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ABSTRACT: 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 [ABSTRACT FROM AUTHOR]

ABSTRACT Metathesis polytricyclononenes were synthesized via ROMP polymerization in the presence of the 1-st generation Grubbs catalyst and their gas-transport properties were studied for the first time. The aim of this work was to evaluate the influence of Me3E-groups (E = C, Si, Ge) on gas permeation parameters of ROMP materials. New metathesis poly(3- tert-butyltricyclononene-7) and poly(3-trimethylgermyltricyclononene-7) were obtained with high yields (up to 95%) and high-molecular weights ( Mw∼3-7×105 g mol−1). The glass transition temperatures of the ROMP polytricyclononenes with Me3E-groups decreased when E was changed from C to Si and then to Ge. It was shown that the polytricyclononene containing Me3Si-groups has the highest gas permeability while the polytricyclononene containing Me3C-substituents has the lowest gas permeability. In addition, the gas permeation parameters were estimated for ROMP Me3Si- and Me3Ge-substituted polytricyclonona-3,7-dienes. So the influence of the second double bond in the monomer units on the permeability of the polymers obtained was studied. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41395. [ABSTRACT FROM AUTHOR]