Synthesis And Properties Of N, N - Bis - Ethylenediamine Diacetate

Gemini Surfactant unique molecular structure gives it unique properties,compared with conventional surfactants,Gemini surfactants with higher surface activity,lower CMC and Krafft,and excellent aqueous solubility.The result shows the tremendous potential of using these surfactant for EOR. Carboxylic Gemini surfactants with mild nature,easily biodegradable and raw materials,is a new type of surfactant with development potential.In this paper,the performance characteristics and applied value of anionic Gemini surfactant were analyzed,and carboxylic gemini surfactants was synthesized.In this paper,N,N-didodecylethylenediaminediacetic acid was synthesized through two-steps reactions of N-alkylation and carboxymethylation with ethylenediamine, Bromodecane,sodium chloroacetate as materials,ethanol as a solvent and KI as an initiator. Then TD-12can be got through neutralization with sodium hydroxide.Similarly,TD-14and TD-16were synthesized by this way.Finaly,the structures of the synthesis products were characterized by IR,1H-NMR and13C-NMR, respectively,and confirmed the fact.The various effects to the reaction were discussed and optimized by single factor and orth-ogonal experients for studying TD-12.Under the optimum reaction ciondition,the target product TD-12yield can reach64.95%. Surface tensions of the three surfactants solution were measured by hanging platinum pieces method at25℃under different concentrations. The results shows that the surfactants had high surface activity, and the surface tensions of TD-12,TD-14and TD-16are24.6mN/m,32.8mN/m,44.7mN/m,respectively; the critical micelle concentration of TD-12, TD-14and TD-16are0.04mmol/L,0.04mmol/L and0.03mmol/L, respectively, compared with the relevant traditional surfactants.Simultaneously, these performance of the three target products were evaluated, including surface activity,CMC,saltresistance,emulsification,synergies,wettability and interfacial tension of oil and water.The result shows that the three surfactants perform a good ability of emulsification,the time of reaching the equilibrium of separating water from emulsions are20min,20min and30min,respectively,the rate of separating water from emulsions becomes slower with increasing the concentration of the surfactants,so emulsification ability is better; the wettability of quartz pieces which were immersed in surfactant solutions for a period of time has improved,and the hydrophilic pieces were still hydrophilic, the Hydrophobic pieces became hydrophilic;the mixed surfactants of TD and traditional surfactants(OP-10, dodecyl trimethyl ammonium bromide) had also high compatibility at different ratio. And the surface tensions are23.8mN/m, the critical micelle concentration are0.06mmol/L.The interfacial tension of D1oil and water was measured. The composite of TD-12and DTAB at a ratio of1:1was choosed to flooding in the room at100℃. The result shows that the composite can enhance oil recovery10.98%,and the number is more than that of single traditional surfactant.