Microporous Materials Based on Norbornadiene-Based Cross-Linked Polymers
A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky prospekt, 119991 Moscow, Russia
Department of Chemistry and Technology of Polymer Materials and Nanocomposites, A.N. Kosygin Russian State University, 33-1 Sadovnicheskaya st., 117997 Moscow, Russia
Department of Natural Sciences, D.I. Mendeleev University of Chemical Technology of Russia, 9 Miusskaya sq., 125047 Moscow, Russia
N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina st., 119991 Moscow, Russia
Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie gory, 119991 Moscow, Russia
Author to whom correspondence should be addressed.
Polymers 2018, 10(12), 1382; https://doi.org/10.3390/polym10121382
Received: 8 November 2018 / Revised: 3 December 2018 / Accepted: 5 December 2018 / Published: 13 December 2018
(This article belongs to the Special Issue Microporous Organic Polymers: Synthesis, Characterization and Applications)
New microporous homopolymers were readily prepared from norbornadiene-2,5, its dimer and trimer by addition (vinyl) polymerization of the corresponding monomers with 60–98% yields. As a catalyst Pd-N-heterocyclic carbene complex or Ni(II) 2-ethylhexanoate activated with Na+[B(3,5-(CF3)2C6H3)4]− or methylaluminoxane was used. The synthesized polynorbornenes are cross-linked and insoluble. They are glassy and amorphous polymers. Depending on the nature of the catalyst applied, BET surface areas were in the range of 420–970 m2/g. The polymers with the highest surface area were obtained in the presence of Pd-catalysts from the trimer of norbornadiene-2,5. The total pore volume of the polymers varies from 0.39 to 0.79 cm3/g, while the true volume of micropores was 0.14–0.16 cm3/g according to t-plot. These polymers gave CO2 uptake from 1.2 to 1.9 mmol/g at 273 K and 1 atm. The porous structure of new polymers was also studied by means of wide-angle X-ray diffraction and positron annihilation lifetime spectroscopy.