Electrochemical studies of the inhibition of zinc corrosion in hydrochloric acid by phosphonium salts

The performance of five synthesised phosphonium salts, 4-tolyltriphenyl-phosphonium chloride (TTPPC), 4-phenoltriphenylphosphonium chloride (PTPPC), 4-anilinetriphenylphosphonium bromide (ATPPB), 4-benzyl alcoholtriphenylphosphonium chloride (BATPPC), 4-chlorophenyltriphenylphosphonium bromide (CPTPPB) and two commercially available phosphonium salts, tetraphenylphosphonium bromide (TPPB) and methyltriphenylphosphonium bromide (MTPPB) for the inhibition of zinc corrosion in 1 M HCl at 22 ºC has been quantified using electrochemical techniques. The inhibitor concentration ranged from 1*10-3 to 1*10-7 mol dm-3. The degree of corrosion inhibition for zinc in 1 M HCl at 22 ºC was found to be in the order: CPTPPB > TTPPC > TPPB > PTPPC > BATPPC > MTPPB > ATPPB