Poly(p-Phenylenediamine) as an Inhibitor for Mild Steel in Hydrochloric Acid Medium

Abstract

The corrosion behavior of mild steel (MS) in HCl solution containing various concentrations of electropolymerized P(p-phenylenediamine), P(pPD), has been investigated using weight loss and potentiodynamic polarization techniques. The data obtained from the two techniques are comparable and showed that the presence of P(pPD) in the acid solutions suppresses the corrosion rate of MS indicating that these polymers act as corrosion inhibitors (predominantly as anodic inhibitors). The inhibition efficiency (IE%) of the polymer enhances with increasing their concentrations and decrease with an increase in temperature. The inhibition occurs through adsorption and formation of barrier film on the metal surface which separates the metal from direct contact with the corrosive medium and hence protects the metal against the corrosion. The adsorption followed the Langmuir isotherm. The thermodynamic functions of the adsorption and dissolution processes were evaluated.

EDTA as a corrosion inhibitor for Al in 0.5 M HCl: adsorption, thermodynamic and theoretical study

“…These results reveal that EDTA acts as a mixed type inhibitor. The inhibition efficiency IE, at different inhibitor concentrations at 303 K for Al electrode in 0.5 M HCl solution was calculated from the Equation 1 [37][38][39]:…”

“…The significant difference shows reduce impact on the CR of Al in 0.5 M HCl. Both of the surface coverage () and the inhibition efficiency (IE) were calculated using mass loss data according to Equations 3 and 4, respectively [38]. where, w blank is the corrosion rate in the uninhibited environments.…”

Electrochemical Study of the Copolymer Formation Between o-Chlorophenol and o-Hydroxyphenol

“…7. The appearance of a band at 485 nm for π-polaron transition 41,42 in contrast to the spectra of PoCP and PoHP reveals that the copolymer is structurally different and also confirm its formation. This band is attributed to higher conjugation of the coplomer.…”

P(o-chlorophenol–co-o-hydroxyphenol): kinetic formation studies and pH-sensor application

“…The UV-Visible spectrum of P(o-HOPh -co-o-ClPh) shows that the π-π* transition ((E2 band) of the benzene ring and the -band (A1g to B2u)) appear at 257, 307 and 317 nm where the π-polaron transition (conjugation of the aromatic polymeric chain) appears at 485 nm [20,45,50]. This band doesn't appear at both homopolymers [19] which confirm the copolymer formation.…”