Salt endurable and shear resistant polymer systems based on dynamically reversible acyl hydrazone bond

Abstract The macromolecule systems constructed via dynamic covalent bonds may exhibit high viscosity and elasticity. The ketone-based copolymers were prepared via free radical copolymerization of acrylamide (AM) with diacetone acrylamide (DAAM). And the cross-linked copolymer based on dynamic acyl hydrazone bond was formed by ketone-based copolymer and adipic dihydrazide (ADH). The optimum conditions for the construction of the cross-linked copolymer and its salt endurance, shear resistance and temperature tolerance were investigated by viscosity analysis, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Moreover, the viscoelasticity behavior of copolymers in aqueous solution was explored by rheology measurements. The results showed that the system had excellent viscosity with a 1 M ratio of hydrazide at 3000 mg/L. Furthermore, the cross-linked copolymer still maintained a large hydrodynamic radius and considerable viscosity at high salinity, even after high-speed shear. The combination of high molecular weight copolymer and dynamic covalent bond makes the copolymer exhibit excellent salt and shear resistance, which provides an alternative thought of enhancing oil recovery.