对-(月桂基)苄基均质聚氧乙烯醚丙烷磺酸钠的合成与表面活性

以苯为原料先后经酰化、黄鸣龙还原、氯甲基化及威廉逊成醚等反应制得4种具有不同氧乙烯数(其氧乙烯数为1~4)的对-(月桂基)苄基均质聚氧乙烯醚醇,再和1,3-丙烷磺内酯反应得到了对应的对-(月桂基)苄基均质聚氧乙烯醚丙烷磺酸钠。用ESI-MS和1HNMR确定了化合物的结构,用两相滴定法确定了产物中活性物的质量分数均大于99%。用W ilhelmy法测定了30℃时它们在水溶液中的临界胶束浓度(CMC)和临界胶束浓度下的表面张力(γCMC),其CMC(mmol/L)和γCMC(mN/m)分别为:0.176,34.9;0.149,34.8;0.102,33.1;0.142,34.8。结果表明:该类表面活性剂随着氧乙烯基团的增加(1~3),其CMC和γCMC都逐渐减小,但当氧乙烯数继续增大时,两个物理量都开始增大。

Synthesis and Surface Properties of Homogeneous Sodium p-(n-Lauryl)-benzyl Polyoxyethylenated Propane Sulfonates

Four kinds of p-(n-lauryl)-benzyl homogeneous polyoxyethylenated alcohol with different number of ethylene oxide(EO) units(from 1 to 4) were synthesized from benzene through four-step processes,involving Friedel-Crafts acylation,Huang-MinLon reduction,chloromethylation and Williamson reaction.Then,these intermediates reacted with 1,3-propanesultone to get the corresponding sodium p-(n-lauryl)-benzyl polyoxyethylenated propane sulfonates.Their structures were identified by ESI-MS and ~1HNMR.The mass fractions of active substances in the products,determined by two-phase titration,were all above 99%.The critical micelle concentration(CMC) and the surface tension(γ_(CMC)) of four surfactants(EO unit=1～4) in aqueous solutions were measured by Wilhelmy-Plate method at 30 ℃,and the values of CMC(mmol/L) and γ_(CMC)(mN/m) were respectively: 0.176,34.9;0.149,34.8;0.102,33.1;0.142,34.8.Both the values of CMC and γ_(CMC) decrease gradually as the number of EO units increases from one to three.However,the values of CMC and γ_(CMC) increase as the number of EO units increases from three to four.