关键词: 聚合物, 微观结构, 扫描电镜, 动态光散射, 粘弹性, 提高采收率

Abstract: The microstructures of comb-shape polymer(CP)solution,hydrophobic associating polymer(HAP)solution and polyacrylamide(HPAM)solution were studied with microscope,dynamic light scattering and rheological analysis technologies.Hydrodynamic radius of single molecule of HPAM and CP samples normally distributed in the order of magnitude range of 10 to 100 nm.Polymer molecules generally distribute randomly in solution to form non-uniform net skeletons,in which there are thick backbones attached with thin branches.Most skeletons were built up with the aggregations of polymer molecules.Some orderly net structures have self similarity with fractal characteristics under a certain condition.This kind of net skeletons either sustain the bulk of the solution or adsorb and wrap water molecules to produce resistance to deformation.More perfect net structures have higher viscosifying ability.Salts could be enriched around electriferous groups of polymer molecules in solution,which formed a salt concentration gradient.Several kinds of surfactants could make HAP molecules curl and aggregate together,which reduced the number of water molecule adsorbed and packaged by HAP molecules and led to rapid drop of HAP solution in viscosity.In addition,when HAP solution flows through porous medium,the pore throats of rock could make the structure of HAP molecule broken,which results in a great loss in viscosifying ability of HAP.

Key words: polymer, microstructure, scanning electron microscope, dynamic light scattering, viscoelasticity, enhanced oil recovery