Synthesis and Functionalization of Ynone-Based Tubular Microporous Polymer Networks and Their Carbonized Products for CO2 Capture

Ynone-based microporous polymer networks (YMPNs) were synthesized by the reaction of aromatic dicarboxylic acid chloride and alkyne groups under Sono-gashira cross-coupling reaction conditions. As the reaction proceeded in a mixture of toluene and triethylamine (TEA), tubular precipitates formed rapidly. The microscopic and XRD studies showed thatthe precipitates had a core-shell structure with a rod-shaped triethylammonium chloride (TEA-HC1) crystalline core and a polymeric shell. The core was removed by washing with methanol to provide a hollow polymeric tube. The TEA-HC1 rod formed in situ during the cross-coupling reaction and served as a template in forming the tubular morphology. YMPNs could be modified with ease because of the presence of highly reactive ynone groups. YMPNs were functionalized with ethylenediamine by the Michael-type addition reaction. The amino group functionalized YMPNs were used as precursors of nitrogen-doped porous carbons. The pyrolysis of the polymers at 800 °C produced microporous carbon materials withoutthe activation process. The carbon materials showed significantly enhanced Brunauer-Emmett-Teller (BET) surface areas and CO2 uptake capacities compared to their precursor polymers.