ORGANIC CORROSION-INHIBITORS IN NEUTRAL SOLUTIONS .1. INHIBITION OF STEEL, COPPER, AND ALUMINUM BY STRAIGHT-CHAIN CARBOXYLATES

Electrochemical methods were used in a systematic investigation of the abilities of the homologous straight chain mono- and alpha,omega-dica rboxylates to inhibit corrosion of mild steel, copper, and aluminum in aerated, mildly saline, and near-neutral aqueous solutions. Performan ce of both compound types was shown to be critically dependent upon th eir chain length the metal and the number of carboxylate groups. For d icarboxylates, with the possible exception of mild steel, longer chain lengths were found advantageous, This was not true for monocarboxylat es, which showed abrupt decreases in inhibitor ability outside the opt imal range. The dramatic variations in inhibitor efficiencies probably resulted from competing reactions, such as adsorption and complexatio n at the metal (hydr/oxide) surface, solubility, and micelle formation .