Microporous Functionalized Triazine-Based Polyimides with High CO2 Capture Capacity

• Published in: Chemistry of materials Vol. 25; no. 6; pp. 970 - 980
• Main Authors: Liebl, Mario R, Senker, Jürgen
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.03.2013
• Subjects: carbon dioxide capture; argon sorption; gas separation; porous organic polymers
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm4000894

Porous organic polymers with polar surfaces are promising materials for capture and storage applications for carbon dioxide. Here, we present the synthesis and characterization of seven triazine-based porous polyimide (TPI) polymer networks and evaluate their applicability as CO2 sorbent materials. The TPIs were synthesized in good yields by a condensation reaction of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and the respective dianhydride building blocks in m-cresol. The resulting TPI polymer networks exhibited high chemical and thermal stability under air (up to 450 °C). Argon sorption isotherms demonstrated that specific BET equivalent surface areas up to 809 m2 g–1 (TPI-1) were reached. The characterization of the pore structure revealed mainly micropores with pore diameters ranging from 0.4 to 3 nm. The highest uptake values for CO2 (2.45 mmol g–1) were observed for TPI-1 and TPI-2 at 273 K and 1 bar. The highest binding selectivity (56) for CO2 over N2 at 298 K was observed for TPI-7. The high degree of functionalization led to comparatively high CO2 adsorption heats for TPI polymer networks between 29 kJ mol–1 (TPI-6) and 34 kJ mol–1 (TPI-1). As a result, the TPI networks showed high CO2 uptakes relative to their moderate BET equivalent surface areas. In combination with a facile modular synthesis procedure, a high chemical and thermal stability, and the tunability of the CO2/N2 binding selectivities, TPIs might be classified as promising materials for CO2 storage and separation applications.