Synthesis And Properties Of A Novel Of Amphoteric Surfactants Sulfobetaines

There is quite a few reports on synthesis of betaine surfactant.However the renewable resources oleicacid is used in this paper. Then aromatic group is introduced to the oleic acid and three kinds of theintermediates of tertiary amine were synthesized through amidation condensation reaction withN,N-Dimethyl-1,3-propanediamine and Aryl methyl oleate.Finally three types of sulphobetaines surfactantswere prepared through quaternization reaction with Sodium3-Chloro-2-Hydroxy Propanesulfate andtertiary amine above. Structures of the products were characterized by using IR and NMR. The syntheticprocess, the surface tension performance, interfacial properties of crude oil/water, foamproperties emulsifying capacity were also discussed. Theoretical basis has been offered for suchsurfactants in oil field applications.The surface tensions of three sulfobetaine amphoteric surfactants which weresynthesized by our laboratory were measured at different temperature by drop-volume method.And the plots of γ-lgc were drew.Then sueface parameters were calculated by the plots of γ-lgc andGibbs adsorption equation. The results showed that an increase of the aromatic ring size in thealkyl chain increased the cmc and γcmc. However, with the increase of the aromatic ring size,the adsorption of arylalkyl surfactants began to weaken. Through the measurement ofthermodynamic parameters in the formation of micelle, it can be examinied that the process ofmicellization was mainly driven by the entropy and there was entropy-enthalpy compensationphenomenon.The effects of the concentration and temperature on their foam properties wereinvestigated by Ross-Miles method. As the mass concentration of three kinds of surfactantsraised,the foaming power increased firstly,and then tended to a certain value.The foamstability was enhanced gradually with increasing the concentration.As the temperatureincreased,the foaming power was heightened significantly,while foam stability decreased. Theemulsifying properties of three kinds of sulfobetaines were investigated by a water diversionmethod.As the concentration was increased,the emulsifying power of three kinds ofsurfactants increased firstly and then reached to a certain value. Spectrophotometry was usedto study the solubilization of the three kinds of sulfobetaine surfactants.The result showed thatwith aryl volume increases, the solubilization ability was enhanced. Oil/water interfacialproperties of the three kinds of sulfobetaine surfactants were examined by the spinning dropmethod. Interfacial tension decreased with the increase of volume of the aromatic ring. Withincreasing the concentration of NaCl, the interfacial tension of m-dimethylphenyl-OASBdecreases.