Synthesis Of Alkylbenzene Sulfonates And Application Of Topological Method

Surfactants of alkylbenzene sulfonates that were tested in domestic oil field for EOR are made of complicated mixtures, a majority of them depends on import, so the synthesis of pure alkylbenzene sulfonates is the academic base of the study for the relation between structure and property, the complex for surfactants of alkylbenzene sulfonates. Through these studies this kind of surfactant can be efficiently used for EOR.Six kinds of isomers of sodium alklybenzene sulfonates were synthesized from chloride and o-xylene through five-step process, involving Friedel-Crafts reaction, Grignard reaction, reduction, sulfonation and neutralization. The structures of the intermediates and the final products were characterized by FT-IR, ESI-MS 13C NMR and 1H NMR. The relationship between boiling point of polyalkylbenzene and their molecular structure were studiedThe surface tension of dilute aqueous solutions of products was measured at 25℃by Drop-volume method and then the critical micelle concentration (CMC) was determined. The values of CMC( mmol·L-1) andγCMC ( mN·m-1) were listed as follows :Ⅰ: 0.25, 30.00;Ⅱ: 0.50, 28.21;Ⅲ: 0.79, 28.10;Ⅳ: 1.00, 27.01;Ⅴ: 2.00, 26.41;Ⅳ: 2.50, 26.40. These results indicated that as the CMC increasing, theγCMC reduced with the moving of the benzene ring from the edge to the middle of the long chain alkyl.The interfacial tension behavior of this series of alkylbenzene sulfonates was investigated in alkane/aqueous system and crude oil/aqueous system respectively. The dynamic interfacial tension behavior shows that these six kinds of surfacrants have different interfacial tension.