交联聚合物溶液与聚合物溶液的特性差异

DIFFERENCE BETWEEN LINKED POLYMER SOLUTION AND POLYMER SOLUTION

采用光学显微摄影、动态光散射和核孔膜过滤等方法,研究了低浓度部分水解聚丙烯酰胺(HPAM)与柠檬酸铝(AlCit)形成的交联聚合物溶液(LPS)中交联聚合物线团(LPC)的形态、尺寸、变形性等特性。结果表明,LPC与聚合物线团(PC)相比,在形态、尺寸、变形性能等方面存在明显差异。干燥后的LPS样品中,LPC为球形,PC的形状不清晰。低于某一临界质量浓度(0.200～0.300g/l)时,LPC尺寸略小于PC;高于此浓度后,LPC的尺寸始终大于PC。HPAM/AlCit交联体系的临界质量浓度(0.280g/l)略高于聚合物溶液的临界交叠质量浓度(0.250g/l)。由于分子内的交联作用,与PC相比,LPC的剪切变形能力和水化变形能力有限,LPC较强的抗剪切变形特性使其具有特殊的封堵多孔介质的能力。

Linked polymer coils (LPC) dispersing in the cross-linking system was prepared from low concentration partially hydrolyzed polyacrylamide (HPAM) (the polymer mass concentration is lower than 0.300 g/l) linked with aluminum citrate (AlCit, cross-linker). Micro-filtration, dynamic light scattering (DLS) and optical microscopy were used to study the conformation, size and deformation properties of LPC. The results showed that under the same conditions, obvious differences in shape, size and deformation properties between the LPC and the normal polymer coils (PC) were observed. The shape of the dried LPC seemed like a round particle, while the shape of the dried PC appeared blurring on the photographs. When the mass concentration of HPAM was lower than the critical value (0.200-0.300 g/l), the size of the LPC was a little smaller than that of the PC. When the concentration of HPAM was beyond the critical value, the size of the LPC was always larger than that of the PC. The critical concentration value of the cross-linking system (HPAM cross-linked with AlCit) was slightly higher than the critical overlapping concentration value of the polymer solution. Compared with the PC, because of cross-linking within molecule, the deformation of LPC caused by shear or movement of hydrating equilibrium was more restricted, which contributed to the effective plugging in the throats of porous media.