N-月桂酰基甲基丙氨酸钠的合成与性能研究

Study on the synthesis and performance of sodium N-lauroyl methylalaninate

以甲基丙氨酸和月桂酰氯为主要原料,在碱性条件下合成了一种阴离子型氨基酸表面活性剂N-月桂酰基甲基丙氨酸钠(SLMA),通过FT-IR、MS和1H NMR对产物结构进行表征,测定了SLMA的Krafft点、临界胶束浓度(cmc)、表面张力、乳化、润湿、泡沫、去污性能,以及SLMA不同温度下的电导率、微极性及临界胶束聚集数。结果表明:SLMA的Krafft点低于0℃;25,35,45和55℃下SLMA的cmc分别为8.23×10^(-3),8.27×10^(-3),8.29×10^(-3)和8.34×10^(-3) mol/L,γcmc分别为33.00,32.90,32.80和32.10 mN/m;SLMA的乳化和润湿性能优于N-月桂酰基肌氨酸钠(LS),起泡性、稳泡性及去污值与LS相当;在25,35,45和55℃下SLMA的临界胶束聚集数分别为11,35,60和79。

Using methylalanine and lauroyl chloride as the main raw materials,an anionic amino acid surfactant,N-lauroyl methylalanine sodium salt(SLMA),was synthesized under alkaline conditions.The structure of the product was characterized through FT-IR,MS and 1H NMR.The Krafft point,critical micelle concentration(cmc),surface tension,emulsification,wetting,foaming and detergency of SLMA were determined,as well as the conductivity,micropolarity and critical micelle aggregation number of SLMA at different temperatures.The results show that the Krafft point of SLMA is lower than 0℃.The cmc’s of SLMA are 8.23×10^(-3),8.27×10^(-3),8.29×10^(-3) and 8.34×10^(-3) mol/L at 25,35,45 and 55℃,respectively,and theγcmc are 33.00,32.90,32.80 and 32.10 mN/m,respectively.The emulsification and wetting properties of SLMA are better than those of sodium N-lauroyl sarcosinate(LS).The foaming,foam stabilization and detergency values of SLMA are equivalent to those of LS.The critical micelle aggregation number of SLMA are 11,35,60 and 79 at 25,35,45 and 55℃,respectively.