Corrosion Protection Enhancement via Rheology‐Optimized Clay‐Reinforced Fluoropolymer Coatings

ABSTRACT Poor adhesion and limited barrier performance constrain the corrosion protection efficacy of poly(vinylidene fluoride‐ co ‐hexafluoropropylene) (PVDF‐HFP) coatings. To enhance interfacial compatibility and dispersion, organomodified montmorillonite (OMMT), functionalized with cetyltrimethylammonium bromide (CTAB), is incorporated into PVDF‐HFP. Composite coatings containing 1–4 wt% OMMT are prepared via dip‐coating, forming uniform films with thicknesses ranging from 11.8 to 13.1 μm. Rheological analysis identifies the 3 wt% OMMT formulation as exhibiting the highest low‐frequency storage modulus and complex viscosity, indicating the formation of a percolated filler network. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests in 0.5 M NaCl solution demonstrate that this formulation achieves the highest low‐frequency impedance and the lowest corrosion current density after 7 days of immersion. Adhesion strength improves from 0B to 3B on the ASTM D3359 scale with OMMT addition. Scanning electron microscopy reveals reduced void formation and more uniform morphology at intermediate loadings. Enhanced corrosion resistance is associated with improved viscoelasticity, which possibly promotes uniform filler distribution and tortuous diffusion paths. The results suggest that CTAB‐functionalized OMMT enhances both the structural and electrochemical performance of PVDF‐HFP coatings, offering a scalable route to high‐performance anticorrosive fluoropolymer systems.