Sumitesh Das

Anticorrosive and lubricating polyphenol coatings on galvanneal steel

Phosphate ion containing acidic polyphenol coating solutions were developed as to mitigate the deleterious effect of corrosion on galvannealed iron surface. The influence of manganese sulphate, manganese phosphate and polyethylene wax in polyphenol coatings were investigated to reduce the powdering of complex-shaped galvannealed structures and corrosion effect. Moreover, the reactivity of coating at the surface was evaluated by glow discharge optical emission spectroscopy, scanning electron microscopy and energy dispersive spectroscopy. Low surface integration within 3.5% NaCl environment and frictional behaviour was achieved with 0.5% manganese phosphate in polyphenol coated coupon by electrochemical and mechanical testing respectively.

Significance of formed adherent complex by use of phosphorylated polyphenol coating

Purpose n n n n nThe purpose of this paper is to report on the use of phosphorylated polyphenol (PP)-coated galvanised iron (GI) surface to study the degradation of coating with different time intervals and long-term exposure in different salty media. n n n n nDesign/methodology/approach n n n n nThe as-obtained PP complex on GI was evident by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The coated coupons were exposed to different salty media such as 3.5 per cent NaCl, 1.5 per cent Na2SO4 and tap water at set time intervals. Electrochemical polarisation was performed to study the anodic and cathodic polarisation behaviour at each time interval. n n n n nFindings n n n n nThe adherent foliolate nanopattern of iron zinc phosphate and zinc dihydrogen phosphate on GI surface was evident by SEM, FT-IR, EDS and XRD. The coated coupons exhibited good corrosion resistance. This coating performs as an alternative to time-consuming multistep operations of phosphating treatment. n n n n nOriginality/value n n n n nThe mode of the experiment treatment using modified PP coating especially on GI in different corrosive exposures at set time intervals is a novel approach in this research.