Spraying SiO2 – PMMA warehousing protective layer onto AISI 1036 steel with barrier properties at atmospheric pollutants

Abstract

In this work, a hybrid SiO₂-PMMA coating with barrier properties to atmospheric pollutants was synthesized by sol-gel at room temperature (25°C). The inorganic SiO₂ precursors used were TEOS:Ethanol:Water 0.1:0.4;1.2 in molar ratio. As organic precursor, 100 ml of MMA monomer with 0.4 g of BPO as free radical polymerization catalyst to obtain the PMMA polymer. Homogeneous films were obtained, applied by the spray method on metallic substrates of AISI 1036 steel. The thickness of the layer obtained was 30 µm as a dry film, without any thermal drying treatment, the substrates were prepared with chemical cleaning under the ASTM G1 standard. These SiO₂-PMMA hybrid coatings are well adhered to the metal substrate with adhesion grade 5B according to the ASTM D3359 standard, and have high transparency in the visible range with 95%T and anticorrosive capacity of -472.44 mV. The latter was evaluated by the electrochemical technique of Polarization Curves and OCP with both techniques it was detected that there is no ion exchange and that the hybrid coating of SiO₂-PMMA generates the protection between the AISI 1036 steel and the electrolyte solution.