Ultrapermeable Polymers of Intrinsic Microporosity Containing Spirocyclic Units with Fused Triptycenes

Polymers of intrinsic microporosity (PIMs), such as the archetypal spirobisindane-based PIM-1, are among most promising new materials for making gas separation membranes with high permeance potential use in high-throughput applications. Here it is shown that ultrapermeable PIMs can be prepared by fusing rigid and bulky triptycene (Trip) to spirobisindane (SBI) unit. PIM-SBI-Trip its copolymer PIM-1 (PIM-1/SBI-Trip) both after methanol treatment (PCO2 > 20 000 Barrer). Old films, although less permeable, more selective therefore provide data close recently redefined Robeson upper bounds important CO2/CH4, CO2/N2, O2/N2 pairs. Temperature-dependent permeation measurements analysis entropic energetic contributions transport parameters show enhanced performance these polymers governed strong size-sieving character, mainly due term diffusivity, related their rigidity. Both a relatively weak pressure-dependence mixed permeability experiments up 6 bar, suggesting CO2 capture from flue or upgrading biogas.