxane, MMA and the initial pH of the sol on the mechanisms of siloxane species and condensation polymerization of methacrylate groups. In this context, the aim of this work is to line the tin plate with a hybrid film obtained from sol alkoxides precursors consisting of: 3 -(trimethoxysilylpropyl) methacrylate (TMSM), poly (methyl methacrylate) PMMA and tetraethoxysilane (TEOS) was varied in two levels the pH of the hydrolysis solution (1 and 3). The films were obtained by dip-coating process. The morphology of the films was evaluated by SEM. The coatings were characterized as the electrochemical behavior from monitoring the open circuit potential, polarization curves and electrochemical impedance. The results showed that the hybrid film siloxane-PMMA obtained in more acidic medium (pH=1) showed better electrochemical performance and higher values of layer thickness. (C) 2014 Sociedade Portuguesa de Materiais (SPM). Published by Elsevier Espana, S.L. All rights reserved.