A method which involves the isolation, analysis and characterization of dispersants present in motor oils is disclosed. The method is particularly useful in connection with the characterization of high molecular weight polybutenyl succinimide dispersants present in finished motor oils so as to provide detailed information with respect to the starting material reactants needed to synthesize such dispersants. The method involves breaking down complexation present in the oil followed by the isolation of the dispersant from the oil via dialysis. The isolated dispersant in the form of a dialysis residue is then acidified and passed through an ion exchange chromatographic column to adsorb acid materials away from the dispersant. Dispersant content and total carbonyl content can then be determined. The dispersant is then subjected to saponification with sodium hydroxide to provide a hydrocarbyl sodium succinate and a polyamine. The saponified material is subjected to further dialysis to separate it from remaining oil and then further acidified. The acidification results in the formation of a corresponding succinic acid and a dialkyl ester derivative. Procedures such as GPC and VPO determinations can then be carried out. Model reactant components can then be prepared and reacted to determine if the reaction product obtained matches the original dispersant being analyzed.
本发明公开了一种分离、分析和表征机油中分散剂的方法。该方法尤其适用于表征成品机油中的高分子量聚
丁烯基琥珀
酰亚胺分散剂,从而提供合成此类分散剂所需的起始原料反应物的详细信息。该方法包括分解机油中的络合物,然后通过透析从机油中分离出分散剂。分离出来的分散剂以透析残渣的形式存在,然后将其酸化并通过离子交换色谱柱,将酸性物质从分散剂中吸附出来。然后即可测定分散剂含量和总羰基含量。然后用
氢氧化钠对分散剂进行皂化,得到烃基
琥珀酸钠和
多胺。皂化物进一步透析,使其与剩余的油分离,然后进一步酸化。酸化的结果是形成相应的
琥珀酸和二烷基酯衍
生物。然后就可以进行
GPC 和 VPO 测定等程序。然后可以制备模型反应物成分并进行反应,以确定获得的反应产物是否与正在分析的原始分散剂相匹配。