Viscous and Interfacial Behaviors, and AFM Morphologies of a Tetra-Polymer in Aqueous Solutions for Enhanced Oil Recovery

An acrylamide-based tetra-polymer (PAVO) containing a macro-monomer APEO: allyl-capped octylphenoxy poly(ethylene oxide) and vinyl biphenyl (VP), was measured in 30g/L NaCl with static light scattering. The result shows that the molecular weight is low and the polymer chains are expanded. The apparent viscosities are much higher in 90g/L NaCl than in water for PAVO at polymer concentrations higher than 1g/L, the salt-thickening effects induced by the Na+, Ca2+, and Mg2+ ions are exhibited, and both surface and interfacial tensions are low in water and 90g/L NaCl. In order to reveal the mechanism giving rise to solution properties for this polymer, the effects of polymer concentration on associating behaviors of the polymer chains in water and in 90g/L NaCl, were investigated by the ultraviolet spectral analysis using pyrene as a probe. Resistance factor and residual resistance factor are remarkably higher in 120g/L salt for PAVO than for HPAM. Atomic force microscope (AFM) morphologies of PAVO in water show that the expanded polymer chain bundles are formed at the polymer concentrations of 0.5-1.5g/L, which demonstrates that the introduction of the APEO macro-monomer together with VP can make the polymer chains expanded.