Interaction between HPAM and urea in aqueous solution and rheological properties

In this study, we report the effect of interplay on the rheological properties of partially hydrolyzed polyacrylamide (HPAM) for oil field application. Rheological properties of solution refer to polymer structure, component, conformation, and macromolecular interplay. Through molecular interplay, the alternation of polymer conformation and improvement of rheological behaviors can be realized. The molecular interactions between HPAM and urea (UR) in aqueous solution were studied by ubbelohde viscometer and TA-Rheometer, as well as its rheological properties. In addition, the influence of temperature on interplay between HPAM and agents is explored by rheology and 2D correlation analysis to observe the viscoelasticity of blend solution. Apparent viscosity of samples was measured under conditions of variable temperatures. In addition, the storage modulus and loss modulus of blending solutions were measured. The results indicated that intrinsic viscosity increased with rising UR content in saline solution. Comparing with urea, there was little improvement in intrinsic viscosity when ethylene diamine was added in solution. This was in accordance with data of shear rheology. By combining results of 2D correlation analysis and dynamic light scattering some further evidences were given that there were molecular interactions between carbonyl groups on HPAM lateral chains and amino groups of urea in aqueous solution under variable temperature conditions and from different perspectives.