Effect Of Hydroxyl Substituted Unsaturated Organic Compounds On Corrosion Inhibition Of Mannich Base

In this paper,Mannich base inhibitors were synthesized using acetophenone,arylamine and paraformaldehyde as raw materials,and the conditions for the synthesis of Mannich base were optimized by orthogonal experiments.The influence of factors such as the ratio of raw materials,reaction temperature,and reaction time on corrosion inhibition properties was investigated,and the synthesis conditions of Mannich base were optimized.By using Mannich base as the main inhibitor,compounding with peregal,propynol and solvents,a corrosion inhibitor with excellent corrosion inhibition performance was obtained.The corrosion rate of N80 steel was 0.6850 g·m^-2·h^-1,and the corrosion inhibition rate can reach 99.88%at 90?in20%hydrochloric acid solution when the amount of corrosion inhibitor was 1%.The results of scanning electron microscope,energy spectrum analysis,electrochemical test and thermodynamic study showed that the corrosion inhibitor obtained by the combination of Mannich base,peregal,propynol and solvents were mixed corrosion inhibitor,and its adsorption on the surface of N80 steel was a process of reducing entropy and exotherm.The adsorption behavior accordsed with the isothermal formula of Langmuir adsorption and exhibited strong chemisorption characteristics.With mannich bases as main agent,the corrosion inhibitor effect of 1,4-Butynediol,3-methylbutynyl alcohol,3-Methyl-1-pentyn-3-ol,1,1,3-triphenylpropargyl alcohol,Propynol Ethoxylate,Propargyl alcohol propoxylate were tested.Simultaneously the effect of mannich base and propargyl alcohol combined with other alkyl alcohol compounds on the inhibition performance were investigated.The experimental results showed that the compounding of a single alkynol compound with Mannich base can reduce the corrosion rate of steel in hydrochloric acid,and the corrosion inhibition performance was enhanced with the increase of the concentration of alkynol.The addition of propynyl alcohol can further improve the corrosion inhibition performance.The DFT method was used to analyze and calculate molecular orbital parameters such as E_HOMO?E_LUMO??35?E?E_T,and summarize the relationship between molecular structure and corrosion inhibition.Two hydroxy unsaturated organic compounds BAA and BHHA were synthesized by reacting acetophenone with paraformaldehyde and glucose.In Mannich base system,the effects of BAA and BHHA on the performance of alkyl alcohols such as 1,4-Butynediol,3-methylbutynyl alcohol,3-Methyl-1-pentyn-3-ol,1,1,3-triphenylpropargyl alcohol,Propynol Ethoxylate,Propargyl alcohol propoxylate were studied.It was found that in Mannich base and alkynol compound systems,the corrosion inhibition performance was further improved after adding BAA and BHHA.Quantum chemical calculation results showed that the ability of BHHA to obtain or donate electrons is stronger,which is beneficial to the interaction with metal surfaces.The results of quantum chemical calculation showed that BHHA has stronger ability to obtain or donate electrons,which was beneficial to the interaction with metal surface,and the corrosion inhibition performance of BHHA is better than that of BAA.