电聚合聚吡咯双层复合涂层对不锈钢的防腐蚀研究

Study on the Anticorrosion Performance of the Electropolymerized Bilayer Polypyrrole Composite Coatings for Stainless Steel

为了提高不锈钢材料在酸性环境中的耐腐蚀性,通过电聚合技术于304不锈钢基体上沉积内层掺杂磷钼酸、外层掺杂樟脑磺酸的导电性聚吡咯复合防腐蚀涂层(PPY-PMA/PPY-CSA),通过FT-IR、SEM、EDX、电化学性能测试等手段探讨了其与单层磷钼酸掺杂的聚吡咯涂层(PPY-PMA)之间的组成、结构、形貌和防腐蚀性能的差异。结果表明:PPY-PMA/PPY-CSA复合涂层附着力强,结构更为致密,在0.3 mol/L的H2SO4溶液中,PPY-PMA/PPY-CSA复合涂层可通过内、外层涂层的相互作用及缓蚀剂的释放为304不锈钢提供优异的防腐蚀作用。在288 h服役期间内,PPY-PMA/PPY-CSA复合涂层未出现退化现象,相对于PPY-PMA涂层防腐蚀性能更为稳定。

In order to improve the corrosion resistance of stainless steel material in acidic environment,a conductive polypyrrole composite coatings which was composed of an inner polypyrrole layer doped with phosphomolybdic acid(PPY-PMA)and an outer polypyrrole layer doped with camphorsulfonic acid(PPY-CSA)was prepared by electropolymerization on 304 stainless steel(304SS).The differences in composition,structure,morphology and anticorrosion performance between the bilayer composite coatings(PPY-PMA/PPY-CSA)and the single layer phosphomolybdic acid doped polypyrrole coating(PPY-PMA)were explored by means of FT-IR,SEM,EDX and the electrochemical tests.The results indicated that the PPY-PMA/PPY-CSA composite coatings displayed more compact structure and better adhesion,and exhibited satisfactory corrosion protection ability for 304 SS in 0.3 mol/L H2SO4 solution due to the interaction between the inner and outer PPY layers,as well as the release of corrosion inhibitors.During the 288h of service time,the PPY-PMA/PPY-CSA composite coatings showed no degradation and was more stable than the single layer PPY-PMA coatings.