Synthesis and Properties Evaluation of Sodium Fatty Alcohol Polyoxyethylene Ether Sulfonate

Abstract

Abstract Sodium salts of fatty alcohol polyoxyethylene ether sulfonates with different length of hydrophobic chain (CnE3SO3, n +; 14, 16, 18) were synthesized from sodium isethionate, then the structure was verified by IR. The temperature resistance, calcium-tolerant stability and salt tolerance were evaluated by pyrogenetic decomposition, phase separation and middle phase emulsion respectively. In addition the mixture of CnE3SO3 and heavy alkylbenzene sulfonate (HABS) was studied. The results showed that: (1) CnE3SO3 was very stable at 150°C especially in neutral, weak acid and weak alkaline conditions; (2) CnE3SO3 performed a good salt tolerance and have a rank of C18E3SO3 > C16 E3SO3 > C14E3SO3; (3) the calcium-tolerant stability of CnE3SO3 reached 8700 mg/L, 9500 mg/L and 10000 mg/L respectively; (4) CnE3SO3 was very good for improving the salt tolerance of mixture of CnE3SO3 and HABS. C18E3SO3 was the best in mixtures of Daqing crude oil/water containing C18E3SO3 and HABS in a ratio of ω(C18E3SO3):ω(HABS) = 3:7 and showed the strongest synergistic effect. The interfacial tension in the system Daqing crude oil/water reached a minimum in the order of 10–3 mN/m and was always below 10–2 mN/m for cNaCl from 0 to 15000 mg/L.