One-Step Synthesis Of Hydroxyl-Functionalized Fully Carbon Main Chain Pims Via A Friedel-Crafts Reaction For Efficient Gas Separation

High performance, robust polymeric membranes are playing more and more important roles in recent large scale industrial gas separation applications. One of the biggest challenges is scaling up the high performance polymeric materials. Herein, a one-step super-acid catalyzed condensation reaction was reported to synthesize two novel hydroxyl-functionalized fully carbon main chain intrinsic microporous polymers (HSBI-Is and HBIN-Is) with high efficiency. Both polymers demonstrated high molecular weight, good thermal stability with Td above 360 degrees C, and modest microporosity. HSBI-Is exhibited a more open structure with higher BET surface area (523 vs 57 m(2) g(-1)), larger fractional free volume (0.212 vs 0.162), and d-spacing (5.16 vs 3.68 angstrom) than HBIN-Is due to its more rigid and bulky spirobisindane (SBI) site of contortion. Membranes based on HSBI-Is and HBIN-Is showed moderate to high permeabilities and selectivitites with H-2/N-2, H-2/CH4, O-2/N-2 and CO2/CH4 close to or even beat the 2008 trade-off curves. In which, the HBIN-Is showed a remarkable CO2/CH4 selectivity of 73.8, and the HSBI-Is demonstrated a remarkable O-2/N-2 selectivity of 10.4 at-20 degrees C due to the sharply increased diffusion selectivity. Both polymer membranes showed excellent plasticization resistance up to 25 bar upstream pressure, endowing the polymerization method and the hydroxyl functionalized intrinsic microporous polymers of great potential in real gas separation applications.