Preparation and properties of alkyl diphenyl ethers/alkyl benzene mixed sulfonates

In this study, alkyl diphenyl ether/alkyl benzene mixture was used as raw material to prepare alkyl diphenyl ether/alkyl benzene mixed sulfonate (named after DL-n, where <i>n</i> = 3, 5, 7, <i>n</i> = 3 refers to the mass ratio of alkyl diphenyl ether in raw material is 3 parts, the mass ratio of alkyl benzene is 7 parts, and the rest are the same) by gas SO₃ membrane sulfonation process. The composition analysis and structural characterization were carried out. The equilibrium surface tension, dynamic surface tension, alkali resistance, foam, emulsification and contact angle of DL-n were measured and compared with sodium dodecyl benzene sulfonate (LAS) and sodium dodecyldiphenyl ether disulfonate (MADS). The results show that the critical micelle concentration (CMC) and the surface tension change in the order of MADS &gt; DL-7 &gt; DL-3 &gt; DL-5 &gt; LAS. With the increase of the proportion of alkyl diphenyl ether sulfonates in the mixture, the foamability decreased, and DL-n showed excellent foamability. Improved alkali resistance, can be applied to high alkali environment; Emulsifying capacity decreased; The contact angle increases.