壬基酚聚氧乙烯醚型Gemini季铵盐表面活性剂的合成 及其表面性质的研究

合成了系列壬基酚聚氧乙烯醚型Gemini季铵盐表面活性剂(GNPQA), 用核磁、红外和元素分析对它们的结构进行了表征, 考察了反应条件对转化率的影响, 并用表面张力法和稳态荧光探针法对GNPQA的表面性能及胶束聚集数(N)进行了研究. 结果表明, 较优的反应条件: 反应时间为12 h, 反应温度为70 ℃, 反应原料摩尔比为n(双聚壬基酚聚氧乙烯醚)∶n(三乙胺)∶n(环氧氯丙烷)＝1∶1∶1; GNPQA的临界胶束浓度(CMC)值较相应的单体壬基酚聚氧乙烯醚型季铵盐表面活性剂(NPQA)降低了1～2个数量级, 显示了较高的表面活性; 当GNPQA溶液浓度为5～9倍CMC时, N值随浓度增大而线性增大; 随着氧乙烯(EO)单元数的增长, GNPQA的CMC和N值均逐渐减小; 结合GNPQA的表面性能参数和N值的变化规律, 探讨了这类表面活性剂表面及胶束聚集体的结构形态.

Synthesis and Surface Activity Properties of Cationic Surfactants of Gemini Nonylphenol Polyoxyethylene Quaternary Ammonium Chloride

A series of cationic surfactants of gemini nonylphenol polyoxyethylene quaternary ammonium chloride (GNPQA) were synthesized and structurally confirmed by 1H NNR, FT-IR and elemental analysis. The influences of reaction conditions on conversion ratio have been investigated, and the optimal conditions were obtained as follows: the reaction time was 12 h, the reaction temperature was 70 ℃, n(GNP)∶n(TEA)∶n(EPI)＝1∶1∶1 (molar ratio). Surface activity properties and micelle aggregation numbers (N) of the GNPQA were determined by a surface tension method and a steady-state fluorescence probe method. The experimental results showed that critical micelle concentration (CMC) of the GNPQA was 1～2 orders of magnitude smaller than that of cationic surfactant of nonylphenol polyoxyethylene quaternary ammonium chloride (NPQA), which has exhibited predominant surface activity of the GNPQA. The N value increased linearly with the increase of the GNPQA concentration in the range of 5～9 times of CMC; CMC and N of the GNPQA decreased with increasing the oxyethylene (EO) unit amount. The micropolarities of surface activities and micelle aggregates of the GNPQA were inferred by the change of surface properties and N values.