双季铵盐表面活性剂的合成及表面活性研究

用脂肪酸制备了乙撑双(二甲基)季铵盐基双脂肪酸甲酯(B)及乙撑双(二甲基)季铵盐基双脂肪酸钠盐(C),用红外光谱对其结构进行了表征.经测定,分别用十二酸和十四酸制备的B1和B2其临界胶束浓度(cmc)分别为1.4×10-4和2.2×10-4 mol/L,其表面张力(γcmc)分别为30.5和37.8 mN/m;C1和C2的cmc分别为7.8×10-5和3.0×10-4 mol/L,γcmc分别为28.9和36.9 mN/m.结果表明,与普通表面活性剂相比,双子表面活性剂B1和B2的cmc要低1～2个数量级,γcmc也低了2～9个mN/m;C1、C2的cmc仅为普通表面活性剂的1/60～1/230,而γcmc相差不大.

Studies on Synthesis and Surface Activity of Quaternary Ammonium Salt Gimini Surfactants

The dimethylene-1,2-(bisquaternary ammonium bromine group connected)bis(carboxylic ester)(called B) and the dimethyl-ene-1,2-(bisquaternary ammonium bromine group connected) bis(carboxylic salt)(called C) are synthesized with fatty acid.The chemical structure of products are characterized by infrared spectroscopy.The surface activities of the products are measured and the B1and B2 are synthesized respectively with lauric acid and myristic acid.The critical micelle concentrations(CMC) are respectively 1.4×10-4 and 2.2×10-4 mol/L,and surface tensions(γcmc) are respectively 30.5 and 37.8 mN/m.The CMC of C1and C2 are respectively 7.8×10-5 and 3.0×10-4 mol/L,while the γcmc are respectively 28.9 and 36.9 mN/m.The results show that their CMC of the gemini surfactants B1 and B2 are 1/10~1/100 of their "monomer".Their surface tensions are 2~9 mN/m lowering than their "monomer".Their CMC of the gemini surfactants C1and C2 are 1/60~1/230 of their "monomer",but their surface tensions are similar to their corresponding "monomer".