Synthesis of Cooligomer Based on 2-Allylphenol, Formaldehyde, and Ethylenediamine and Study of Its Structured Product as a Sorbent for Extraction of Uranyl Ions from Aqueous Systems

Abstract

A cooligomer has been synthesized with a yield of 93% by triple condensation of 2-allylphenol, formaldehyde, and ethylenediamine (0.5 : 4.0 : 1.0). The molecular weight and molecular weight distribution of the product were determined (M_w = 860 and M_n = 470), and it was revealed that cooligomer has sufficiently high thermal stability (a significant loss of cooligomer mass was observed at ~400°C). Thermal self-crosslinking (up to 280°C) of the cooligomer and its crosslinking with acrylonitrile in the presence of the initiator benzoyl peroxide (1%) followed by hydrolysis of the resulting polymer in the presence of KOH were carried out. Their structure was studied by IR spectroscopy. The sorption properties of the crosslinked hydrolyzed polymer were examined for the extraction of uranyl ions from model aqueous systems under batch conditions at various pH values, concentrations, and sorption times. It has been found that the maximum recovery of uranyl ions by the hydrolysis product of the crosslinked polymer at pH 7 is 90.8% and the sorption capacity is 203.5 mg/g. The dependence of the batch (“static”) sorption capacity of the crosslinked polymer on the equilibrium and initial concentration of uranyl ions was considered. It has been shown that the sorption capacity stabilizes at ~300 mg/g. The sorption properties of the crosslinked polymer were confirmed by both IR spectroscopy data and by the results of energy dispersive X-ray spectroscopy and scanning electron microscopy.