| Abstract: | Investigation into the passivation effect of organic oxidizing agents on the corrosion of iron in neutral weakly acid solutions. 2nd communication: Aromatic nitrocompounds The present communication is con cerned with the corrosion inhibiting properties of aromatic nitro compounds on iron in the neutral range. Nitrobenzenes (m-nitroaniline, p-chloronitrobenzene, M-nitrobenzoic acid, ethylester, p-nitrobenzaldehyde, p-nitrobenzonitrile) in concentrations between 0,25 · 10?2 and 0.5 · 1?2 Mole/litre act as stimulators in airsaturated 20% methanol of pH 6.8. Their combination with a 20% methanolic boric acid/borate solution of pH 6.8 – which, as such, only maintains passivity, yields passivating systems. From these examples as well as from others involving known inhibitors it appears highly probable that the prassivation of iron by corrosion inhibiting addition in the neutral range, too, requires a communication of oxidizing and non-oxidizing agents (combination principle )able to lower the critical passivation current density. |
