Study On Synthesis Of Inhibitors Of Carbon Steels Containing Carbohydrate And Carbon Quantum Dots And Their Corrosion Performance In Acid Environment

In recent years,a series of relative policies limiting the use of toxic and harmful inhibitors had been issued in the metal corrosion and protection industry in order to protect the environment.So far,many scholars are focusing their attention on the development of environment-friendly corrosion inhibitors to prevent metal corrosion.Therefore,three environmentally friendly carbon steel corrosion inhibitors were synthesized in this paper,and their performance of corrosion inhibition were studied in1 mol/L HCl.This research provides a certain experimental and theoretical basis for the development of environment-friendly corrosion inhibitors in the future.The specific experiment content is as follows:1.D-Glucosamine hydrochloride schiff base inhibitor（Glu-SB）and polymer inhibitor（SB-g-p-AA）were synthesized by glucosamine hydrochloride and4-dimethylaminobenzaldehyde.The effects of different concentrations of Glu-SB and SB-g-p-AA on the corrosion inhibition performance of Q235 carbon steel were studied by electrochemical test methods.The experimental results showed that SB-g-p-AA was more effective than Glu-SB with the increase of the inhibitor.In addition,Glu-SB had a Schiff base structure,and SB-g-p-AA had ester functional group of-C=O by FTIR analysis.Results of electrochemical and weightlessness method indicated that the corrosion inhibition rate reached a maximum of 90.2%in 1 mol/L HCl solution when the dosage of SB-g-p-AA was 400 mg/L.Finally,the scale inhibition performance of SB-g-p-AA was studied,and the scale inhibition rate was 46.27%when the dosage was40 mg/L,which showed that SB-g-p-AA had a good corrosion inhibition effect but the scale inhibition is poor.Therefore,SB-g-p-AA is more suitable for corrosion resistance in acid environment2.The terpolymer（SAAC）was synthesized using starch,acrylic acid and chitosan as raw materials,and its structure was characterized.The FT-IR and XRD spectras indicated that SAAC polymer was prepared successfully.The effect of concentration on the corrosion inhibition performance of SAAC was studied by electrochemical methods and weightlessness method.The results showed that the corrosion inhibition efficiency of SAAC gradually increased with the increase of the concentration of corrosion inhibitor.The corrosion inhibition efficiency can reach 90.1%when the dosage of SAAC was 200 mg/L,while the corrosion inhibition efficiency is 72.6%in 0.5 mol/L H₂SO₄environment.Finally,the SAAC adsorption isotherm model was explored,and it was found that it fits the Langmuir adsorption isotherm model and its adsorption on the surface of carbon steel has both physical adsorption and chemical adsorption3.Hexamethylenetetramine quantum dots（CD₁）,itaconic acid quantum dots（CD₂）and composite quantum dots（CD₁-CD₂）were synthesized by hydrothermal method at150 ^oC using hexamethylenetetramine and itaconic acid as raw materials.Three quantum dots were characterized by infrared spectrophotometer（FT-IR）,ultraviolet spectrophotometer（UV）and fluorescence spectrophotometer,indicating that CD₁,CD₂and CD₁-CD₂was prepared successfully.The corrosion inhibition performance of CD₁,CD₂and CD₁-CD₂was compared,the results showed that the corrosion inhibition performance of CD₁-CD₂was significantly stronger than that of CD₁and CD₂using electrochemical methods.Moreover,the corrosion inhibition properties of composite quantum dots synthesized by different molar ratios of hexamethylenetetramine and itaconic acid to Q235 carbon steel were studied by electrochemical methods.The results showed that when the molar ratio of hexamethylenetetramine and itaconic acid was 1:3,the composite quantum dots had the best corrosion inhibition performance.Subsequently,the effect of concentration on the corrosion inhibition performance of composite quantum dots was also studied.The results showed that the corrosion inhibition efficiency reached a maximum of 90.5%when the dosage of composite quantum dots was 200 mg/L.It was observed by SEM that the surface corrosion of the carbon steel surface was severe when the corrosion inhibitor was not added.However,the surface corrosion of the carbon steel was flat after adding 25 mg/L and 200 mg/L corrosion inhibitor,indicating the corrosion of carbon steel in hydrochloric acid was hindered after adding CD₁-CD₂.Thus,CD₁-CD₂is excellent in corrosion inhibition performance.