Corrosion-resistant coatings are essential for prolonging the lifespan of metal structures, yet conventional formulations often lack sufficient mechanical strength and chemical durability. This study focuses on the development of polyurethane/epoxy hybrid coatings (PUAE) with varying epoxy resin content (5%, 10%, and 15% by weight) to enhance performance. The hybrid films demonstrated improved mechanical properties with increasing epoxy content, including a rise in tensile strength from 39.1 MPa (PUA) to 86.3 MPa (PUAE15) and adhesion from 2.5 MPa to 8.3 MPa. Hardness also increased from 69 Shore A to 98 Shore A, while elongation at break decreased from 158% to 95%, indicating a shift toward a stiffer material. The thermal stability, assessed by TGA, showed higher degradation temperatures, with PUAE15 reaching a maximum decomposition temperature of 390 °C, compared to 320 °C for pure polyurethane. Viscosity at 5 rpm increased from 12.300 mPa·s to 18.563 mPa·s, and the contact angle improved from 105° to 149°, highlighting enhanced hydrophobicity. PUAE15 also displayed superior resistance to solvents and acidic environments. These results affirm that epoxy content significantly influences the structural, mechanical, and corrosion-resistant properties of polyurethane-based coatings, making PUAE15 a promising candidate for advanced anticorrosive applications.

The physical, and mechanical properties as well as chemical and corrosion resistance of hybrid coatings comprising polyurethane/acrylic hybrids (PUA/AC) and acrylic polymers (AK) were investigated. Polyurethane (PUA) was synthesized through polyaddition polymerization of isocyanates [Isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI)] with polyols (GP 2000 and GP 4000) at an NCO/OH ratio of 0.85 and a temperature of 100°C. The acrylic copolymer (AC), based on methyl methacrylate (MMA) and butyl methacrylate (BuMA), was produced via bulk polymerization with benzoyl peroxide as a catalyst. The acrylic copolymer (AK) was prepared by grafting xanthan gum with styrene in various ratios (XG: St = 1:1.6, 1:5, and 1:8 w/w%). The results revealed that hybrid coatings demonstrated optimal chemical and corrosion resistance when PUA/AC hybrids were combined with AK. Enhancing both mechanical properties and corrosion resistance was achieved by integrating PUA/AC-10 with AK containing 8% styrene, resulting in superior anticorrosion performance including chemical and solvent resistances for the hybrid coating.