Preparation of hyper-crosslinked polymers with hierarchical porous structure from hyperbranched polymers for adsorption of naphthalene and 1-naphthylamine

A novel strategy to synthesize hyper-crosslinked polymers (HCPs) with hierarchical porous structure, high surface area, and high conjugated structure was developed. The hyperbranched poly(p-(2,2,2-triphenylethyl)styrene) (PTPES) polymer was designed as a precursor for hyper-crosslinking via Friedel-Crafts reaction. The unique three-dimensional molecular configuration of hyperbranched polymer and a large number of bulk end groups contribute to the construction of hyper-crosslinked hierarchical porous polymer. And the effect of branching degree of hyperbranched polymer on the porosity was clarified. The BET specific surface areas, total pore volumes, and average pore sizes of HCPs increase with the increase of branching degree of hyperbranched polymer. The resulting HCPs have a maximum BET specific surface area of 1068 m(2) g(-1) with hierarchical porous structure, and the highest total pore volume is up to 0.895 cm(3)/g. Furthermore, the adsorption performance of HCPs with aromatic pollutants was investigated by selecting naphthalene (N) and 1-naphthylamine (NA) as model adsorbates. The pseudo-second-order kinetic model and Freundlich isotherm model were found to fit well with adsorption processes of N and NA on HCPs. According to thermodynamic experiments, the adsorption of N and NA were exothermal and spontaneous. This strategy may provide a new approach for designing HCPs with hierarchical pores for water treatment.