缩醛型可分解表面活性剂的合成

Synthesis of the Acetal Cleavable Surfactants

在对甲苯磺酸的催化下,庚醛、癸醛分别与3-氯-1,2-丙二醇通过缩合反应制备了氯代缩醛2-烷基-4-氯甲基-1,3-二氧杂环戊烷;再分别与亚硫酸钠进行磺化反应,合成了缩醛型可分解表面活性剂(2-烷基-1,3-二氧杂环-4)甲烷-1-磺酸钠盐,磺化产率分别为87.9%和87.3%;所得中间体和产物的结构经IR、1HNMR表征。对缩合反应的物料摩尔比、催化剂用量、反应时间等进行了优化,结果表明:n(庚醛)∶n(3-氯-1,2-丙二醇)=1∶1.2,对甲苯磺酸0.4g,反应时间20h为较佳合成条件,产率达66.51%～68.70%。测试了可分解表面活性剂Ⅱa、Ⅱb在盐酸溶液中的分解率,结果显示:分别在1.5、3h,分解率就可达100%。

The 2-alkyl-4-chloromethyl-1,3-dioxolane acetals were synthesized from heptanal or decanal with 3-chloro-1,2-propanediol, catalyzed by toluene-p-sulfonic acid. Then after reaction with sodium sulfite, the cleavable surfaetants sodium （2-alkyl-1, 3-dioxolan-4-yl ）methane-1-sulfonate were prepared. The yields were 87.9% and 87.3%, respectively. The structures of intermediates and the prepared products were characterized by IR, and ^1HNMR spectra. Consequently, the optimum conditions of material ratio, the amount of the catalyst and the reaction time of the intermediates were studied in detail. The favorable reaction conditions were n （ heptanal ） ： n （ 3-chloro-1,2-propanediol ） = 1 ： 1.2, toluene-p-sulfonic acid dosage 0.4 g, reaction time 20 h. The yield was 66.51% - 68.70%. The destructibility of cleavable surfactants Ⅱ a and Ⅱ b were also determined in HCl. The results showed that the 100% destructibility of surfaetants was between 1.5 h and 3 h.