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

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

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Wilhelmy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。

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 （γCMC） of four surfactants（ EO unit -1 -4） in aqueous solutions were measured by WilhelmyPlate method at 30 ℃, and the values of CMC （mmol/L） and YCMC （raN/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 YCMC decrease gradually as the number of EO units increases from one to three. However, the values of CMC and γCMC increase as the number of EO units increases from three to four.