苯并咪唑阳离子缩醛型表面活性剂的合成及性能

Synthesis and properties of acetal cationic surfactant containing Benzimidazole

摘要:

以醛、环氧溴丙烷、苯并咪唑为原料制备1-[(2-烷基-1，3-二氧杂环-4）甲基]- 1-苯并咪唑，再与硫酸二甲酯反应合成两种含苯并咪唑的缩醛型可分解阳离子表面活性剂：1-[(2-己基-1，3-二氧杂环-4）甲基]- 1-甲基-苯并咪唑甲基硫酸盐（3a）；1-[(2-壬基-1，3-二氧杂环-4）甲基]- 1-甲基-苯并咪唑甲基硫酸盐（3b）。对中间体[(2-壬基-1，3-二氧杂环-4）甲基]- 1-苯并咪唑(2b)的合成条件进行优化选择，其较佳的合成条件：甲苯为溶剂，n（癸缩醛）：n（苯并咪唑）：n（NaOH）=1：1.1：4，回流24h。所得中间体（2b）产率52.0%。分别测定3a，3b的表面性能：20℃时临界胶束浓度1.4×10-3 mol/L和1.2×10-3 mol/L ；Krafft点均低于20℃；泡沫稳定性70.2%和77.4%；乳化性31min和33min。所有中间体和目标化合物结构经IR、1HNMR表征。

Abstract:

[(2 – alkyl-1, 3 - dioxane -4) methyl] - 1 – benzimidazole was prepared through condensation reaction using aldehyde, epoxy bromopropane and benzimidazole as raw materials. The resulting reacted with dimethyl sulfate to afford two acetal cationic surfactants containing benzimidazole of 1 - [(2 - hexyl 1, 3 - dioxane -4) methyl] - 1 - methyl - methyl sulfate benzimidazole (3a) and 1 - [(2 - nonyl 1, 3 - dioxane -4) methyl] - 1 - methyl - methyl sulfate benzimidazole (3b). The optimal synthetic condition of intermediate [(2 – nonyl- 1, 3 - dioxane -4) methyl] - 1 - benzimidazole was: n (capric acetal): n (benzimidazole): n (NaOH) = 1:1.1:4, refluxing for 24h. The yield of intermediate was 52.0%. The surface properties of 3a and 3b were respective measured. The critical micelle concentration were 1.4 × 10-3 mol / L and 1.2 × 10-3 mol / L in 20℃; Krafft points were lower than 20 ℃; Foam stability was 70.2% and 77.4%; emulsification was the 31min and 33min. The structure of intermediate and target compounds were characterized by IR, 1HNMR spectra.