脂肪酸三乙醇胺单酯琥珀酸酯磺酸盐的制备及表面活性

Preparation and Surface Activity of Fatty Acid Triethanolamine Monoester Sulfosuccinate

以三乙醇胺、长链脂肪酸为原料，制得脂肪酸三乙醇胺单酯（FTME），再经磺化反应合成了4种脂肪酸三乙醇胺单酯琥珀酸酯磺酸盐（FTMS）两性表面活性剂，以月桂酸、棕榈酸、硬脂酸、油酸为脂肪酸合成的FTMS分别命名为FTMS-1、FTMS-2、FTMS-3、FTMS-4。分别用碱性亚甲基蓝法和酸性溴酚蓝法验证了产物的离子性，并考察了FTMS结构中的烷基链长度及其不饱和度对表面张力、Krafft点、样品液粒径及粒径分布、乳化能力的影响。结果表明：产物显示出两性离子的特征，随着脂肪链碳数增加，其Krafft点升高，平均粒径逐渐增大，但脂肪链中的不饱和双键有助于Krafft点的降低和粒径的减小。FTMS-1和FTMS-4具有优异的表面活性。其中，FTMS-1的临界胶束质量浓度（CMC）为52．97mg／L，表面张力γcmc为36．1mN／m，其乳化能力与脂肪醇聚氧乙烯醚（AEO-9）相当且优于十二烷基磺酸钠。

Fatty acid triethanolamine monoester （FTME） was synthesized from fatty acid and triethanolamine. Subsequently, four kinds of fatty acid triethanolamine monoester sulfosuccinate （FTMS） surfactants were obtained by esterification of FTME with maleic anhydride and then sulfonation with sodium sulfite, wherein, the FTMS products synthesized by laurate, palmitate, stearic acid and oleic acid were named as FTMS-1, FTMS-2, FTMS-3 and FTMS-4, respectively. The ionicity of the products were verified by alkaline methylene blue and acid bromophenol blue. The effects of alkyl chain length and unsaturation of products on the surface tension, Kraffl point, particle size, particle size distribution and emulsifying ability were investigated. The results showed that the amphoteric products were successfully obtained. Krafft point and average particle size increased with the increase of alkyl chain length, however, the unsaturation in alkyl chain was conducive to the decrease of Krafft point and average particle size. Especially, FTMS-1 and FTMS-4 exhibited excellent surfactivity. The critical micelle concentration （CMC） of FTMS-1 was 52.97 mg/L, and the surface tension at CMC （γcmc） reached 36.1 mN/m. The emulsifying ability of FTMS-1 was equivalent to that of AEO-9 and superior to that of sodium dodecyl sulfate.