含酯基和酰胺基季铵盐阳离子表面活性剂的合成

Synthesis of quaternary ammonium cationic surfactants containing ester and amide

以取代苯甲酰氯、长链伯胺(n为12,14,16)、氯乙酰氯和N,N-二甲基乙醇胺为原料,合成了一系列、含酯基和酰胺基的季铵盐阳离子表面活性剂目标产物(I-12,I-14,I-16)。通过FTIR和1 H-NMR对中间体和目标产物分子结构进行表征。在25℃,用电导率法和界面张力法分别测定表面活性剂的临界胶束浓度(CMC)和表面张力(γ),I-16的CMC值达到4.30×10^-5 mol·L^-1,计算目标产物胶束化标准吉布斯自由能(ΔGmic^0)、饱和吸附量(Γmax)、空气-水界面上吸附分子的最小截面积(Amin)、降低溶液表面张力的效率(pC20)和降低溶液表面张力的能力(πCMC)。用透射电子显微镜(TEM)和动态光散射(DLS)研究I-16在水溶液中的聚集行为。在25℃,测试了表面活性剂的泡沫性能和乳化性能。结果表明,该系列表面活性剂具有较好的表面活性,其中I-16泡沫稳定性达到100%,I-14乳化性最好,乳化时间为2388s。

A series of Gemini surfactant target products(I-12,I-14,I-16)containing ester group and amide group were synthesized by using substituent group benzoyl chloride,long alkyl chain primary amine(n was 12,14,16),chloroacetyl chloride,and N,N-dimethylethanolamine as main raw materials.The intermediate and target products were characterized by FTIR and 1 H-NMR.The critical micelle concentrations(CMC)and the surface tension(γCMC)of surfactants were determined by electrical conductivity measurements and surface tension method at 25℃,respectively.The CMC value of I-16 reached 4.30×10^-5 mol·L^-1.The standard Gibbs energy of micellization(ΔGmic^0),the maximum adsorbed amount of surfactant(Γmax),the area occupied by a single surfactant molecule at the air/water interface(Amin),the adsorption efficiency(pC20)and the effectiveness of surface tension decrease(πCMC)were calculated.The transmission electron microscope(TEM)and dynamic light scattering(DLS)were used to study the aggregation behavior of I-16 in aqueous solution.At 25℃,the foaming and emulsifying properties of the surfactants were tested.The results show that this series of surfactants had good surface activity.Among these products,I-16 foam stability reached 100%,I-14 had the best emulsification and emulsification time was 2388s.