Brominated pyrazole-based epoxy coating: Synthesis, DFT, docking, corrosion study

In this study, a brominated pyrazole derivative was successfully synthesized and incorporated into an epoxy matrix to develop a multifunctional protective coating. Structural confirmation was achieved via FTIR, 1 H NMR, and 13 C NMR. Characterization techniques (TGA, SEM–EDX, and EIS) revealed superior barrier properties, thermal stability, and mechanical strength. Notably, polarization resistance (Rp) increased from 2.7 × 10 3 to 1.25 × 10 4 Ω·cm 2 , corresponding to a corrosion inhibition efficiency of 78.4%. The modified coating also exhibited strong resistance to aggressive chemical environments and salt-spray exposure. The MIC values reported (50–100 µg/mL) were determined for the free pyrazole compound dissolved in the test medium. No extraction or leaching tests were performed on the cured coating. Fungal resistance tests (ASTM G21) demonstrated complete inhibition of visible microbial growth on the coating surface for 28 days. Density Functional Theory (DFT) analysis revealed a narrow HOMO–LUMO energy gap and a high electrophilicity index, supporting a tendency to interact with metal surfaces. Additionally, molecular docking against S. aureus DHFR indicates moderate predicted binding affinity (–5.016 kcal/mol) as a computational indicator of possible interaction. These results imply that the pyrazole derivative is a promising additive for multifunctional protective coatings.