Study On Synthesis And Performance Of New Type Of Double Schiff Base Acidizing Corrosion Inhibitor

Carbon steel is widely used as an important engineering material.However,carbon steel is extremely susceptible to corrosion,and the destruction of the metal equipment structure will cause various safety problems and economic losses.Adding organic corrosion inhibitors is the most commonly used anti-corrosion method.Schiff base,-C=N contained in the molecule,can spontaneously adsorb on the steel substrate to form a protective layer,with good performance,easy synthesis,low cost,high purity and low toxicity.Compared with the double Schiff base,it has more active sites and larger conjugated system,which is expected to have a better protective effect on the metal matrix.Therefore,exploring double Schiff base corrosion inhibitors as corrosion inhibitors for acidified environments and revealing the relationship between the effect of the corrosion inhibitor and the molecular structure has great significance development of the corrosion inhibitor field.The results of the weight loss method showed that the performance of the three corrosion inhibitors.The three corrosion inhibitor increased with the increase of concentration,and decreased with the increase of temperature.When the temperature is 60℃ and the added amount of corrosion inhibitor is 0.1 wt.%,the corrosion inhibition efficiencies of the three corrosion inhibitors are 79.19%,84%,96%,respectively,and the effect is RGQ>BDQ>BJQ;The results of electrochemical experiments show that the corrosion inhibitors of the three corrosion inhibitors are all mixed inhibition type corrosion inhibitors;within 60°C,the three corrosion inhibitors all comply with the Langmuir isotherm equation and the three corrosion inhibitors are mainly physically and chemically adsorbed.When the temperature rises further,the adsorption mechanism of BJQ and BDQ changes,and RGQ is resistant to the best temperature.The results of quantum chemistry method show that RGQ has the lowest energy gap 2.548 e V,the smallest chemical potential μ-3.339 e V,the smallest absolute hardness η 1.274 e V,the largest global softness S 0.784929 e V and the most activity Site.The results of molecular dynamics show that the three molecules are adsorbed on Fe(001)in parallel positions,the bond length between the corrosion inhibitor and the metal surface is BJQ>BDQ>RGQ,and the binding energies of BJQ,BDQ and RGQ are 44080 kcal/mol,44561 kcal/mol,44669 kcal/mol.Among the three molecules,RGQ adsorbs more closely to the metal surface and has a better protective effect,and the conclusion is consistent with the experimental results.