钢板电镀锌表面聚苯胺膜硅烷改性的研究

STUDY OF SILANE MODIFIED POLYANILINE COATINGS ELECTROPOLYMERIZED ON ZINC-ELECTROPLATED STEEL SHEET

在加入硅烷偶联剂γ-APS的苯胺中性溶液中采用恒电流法在电镀锌钢板上制备聚苯胺膜,采用SEM观测其表面形貌,测试不同条件下聚合膜的厚度．交流阻抗和盐雾实验表明,加入γ-APS后,聚苯胺膜层的致密性和防护性明显提高,接近铬酸盐钝化膜．通过XPS分析,得到γ-APS改性聚笨胺膜掺杂度为11%、氧化度为64%;与改性前聚苯胺膜相比较,掺杂度降低、氧化度增高．结合红外光谱和XPS分析,发现聚苯胺膜中仔在4种化学环境:C-Si-O-Si,C-Si-OH,C-Si-O-C, C-Si-O-Zn．

The effects of silane on the formation of polyaniline coatings electropolymerized on zinc-electroplated steel sheet have been investigated by chronopotentiometry technique. The morphol- ogy and thickness of polyaniline coatings are measured by SEM. Corrosion behaviors of chromating films and polyaniline coatings in 3.5% NaCl solution are studied by salt spray test and electrochemical impedance spectroscopy （EIS） method. Experimental results show that the anticorrosion properties of polyaniline coatings are close to that of chromating film because of its good shielding and inhibiting properties. From the FTIR and XPS data, the following conclusions can be obtained： （1） The doping level for the polyaniline films modified by γ-APS is increased and the oxidation level is reduced comparing with polyaniline films without modification, which are 11% and 64% respectively;（2）There are four chemical environment： C-Si-O-Si. C-Si-OH. C-Si-O-C, C-Si-O-Zn.