Eco-Friendly Fabrication of a Highly Selective Amide-Based Polymer for CO₂ Capture

Abstract

Porous polymeric adsorbents for CO2 capture (HCP-MAAMs) were fabricated by copolymerization of methacrylamide (MAAM) and ethylene glycol dimethacrylate 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 polymer 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 cross-linking density exhibited an 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.