Synthesis of polymeric Schiff bases and their application in carbon dioxide adsorption

Abstract

The emission of carbon dioxide (CO2) is not only the primary cause of global warming but also results in severe environmental issues like an increase in Earth's average temperature. Herein, polymeric Schiff bases, OPVA-ED and OPVA-HMD, are synthesized via the condensation of partially oxidized polyviny1 alcohol (OPVA) with 1,2-ethylene diamine (ED) and 1,6-hexamethylene diamine (HMD), respectively, and their potential toward CO2 adsorption is investigated. Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR), and X-ray diffraction (XRD) are employed for the structural elucidation of these Schiff bases, and their physical properties are determined using thermogravimetric analysis (TGA), and gas adsorption experiments. The capture/release of CO2, using these Schiff bases as adsorbent, is assessed at 25°C. The results suggest that OPVA-ED is a more efficient adsorbent for CO2 as compared to OPVA-HMD, as the capacity of CO2 adsorption reaches up to 0.22 mmol/g and 0.18 mmol/g at 15 bars for OPVA-ED and OPVA-HMD, respectively.