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

Physicochemical characteristics and inhibition effect of curcumin-based Schiff bases on industrially important mild steel corrosion in acidic medium

Ashwini Narayanswamy, Dileep Ramakrishna, and Ranganatha Sudhakar

Department of Chemistry, Presidency University, Rajanakunte, Bengaluru, India

E-mail: kamath.ranganath@gmail.com

Received: 20 September 2024  Accepted: 30 October 2024

Abstract:

The curcumin-based Schiff bases p-Nitro[(Curcumin)]-aniline (PNCA), p-Bromo[(Curcumin)]-aniline (PBCA) have been synthesized and evaluated in 1 M HCl for the effectiveness of its corrosion prevention on industrially important mild steel (MS). Gravimetric measurements along with electrochemical investigations such as potentiodynamic polarization and electrochemical impedance spectroscopy show the inhibition performance of the synthesized molecules on MS. Obeying Langmuir adsorption isotherm, these molecules inhibit corrosion with mixed type of mechanism. When the concentration of the inhibitor rises, so does the molecules (PNCA, PBCA) protection ability, which falls as the temperature rises. PNCA and PBCA molecules exhibit corrosion inhibition efficiency of 96.7% and 99%, respectively, as obtained from gravimetric experiments at 50 µM concentration proving their superior character. Quantum chemical studies were performed, and the parameters thus obtained were used to determine the correlation between (PNCA), (PBCA), molecular structure and inhibition effect.

Keywords: Mild steel; Corrosion inhibitor; Acid corrosion; Polarization; Electrochemical impedance spectroscopy (EIS)

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03783-x

Chemical Papers 79 (1) 333–352 (2025)