N-十二烷基亚氨基二乙酸钠水溶液性质的研究  

Properties of disodium-N-dodecyliminodiacetate in aqueous solution

作　　者：刘玲红[1] 赵剑曦[1] 

机构地区：[1]福州大学化学化工学院应用化学系,福建福州350002

出　　处：《日用化学工业》2005年第6期343-345,349,共4页China Surfactant Detergent & Cosmetics

基　　金：国家自然科学基金资助项目(20173010和20373012)

摘　　要：合成了N-十二烷基亚氨基二乙酸钠(C12H25N(CH2COONa)2)。研究结果表明,分子中的亚氨基在水溶液中极易水解结合质子,使溶液pH随C12H25N(CH2COONa)2浓度增大而增大,羧基则基本处于碱式形态。这种两性分子形式使其水溶液的表面张力曲线具有明确的转折点,而不象月桂酸钠那样出现最低点。该转折点表示临界胶团浓度cmc(=22.1 mmol.L-1)。最低表面张力γcmc和降低水表面张力20 mN.m-1所需的表面活性剂浓度c20分别为44.8 mN.m-1和10.5 mmol.L-1。Disodium - N - dodecyliminodiacetate （ C12H25N （CH2COONa）2） was synthesized. The results showed the nitrogen atom in the imino group of C12H25N（CH2COONa）2 molecule is easily protonated by hydrolysis, which leads to in significant increase of pH with increasing of the concentration of C12H25N（CH2COONa）2 in aqueous solution, while the carboxyl groups are mostly in basic form. The zwitterionic characteristic of C12H25N（ CH2COONa）2 produces a clear inflection point in the plot of surface tension（γ） against logarithmic concentration（lg c） and the inflection point refers to the critical micelle concentration cmc（ = 22.1 mmol·L^-1 ）. This is different from that of sodium laurate aqueous solution, which shows the characteristic dip prior to the cmc in the plot of γ～lg c. The minimum surface tension γcmc and the surfactant concentration required for lowering the surface tension of water for 20 mN·m^-1（c20） are 44.8 mN·m^-1 and 10.5 mmol·L^-1 ,respectively.

关 键 词：两性表面活性剂 N-十二烷基亚氨基二乙酸钠 水溶液性质 

分 类 号：O627.11[理学—有机化学]