Cardanol and bisphenol-F based benzoxazines with zirconium phosphate reinforced composites coating for protecting the mild steel surface from corrosion

The present work is to develop and characterize the benzoxazines from cardanol and bisphenol-F with imdazole core based amine in order to utilize them in the form of (50/50 wt%) blended composites coating for corrosion resistance application. The benzoxazine blends were reinforced with varying weight percentages of (0.5, 1, 1.5, 2.0 and 2.5 wt%) of 3-glycidoxypropyltrimethoxysilane (GPTMS) functionalized zirconium phosphate (ZrP) to obtain respective composites blended coatings. The thermal stability of composites was studied by thermogravimetric analysis (TGA). In order to ascertain their hydrophobic behavior the water contact angle studies were carried out and the values obtained for 0.5, 1, 1.5, 2.0 and 2.5 wt% GPTMS functionalized ZrP reinforced (50/50 wt% of C-ima/BF-ima) benzoxazines blended composites are 114,116,117,119,120 and 123 degrees respectively. The UV shielding behavior of ZrP reinforced polybenzoxazine blended composites material was also studied by UV-Vis spectroscopic technique and the results obtained infer that these materials possess good UV shielding behavior. ZrP reinforced benzoxazine blended composites were coated on the mild steel specimens and their corrosion resisting behavior was studied. Results of Nyquist plot and Tafel plot, ascertain that among the coated specimens, the specimen coated with 2.5 wt% ZrP reinforced poly(C-ima/BF-ima) blended composites exhibits highest corrosion resisting efficiency.

Automated summary

The present work focuses on developing and characterizing benzoxazines for corrosion resistance applications. Blends of benzoxazines were reinforced with functionalized zirconium phosphate and their thermal stability, hydrophobic behavior, UV shielding behavior, and corrosion resistance were evaluated. Results showed that the benzoxazine blends exhibited good thermal stability, hydrophobicity, and UV shielding behavior. The specimen coated with 2.5 wt% functionalized zirconium phosphate showed the highest corrosion resistance.