Preparation of poly (sodium acrylate) polymer-brush-grafted polystyrene-divinylbenzene resins and their adsorption performance toward nitrogen-containing organic compounds

Purpose The purpose of this paper is to synthesize a good adsorbent, poly (sodium acrylate) polymer brushes grafted polystyrene-divinyl-benzene (PS-DVB-P[AA-Na]-SPABA), which can selectively adsorb berberine from complex nitrogen-containing organic compound systems, and to systematically investigate its adsorption performance. Design/methodology/approach In this work, a novel polymer microsphere, PS-DVB-P(AA-Na)-SPABA, was synthesized by grafting poly(sodium acrylate) (P[AA-Na]) polymer brushes onto polystyrene-divinylbenzene (PS-DVB) via surface-initiated atom transfer radical polymerization, followed by modification with p-aminobenzoic acid (SPABA). The chemical structure of PS-DVB-P(AA-Na)-SPABA was confirmed by multiple methods, such as Fourier transform infrared and X-ray photoelectron spectroscopy analysis. Findings The adsorption process showed a good fit with the pseudo-second-order kinetic and Freundlich isotherm models. The thermodynamic parameters of the berberine adsorption process revealed that adsorption was spontaneous and endothermic. The resulting polymers were promising for the adsorption of berberine, with a maximum capacity of 221.22 mg/g. Electrostatic interaction, hydrogen bond interaction and p-p interaction are likely to govern the adsorption process of berberine. Furthermore, PS-DVB-P(AA-Na)-SPABA retained a favorable adsorption performance for berberine after five cycles, indicating that the material possesses regenerability and reusability. Originality/value This paper presents a novel resin for adsorbing nitrogen-containing compounds synthesized via the Surface-Initiated Atom Transfer Radical Polymerization reaction, which providing research insights for the separation and purification of nitrogen-containing compounds from natural products.