The Synthesis Of Azole Organic Compounds And Study On Corrosion Inhibition For Copper In NaHCO₃ Medium

In this paper, Heterocyclic compounds have been synthesized, including four Schiff base tetrazole compounds of BIT, BIOHT, BIMHT and BIMMT, four thiadi -azole compounds of AAMTH, AMETH, APHTH and ABUTH, and two trazole compounds of PMAT and MAT. These compounds corrosion inhibition for copper in 5% NaHCO3 solution was studied by gravimetric measurements, potentio -dynamic polarization curves and electrochemical impedance. The paper has two parts: review section and experimental section.In review section, the development of the corrosion inhibitors about copper was firstly reviewed. The author introduced the kinds of copper corrosion inhibitor and measurements detecting performance of inhibition. Based on this, we introduced the development of copper corrosion inhibitor in the different medium, including corrosion mechanism and synergistic reaction of corrosion inhibitor.In experimental section, BIT,BIOHT,BIMMT,BIMHT,AAMTH,AMETH,APHTH,ABUTH,PMAT and MAT were synthesized by simple method. Their structures were characterized by IR spectrum and elemental analysis. Their corrosion inhibition for copper in5%NaHCO3 solution was studied by electro -chemical impedance spectroscopy (EIS), potentiodynamic polarization curves and gravimetric measurement. The corrosion kinetics and the effect of temperature on inhibition efficiency were also investigated. Their adsorption actions on the surface of copper and inhibition mechanism were discussed simply. We made some conclusions through experiment:(1) BIT,BIOHT,BIMMT,BIMHT,AAMTH,AMETH,APHTH,ABUTH,PMAT and MAT had good performance on copper in 5%NaHCO3 solution. The results of experiments revealed that the efficiency of these compounds have increased with the increase of concentration, but the inhibition efficiency of these compounds reached maximum value at some concentration.(2) The behavior of absorption of these compounds on the copper surface has been discussed elementarily. The results revealed their absorptions on the copper surface followed Langmuir isotherm.(3) We have studied the relationship between temperature and inhibition efficiency of these compounds. The results showed that these compounds of BIT,BIOHT,BIMHT,BIMMT,AAMTH,AMETH,APHTH,ABUTH,PMAT and MAT had good inhibition efficiency in the temperature range researched, but the inhibition efficiency of these compounds was decreased with the crease of temperature.(4) Potentiodynamic polarization studies showed that these compounds of AAMTH,AMETH,APHTH,ABUTH,were mixed type inhibitors. But PMAT and MAT inhibited mainly anode corrosion reactions and they were anodic type inhibitors.(5) The obtained values ofâ–³G_m showed their adsorptions of BIT,BIOHT,BIMMT,BIMHT,AAMTH,AMETH,APHTH,ABUTH,PMAT and MAT on the copper surface were spontaneous in isothermal-isobaric condition. At the same time, the obtained values ofâ–³H_m for these compounds showed their adsorptions of BIT,BIOHT,BIMMT,BIMHT,AAMTH,AMETH,APHTH,ABUTH,PMAT and MAT were exothermic reaction.