β-Cyclodextrin modified anionic and cationic acrylamide polymers for enhancing oil recovery

► Anionic and cationic acrylamide polymers containing cyclodextrin are synthesized. ► The copolymers can effectively improve the interfacial tension of surfactant. ► The copolymers own excellent salt resistance and temperature tolerance. ► The polymers have superior viscosification property and shear resistance.