ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A comprehensive study of mild steel corrosion in the aggressive acidic environment using CMPPC, a substituted pyrazole derivative

Asha Thomas, P. Rugmini Ammal, and Abraham Joseph

Department of Chemistry, University of Calicut, Calicut University P O, Kozhikode, India

E-mail: drabrahamj@gmail.com

Received: 4 December 2019  Accepted: 18 March 2020

Abstract:

CMPPC, 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde was synthesised from 3-methyl-1-phenyl-5-pyrazolone, and its corrosion protection properties for mild steel in HCl were studied using mass loss studies, impedance spectroscopy, polarisation studies, adsorption studies and basic quantum chemical calculations. The protection efficiency decreases with an increase in temperature and acid concentration but increases with an increase in the concentration of the inhibitor. Electroanalytical screening reveals that the molecule behaves like a mixed-type inhibitor. CMPPC adsorbs on the metal surface, and the phenomenon obeys Langmuir adsorption isotherm pattern. Various kinetic and thermodynamic parameters are calculated using Arrhenius and Van’t Hoff approaches. Molecular dynamics simulations are employed using computational chemistry protocols. The results indicate that the CMPPC offers maximum interaction on Fe(111) plane of the metal surface.

Keywords: CMPPC; Corrosion inhibition; EIS; PDP; Adsorption; Molecular dynamics

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01142-0

Chemical Papers 74 (9) 3025–3037 (2020)