Enhanced mechanical and anti‐corrosion performance of polyurea nanocomposite coatings via amino‐functionalization of boron carbide nanosheets

Abstract Polyaspartate polyurea (PAEp) generally has insufficient protective properties and limited chemical corrosion resistance. To address these limitations, boron carbide (B 4 C) nanosheets were modified using mechanochemical surface grafting with amino functional groups to create KP‐B 4 C. These nanosheets were incorporated into PAEp to produce nanocomposite materials. The addition of 0.5 wt% KP‐B 4 C significantly enhanced the mechanical properties of the nanocomposites. Tensile strength increased by 127.12%, while elongation improved by 45.08%. The impact resistance of the material was also notably improved. The prepared nanocomposites also demonstrated strong resilience against environmental factors such as moisture, heat, UV exposure, and friction. PAEp composite coatings with 0.5 wt% KP‐B 4 C particles had significantly improved anticorrosion properties compared to unmodified PAEp. Electrochemical corrosion tests have shown that KP‐B 4 C nanocomposites provide a robust protective coating even after prolonged immersion in corrosive liquids (e.g., NaCl, NaOH, H 2 SO 4 ). This improvement is attributed to the uniform dispersion of KP‐B 4 C particles in the matrix and the effective barrier properties against aggressive substances. The study highlighted the importance of adding a reinforcing phase and chemical modification in PAEp nanocomposites in order to achieve high mechanical performance and multifunctional protective coatings. Highlights Tensile strength and elongation at break increased by 127.12% and 45.08%; Enhanced impact strength on Al and epoxy substrates; Exceptional abrasion resistance, reducing wear index to 1.18%.