Synthesis And Corrosion Inhibition Performance Of N,N-Diethylhydroxypropyl Alkoxylated Amine Oxide

The halogenated alkanes with different carbon chain lengths were synthesized by substituting dodecyl alcohol,tetradyl alcohol,cetyl alcohol and octadecanol as starting agents with sodium hydroxide and epichlorohydrin.Then the corresponding tertiary amines with different carbon chain lengths were synthesized by introducing diethyl group into halogenated alkanes and diethylamines.Finally,the corresponding amine oxide was prepared by hydrogen peroxide process.After purification,the product was characterized by FT-IR,and the structure of the product and the target product were confirmed to be consistent.On the basis of synthesis and characterization,the physical and chemical properties of the target product such as surface tension,salt tolerance,foam properties and emulsifying properties were determined.The results showed that the four amine oxides had good surface activity,and the surface tension increased slightly with the increase of carbon chain length.Among them,the surface activity of C12-HDAO was the best,with the cmc value of2.54×10^-44 mol/L and theγ_cmcmc value of 27.06 mN/m.Theγ_cmcmc value of the four kinds of amine oxides decreased under acidic condition and almost remained the same under neutral and basic conditions.With the increase of salinity,the value ofγ_cmcmc decreased slightly.The foaming ability is general,the stable performance is superior,and the stability coefficient is above 0.9.It has good emulsifying ability,and the emulsifying ability decreases with the increase of carbon chain length.Based on the investigation of some physical and chemical properties of the target product,the corrosion inhibition properties of the product were further investigated in this paper.Their corrosion inhibition properties at different temperatures and concentrations in 1 mol/L hydrochloric acid solution were investigated and compared with dodecyl dimethyl oxide amine（DDAO）which has been commercially used.The experimental results showed that all the five kinds of amine oxides had good corrosion inhibition performance,which was shown as C12-HDAO>C14-HDAO≈DDAO>C16-HDAO>C18-HDAO.Homologue between corrosion ability increased with the increase of carbon chain length is reduced,along with the rise of temperature drop,the C12-HDAO corrosion performance is the best,the efficiency of the corrosion at 70℃still reached 90%.We also investigated the corrosion inhibition performance of four amine oxides under CO₂,and explored the influence of different temperatures and different partial pressures of CO₂ on the corrosion inhibition performance.The results show that the corrosion inhibition ability decreases with the increase of CO₂partial pressure within the exploration pressure range;with the rise of temperature,the research temperature shows a trend of first decline and then rise;The law of corrosion inhibition with the length of carbon chain is the same as that in hydrochloric acid.