A corrosion inhibition study of iron by phosphonic acids in sodium chloride solution
A corrosion inhibition study of iron by phosphonic acids in sodium chloride solution
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DOI：
10.1016/s0022-0728(03)00388-7
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发表时间：
2003-10-30
影响因子：
4.5
通讯作者：
Moreau, B
中科院分区：
文献类型：
--
作者：
Amar, H;Benzakour, J;Moreau, B
采用电化学测量方法研究了一类新型缓蚀剂胡椒碱-1-酰基膦酸（PPA）和（4-膦-胡椒碱-1-酰基）膦酸（PPPA）对NaCl介质中铁的腐蚀作用。动电位极化研究清楚地揭示了抑制剂的类型。随着磷酸浓度的增加，点蚀电位（E-pit）向正方向移动，表明添加的磷酸对点蚀的抑制作用。腐蚀电位向负值移动，腐蚀电流减小。PPA和PPPA存在时，电流值较低。这可以用电极的大部分表面被吸附的分子所覆盖的事实来解释。PPPA对氯化物点蚀具有较强的抑制作用，似乎是在PPA对位上加入NCH2PO3H基团（中心吸附），给予PPPA，强化了该分子的活性位点，从而提高了其缓蚀效率。(C) 2003 Elsevier B.V.版权所有
The effect of a new class of corrosion inhibitors, namely piperidin-1-yl-phosphonic acid (PPA) and (4-phosphono-piperazin-1-yl) phosphonic acid (PPPA) on the corrosion of iron in NaCl medium has been investigated by electrochemical measurements. Potentiodynamic polarization studies clearly reveal the type of the inhibitor. The addition of increasing concentrations of phosphonic acids causes a shift of the pitting potential (E-pit) in the positive direction, indicating the inhibitive effect of the added phosphonic acid on the pitting attack. The potential of corrosion is moved towards negative values and the corrosion current is reduced. The values of the current are lower in the presence of PPA and PPPA. This is explained by the fact that most of the surface of the electrode is covered by the molecules adsorbed. PPPA has a strongly inhibitive effect on chloride pitting corrosion, it seems that the addition of the NCH2PO3H group (center adsorption) in the PPA para-position, giving PPPA, reinforces the active sites of this molecule and consequently increases its inhibition efficiency. (C) 2003 Elsevier B.V. All rights reserved.