Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (06): 1253-1259.doi: 10.3866/PKU.WHXB201303251

• SOFT MATTER • Previous Articles     Next Articles

Aggregation Behavior of Branched Block Polyethers at Interface and Their Demulsification for Crude Oil Emulsion

ZHAI Xue-Ru1, LIU Teng1, XU Gui-Ying1, TAN Guo-Rong2, Lü Xin2, ZHANG Jian2   

  1. 1 Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, P. R. China;
    2 Technology Research Dept. CNOOC Research Center, State Key Laboratory of Offshore Oil Exploitation, Beijing 100027, P. R. China
  • Received:2013-01-29 Revised:2013-03-25 Published:2013-05-17
  • Supported by:

    The project was supported by the Special Program for Major Research of the Science and Technology, China (2011ZX05024-004-08).

Abstract:

Three poly(propylene oxide)-poly(ethylene oxide) branched block polyethers containing a benzene ring moiety were synthesized, with different molecular weights and propylene oxide/ethylene oxide (PPO/PEO) compositions. Their aggregation behaviors at air/water and oil/water interfaces were investigated by interfacial tension, surface pressure and interfacial dilational rheology methods. Aggregation and the emulsion breaking properties (demulsification) for crude oil were studied based on the polymer PEO content and molecular weight. The demulsification performance of these polyethers and their crosslinked counterparts were compared at different temperatures. The results showed that a polyether with a higher proportion of PEO groups and larger molecular weight occupied a larger area at the air/water interface, reached equilibrium faster, and featured a larger dilational modulus at the oil/water interface. However, the demulsification experiments showed that the polyether with a moderate level of PEO content gave better performance. The cross linking method did not improve demulsification ability in the polyether with large molecular weights. Temperature was also found to have no explicit influence on the demulsification of the cross linked polyethers. This study provides useful data for the selection and application of chemicals used in processing of crude oil.

Key words: Branched block polyether, Interfacial activity, Interfacial dilational rheology, Demulsification

MSC2000: 

  • O648