The Study Of The Properties Of Grapefruit Peel Extract As A Pickling Inhibitor

In this paper,active ingredients in fresh pomelo peels were extracted by Soxhlet extraction,and ethanol solution was as extraction agent.The products were used as pickling inhibitor.The optimum extraction condition was obtained through 4 factors and 3 levels orthogonal experiment.Weight-loss method,electrochemical impedance spectroscopy and polarization curve method were used to study the inhibition effect of shaddock peel corrosion inhibitor on A3 carbon steel in 1 mol/L HCl,compared with the inhibition effect of compound corrosion inhibitor.Finally,the inhibition mechanism of shaddock peel corrosion inhibitor was inferred through FT-IR,GC-MS and SEM analysis.The results of weight loss method showed that shaddock peel corrosion inhibitor had good corrosion inhibition performance.The inhibition efficiency increases with the concentration of inhibitor and decrease with the increase of temperature.In 1 mol/L hydrochloric acid solution,the concentration of inhibitor was 200 mg/L,inhibition rate reach 91.74%and the 71.17%under the condition of 25 degree and 45 degree,respectively.Adsorption isotherm analysis results showed that the adsorption model of shaddock peel corrosion inhibitor in the surface of A3 carbon steel is monolayer adsorption and the adsorption model obeys the Langmuir adsorption isotherm.The electrochemical results showed that shaddock peel corrosion inhibitor is the interface inhibitor resistance.The corrosion inhibitor by increasing the charge transfer resistance between the metal interface and adsorbent to achieve the corrosion inhibition effect.Shaddock peel corrosion inhibitor was a mixed corrosion inhibitor,which could inhibit the cathodic and anodic reaction of A3 steel at the same time.At the temperature was 25 degree and the concentration was 200 mg/L,the results of impedance curve and polarization curve showed that the rate of corrosion inhibition are 90.76%and 90.87%,respectively.The results are basically consistent with the weight loss method.The experiment was carried out through the extraction of pomelo peel combined with potassium iodide(KI),twelve sodium alkyl benzene sulfonate(SDBS),benzyl chloride and amine(eighteen),and the results showed that they had good corrosion inhibition performance partly.At the temperature was 25 degree and the concentration was 200 mg/L,the rate of corrosion inhibition are 94.16%and 97.53%,respectively.However,the combination of shaddock peel corrosion inhibitor with benzyl chloride or amine(eighteen)has bad performance.