Corrosion Resistance of Mild Steel Coated with Phthalimide-Functionalized Polybenzoxazines

Abstract

Herein, we synthesized two new phthalimide-functionalized benzoxazine monomers, pPP-BZ and oPP-BZ, through Mannich reactions of 2-(4-hydroxyphenyl)isoindoline-1,3-dione (pPP) and 2-(2-hydroxyphenyl)isoindoline-1,3-dione (oPP), respectively, with p-toluidine and paraformaldehyde. The structures of these two monomers were confirmed using Fourier transform infrared (FTIR) and nuclear magnetic resonance spectroscopy. We used differential scanning calorimetry, FTIR spectroscopy, and thermogravimetric analysis to study the polymerization behavior and thermal stability of the monomers and their corresponding polybenzoxazines. Poly(pPP-BZ) and poly(oPP-BZ) were formed on mild steel (MS) through spin-coating and subsequent thermal curing polymerization. We used various corrosion testing methods to examine the effect of the curing temperature on the corrosion resistance of the coated MS samples in 3.5 wt.% aqueous solution of NaCl. Among our tested systems, the corrosion rate reached a low of 2.78 µm·Y−1 for the MS coated with poly(pPP-BZ)180 (i.e., the coating that had been cured at 180 °C); this value is much lower than that (4.8 µm·Y−1) reported for a maleimide-based benzoxazine compound (MI-Bz)/33 wt.% ACAT (amine-capped aniline trimer) blend. Thus, the incorporation of the imide functional group into the PBZ coatings is an effective strategy for affording high-performance corrosion resistance.

Evaluation of synthesized polyaniline nanofibres as corrosion protection film coating on copper substrate by electrophoretic deposition

“…Colloidal suspension of PANI was then prepared by dissolving 35 ml of the stock solution into 15 ml of acetonitrile to obtain 50 mg/mL. The mixture was sonicated for 5 min to fully dispersed the PANI colloids [22] Sample preparation for EPD A copper sheet of 99% purity that is 1 mm thick was purchased from a local market in Alexandria, Egypt. The sheets were cut at 4 cm 9 1 cm, length by width, respectively.…”

“…For instance, the high performance of anti-corrosion of nanocomposites coatings of benzoxazine monomer could be assigned to the modified nano-clay, leading to improved properties of the barrier as a result of decreasing coatings permeability for water and oxygen species [21]. The amide functional group incorporation into the coatings of polybenzoxazine was found to be the effective approach for obtaining high-performance corrosion protection [22]. The addition of 3.0 wt% nano-clay and 20 wt% epoxidized soybean oil reduced the rate of corrosion by an order of one magnitude (2.653 9 10 -3 mm year -1 ) in comparison with the pure poly-cyclohexane functionalized polybenzexozine (1.292 9 10 -2 mm year -1 ) in an order of two magnitudes when compared to bare mild steel (1.094 9 10 -1 mm year -1 ) with a resistance efficiency of 98.16%, which remarkably reveals increment in the properties of the barrier of the composite coatings about the corrosive species [23].…”

Low Temperature Curable Polyaniline/Bio-based polybenzoxazine Coated Cotton Fabric with Superior UV shielding and Oil-water Separation behaviours

“…% PANI, only Tg value as high as 143.5 ºC(Table 1). This phenomenon could be attributed to the (i) inherent exible network of PANI as well as (ii) intercalation of PANI in between the polybenzoxazine matrices [55].In general, polybenzoxazine are widely used as coating material to avoid corrosion due to their superior hydrophobicity [56,57]. Hence, in the present work to verify the real time utility of PANI/poly(C-ddm) the samples were coated over cotton fabric and subsequently studied for UV shielding and surface properties along with oil-water separation behaviour.…”

Microporous Carbon and Carbon/Metal Composite Materials Derived from Bio-Benzoxazine-Linked Precursor for CO2 Capture and Energy Storage Applications

“…Nevertheless, the application of PBZ materials has been restricted industrially because the ROP of BZ resins to afford PBZs generally occurs at temperatures between 220 and 280 °C [ 10 , 11 , 12 , 13 , 14 ]. As a result, lowering the exothermic curing temperatures of BZ precursors has become desirable to encourage the use of these materials in industrial applications and academic settings [ 1 , 2 , 3 , 4 , 5 ].…”