Poly(vinyl alcohol–proline) as corrosion inhibitor for mild steel in 1M hydrochloric acid

A. Ali Fathima Sabirneeza,S. Subhashini

doi:10.1007/s40090-014-0022-8

A. Ali Fathima Sabirneeza, S. Subhashini

Open Access

https://doi.org/10.1007/s40090-014-0022-8

Copy DOI

Abstract

Corrosion inhibitive behavior of newly synthesized water soluble semiconducting polymer composite poly(vinyl alcohol–proline) (PVAP) is focused in this article. The polymer was characterized by FTIR, SEM-EDX, and XRD techniques. Thermogravimetry and differential thermal analysis proved the thermal stability of PVAP. Gravimetry and electrochemical techniques were employed to study the corrosion inhibition performance of PVAP on mild steel in molar hydrochloric acid. 0.6 % (wt.) of PVAP provides a maximum inhibition efficiency of 94 % at 303 K. The role of concentration of PVAP, exposure time and solution temperature on the mild steel corrosion has been investigated. The polarization results showed that PVAP acts as mixed-type inhibitor and could serve as an effective corrosion inhibitor for mild steel in acid medium. Surface morphology of the mild steel specimen by FTIR spectroscopy proved the formation of polymer film.

Highlights

Steels are the most important engineering materials and cover a wide range of alloys based on iron and carbon
The polarization results showed that poly(vinyl alcohol–proline) (PVAP) acts as mixed-type inhibitor and could serve as an effective corrosion inhibitor for mild steel in acid medium
In our previous communications polyvinyl alcohol was composited with various amino acids like leucine, histidine, threonine, and cysteine which are reported to have more than 92 % inhibition efficiency in 1M HCl [15,16,17]

Summary

Introduction

Steels are the most important engineering materials and cover a wide range of alloys based on iron and carbon. The corrosion rate surface coverage and inhibition efficiency of PVAP were calculated from the monitoring parameter using the standard relations as explained in our previous communications [15, 16]. Corrosion potential (Ecorr), corrosion current density (Icorr) and Tafel slopes (bc and ba) for the corrosion of mild steel in 1M HCl containing different concentrations of PVAP are summarized in Table 2 along with the calculated inhibition efficiencies (IEIcorr) of PVAP.

Results

Conclusion