Transforming waste polyurethane foam into high value-added hyper-crosslinked polymer for efficient removal of multiple contaminants from wastewater

Waste plastics upcycling and wastewater remediation are environmental issues of global concern that need to be solved urgently. In this study, waste polyurethane foam (PUF) was used as raw material to prepare a high valueadded hyper-crosslinked polymer (HCP-PUF) via Friedel - Crafts alkylation reaction with 1,4-p-dichlorobenzyl as external cross-linker. HCP-PUF exhibited high specific surface areas of 942.20 m2/g and abundant pore volumes of 1.03 cm3/g. The maximum adsorption capacities of HCP-PUF for diclofenac sodium (DS) and Congo red (CR) reached to 248.76 mg/g and 1811.04 mg/g at 298 K, respectively. The relatively stable adsorption performance during continuous five cycles experiments suggested the excellent recyclability of HCP-PUF. And the HCP-PUF can be considered as a broad-spectrum adsorbent toward other pollutants including tetracycline, bisphenol A, rhodamine B, Ni2+ and Cu2+. Furthermore, the excellent adsorption performance for DS and CR in actual wastewater indicated that the HCP-PUF had a wide range of application prospects. Hence, this work provided a new pathway for the high-value conversion of waste PUF and prepared an efficient adsorbent for the removal of multiple pollutants from wastewater, embodying the environmental concept of treating waste with waste.