Cardanol‐Modified Alkyd Resin‐Based Polyurethane/MoS 2 Nanocomposite Coatings

The present study demonstrated the development of polyurethane (PU) nanocomposite coatings incorporating biobased cardanol‐modified alkyd polyol and MoS 2 nanoparticles. Initially, biobased cardanol diol was synthesized by ring‐opening of cardanol monoglycidyl ether. Thereafter, alkyd resin was produced from prepared cardanol diol by solution condensation polymerization. ATR‐FTIR and 1 H NMR spectroscopies were used for the polyol structure confirmation. Then, the polyol was converted to PU coatings by reacting it with isophorone diisocyanate (IPDI) and modified using a loading of changing percentages (0.5%, 1%, 2%, and 4%) of MoS 2 nanoparticles. The corrosion performance of the resulting coatings was studied using immersion and electrochemical methods. The results showed that increasing the concentration of MoS 2 nanoparticles enhanced the corrosion resistance of PU nanocomposite coatings. The uniform distribution of MoS 2 nanoparticles was observed in the coatings, as evidenced by optical microscopy and scanning electron microscopy (SEM). Thermal stability was investigated by thermogravimetric analyzer (TGA), which showed increased stability with increasing nanoparticle loading percentage. The nanocomposite coatings exhibited better adhesion, flexibility, hydrophobicity, and chemical resistance than the PU coating in the absence of nanoparticles and the uncoated sample (mild steel panel). The amorphous and hydrophobic natures of coatings were observed by X‐ray diffraction (XRD) and contact angle estimation, respectively.