水解聚丙烯酰胺/胞外多糖复合体系的流变性

Rheological Properties of Hydrolyzed Polyacrylamide/Exopolysaccharide Complex System

田玉芹 钱钦 李海平 陈雷 郭宏伟 辛爱渊 侯万国

TIAN Yuqin QIAN Qin LI Haiping CHEN Lei GUO Hongwei XIN Aiyuan HOUWanguo

为探究聚合物驱油体系中柔性、刚性大分子间的相互作用，详细研究了部分水解聚丙烯酰胺（HPAM，柔性 分子）和深海中温菌Wangia profunda SM-A87 分泌的阴离子胞外多糖（EPS，刚性分子）复合体系的流变性。研究 结果表明，HPAM和EPS 在亚浓溶液区的氢键复合具有降黏效应，这在氢键复合物体系中鲜见报道。随溶液中 电解质浓度和剪切速率增加，HPAM和EPS的复配降黏效应可转变为复配增黏效应。当溶液pH ＜5 或＞11 时， HPAM和EPS也可复配增黏。HPAM和EPS的复配增黏或降黏取决于复合溶液中的分子构型，而分子构型受溶 液pH、电解质浓度和剪切速率的影响。与HPAM体系相比，HPAM/EPS复合体系具有更强的抗盐性，表明其在 三次采油领域具应用潜力。本文可为柔性/刚性阴离子高分子复合体系研究提供理论指导。图20参33

To probe the interactions between flexible and rigid macromolecules in polymer flooding systems，the rheological properties of mixed solutions containing flexible partially hydrolyzed polyacrylamide （HPAM） and a rigid anionic exopolysaccharide（EPS）secreted by a deep-sea mesophilic bacterium Wangia profunda SM-A87 were studied in detail. Results showed that mixing of HPAM and EPS leaded to a viscosity decrease of their mixed solutions in the semidilute regime，which was rarely seen in hydrogen-bonded complex systems. With increasing electrolyte concentrations and shear rates，the viscosity decrease of HPAM/EPS solutions could turn into the viscosity increase. The viscosity increase of HPAM/EPS solutions was also observed when tuning the solution pH to be ＜5 or ＞11. The viscosity decrease or increase of the HPAM/EPS solutions resulted from variation of the molecular configuration that could be influenced by electrolyte concentrations，pH，and shear rates. Compared with the HPAM system，the HPAM/EPS complex system exhibited stronger salt resistance and thus great potential for application in tertiary oil recovery. This work can direct research on other similar systems composed of flexible and rigid anionic macromolecules.

10.19346/j.cnki.1000-4092.2021.01.024