Hypercrosslinked poly(AN-co-EGDMA-co-VBC): synthesis via suspension polymerization, characterizations, and potential to adsorb diclofenac and metformin from aqueous solution

Poly(acrylonitrile- co -ethylene glycol dimethacrylate- co -vinylbenzyl chloride) (poly(AN- co -EGDMA- co -VBC)) was synthesized by suspension polymerization and further hypercrosslinked by Friedel-Crafts reaction to serve as a sorbent to remove the pharmaceuticals. Energy dispersive X-ray analysis showed decreased chlorine content in the polymers, confirming a successful hypercrosslinking. BET analysis revealed that the hypercrosslinked (HXL) poly(AN- co -EGDMA- co -VBC) had a specific surface area up to 363 m 2 g −1 with an average particle size of 77.2–174.1 μm. Hypercrosslinking of the polymer increased the specific surface area up to 42%, even at low VBC content (10%). Pore size distribution showed that the terpolymers were mesoporous. The maximum adsorption capacity of diclofenac (DCF) and metformin (MET) determined by the Langmuir isotherm model were up to 61.0 mg g −1 and 5.1 mg g −1 , respectively and the adsorption kinetic followed pseudo-second-order rate equation. The equilibrium capacity of the sorbent decreased to approximately 78% for DCF and 72% for MET after four cycles of adsorption-desorption process, exhibiting good reusability property. Graphical abstract