Epoxy‐based PANI/zinc oxide/glass fiber nanocomposite coating for corrosion protection of carbon steel

Abstract

In this work, a nanocomposite based on conductive polyaniline (PANI) was polymerized, via reverse microemulsion polymerization, in the presence of phosphoric acid and dodecylbenzenesulfonic acid. Applied simultaneously, these acids act as dopants, increasing the solubility of PANI in organic solvents. They further improve the corrosion protection performance of PANI by forming phosphate‐metal complex on metal surface. Zinc oxide nanoparticles were added to the PANI mixture before introducing ammonium persulfate. The final product of polymerization was added to an epoxy resin which served as the matrix for the coating. In order to improve coating elasticity, which can enhance coating resistance against impacts, E‐glass fiber (GF) was added to the coating formulation. It was observed that, with an optimized w/w%, the PANI/zinc oxide/GF composite improved the coating characteristics. Coatings were further subjected to stress‐strain and DC polarization tests, and their cross‐sections were investigated at break point by means of SEM. DC polarization plots revealed that the addition of zinc oxide can also shift the corrosion potential of steel toward positive potentials.

Investigation of Alumina-Doped Prunus domestica Gum Grafted Polyaniline Epoxy Resin for Corrosion Protection Coatings for Mild Steel and Stainless Steel

“…The pristine epoxy coating on MS also shows an inhibition efficiency of 89.3%. Incorporation of the PDG-g-PANI/Al 2 O 3 composite into the epoxy coating inhibits the surface of MS by two simultaneous effects: (1) the inorganic Al 2 O 3 particles in polymer coating provides a physical barrier for the corrosive environment from reaching the metal surface by filling the nanopores and micropores in the coating [ 32 , 33 ]; (2) the PDG-g-PANI matrix enhances the corrosion protection of epoxy coating due to its electrical conductivity and the formation of a strong protective oxide layer on the MS surface [ 34 ]. The lowest current density and inhibition efficiency of 99.9% indicates that the presence of Al 2 O 3 has a great impact on epoxy/composite coating.…”

Positive effect of the addition of polyaniline on the anticorrosive property of polyethersulfone two‐layer composite coating

“…In addition, after contacting with the metal, the PANI will switch between the oxidation state and the reducing state, so as to protect the metal matrix. After the PANI has come into contact with the corrosive medium and the metal substrate, a passivation film will be formed on the metal surface to realize the secondary protection of the metal 30,31 . Situ et al investigated the positive effect of adding PANI‐TiN nanocomposites to epoxy coatings on long‐term corrosion resistance 32 .…”

“…After the PANI has come into contact with the corrosive medium and the metal substrate, a passivation film will be formed on the metal surface to realize the secondary protection of the metal. 30,31 Situ et al investigated the positive effect of adding PANI-TiN nanocomposites to epoxy coatings on long-term corrosion resistance. 32 The results indicated that the PANI-TiN/epoxy composite coating exhibited the better corrosion resistant performance.…”

Studies on coatings containing nano‐zinc oxide for steel protection

“…In addition, epoxy coatings exhibit poor abrasion and wear resistance, as well as crack resistance. [5][6][7][8][9][10] Nanoparticles (NPs) as coatings additives have been shown to improve material's thermal stability, scratch as well as corrosion and abrasion resistance. [11][12][13][14][15][16] Several studies [17][18][19][20] have been conducted on PU coatings containing Nano-ZnO on mild steel panels using different techniques such as water spray-drying cycles during exposure to ultraviolet radiation, visual comparison of photographic reference, and dynamic mechanical thermal analysis.…”