The article presents the results of three-component condensation of 4-isopropenylphenol, formaldehyde and 4-(1-methyl)-1-dimethoxsiphosphorylethyl)phenol cooligomers, their structuring with acrylonitrile. In order to include the carboxyl group in the structure of the cross-linked copolymer, hydrolysis was carried out in the presence of an aqueous solution of potassium hydroxide. The process of sorption of uranyl ions from model aqueous systems by structured (crosslinked) with acrylonitrile and their product of hydrolyze. The structure of the cross-linked copolymer was confirmed by IR spectroscopy data. It has been established that the process of sorption of uranyl ions is significantly affected by the pH of the medium. The best results in the extraction of uranyl ions by the sorbent are achieved at pH 7–8 (at room temperature, the degree of their sorption is ~89–93%, and SCS is ~229–239 mg/g). It has been established that the process is completed within 24 hours, cross-linked co-oligomers can be reused after desorption of uranyl ions by mineral acids