Thermally Rearranged Bismaleimide (TR-BMI) Polymer Membranes for Gas Separation

Polymer membranes have been faced with trade-off relationships between gas permeability and selectivity. Recent progress in thermally rearranged (TR) membranes are focused on the integration of cross-linkable sites with enhanced polymer rigidity [1-3].

In this study, TR membranes induced from bismaleimide-based network polymers (BMIs) were investigated [4]. BMIs are classified as a representative rigid network structure with good thermal stability. The resultant thermally rearranged bismaleimide polymer membranes (TR-BMIs) presented distinctive physicochemical properties including high thermal stability and noticeable BET surface area. Therefore, they exhibited outstanding CO₂ permeability of ~ 5440 Barrer with CO₂/N₂ selectivity of ~25, surpassing the Robeson upper bound revisited plot. For other industrially important gas separation applications like CO₂/CH₄ and O₂/N₂ gas pair, TR-BMI membranes still presented remarkable gas separation performances.

Less than 5 wt% of TR-BMIs were incorporated into reported polyimides to form semi-interpenetrating polymer networks (SIPNs). SIPN membranes bearing TR-BMIs were successfully fabricated and exhibited increment in gas permeability compared to pristine polyimide membranes.

References

1. H. B. Park et al., Science 318 254-258 (2007)
2. M. D. Guiver and Y. M. Lee, Science 339 284-285 (2013)
3. M. Calle et al., Macromolecules 48 2603-2613 (2015)
4. Y. S. Do et al., Chem. Commun. 52 13556-13559 (2016)