The highly polar H2S and polarizable CO2 molecules can strongly interact with the polymer membranes causing swelling and plasticization[1] due to high levels of impurities. Polyamide-imides can resist plasticization because of the strong intermolecular interactions arising from the polyimide functions as well as the ability of the polymer chains to hydrogen bond with one another as a result of the amide bond. Although not currently used in any major industrial separation, polyamide-imides could be used for these types of processes where chemical and mechanical stability are required.