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本工作研究和比较了苯并噻唑与2-巯基苯并噻唑在 HCl 溶液中对碳钢腐蚀的缓蚀行为。以探讨巯基(-SH)的作用。结果表明,巯基的引入明显地改善了苯并噻唑的缓蚀性能。这种作用主要是通过提高苯并噻唑的表面活性而达到的。琉基的引入并没有改变苯并噻唑的吸附规律和在碳钢电极上的排列方式。极化曲线的结果表明,二者都是以抑制阳极过程为主的混合型缓蚀剂。但是,巯基的引入明显地增加了苯并噻唑对碳钢腐蚀的阴极过程的抑制能力。

The inhibiting effect of benzothiazole(BT)and 2-mereaptobenzothiazole (MBT)and the effect of -SH group in this respect on the corrosion of a car- bon steel in HCl solutions at various concentrations and temperatures were investigated.It is shown that the inhibiting effect of MBT is much more pro- nounced than that of BT due to increased surface activity of BT raised by -SH group.Langmiur isotherm equation is observed by both compounds ad- sorbed on steel surface when their concentrations in HCl solutions are not very high.The values of the equilibrium constant B of the adsorption process were determined at θ=0.5.It was found the value of B for MBT (10~5 is of one order of magnitude higher than that for BT(10~4).Impedance measure- ments showed that for both compounds the data of electrode boundary capa- citance which vary with the value of θ fall on the same straight line,and the same value of boundary capacitance (14μF/cm~2)was obtained by extra- polating the experimental data to θ=1.These facts imply that there are no changes in the characteristics of adsorption and the mode of arrangements of the molecules adsorbed on the electrode surface when the -SH group is intro- duced onto the BT.Polarization measurements indicated that both inhibitors belong to the mixed type with predominant anodic control.However,the inhibitive action to the cathodic reaction of the corrosion process is some- what strengthened by introducing the -SH group onto BT molecules.