Hydrophobic Dendritic Modification of a Poly(acrylamide-co-acrylic Acid) Copolymer with Behera′s Amine as Viscous Agent

Water-soluble polymers viscosifying properties can be enhanced through the incorporation of hydrophobic dendric monomers. In a specific mole ratio, these monomers establish both intra- and intermolecular associations that can affect their behavior in aqueous solution. These custom-made polymers, find applications in various stages of crude oil production, particularly in enhanced oil recovery. This study aims to modify a copolymer of acrylamide and acrylic acid through amidation of between the carboxylic acid of the copolymer with primary amine of a dendronized aminotriester (Behera's amine) to obtain a copolymer with enhanced viscosifying properties in aqueous solution. Spectroscopic methods such as Fourier Transform Infrared Spectroscopy (FTIR), 1H and 13C NMR were employed to confirm the incorporation of the dendron in the copolymer chain. Size exclusion chromatography–multi-angle light scattering–differential refractometer index detectors (SEC-MALS-dRI) and dynamic light scattering (DLS) were employed to determine the weight-average molar mass, dispersity, and radius of gyration and hydrodynamic radii of the polymer in solution, respectively. Additionally, the viscosity and viscoelastic parameters of the new copolymers in aqueous solution were evaluated by rheometry. The results demonstrate that the incorporation of Behera's amine through amidation leads to an increase in viscosity by at least 2.2 times compared to the unmodified acrylamide–acrylic acid copolymer.