Synthesis and Properties Evaluation of Sodium Fatty Alcohol Polyoxyethylene Ether Sulfonate

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 degrees 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 omega(C(18)E(3)SO(3)):omega(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 15 000 mg/L.