聚吡咯的电化学合成及其对不锈钢的保护作用

ELECTROSYNTHESIS OF POLYPYRROLE AND CORROSION PROTECTION FOR STAINLESS STEEL

根据聚吡咯(Ppy)的电化学自催化聚合特性,采用两步法在1Cr18Ni9不锈钢和Pt表面合成了导电高分子Ppy膜,研究其的氧化还原特性和不锈钢/Ppy在3.5%NaCl溶液中的腐蚀电化学行为。结果表明,Ppy有两个还原过程,分别对应于阴离子脱掺杂与阳离子嵌入,其氧化掺杂电位具有上限值。Ppy膜可使不锈钢表面形成致密的氧化膜,从而降低腐蚀速度,有效抑制不锈钢腐蚀。

A two-step electrosynthesis of polypyrrole film （Ppy） on 1Cr18Ni9 stainless steel and Pt substrates was performed based on the self-catalysed property of Ppy synthesis, and smooth conductive polymer film was obtained. The redox character of Ppy and corrosion behavior of stainless steel protected by Ppy film in 3.5% NaCl solution were investigated.Results show that the reduction of Ppy contains two processions including anion dedopping and cation insertion, and that reversible oxidation （doping） can only occur at low potential. It is confirmed that stainless steel corrosion can be inhibited effectively by Ppy film and the physical barrier is not the major factor of corrosion protection.It is possible that Ppy coating has a catalytic effect on passivation of metal with protective oxide layer, and corrosion could be inhibited.