聚醚类破乳剂的界面扩张流变性质

采用悬挂滴方法研究了不同结构聚醚类破乳剂与煤油间的界面张力及界面扩张流变性质. 结果表明, 4种聚醚类破乳剂均具有较强的降低界面张力能力, 且支链化程度越低分子在界面上排列越紧密, 直线型破乳剂在低浓度条件下界面张力最低. 破乳剂的分子尺寸较大, 慢弛豫过程控制界面膜性质, 吸附膜以弹性为主. 同时, 柔性聚氧乙烯链和聚氧丙烯链对界面膜性质的影响较大, 随着支链化程度增大, 界面分子间相互作用增强, 界面膜弹性增强, 黏性降低.

Interfacial Dilational Rheology of Polyether Demulsifiers

The interfacial tension and dilational rheological properties between polyether demulsifiers with different structures and kerosene were investigated by means of oscillating drop method. The experimental results show that four types of polyether demulsifiers have good abilities in reducing interfacial tension. The demulsifier with straight-chain reduces interfacial tension dramatically at low concentration because the demulsifier with low branched permits closer packing. The slow relaxation process dominates the nature of interfacial film due to larger molecular size of demulsifier. Therefore, all interfacial films of four polyether demulsifiers appear strongly elastic nature. At the same time, the flexible ethylene oxide chains and propylene oxide chains have a big influence on the properties of interfacial film: highly branched of polyether demulsifier enhances the molecular interaction, which results the increase in the elastic nature of film and the decrease of dilational viscosity.