Synthesis and characterization of hybrid coatings in A36 steel for anticorrosive applications/ Sintese e caracterizacao de revestimentos hibridos em aco A36 para aplicacoes anticorrosivas

Steel is a material widely used by the industry, and corrosion is responsible for its functional loss. So, hydrophobic materials can help, since they have moisture resistance as a functional characteristic, reducing corrosion. This article aims to prepare coatings using the sol-gel process, as an alternative for anticorrosive coatings on metallic surfaces. For this, precursor solutions containing different concentrations of water, ethanol, tetraethylorthosilicate, cetitrimethyl ammonium bromide and polyetheramine were prepared and then the coatings were deposited at different speeds by the dip-coating technique on borosilicate and A36 steel substrates. Therefore, signs of corrosion were not observed in substrates with coatings deposited with immersion in the precursor solution for 24h, whereas those with deposition of 300 mm/min showed signs of corrosion. This fact could be attributed to the difference in the thickness of the coatings. Finally, the tests for the evaluation of the hydrophobicity of the coatings showed that the samples with a greater amount of PPO400 and a shorter time of deposition of the coating are less hydrophilic.