某些杂环化合物对青铜的缓蚀作用

Studies on some heterocyclic compounds as corrosion inhibitors of bronze

通过极化曲线法、失重法和气体加速腐蚀法研究了咪唑（ＩＡ）、苯并咪唑（ＢＩＡ）、巯基苯并四氮唑（ＰＭＴＡ）、苯并三氮唑（ＢＴＡ）、巯基苯并噻唑（ＭＢＴ）等五种缓蚀剂对青铜的缓蚀作用．实验发现，ＭＢＴ的效果最好．在５０℃、３．５％ＮａＣｌ溶液加速腐蚀条件下，在缓蚀剂浓度为１０－２ｍｏｌ·Ｌ－１时，ＭＢＴ的缓蚀效率为９９．１％，而ＢＴＡ的缓蚀效率为９２．４％．经ＭＢＴ处理后的青铜样块，色泽无明显变化，且有一定的耐酸碱能力．复合缓蚀剂［（ＭＢＴ＋ＢＴＡ）或（ＭＢＴ＋ＰＭＴＡ）］在低浓度时比单一缓蚀剂的效果好．红外光谱表明，铜与杂环上有孤对电子的硫、巯基上的硫及氮配位．铜与ＭＢＴ可能形成面型配合物膜，其成膜速度及覆盖度均较ＢＴＡ为大．

The inhibition efficiency of various corrosion inhibitors,imidazole (IA),benzoimidazole (BIA), 1-phenyl-5-mercapto-tetrazole (PMTA), benzotriazole (BTA) and 2-mercapto-benzothiazole (MBT) etc,for bronze have been investigated by means of polarzation curve method,weightloss test and corrosion acceleration method with SO2. The results show that in relatively low concentration (10-2 mol·L-1),the inhibition efficiency of MBT is the best,about 99.1 %,that of BTA is only 92. 4%. The mixture of MBT and BTA or of MBT and PMTA has synergistic effect. IR spectra indicate that copper may be coordinate with N,S atoms having lone pair electrons in heterocycle and mercapto of MBT. Copper and MBT may form a two dimensions coordinate compound film. The forming film rate and coverage of MBT in bronze surface is better than that of BTA.