(354c) “Click”-Crosslinkable CO2-Philic Crosslinking of Poly(ethylene glycol) (PEG) Based Membranes for Natural Gas Separations

Processing sub-quality natural gas remains an economic and environmental challenge, especially as natural gas demand increases. Toxic and/or corrosive sour gas contaminants, such as H₂S and CO₂, must be removed from methane (CH₄) to meet pipeline specifications. Gas separation membrane technology offers a low-cost alternative to traditionally energy-intensive adsorption-based separations. This work describes a route towards improving the CO₂ separation performance of high-performing poly(ethylene glycol) rubbery membrane by incorporation of CO₂-philic crosslinkers. Novel “click” crosslinkable CO₂-philic melamine derivative using as a crosslinker was functionalized by a typically unreactive melamine molecule with reactive alkyne moieties. A series of hydrophilic networks of highly crosslinked poly(ethylene glycol) rubbery membranes were cased directly on top of membrane supports via a reaction of this click crosslinker with different molecular weight PEG-azides through alkyne-azide click chemistry that enable discrete interactions with sour gas species. The effect of molecular weight of PEG-azides on the membrane physical and transport properties was investigated. Such crosslink-engineered PEG composition membranes demonstrate enhanced CO₂/CH₄ separation performance compared to PEG crosslinked with a non-CO₂-philic crosslinker.