In this study, we developed an effective approach for increasing the equilibrium adsorption capacity of the interpenetrating polymer networks (IPNs) toward polar aromatic compounds. For this purpose, a novel post-cross-linked polystyrene/poly (methyl acryloyl diethylenetriamine) (CMPS_pc/PMADETA) IPNs was synthesized and its adsorption was evaluated from aqueous solution using p-hydroxybenzoic acid as the adsorbate. CMPS_pc/PMADETA IPNs possessed a relatively high Brunauer-Emmett-Teller (BET) surface area and hydrophobic networks as well as hydrophilic networks, inducing a much enhanced adsorption toward p-hydroxybenzoic acid. The equilibrium adsorption capacity of p-hydroxybenzoic acid on CMPS_pc/PMADETA IPNs was remarkably larger than that on its precursors and the equilibrium data were correlated better by Sips model than the Langmuir and Freundlich models. Furthermore, the adsorption was a fast process, and the micropore diffusion model characterized the kinetic data very well. At a feed concentration of 1060.8 mg/L and a flow rate of 10.8 BV/h, the dynamic adsorption capacity was calculated to be 200.8 mg/mL wet resin. (C) 2015 Elsevier Inc. All rights reserved.