Study On Synthesis And Properties Ofamphoteric Surfactant—alkyl-amido-hydroxyl-sulfobetaines

Betaine surfactant is a typical type of amphoteric surfactant with unique properties. Currently, betaine surfactant can not satisfy the related fields requirements in variety and quality owing to their technology and price problems. Therefore, betaine surfactant is increasingly attracting the interest of researchers both in synthesis and industrial applications.There is quite a few reports on application of betaine surfactant in tertiary oil recovery. This type surfactant is applicable to foam flooding due to their excellent foamability and high foam stability. In view of this, Alkyl-Amido-Hydroxyl -Sulfobetaines was synthesized in this study. The synthetic process, the surface tension performance, interfacial properties of crude oil/water and foam properties were also discussed. Preliminary exploration has been made for use of oil-displacing surfactant in tertiary oil recovery.Four kinds of the intermediates of tertiary amine were synthesized through amidation condensation reaction with N,N-Dimethyl-1,3-propanediamine and different carbon chain length of fatty acids. They are respectively Dodecyl-Amido -Propyl-Dimethyl-Amine(DAPDA),Tetradecyl-Amido-Propyl-Dimethyl-Amine(TAPDA), Hexadecyl-Amido-Propyl-Dimethyl-Amine (HAPDA) and Octadecyl-Amido -Propyl-Dimethyl-Amine (OAPDA). Based on the indicators of the evaluation of the fatty acid conversion. Influence of reaction temperature and time on synthetic reaction was emphatically discussed. It showed that a conversion of the fatty acid higher than 94% can be achieved when reacted for 7 hours at 150℃. Four types of Betaine Surfactant were prepared through quaternization reaction with Sodium 3-Chloro-2-Hydroxy Propanesulfate (a laboratory made) and tertiary amine above. They are respectively Dodecyl-Amido-Hydroxyl-Sulfobetaines (DAHSB), Tetradecyl -Amido-Hydroxyl-Sulfobetaines(TAHSB),Hexadecyl-Amido-Hydroxyl-Sulfobetaines (HAHSB) and Octadecyl-Amido-Hydroxyl-Sulfobetaines (OAHSB).Set the reaction of HAHSB as an example, the optimum experimental condition was approached by Orthogonal Design.The results showed that the optimal condition was obtained: reacted for 6 hours at 85℃, tertiary amine: 3-Chloro-2-Hydroxy Propanesulfate=1:1.1 (mol), 30 percent of materials, the yields of 83.6%, when using water as solvent; reacted for 6 hours at 80℃, tertiary amine: 3-Chloro-2-Hydroxy Propanesulfate=1:1.1 (mol), isopropanol:water=1:2 (volume), the yields of 88.9%, when using isopropanol and water as mixed solvents. IR, UV, NMR and MS were confirmed to be in good agreement with that of the target chemicals.Aiming at present condition of Daqing Oil Field, the surface tension performance and critical micelle concentration were researched, interfacial tension minima and dynamic interfacial tensions of Betaine Surfactant above against crude oil was observed with changes of surfactant and alkali concentrations, the stability quality of interfacial tensions was also investigated, the foaming characteristics was discussed too. It was having optimal surfactant concentrations (0.1wt%) and alkali concentrations (0.5wt%). On this condition, the interfacial tension minima of all the Betaine Surfactant above can reach 10-3 mN/m. Better foam composite index (FCI) was obtained when the concentration of the Betaine Surfactant is 0.3wt%. For example, the FCI of DAHSB was up to 117117.