Study Of The Molecular Structure And The Structure-Property Relationship Of Alkyl Benzene Sulfonates

Alkyl benzene sulfonates are found in most surfactants used to enhance the oil recovery. It is significant to study the relationship between structures and interfacial properties of these surfactants for mechanism research of the oiling recovery. Linear alkyl benzenes and linear alkyl dimethyl benzenes, prepared by the alkylate reaction of linear alpha olefin with benzene or dimethyl benzene which were sulfonated by chlorosulfonic acid and then neutralized to produce linear alkyl benzene sulfonates and linear alkyl dimethyl benzene sulfonates. The equivalent alkane carbon numbers of synthesized surfactants and crude oil from Daqing Production Plant No.4 were determined by the method of interfacial tension scanning. Studied the influence situation of surfactants concentration on the equivalent alkane carbon number. Studied the interfacial tension of surfactants against Daqing Production Plant No.4's crude oil. The interfacial tensions were observed with changes of surfactant and the interfacial effects were compared with changes of the NaOH,Na₂CO₃ and NaCl concentration .Also gives explanations to some phenomenons. An approach based on the molecular topology was used to characterize the molecular structure of the linear alkyl benzene sulfonates. Based on the characteristics of molecular structure, the distance matrix was used to characterize the connectivity of the groups in the molecules. It showed that there exists very good correlation between the coding and 4 properties of linear alkyl benzene sulfonates. The correlation coefficients (r) of MLR equation for quantitative structure-property relationship on critical micelle concentration, biodegradability, hydrophile lipophile balance value and equivalent alkane carbon number are respectively 0.9978,0.9848,0.9999,0.9970.