The Research Of Five Selected Triazole Compounds And Study On Their Inhibitory Behavior In Synthetic Seawater

Copper is an important metal material, it has excellent mechanical properties,good thermal and electrical conductivity and it is relatively stable in nature, so it iswidely used in industrial production. But in extreme environments, especially in thepresence of a large number of chloride ions, copper could occur serious corrosionphenomenon which might bring life and production huge losses and even disaster.Thus, copper corrosion is particularly important. There are a lot of measures for coppercorrosion now, of which the use of anti-corrosion inhibitors is a safer and moreefficient method, especially organic corrosion inhibitors.Triazole compounds is an important organic corrosion inhibitor, its basic structureis a five membered heterocyclic by substituting nitrogen atoms for the carbon atoms inthe imidazole ring, and many of their derivatives have a benzene ring, C-N unsaturatedbond and other groups, its special structure has a very strong complexing ability withmetal ions and a hydrogen bond-forming ability. Because of excellent corrosioninhibiting effect, triazole compound has become a hot research field of organiccorrosion inhibitors.In this article we selected five kinds of triazole compounds as corrosion inhibitorsselectively. In a3.5%NaCl solution (simulated seawater), taking adding corrosioninhibitors and not adding corrosion inhibitors samples as the research objects, weconducted a lot of experiments to study the effects of corrosion of the five kinds oftriazole compounds for copper by such experimental methods as weight loss,potentiodynamic polarization curves, electrochemical impedance spectroscopy,quantum chemistry at the different concentration or the same concentration butdifferent medium and pH. As well, the corrosion mechanism of these compounds werediscussed. The results are as follows:The compounds at different concentrations all play better corrosion inhibition forcopper, and inhibition efficiency increased with the concentrations increasing at firstand arrived at a maximum inhibition efficiency then decreased. Inhibition mechanismis that corrosion inhibitor can be effectively adsorbed on the copper surface, playing acorrosion protective role by forming a protective film on the copper surface, and theadsorption follows the Langmiur adsorption isotherm model. And the corrosion inhibitor added in the media plays a good suppression for the dissolve of anode copperand the reduction of cathodic oxygen and hydrogen, as well reduce the corrosioncurrent density value. So the five kinds of corrosion inhibitors belong to a mixed typeof inhibitor.The five kinds of compounds all play a better corrosion inhibition on the copperin the different concentration, pH environment and temperature media, and thecorrosion inhibitor added in the media plays a good suppression for the dissolve ofanode copper and the reduction of cathodic oxygen and hydrogen.Compared with the blank sample which has no corrosion inhibitors, throughscanning electron microscopy experiments, it concludes that corrosion inhibitors play avery good corrosion protection effect at the copper surface.Through quantum chemistry experiments, we simulate the chemical adsorptionactivity center of the five kinds of corrosion inhibitors. Quantum chemistryexperiments provide the important theoretical basis for the corrosion performancedifference between different corrosion inhibitors and the copper surface adsorption.