Evaluation of corrosion inhibition performance of phosphorus polymer for carbon steel in [1 M] HCl: Computational studies (DFT, MC and MD simulations)

TLDR

PGEPBAP forms a protective film on carbon steel by adsorption following the Langmuir isotherm. The study employed PDP, EIS, WL, SEM, and computational methods (DFT, ESP, RDF, MD, MC) to investigate PGEPBAP’s inhibition mechanism on carbon steel. PGEPBAP achieved inhibition efficiencies of 94.18 % (PDP), 91.79 % (EIS), and 91.3 % (WL) at 10⁻³ M, with a ΔE_corr of 23.7 mV indicating a mixed‑type inhibitor and SEM showing effective chemisorption blocking acid attack.

Abstract

Pentaglycidyl ether pentabisphenol A of phosphorus (PGEPBAP) phosphorus polymer was investigated as corrosion inhibition for carbon steel in aggressive solution using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), weight loss (WL), scanning electron microscope (SEM), density functional theory (DFT), electrostatic potential (ESP), radial distribution function (RDF), molecular dynamics (MD) and Monte Carlo (MC) simulations. The higher inhibition efficiencies for PDP, EIS and WL studies at 10−3 M concentration of PGEPBA phosphorus polymer are 94.18 %, 91.79 % and 91.3 %, respectively. ΔEcorr (23.7 mV) value of PGEPBAP phosphorus polymer is lower than 85 mV has been assigned to mixed type inhibitor. PGEPBAP formed protective film on carbon steel surface by adsorption according to Langmuir adsorption isotherm. SEM morphology suggested that PGEPBAP could effectively block acid attack by chemisorption on metal surface. To evaluate the polymer inhibitor and potential mechanism were especially realized DFT, ESP, RDF, MD and MC simulations.