An Aromatic Fluoropolymer for Hydrogen Separation from Hydrocarbons.

Plasticization is a critical challenge in membrane-based gas separation. Here a novel fluoropolymer, poly(trifluoro styrene) (PTFS), is reported for hydrogen separation from hydrocarbons. The polymer structure is first characterized by different techniques such as nuclear magnetic resonance (NMR) and positron annihilation lifetime spectroscopy (PALS). Then, gas separation performances of the polymer are studied. The separation of H 2 /CH 4 is found to outperform most other fluorinated polymers and surpass the Robeson 1991 upper bound. Furthermore, the polymer demonstrates stable or increasing selectivity for hydrogen over hydrocarbons (e.g., CH 4 , C 2 H 6 , and C 3 H 8 ) at higher pressure, suggesting excellent resistance to plasticization.