柠檬酸型络合表面活性剂的合成及其溶液性质

摘要

Three kinds of chelating surfactants, tetradecanol monoester of citric acid (NM14), hexadecanol monoester of citric acid (NM16) and octodecanol monoester of citric acid (NM18) were synthesized with citric acid, acetic anhydride and fatty alcohols through indirect esterification. The products were characterized by IR and elemental analysis. The surface properties of the surfactants in inorganic salts were determined. The results showed that the salt of NM has a low level of critical micelle concentration (cmc) at 25 ℃:2.21, 1.20 and 0.75 g/L for NM14, NM16 and NM18, respectively. They also have good properties of salt resistance and chelating stability to Fe3+ .%以柠檬酸、乙酸酐和脂肪醇为主要原料,通过间接酯化法先合成了柠檬酸酐,然后与脂肪醇合成了碳数为14,16和18的柠檬酸高级脂肪醇单酯,并用IR、元素分析对产物结构进行了表征,测定了活性剂在NaCl、CaCl2溶液中的表面性质和对Fe3+的络合性能.结果表明,产物纯度高,柠檬酸高级脂肪醇单酯盐的临界胶束浓度(cmc)与疏水基碳数成正比,cmc分别为2.21,1.20和0.75 g/L,对应的γcmc分别是38.21,33.42和29.61 mN/m,对多价阳离子Ca2+和Fe3+具有较好的络合稳定性,其中对Fe3+的络合稳定能力分别为2.6,2.3和1.27 g/g.