Tertiary Amine Methacrylate based Polymers as Corrosion Inhibitors in HCl Solution. Part II

Abstract

In this study, the inhibitive performance of novel synthesised water-soluble of different molecular weight diblock copolymers of derivative methyl methacrylate (VB84, VB206, VB207, VB361, VB371,VB406) on the corrosion behavior of AISI 304 stainless steel in 10^–3 M HCl containing various concentrations of polymers was investigated using potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), scanning electron microscopy(SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and inductively coupled plasma optical emmision spectrometry (ICP-OES) methods. Polarisation curves indicated that all studied polymers were acting as mixed type inhibitors. All electrochemical measurements showed that inhibition efficiencies increased with increasing polymer concentration. It was determined that the increase of inhibitor efficiency by concentration resulted from the adsorption of polymers to metal surface, and the adsorption fitted to the Langmuir adsorption equation. The variation in inhibitive efficiency mainly depends on the type and the nature of the substituents present in the polymer molecule and also depends on the molecular weight of the polymer. The best inhibition in 10^-3 M HCl shows VB84 homopolymer. Surface images obtained with SEM, EDX, and AFM methods determined by verifying these results that inhibitors decrease the dissolution of metal, prevented the corrosion.