Studies Of N-Containing Corrosion Inhibitors In Acidic Solution

Abstract

The purpose of the research presented in this thesis was to investigate the functionality of dodecyltrimethylammonium chloride (DDTMAC) and dodecyltrimethylammonium bromide (DDTMAB) as corrosion inhibitors of 0.08% C-steel and high purity iron in hydrochloric acid (HCl) and hydrobromic acid, respectively. Furthermore, the performance of DDTMAC was compared to a commercial analogue (ARQUAD C-35), formulated by AkzoNobel, to determine if there are any significant differences. For this work electrochemical techniques were applied in combination with interface and solution analysis.Linear polarization resistance (LPR) and potentiodynamic polarisation (PDP) results demonstrate that both DDTMAC and DDTMAB are effective mixed-type corrosion inhibitors in the environments of interest, i.e. 1 HCl/HBr at room temperature. Moreover, it was found that they achieve optimal performance well below their critical micelle concentrations (CMC) in these media, suggesting that a significant surface coverage is already achieved in this regime. Both electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) results support this conclusion, with the latter suggesting that the interfacial layer is comprised of both cationic and anionic components (i.e. primarily, DDMA+ and Cl-/Br-).Concerning the comparison between DDTMAC and ARQUAD C-35, their corrosion inhibition performance was determined to be very similar.

Date of Award	1 Aug 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Rob Lindsay (Supervisor) & Stuart Lyon (Supervisor)