Modifications of addition poly(5-vinyl-2-norbornene) and gas-transport properties of the obtained polymers
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01.04.2020 |
Wozniak A.
Bermesheva E.
Andreyanov F.
Borisov I.
Zarezin D.
Bakhtin D.
Gavrilova N.
Ilyasov I.
Nechaev M.
Asachenko A.
Topchiy M.
Volkov A.
Finkelshtein E.
Ren X.
Bermeshev M.
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Reactive and Functional Polymers |
10.1016/j.reactfunctpolym.2020.104513 |
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© 2020 Elsevier B.V. Herein four modified polymers were prepared from readily available addition poly(5-vinyl-2-norbornene) (PVNB) and their gas-transport properties were studied in detail. Hydrogenation, epoxidation, cyclopropanation and thiol-en reactions were chosen for the modifications of PVNB. Hydrogenation of PVNB was performed using p-toluenesulfonyl hydrazide. Epoxidation of PVNB was realized employing m-chloroperoxybenzoic acid. Cyclopropanation of PVNB was carried out using diazomethane in the presence of a Pd-catalyst. For thiol-en reaction, thioacetic acid was applied as the source of a thiol and AIBN as an initiator. All listed modifications were performed in high yields (≥80%) without the destruction of polymer main chains. The degree of functionalizations was up to 99%. The influence of these modifications on the properties of the resulting polymers was evaluated. Cyclopropanation and hydrogenation of PVNB led to an enhancement of gas permeability with minimal decrease in selectivity, while epoxidation or thioacetylation gave a substantial increase in CO2/N2 selectivity with decrease in permeability. The modified polymers with polar side-groups exhibited attractive selectivities for CO2/N2, CO2/CH4 and H2/N2 gas separations.
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Addition Polyalkylnorbornenes: A Promising New Class of Si-Free Membrane Materials for Hydrocarbons Separation
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01.10.2019 |
Wozniak A.
Bermesheva E.
Borisov I.
Petukhov D.
Bermeshev M.
Volkov A.
Finkelshtein E.
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Macromolecular Rapid Communications |
10.1002/marc.201900206 |
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© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Nanoporous glassy polymers are perspective materials for the fabrication of gas separation membranes, especially for the application of gaseous hydrocarbon separation. However, the drawback of such materials is the pronounced physical aging resulting in the dramatic drop of gas transport properties due to relaxation of high-free-volume fraction in time. Herein, a novel and readily available group of such glassy polymers is reported based on 5-alkylnorbornenes. These polymers are easily synthesized from dicyclopentadiene and α-olefins by Diels-Alder reaction and vinyl (addition) polymerization of the formed cycloadducts in the presence of ([(η3-C3H5)PdCl]2/PCy3/Na+[B(3,5-(CF3)2C6H3)4]− catalyst. The obtained polymers display low-fraction free volume, stable gas permeability over time, and possess a unique feature for the glassy polymers—solubility controlled permeation of hydrocarbons and enhanced C4H10/CH4 selectivity.
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Stereoselective synthesis and polymerization of Exo-5-trimethylsilylnorbornene
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15.06.2018 |
Alentiev D.
Bermeshev M.
Starannikova L.
Bermesheva E.
Shantarovich V.
Bekeshev V.
Yampolskii Y.
Finkelshtein E.
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Journal of Polymer Science, Part A: Polymer Chemistry |
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10 |
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© 2018 Wiley Periodicals, Inc. Herein the stereoselective two-step synthesis of pure exo-5-trimethylsilylnorbornene is reported. The monomer proved to be highly reactive in both metathesis and addition polymerization. ROMP polymerization was catalyzed by the first-generation Grubbs catalyst. High-molecular-weight saturated addition polymers were prepared using nickel or palladium complexes as precatalysts and Na+[B(3,5-(CF3)2C6H3)4]− and/or MAO as cocatalysts. The obtained addition polynorbornenes are highly gas permeable and microporous materials possessing large free volume and BET surface area (up to 540 m2/g). The influence of the substituent orientation (exo- vs. exo-/endo-mixture) on polymer properties was established. The metathesis polymer based on exo-isomer exhibits 1.5- to 2-fold increase of permeability coefficients for all gases in comparison to the similar polymer based on the mixture of exo- and endo-isomers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1234–1248.
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