低浓度部分水解聚丙烯酰胺/柠檬酸铝交联体系剪切稳定性研究

采用粘度法、核孔膜过滤和动态光散射(DLS)法,研究了高分子量低浓度的部分水解聚丙烯酰胺(HPAM)与柠檬酸铝(AlCit)反应所形成的交联体系的剪切稳定性和HPAM剪切降解后与AlCit反应所形成的体系的封堵性能及降解机理.研究结果表明,低浓度的HPAM与AlCit反应所形成的交联聚合物体系随剪切速率增加,其对1.2μm的核孔膜的封堵能力降低.HPAM稀溶液剪切降解后再与AlCit反应,低剪切速率对其封堵性能影响较小,而高剪切速率会使得其封堵性能大大降低.HPAM/AlCit交联体系和HPAM剪切降解后形成的交联体系的封堵性能下降的原因是HPAM/AlCit交联体系中交联聚合物线团(LPC)尺寸和HPAM中高分子线团的尺寸变小.

STUDY ON THE SHEAR-STABILITY OF LOW CONCENTRATION HPAM/AlCIT CROSSLINKED POLYMER SYSTEM

The shear stability and degradation mechanism of crosslinked polymer systems comprising of low concentration and high molecular weight partially hydrolyzed polyacrylamides (HPAM) and aluminum citrate (AlCit) were investigated by viscometry,nuclear pore membrane filtration and dynamic light scattering.The results indicated that the filtering rate in 1.2 μm nuclear pore membrane of crosslinked polymer system formed by low concentration HPAM and AlCit increased and the plugging efficiency decreased,while the shear rate became high.The shear stability of this system was not good,so its plugging efficiency was weak under shear.For crosslinked polymer systems formed by the degraded HPAM in high shear rate and AlCit,the plugging efficiency was little affected under low shear rates,but was lowered obviously in the range of high shear rate.The cross-linked polymer system formed by the degraded HPAM in high shear rate was almost not able to plug the 1.2 μm nuclear pore membrane,but was able to plug the 0.4 μm nuclear pore membrane.Low concentration HPAM which had the same concentration with the former could not plug the 0.4 μm nuclear pore membrane,but the pore membrane with a less small pore diameter after shear.The size of cross-linked polymer coils (LPC) in the crosslinked polymer system and the low concentration HPAM and high molecular weight partially hydrolyzed polyacrylamides (HPAM) coils gradually became smaller while the shear rate became high.The reason that the plugging efficiency of cross-linked polymer system after degradation decreased at high shear rate was that the size of LPC and high molecular weight partially hydrolyzed polyacrylamides (HPAM) coils became smaller because of the rupture of crosslinked polymer coils (LPC) and the partially hydrolyzed polyacrylamides (HPAM) molecules.