Due to the presence of a three-dimensional hydrophilic network structure, hydrogels are a cross-linked polymer system capable of absorbing large amounts of water. This unique property laid the foundation for their widespread use in industry, medicine, pharmaceuticals, and agriculture. On their basis, soft contact lenses, dressings, medicines, superabsorbents, catalysts, means that structure the soil, prevent root drying and improve plant survival, have been created. The aim of this work is to synthesize new water-swellable polymer composites by combining monomer units of different nature, differing in hydrophilic-hydrophobic balance. Research objects: double and ternary polymer composites based on acrylic acid and agar-agar with imidazole. Research methods: Copolymerization of synthetic monomers with natural polymers, complexation of hydrogels and polymer composites with transition metal ions in an aqueous medium, determination of the degree of swelling, IR spectroscopy. Results and discussion: The synthesis of new double and ternary polymer composites based on acrylic acid and agar-agar with imidazole was carried out, their physicochemical and complex-forming properties with transition metal ions in an aqueous medium were investigated.