Synthesis and Properties Evaluation of Sodium Fatty Alcohol Polyoxyethylene Ether Sulfonate

Abstract Sodium salts of fatty alcohol polyoxyethylene ether sulfonates with different length of hydrophobic chain (C n E 3 SO 3 , 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 C n E 3 SO 3 and heavy alkylbenzene sulfonate (HABS) was studied. The results showed that: (1) C n E 3 SO 3 was very stable at 150°C especially in neutral, weak acid and weak alkaline conditions; (2) C n E 3 SO 3 performed a good salt tolerance and have a rank of C 18 E 3 SO 3 > C 16 E 3 SO 3 > C 14 E 3 SO 3 ; (3) the calcium-tolerant stability of C n E 3 SO 3 reached 8700 mg/L, 9500 mg/L and 10000 mg/L respectively; (4) C n E 3 SO 3 was very good for improving the salt tolerance of mixture of C n E 3 SO 3 and HABS. C 18 E 3 SO 3 was the best in mixtures of Daqing crude oil/water containing C 18 E 3 SO 3 and HABS in a ratio of ω(C 18 E 3 SO 3 ):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 c NaCl from 0 to 15000 mg/L.