系列反应型阳离子Gemini表面活性剂的合成及性能

通过三步反应,以甲基丙烯酸二甲氨基乙酯(DM)、环氧氯丙烷(ECH)和3种长链烷基叔胺(十二烷基叔胺、十四烷基叔胺、十六烷基叔胺)为主要原料,合成了3种反应型阳离子Gemini 表面活性剂,即C₁₂-3(OH)-DM、C₁₄-3(OH)-DM和C₁₆-3(OH)-DM。利用傅里叶变换红外光谱仪(FTIR)、核磁共振仪(¹H NMR)和元素分析仪表征了目标产物结构,通过 DCTA21 表面界面张力仪测定其在水溶液中的表面张力、临界胶束浓度(cmc)以及其热力学常数,并测定了其水溶液的乳化性能和泡沫性能。结果表明:与传统单子季铵盐型表面活性剂相比,Gemini 表面活性剂C_m-3(OH)-DM(m=12,14,16)具有更高的表面活性,其临界胶束浓度(cmc)分别为 0.0265mmol/L、0.0169mmol/L、0.0083mmol/L,对应的表面张力γ_cmc分别为 32.1mN/m、30.1mN/m、27.7mN/m。

Synthesis and performance of a series of reactive cationic gemini surfactants

Three reactive cationic Gemini surfactants, C₁₂-3(OH)-DM, C₁₄-3(OH)-DM and C₁₆-3(OH)- DM, were synthesized through three-step reaction using 2-dimethylamino ethyl methacrylate (DM), Epichlorohydrin (ECH) and three kinds of long chain alkyl tertiary amine(N, N-dimethyldodecylamine, N, N-Dimethyltetradecylamine and N, N-dimethylhexadecylamine) as main raw material. The structure of Gemini surfactants was confirmed by FTIR, ¹H NMR and elemental analysis, and their abilities to lower water surface tension and critical micelle concentrations (cmc) were also evaluated by surface tension measurement. Foaming and emulsification properties were also studied. The results showed that three reactive cationic Gemini surfactants C_m-3(OH)-DM(m=12, 14, 16)showed superior surface properties to conventional monomeric surfactant, and their critical micelle concentrations (cmc) were 0.0265mmol/L, 0.0169mmol/L and 0.0083mmol/L, γ_cmc were 32.1mN/m, 30.1mN/m and 27.7mN/m.