Mono- and dicationic benzothiazolic quaternary ammonium bromides as mild steel corrosion inhibitors. Part III: Influence of the temperature on the inhibition process

• Seven benzothiazolic ammonium bromides were investigated at high temperature.
• The impedance data were described using two structure models.
• The activation energy in 1 M HCl and the inhibitor efficiency were determined.

The influence of the temperature on the inhibitive properties of seven mono- and dicationic quaternary ammonium bromides on mild steel was investigated in 1 M HCl and 1 M H2SO4. Impedance, polarisation resistance and polarisation curves methods were used. Two adequate structural models of the interface metal/1 M HCl + inhibitor were proposed to describe the processes in different temperature ranges. The values of the models’ parameters were determined. The influence of the temperature on the inhibitor efficiency was studied as well. The apparent activation energy was found using two independent methods. Conclusions were made about the inhibitors’ adsorption type.