薄层色谱法测定聚氧乙烯型阴离子表面活性剂氧乙烯数分布

Determination of Ethoxylate Oligomer Distribution in Polyoxyethylene Surfactants by Thin-Layer Chromatography

含有聚氧乙烯链(EO)的阴离子表面活性剂(a-S_a)兼有阴离子和非离子两类活性剂共同的优点,近年来在石油、轻工和化工行业中获得了广泛的应用。环氧乙烷的阶梯式加成,使这类a-S_a的加成产品成为具有一定EO数分布而非单一聚合度的调聚物。因EO加成数的多少及EO数的分布情况对活性剂的物化性能有很大影响,因此需要测定其EO数分布及纯度。 对聚氧乙烯型非离子表面活性剂EO数分布的测定,国内外已做了许多工作,而对a-sa EO数分布的测定目前很少报道。本文采用薄层色谱法(TLC)

The number of ethylene oxide (EO) and its distribution in four oxyethylenated anionic surfactants were determined by TLC and Field Desorption Mass Spectrometry. The EO number distributions in purified samples and crude products have been determined with one-and two-dimensional TLC respectively,and similar results have been obtained.