Aminated poly(vinyl chloride) solid state adsorbents with hydrophobic function for post-combustion CO₂ capture

In this paper, we show a novel sustainable route for the production of sorption materials for carbon capture technologies by utilizing a general plastic waste. By supporting aminated poly(vinyl chloride) on mesoporous silicas, a family of polymer/silica composites was synthesized, characterized and tested gravimetrically for adsorption of CO₂ from the 1:1 v/v CO₂-N₂ mixture. The composites show good adsorption capacity for CO₂ peaking at 12 cm³ g^-1 for ethylenediamine-treated PVC products on SBA-15 support. The adsorption efficiency (CO₂:N ratio) is comparable to those observed for other nanoporous materials, such as amine-grafted mesoporous silicas. Ethylenediamine was found to be the best aminating reagent for PVC as the composite prepared from EDA-PVC gave the highest CO₂ adsorption efficiency. Moreover, contact angle measurements suggested a significant improvement in hydrophobicity of the selected composites when they were compared with the unfunctionalized silica supports. This very useful development could make the composites suitable for applications in elevated moisture content environments found in flue vapours of gas-fired power plants.