Study On Synthesis And Properties Of Sulfonated Betaine Gemini Surfactant Based On Cardanol

The molecular structure of surfactant has a great influence on the properties of its physicochemical properties.In this paper,an sulfonate betaine Gemini surfactant basedon cardanol with novel structure and high purity was synthesised from cashew phenol,polyoxymethylene,epichlorohydrin,dimethylamine and sodium 3-chloro-2-hydroxy propanesulfate by dehydration condensation,etherification,tertiary amination and quaternification,whose abbreviation is GCSB.The optimum reaction of intermediate and target products were determined by single-factor analysis experiment and orthogonal experiment andthe content of active substances in target products was detected by phosphotungstic acid method,the result was 87%wt.In adition,the structures of intermediate and tar get products were characterized by FT-IR and 1HNMR,the results indicate that the mo lecular structure is consistent with expectations.The surface tension was measured by drop volume method,the surface and ther modynamic properties of micelle were studied systematically and compared with other traditional surfactants.The results indicate that the critical micelle concentration(cmc)of GCSB and the surface tension of cmc were 0.028mmol×L-1 and 26.62 m N×M-1 resp ectively,which were all lower than those of the comparison,such as sodium dodecyl benzene sulfonate(SDBS),hexadecyl trimethyl ammonium bromide(CTAB),sulfobetaine surfactant based on Cardanol(CSB).The cmc value decreases with the increase of temperature gradually.The results of thermodynamic properties study indicate that the micellationprocess in aqueous solution is mainly from entropy drive,and there is enthal py entropy compensation in the process.Foam,emulsifyin,wettability and adsorption properties of GCSB were determined by stirring method,bubbing method,watershed time method and contact angle measur ement.Results show that,the foaming ability of GCSB system is not outstanding,but the synergistic interaction between GCSB and sodium dodecyl benzene sulfonate is strong,which can improve foam stability greatly.The increase of temperature will lead t o the rapid decrease of foam half-time and the increase of foam volume.When the salinity was 35000mg/L,the foam system could still maintain excellent foaming and stab ilizing ability and showed significant salt tolerance.The optimal concentration of GCSB as emulsifier was 4×10-5mol×L-1 at 308 K,the stability of emulsion increased firstly and then decreased with increasing concentration and decreased with increasing temperature.When alky chain of oil phase increased,the emulsifying properties would also become worse.The minimum contact angle of GCSB aqueous solution on quartz sur face was 18.2° and the maximum value was 53.6°,the contact angle increased at first and then decreased with increasing concentration.The adsorption amount of GCSB on oil sand surface increased and then maintained stable with the increase of concentrati on,adsorption timeand liquid solid ratio.Finally,the effect of concentration,temperature and salinity on the interfacial tension between GCSB and oil was studied by spinning drop method.The results showed that oil-water interfacial tension could be reduced to ultra-low level by GCSB and the fluctuation of interfacial tension was not large after changing temperature and salinity,indicating that GCSB has excellent temperature-resistance and salt-resistance.