Pentiptycene-based ladder polymers with configurational free volume for enhanced gas separation performance and physical aging resistance.

Polymers of intrinsic microporosity (PIMs) have shown promise in pushing the limits of gas separation membranes, recently redefining upper bounds for a variety of gas pair separations. However, many of these membranes still suffer from reductions in permeability over time, removing the primary advantage of this class of polymer. In this work, a series of pentiptycene-based PIMs incorporated into copolymers with PIM-1 are examined to identify fundamental structure-property relationships between the configuration of the pentiptycene backbone and its accompanying linear or branched substituent group.