低浓度HPAM/AlCit交联聚合物溶液性质研究

Study on Properties of the Linked Polymer Solution with Low Polymer Concentration

采用粘度法、扫描电镜(SEM)、核孔膜过滤、动态光散射(DLS)和27AlNMR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)体系交联反应过程溶液性质变化.结果表明,HPAM与AlCit反应在低剪切速率时体系粘度随反应进行而降低,在剪切速率较高时具有剪切稠化现象,HPAM与AlCit反应过程中交联态Al的自旋-晶格弛豫时间随反应进行变短.低浓度的HPAM与AlCit发生分子内交联反应形成交联聚合物线团(LPC)在水中的分散体系,即交联聚合物溶液(LPS).交联聚合物溶液中LPC的平均流体力学半径约为238nm,其形态接近球形,具有多分散性.LPS对1.2μm核孔膜的封堵程度与其反应时间有关.

The properties of solution in the reaction process of low concentration and high molecular weight partially hydrolyzed polyacrylamide(HPAM) and aluminum citrate(AlCit) system are investigated by using viscometer, SEM, nuclear pore membrane, dynamic light scattering and Al-27 NMR. The experimental results show that the viscosity of HPAM/AlCit crosslinking system is decreased with reaction time in lower shear rate and the system is shear thickening in higher shear rate. After crosslinking the spin-lattice relaxation time(T-1) of Al decreases with the reaction time. The linked polymer solution is formed by intra-molecular crosslink of HPAM and AlCit forming linked polymer coil(LPC) in lower concentration of the system. The LPC is a spherical coil with a mean hydrodynamic radius of 238 nm. The ability of the LPS to block the neclear pore film is related to the reaction time of HPAM/AlCit system.