Synthesis, characterization and protective efficiency of novel polybenzoxazine precursor as an anticorrosive coating for mild steel

Ahmed M M Soliman; Kamal I Aly; Mohamed Gamal Mohamed; Amer A Amer; Mostafa R Belal; Mohamed Abdel-Hakim

doi:10.1038/s41598-023-30364-x

Synthesis, characterization and protective efficiency of novel polybenzoxazine precursor as an anticorrosive coating for mild steel

Sci Rep. 2023 Apr 5;13(1):5581. doi: 10.1038/s41598-023-30364-x.

Authors

Ahmed M M Soliman¹, Kamal I Aly², Mohamed Gamal Mohamed^{3

4}, Amer A Amer¹, Mostafa R Belal¹, Mohamed Abdel-Hakim⁵

Affiliations

¹ Department of Chemistry, Faculty of Science, Sohag University, Sohag, 82524, Egypt.
² Polymer Research Laboratory, Chemistry Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt. kamalaly@aun.edu.eg.
³ Polymer Research Laboratory, Chemistry Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt. mgamal.eldin12@aun.edu.eg.
⁴ Department of Materials and Optoelectronic Science, Center for Functional Polymers and Supramolecular Materials, National Sun Yat-Sen University, Kaohsiung, Taiwan. mgamal.eldin12@aun.edu.eg.
⁵ Chemistry Department, Faculty of Science, Al-Azhar University, Assiut, 71524, Egypt.

Abstract

In this study, 2-[(E)-(hexylimino)methyl] phenol (SA-Hex-SF) was synthesized by adding salicylaldehyde (SA) and n-hexylamine (Hex-NH₂), which was subsequently reduced by sodium borohydride to produce 2-[(hexylamino)methyl] phenol (SA-Hex-NH). Finally, the SA-Hex-NH reacted with formaldehyde to give a benzoxazine monomer (SA-Hex-BZ). Then, the monomer was thermally polymerized at 210 °C to produce the poly(SA-Hex-BZ). The chemical composition of SA-Hex-BZ was examined using FT-IR, ¹H, and ¹³C NMR spectroscopy. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray Diffraction (XRD), respectively, were used to examine the thermal behavior, surface morphology, and crystallinity of the SA-Hex-BZ and its PBZ polymer. Mild steel (MS) was coated by poly(SA-Hex-BZ) which was quickly prepared using spray coating and thermal curing techniques (MS). Finally, the electrochemical tests were used to evaluate the poly(SA-Hex-BZ)-coating on MS as anti-corrosion capabilities. According to this study, the poly(SA-Hex-BZ) coating was hydrophobic, and corrosion efficiency reached 91.7%.