Post-synthetic amination of porous hypercrosslinked polymer for the adsorptive removal of bisphenol-A from water

Abstract

Microporous organic polymers (MOPs) have garnered significant attention in recent years due to their unique structural and functional properties. Among them, hypercrosslinked polymers (HCPs) are particularly promising for environmental applications, including the removal of organic contaminants from water. In this study, we report the synthesis of a novel HCP, designated as PBFC, constructed via Friedel–Crafts knitting alkylation of fluorenone and benzene. Post-synthetic functionalization of PBFC with 1,3-diaminopropane yielded an amine-functionalized polymer, PBFA. The adsorption performance of both polymers was evaluated for the removal of Bisphenol-A (BPA) from aqueous solutions. Notably, PBFA exhibited a high adsorption capacity of 130 mg/g, attributed to the presence of amine groups enhancing interaction with BPA molecules. Adsorption behavior followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer chemisorption. Thermodynamic analyses revealed negative values of ΔG, ΔH, and ΔS, confirming the spontaneous and exothermic nature of the adsorption process. The dominant adsorption mechanisms were identified as hydrogen bonding, π–π interactions, and hydrophobic interactions. These findings highlight the potential of amine-functionalized HCPs as efficient adsorbents for organic pollutant removal from water.