Sodium N-dodecylenediaminetriacetate (NaLED3A) was prepared with dodecanol, ethylenediamine, sodium chloroacetate and NaOH through hromination, N-unialkylation, carboxymethylation and neutralization. Effects of n (monochloroacetic acid sodium ) : n (N-lauryl dialkylaminoethylamine), reaction time and reaction temperature on the yield of the intermediate N-dodecylenediaminetriacetic acid (LED3A) were studied in detail. The surface activity, chelation, foam activity and the ability to inhibit the precipitation of petroleum sulfonates were measured. The results showed that the yield of LED3A can reach 94.8％ with the reaction time of 6 h at 75 ℃ at n(monochloroacetic acid sodium ): n(N-lauryl dialkylaminoethylamine) = 3.7 : 1. NaLED3A had higher surface activity with the critical micelle concentration and the surface tension being 2.0 mmol/L and 18.32 mN/m, respectively, at 45 ℃. NaLED3A's chelating capacity first increased with its concentration, reaching 190.51 mg/g at the concentration of 50 g/L, and then changed slightly with the further increase of the concentration. Stability of NaLED3A solution bubble in hard water was 0. 958, in soft water was 0. 893. And less petroleum sulfonate precipitate would form by adding NaLED3A into the oil flooding system because of the chelation between NaLED3A and multivalent cations.%实验以月桂醇、乙二胺、氯乙酸钠、氢氧化钠为原料,经溴化、N-烷基化、羧甲基化、中和反应合成螯合型表面活性剂N-十二烷基乙二胺三乙酸钠(NaLED3A).讨论了N-十二烷基乙二胺羧甲基化反应中投料摩尔比、反应温度、反应时间对中间体产率的影响,考察了产物NaLED3A的表面活性、螯合性能、泡沫性能及其在油田污水中石油磺酸盐的沉淀损失抑制性能.实验结果表明:氯乙酸钠与N-十二烷基乙二胺摩尔比为3.7:1,反应时间6 h,反应温度75℃时中间体N-十二烷基乙二胺三乙酸(LED3A)收率为94.8%.45℃时NaLED3A临界胶束浓度为2.0 mmol/L、表面张力为18.32 mN/m;随浓度增加,其螯合能力增强,质量浓度为50 g/L时,螯合值最高达190.51 mg/g;在硬水中的泡沫稳定系数为0.958,软水中为0.893;可有效抑制驱油体系中石油磺酸盐的沉淀损失.
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