Silica-reinforced blend nanocomposites for enhanced corrosion resistance

Uniform dispersion of inorganic nanoparticles within polymeric coatings is essential for improving long-term barrier performance. This study investigates the effect of incorporating silica nanoparticles on the mechanical, viscoelastic, and electrochemical behavior of coatings based on blends of an acrylic copolymer (PMMA-2EHA) and polystyrene (PS). Increasing PS content refined the phase morphology and promoted a more uniform nanoparticle distribution, which was reflected in higher stiffness and tensile strength. The elastic modulus increased from 3.5 MPa (neat acrylic matrix) to 289 MPa for the 30 wt% PS blend. Silica addition further reinforced the PS-containing systems, with the 30 PS_6SiO2 formulation reaching an ultimate tensile strength of 6.8 MPa. Dynamic mechanical analysis showed restricted mobility in the PS-rich phase upon nanoparticle incorporation, indicating favorable polymer–particle interactions. Electrochemical impedance spectroscopy revealed that coatings containing 6 wt% silica presented the highest impedance values after 7 days of immersion, up to an order of magnitude higher than the silica-free and 2 wt% formulations. These findings support the potential application of these nanocomposites as durable, mechanically robust, and corrosion-resistant protective coatings.