Anticorrosive Effect of the Size of Silica Nanoparticles on PMMA-Based Hybrid Coatings

Abstract

Some public institutions in Mexico are combining corrosion research with environmental considerations. Therefore, our research group approached the specific goal of developing new corrosion-resistant materials (paints or coatings) for marine environments, where wave energy is obtained. Hybrid coatings were prepared using polymethylmethacrylate (PMMA) filled with silicon dioxide nanoparticles to protect steel in highly corrosive marine environments. The materials were selected by a multidisciplinary group, considering cost, ease of processing, scalability and environmental impact. Coating design was based on the study of physical and structural variables modifications instead of chemical variables or complex assemblies based on multiple materials. ASTM D 4541-09 was performed to evaluate adhesion between PMMA coating and hybrid PMMA-SiO2 nanoparticles coating on carbon steel and stainless steel. Results showed that the SiO2 nanoparticles and PMMA act synergistically to enhance anticorrosive performance. Corrosion resistance properties of the hybrid coatings are related with the sizes of SiO2 nanoparticles added to the polymeric matrix. This effect showed that the smallest nanoparticle size implies the highest protection against corrosion. Functionalized nanoparticles with 3-aminopropyl triethoxysilane increased anticorrosive and adhesion properties. In conclusion, it was possible to obtain a functional hybrid coating for steel corrosion-protection in highly corrosive marine environments, using the less environmental impact materials required by biology experts’ guidelines.