Synthesis and adsorption property of hydrophilic–hydrophobic macroporous crosslinked poly(methyl acryloyl diethylenetriamine)/poly(divinylbenzene) (PMADETA/PDVB) interpenetrating polymer networks (IPNs)

Abstract

Hydrophilic–hydrophobic macroporous crosslinked poly(methyl acryloyl diethylenetriamine)/poly(divinylbenzene) (PMADETA/PDVB) interpenetrating polymer networks (IPNs) were prepared, characterized and evaluated for adsorption of salicylic acid from aqueous solution. PMADETA/PDVB IPNs were prepared by filling PDVB networks in the pores of PGMA networks according to IPNs technology and an amination reaction of PGMA/PDVB IPNs with diethylenetriamine (DETA). The structure of PMADETA/PDVB IPNs was characterized by Fourier transform infrared spectroscopy (FT-IR), N₂ adsorption–desorption isotherms and chemical analysis. PMADETA/PDVB IPNs had a very large equilibrium adsorption capacity to salicylic acid and the equilibrium adsorption capacity was measured to be 196.4 mg g⁻¹ at an equilibrium concentration of 100 mg L⁻¹. The Freundlich model was more appropriate for fitting the equilibrium data than the Langmuir model and the adsorption was shown to be an exothermic and spontaneous process. The adsorption reached equilibrium within 200 min and the pseudo-second-order rate equation characterized the kinetic data better than the pseudo-first-order rate equation. At an initial concentration of 1035 mg L⁻¹ and a flow rate of 84 mL h⁻¹, the breakthrough and saturated capacities were 75.02 and 159.53 mg mL⁻¹ wet resin, respectively, and the resin column could be completely regenerated and repeatedly by 0.01 mol L⁻¹ of NaOH (w/v) and 20% of ethanol (v/v).