基于丙二酰胺的不对称双子表面活性剂的合成及其乳化性能

Synthesis and their emulsification performance of unsymmetrical Gemini surfactants based on malonamide

将二(3-二甲氨基丙基)丙二酰胺分别与溴代十六烷和溴代十四烷反应,生成的季铵盐化产物经丙酮-乙腈重结晶,得到含丙二酰胺基的不对称阳离子双子(Gemini)表面活性剂(命名为16-9-14),总收率为45.9%(以溴代十六烷计);利用红外光谱和核磁共振谱表征了合成产物的结构,采用电导法测定了其临界胶束浓度(CMC),采用滴体积法测定了其临界张力(γCMC),进而初步探讨了其发泡沫性能和乳化性能.结果表明,合成的Gemini表面活性剂的CMC为1.57×10-4 mol/L,γCMC为38.45mN/m;其发泡性能和乳化性能优于相应的单子表面活性剂.

Bis[3-（dimethylamino） propyl] diethyl malonamide was allowed to react with 1-bro- mohexadecane and 1-bromotetradecane, respectively. Resultant quaternary salts were recrystal- lized in the mixed solution of acetone and acetonitrile to afford asymmetrical cationic Gemini surfactants containing malonamide group （coded as 16-9-14） with a total yield of 45.9 （in re- lation to 1-bromohexadecane）. The structure of as-synthesized products was confirmed by in- frared spectrometry and nuclear magnetic resonance spectroscopy. The critical micelle concen- tration （CMC） of the products was determined by conductivity method, their critical surface tension （YcMc） was measured by dripping volume method, and their foaming performance and emulsification performance were primarily evaluated. It was found that as-synthesized Gemini surfactants have a CIVIC of 1.57X 10-4 mol/L and a YCMC of 38.45 raN/m, and they exhibit be- tter foaming performance and emulsification performance than relevant conventional surfac- tants.