Synthesis of waterborne nanopolyanilne latexes and application of nanopolyaniline particles in epoxy paint formulation for smart corrosion resistivity of carbon steel

Abstract

Polyaniline (PANI) latexes were synthesized by emulsion polymerization using dodecyl benzene sulfonic acid (DBSA) and sodium dodecyl sulfate (SDS) as a surfactant. Synthesized PANI–DBSA and PANI–SDS latexes were characterized by IR and UV‐visible spectroscopies, and surface morphology was analyzed by transmission electron microscopy. The PANI–DBSA were found to be nanograin shaped whereas PANI–SDS were as nanofibers. In the second stage rheological properties of waterborne PANI latexes were characterized by viscosity measurement and their dispersion stability in water. The surface morphology of the coating was examined by scanning electron microscope (SEM). The anti‐corrosion performance of uncoated carbon steel, PANI–DBSA and PANI–SDS coated carbon steel was evaluated by tafel slope analysis and immersion test studies of 0.5, 1, and 1.5% PANI/Epoxy coatings were done in 5% NaCl aqueous solution. The results indicated that the nanoPANI in epoxy coating might work as an adhesion promoter and corrosion inhibitor. The waterborne latexes, thus, were found to be highly suitable and avoid the use of organic solvents or strong acids under environmentally benign conditions. Copyright © 2010 John Wiley & Sons, Ltd.

Controlling the Morphology of Poly(N-cyanoethylpyrrole)

“…For example, CPs, including PPy derivatives, have been successfully used as anticorrosive additives in the formulation of organic coatings (i.e., essentially epoxy and alkyd paints), − imparting corrosion protection to metal substrates when they are well dispersed in the resin. Furthermore, in very recent studies, micro- and nanoparticles of polyaniline, a well-known CP, were used to promote the corrosion protection imparted by epoxy paints . Future studies investigating the potential applications proposed for PNCPy microspheres may allow one not only to expand but also to complement the range of applications covered by this CP.…”

“…Furthermore, in very recent studies, micro-and nanoparticles of polyaniline, a well-known CP, were used to promote the corrosion protection imparted by epoxy paints. 49 Future studies investigating the potential applications proposed for PNCPy microspheres may allow one not only to expand but also to complement the range of applications covered by this CP. Thus, such applications would depend on the morphology that in turn is controlled through the polymerization procedure.…”

Synthesis and characterization of phenol–formaldehyde microcapsules containing linseed oil and its use in epoxy for self‐healing and anticorrosive coating

“…The self‐healing anticorrosion function of this coating system was evaluated through immersion studies of damaged and healed microcapsules coated steel samples by comparing with steel samples without microcapsules. Damage was induced by hand scribing using a razor blade, and, after the scribing, the samples were allowed to heal at room temperature for 24 h. Immersion studies of these coatings were carried out with home‐made equipment 20. The samples were tested for a total exposure time of 72 h. The corrosion of the damaged area was monitored by visual inspection using digital camera (Olympus FE‐25).…”

Recent progress in the preparation of polyaniline nanostructures and their applications in anticorrosive coatings

“…In addition to increased corrosion resistance, epoxy-PANI composites improved other unique properties such as thermal, mechanical and conductivity properties. 99,100 For example, PANI can act as a curing agent for epoxy resin with covalent bonds formed between the amine groups of PANI and the epoxy groups of epoxy resin; the heat to cure increases as PANI loading increases. 101 Electrical conductivity of the epoxy-PANI nanocomposites has been achieved by increasing the loading 102 or decreasing the size 98 of PANI, and the morphology effect was studied by Zhang et al 103 For the conductivity study, at the same loading level, volume resistivity in epoxy nano-composites with PANI nanobers was lower than that in epoxy nano-composites with PANI nanospheres.…”