Biomass furfural-derived green polymer microspheres: Synthesis and applications for the removal of environmental pollutants from wastewater

Abstract

A novel polymer was synthesized from the second-generation biomass furfural and maleic anhydride (MAH) via precipitation copolymerization. The biomass furfural was converted to furfuryl alcohol, which subsequently reacted with methacryloyl chloride to form furfuryl methacrylate (FMA). Copolymerization with MAH was conducted using 2,2′-azobis(isobutyronitrile) as an initiator and divinylbenzene as a cross-linking agent. The resulting Poly[FMA-co-MAH] microspheres were modified via amination or hydrolyzation to convert the anhydride groups on the surface of microspheres to amino (Poly-[FMA-co-MAH]-NH2) or carboxyl (Poly[FMA-co-MAH]-COOH) functional groups, respectively. The microspheres were characterized using scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, BET surface area, ultraviolet–visible spectroscopy, and atomic absorption spectrometry. Further, the microspheres were evaluated as an adsorbent for metals and dyes. The maximum adsorption of Congo red dye (pH = 2) using Poly-[FMA-co-MAH]-NH2 and Poly[FMA-co-MAH]-COOH was 164 and 106 mg/g, respectively. Further, the adsorption occurred more readily in an acidic pH. The maximum adsorption of Pb(II) metal using Poly-[FMA-co-MAH]-NH2 and Poly[FMA-co-MAH]-COOH was 177.3 and 194.4 mg/g, respectively. Langmuir modelling and a kinetic study were also performed to assess the adsorption behavior. The recycling and regeneration abilities of the microspheres were evaluated during continued adsorption/desorption cycling, which demonstrated the excellent regeneration ability of the material. The strategy proposed in this study to produce eco-friendly polymeric materials using biomass furfural shows promise for more advanced applications in the near future.