新型环己烯酯基双子表面活性剂的合成及其性能

Synthesis and Properties of Novel Gemini Surfactants with Cyclohexene Ester Group

以4-环己烯-1,2-二甲酸二(N,N-二甲基胺基乙基)酯为原料,分别与溴代十二烷、溴代十四烷和溴代十六烷发生季铵化反应,合成了含环己烯酯基的双子阳离子表面活性剂3a、 3b和3c(3a和3b为新化合物),收率55.8%、 62.6%和58.9%,其结构经~1H NMR, IR和HR-MS(ESI)表征。研究了3a、 3b和3c的表面活性。结果表明:3种表面活性剂的Krafft点均低于0℃;乳化时间分别为310 s、 435 s和519 s;3a起泡性最好,3种表面活性剂均具有良好的稳泡性。采用Gibbs吸附方程计算了表面活性参数(Γ_(max)、A_(min)和pc_(20))及胶束形成的热力学参数(ΔG■、ΔH■和ΔS■)。结果表明:3种表面活性剂的表面活性均较高,胶束形成为熵驱动的自发放热过程。

Three Gemini cationic surfactants( 3a, 3b and 3c, 3a and 3b were new compounds) with cyclohexene ester group were synthesized by quarterisation of dis( N,N -dimethylaminoethyl) 4-cyclohexene-1,2-dicarboxylate with bromododecane, bromotetradecane and bromohexadecane. The yields were 55.8%, 62.6% and 58.9%, respectively. The structures were characterized by ^1H NMR, IR and HR-MS(ESI). The properties were determined. The results showed that the Krafft points of all the products were below 0 ℃, the emulsifying time was 310 s, 435 s and 519 s, respectively. All the surfactants had good foam stabilities, and 3a had the best foaming properties. The surface activity parameters(Γ max , A min , pc 20 ) and the thermodynamic parameters(ΔG^θ m ,ΔH^θ m ,ΔS^θ m ) were calculated by the Gibbs adsorption equation. The results indicated that three surfactants had high surface activities, and the formation of micelles was an entropy-driven self-heating process.