Eco-friendly fabrication of highly selective amide-based polymer for CO2 capture

Porous polymeric adsorbents for CO2 capture (HCP-MAAMs) were fabricated by co-polymerisation of methacrylamide (MAAM) and ethylene glycol dimethacrylate (EGDMA) using acetonitrile and azobisisobutyronitrile as a porogen and initiator, respectively. The X-ray photoelectron and Fourier transform infrared spectra revealed a high density of amide groups in the polymer matrix of HCP-MAAMs, which enabled high selectivity to CO2. The polymers BET surface area and total pore volume was up to 277 m2 g-1 and 0.91 cm3 g-1, respectively. The highest CO2 uptake at 273 K and 1 bar CO2 pressure was 1.45 mmol g-1 and the heat of adsorption was 27-35 kJ mol-1. The polymer with the lowest crosslinking density exhibited unprecedented CO2/N2 selectivity of 394 at 273 K. Life cycle assessment revealed a lower environmental impact of HCP-MAAMs compared to molecularly imprinted polymers. HCP-MAAMs are eco-friendly CO2 adsorbents owing to their low regeneration energy, environmentally benign fabrication process, and high selectivity.