摘要:
采用衣康酸酐、月桂醇、1,4-丁二醇、亚硫酸氢钠为主要原料,依次经单酯化、磺化、双酯化反应,合成了一种新颖的双子表面活性剂-1,4-丁二醇双衣康酸月桂醇双酯磺酸钠(Gemini-12),并通过正交试验对双酯化合成条件进行了优化.较佳工艺条件如下:双酯化反应温度150°C,反应时间6.0h,衣康酸单月桂醇酯磺酸钠与1,4-丁二醇的摩尔比为2.30∶1.00,催化剂用量为物料总量的1.0%(质量分数).通过FTIR和1H NMR对中间产物和Gemini-12的结构进行了确认,并对终产物的物化性能进行了初步袁征,测得其临界胶束浓度(CMC)为1.38× 10-3mol/L,表面张力γCMC为28.60mN/m,效率因子pC20为3.14,表面活性剂的效能CMC/C20为1.91,表面过剩量ΓCMC为1.15mmol/m2,极限分子面积ACMC为1.44× 10-3nm2/mol,标准胶束自由能△Gmicθ为-9.018kJ/mol,标准吸附自由能AGadsθ为-31.22 kJ/mol.随NaCl浓度的增加,Gemini-12的CMC值不断降低.%A new type of Gemini surfactant (Gemini-12) was synthesized with cheap materials such as itaconic anhydride (IAn),lauryl alcohol,1,4-butanediol and sodium bisulfite by the monoesterification,sulfonation and diesterification reaction processes.The optimal reaction conditions of the diesterification obtained via orthogonal experiments were:ratio of sodium lauryl sulfoitaconic monoester to 1,4-butanediol=2.30 ∶ 1.00,and 1.0%p-methyl benzenesulfonic acid at 150°CC for 6.0h.The structures of intermediate products and Gemini-12 were confirmed by FTIR and 1H NMR.Finally,the primary physico-chemical properties of Gemini-12 were characterized.The critical micelle concentration (CMC) was 1.38 × 10-3mol/L,and the surface tension at CMC was 28.60mN/m;the efficient factor pC20 was 3.14;CMC/C20was 1.91;the saturation adsorptionΓcMc was 1.15mmol/m2;the area per molecule at interface was 1.44× 10-3nm2/mole;the standard free energy of micellization was-9.018kJ/mol and the standard free energy of adsorption was-31.22kJ/mol.The CMC of Gemini-12 decreased with the increase of the concentration of NaC1 solution.