一种含酯基的酰胺型阳离子双子表面活性剂的合成及性能

Synthesis and properties of an amide cationic Gemini surfactant with ester groups

以溴乙酸、乙二醇、月桂酸和N,N-二甲基-1,3-二氨基丙烷为原料,通过三步反应合成了一种含酯基的酰胺型阳离子双子表面活性剂C_(12)-(BAE)-C_(12),并通过红外光谱(FT-IR)、核磁共振氢谱(1H NMR)和质谱(MS)对产物结构进行了表征。通过表面张力、电导率和荧光3种不同方法测定了C_(12)-(BAE)-C_(12)的临界胶束浓度(cmc),利用电导率法测定了其在25、35和45℃条件下的热力学函数,以及测定了其乳化和抗静电性能。结果表明,25℃时C_(12)-(BAE)-C_(12)在不同测定方法下的cmc分别为0.3311、0.5328和0.3162 mmol/L,根据相关公式计算所得热力学参数进一步说明其胶束化过程为熵驱动,且升高温度会阻碍体系的胶束化。此外,相关应用性能测定结果还表明C_(12)-(BAE)-C_(12)与传统单链阳离子表面活性剂十二烷基三甲基溴化铵(DTAB)相比具有更好的乳化和抗静电效果。

An amide cationic Gemini surfactant with ester groups(C12-(BAE)-C12)was synthesized in three steps with bromoacetic acid,ethylene glycol,lauric acid and N,N-dimethyl-1,3-diaminopropane as raw materials.The structure of the product was characterized by FT-IR,1 H NMR and mass spectrometry(MS).The critical micelle concentration(cmc)of C12-(BAE)-C12 was determined by measurement of surface tension,conductivity and fluorescence.The thermodynamic parameters of C12-(BAE)-C12 were obtained from the results of conductivity at 25,35 and 45℃.The emulsification and antistatic properties of C12-(BAE)-C12 were also measured.The results show that the cmc values of C12-(BAE)-C12 at 25℃are 0.3311,0.5328 and 0.3162 mmol/L,respectively,as obtained by different methods.According to the results of conductivity,the thermodynamic parameters of micellization were calculated with the thermodynamic formulas.It is determined that the micellization process of C12-(BAE)-C12 is entropy-driven,and the increase of temperature will hinder the micellization of the surfactant.Furthermore,the results of application performance show that C12-(BAE)-C12 has better emulsification and antistatic effects than traditional single-chain cationic surfactant dodecyltrimethylammonium bromide(DTAB).