支状嵌段聚醚的界面聚集行为及对原油乳状液的破乳作用

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

合成了三种不同聚氧丙烯/聚氧乙烯(PPO/PEO)比例的含苯环支状嵌段聚醚, 通过界面张力、界面流变、表面压以及对原油乳状液的破乳脱水效果的测定, 考察了其界面聚集行为和破乳作用对PEO含量和分子量的依赖性, 并且对比研究了三种支状聚醚分子交联前后的破乳性能. 结果表明, PEO含量高且分子量大者,其单分子界面占据面积大, 在油/水界面达到吸附平衡的时间短, 其油/水界面扩张模量及扩张弹性均高于PEO含量较少者. 但是对原油乳状液的破乳脱水效果则是PEO含量居中的聚醚最好. 温度影响和交联与否的研究表明, 交联并不能提高分子量较大的聚醚对原油乳状液的破乳效果, 温度对聚醚分子交联前后的破乳效果有不同的影响规律. 本研究可为原油集输过程中化学品的选择与应用提供一定的依据.

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 demulsiflcation 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.