Unprecedented Sour Mixed-Gas Permeation Properties of Fluorinated Polyazole-Based Membranes

A polyoxadiazole polymer POz-CF3 was prepared, and complete gas permeation properties were investigated on its corresponding membrane using pure-, and multicomponent mixed-gas feeds. The POz-CF3 membrane demonstrated attractive pure- and sweet mixed-gas permeation properties; however, the performance of its membrane declined dramatically during sour mixed-gas testing. The modification of POz-CF3 into its corresponding polytriazole polymers led to changes in their membranes’ mechanical, thermal, processability, and gas permeation properties. For example, the membrane formation of FPT-Ph(NMe2) polytriazole could not be possible due to the polymer low solubility in most solvents. In contrast, the polytriazole FPT-Ph(OH) afforded membranes with improved mechanical properties and enhanced pure- and mixed-gas permeation properties compared to POz-CF3 membrane. The sour mixed-gas results, in particular, are very attractive and superior to most of the aromatic polymeric membranes tested with similar conditions of gas feed (20 vol % H2S) and operational pressure and temperature.