高等学校化学学报

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低温非水环境中疏水缔合聚丙烯酸钠与两性离子表面活性剂的相互作用

韩一秀1,吴殿国2,李宏谱1,殷鸿尧2,梅拥军1,冯玉军2,钟祖勤1   

  1. 1. 中国民航局第二研究所
    2. 四川大学
  • 收稿日期:2020-08-31 修回日期:2020-11-14 出版日期:2020-11-16 发布日期:2020-11-16
  • 通讯作者: 殷鸿尧

Interactions between Hydrophobic Associating Poly(sodium acrylate) and a Zwitterionic Surfactant in Non-Aqueous Media and Low Temperature Environment

  • Received:2020-08-31 Revised:2020-11-14 Online:2020-11-16 Published:2020-11-16

摘要: 疏水缔合聚合物和表面活性剂是构建黏弹性流体的重要物质,二者的相互作用对流体性质具有显著影响,一直是该领域的研究热点,但此前的研究仅聚焦于水溶液中室温及以上温度范围,而零下极端低温环境中的相互作用尚未涉及。本文以疏水缔合聚丙烯酸钠(HMPA)为模型聚合物,研究了其与两性离子表面活性剂N-(顺-二十二碳-13-烯酸酰胺基丙基)-N,N-二甲基羧酸甜菜碱(EDAB)在乙二醇/水混合溶剂中低温环境(?20 ~ 20°C)的相互作用及混合体系的流变性质。先后考察了HMPA溶解于纯水、乙二醇/水混合溶剂的流变行为和HMPA-EDAB乙二醇/水混合溶剂的流变行为及自组装结构形貌。研究发现,加入50 vol%的乙二醇会阻碍HMPA疏水支链形成缔合结构,减弱其增黏性能,但同时也会大幅降低体系的冰点。在HMPA-EDAB混合体系中,HMPA疏水支链会进入EDAB胶束内核自组装形成混合胶束。混合胶束的形貌取决于HMPA和EDAB的浓度以及环境温度,进而影响体系的流变行为。零下低温有助于EDAB形成蠕虫状胶束,因此HMPA与EDAB表现出更强的协同增效作用。

Abstract: Hydrophobic associating polymers and surfactants are the main materials used to fabricate viscoelastic fluids. The interaction between these polymers and surfactants exerts significant effect on the fluids properties, so it has been a popular research topic in this field. However, previous studies only focused on aqueous systems at room temperature or above, there has being few researches related to the extremely low temperature environment. In this paper, the interactions between the neutralized salt of hydrophobically modified polyacrylate acid (HMPA) and zwitterionic surfactant erucyl dimethyl amidopropyl betaine (EDAB) in mixed ethylene glycol/water at low temperature ranging from 20 °C to ?20 °C are studied, and the effects on the rheological properties are examined. The rheological behavior of HMPA in pure water and in the mixed ethylene glycol/water are first investigated, and the rheological response of HMPA-EDAB in ethylene glycol/water and their self-assembly morphology are then studied. It is found that the introduction of ethylene glycol in aqueous solution, on one hand, inhibits the association of hydrophobic chains on HMPA, resulting in the reduction on viscosifying ability. On the other hand, it also largely reduces the freezing point of the mixture. In the HMPA-EDAB system, the hydrophobic chains of HMPA will go into EDAB micelles to form mixed micelles whose morphology is dependent on the concentration of HMPA and EDAB as well as temperature, and thus affecting the fluid rheological properties. The subzero low temperature is beneficial for EDAB forming wormlike micelles, so that the synergistic effect between HMPA and EDAB become more obvious in this case.

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