Synthesis, Characterization, and Electrochemical Studies of Novel Biphenyl Based Compounds

Indolizine quaternary ammonium salt inhibitors, part III: insights into the highly effective low-toxicity acid corrosion inhibitor – synthesis and protection performance

Three indolizine derivatives (Di-BQC, QM-DiBQC, PyM-DiBQC) were prepared facilely in high yield via 1,3-dipolar cycloaddition. These compounds exhibit good inhibition for steel in concentrated acid without the synergism of propargyl alcohol (PA).

Gravimetric, electrochemical and surface studies on the anticorrosive properties of 1-(2-pyridyl)-2-thiourea and 2-(imidazol-2-yl)-pyridine for mild steel in hydrochloric acid

1-(2-Pyridyl)-2-thiourea and 2-(imidazol-2-yl)-pyridine are described here for the first time as inhibitors of mild steel corrosion in acidic medium.

Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers

Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H₂SO₄ medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.

Synthesized photo-cross-linking chalcones as novel corrosion inhibitors for mild steel in acidic medium: experimental, quantum chemical and Monte Carlo simulation studies

Three new chalcone derivatives were synthesized, characterized, investigated for photo-cross-linking characteristics, and used as corrosion inhibitors for mild steel in 1 M HCl using electrochemical, spectroscopic and theoretical methods.