Study On Synthesis And Property Of Monoalkyl Diaryl Disulfonate

Three different spacer group anionic surfactants, monoalkyl diaryl disulfonate (MDDADS-n, n=0,1,2) were synthesized by Friedel-crafts reaction of dodecanol with diaryl alkne in the presence of active bleach clay, followed by sulfonation with liquid sulfur trioxide. The structural characters of MDDADS-n surfactants were verified by electrosray ionization/mass spectrometry (ESI-MS), IR spectrum and’HMNR spectroscopy. The surface activity, dynamic interfacial tension and mimic oil washing efficiency in NaCl and CaCl2solutions of MDDADS-1anionic surfactants were investigated; For MDDADS-n surfactants, the effect of the spacer group on the surface activity, salinity and hardness tolerance and mimic oil washing efficiency were studied. The results could be drawn as follows:1、Monododecyl diphenyl methane disulfonate surfactant(MDDADS-1) showed preferable surface active properties, which critical micelle concentration (cmc) was9.1×10-5mol-L-1; Sodium chloride tolerance and calcium chloride tolerance could reach20.55wt.%and17.01wt.%, respectively; wettability of the matrix surface was alterated from oil-wet to less oil-wet; the emulsification of crude oil was very strong.2, At alkali free condition, the dynamic interfacial tensions in the system of oil/MDDMDS surfactant were in the range of100～10-1mN/m, the effect of different NaCl and CaCl2concentrations on interfacial tension were slight; and in the Daqing analog mineralized water, the dynamic interfacial tension of the blend systems of MDDMDS with HABS were in the range of100mN/m; continuing adding inorganic salts, the dynamic interfacial tension of the blend systems of MDDMDS with HABS were decrease to the range of10-2mN/m; In high-salt and high-calcium condition, the mimic oil washing efficiency of MDDADS-1for paraffinic crude oil was exceeded54%.3、For MDDADS-n surfactants, the critical micelle concentration (cmc), surface tension at cmc (γ cmc), C20and the minimum area per molecule (Am;n) of the anionic surfactants were increased when the spacer group length increased; There were little influence on mimic oil washing efficiency of MDDADS-n when the spacer group changed; all MDDADS-n surfactants showed much lower sensitivity to water hardness and the spacer group variation had little effect on it.