Polymerization of norbornene bearing Si(CH3)3 groups in the 5-position with the opening of double bonds and its copolymerization with 5-(n-hexyl)norbornene were realized in the presence of nickel(II) naphthenate/methylaluminoxane catalyst system. The completely saturated homopolymer containing Si(CH3)3 group (APNSi) and a copolymer containing both Si(CH3)3 and n-hexyl side groups (ACPNHSi) were prepared. The polymers have molecular mass of about 300 000 and a high glass transition temperature (T g > 340 °C). Gas permeation properties of the polymers obtained were studied. APNSi reveals unusually high gas permeation parameters, e.g., P(O2) of about 800 Barrer for different samples. This polymer also exhibits solubility controlled gas permeation:  the permeability coefficients increase in the series of n-alkanes C1−C4 when the size of the penetrant increases. Free volume in addition type substituted polynorbornenes was studied using positron annihilation lifetime spectroscopy (PALS). This method indicated that very large sizes of free volume elements are characteristic for APNSi what explains its great gas permeability. Another interesting feature of this polymer is an independence of the annihilation parameters (lifetimes τ i and intensities I i ) of temperature in a wide range of its variation. Thus, APNSi is a novel representative of high free volume, high permeability glassy polymers, and it is a potential material for gas separation membranes.

Addition polymerization of two tricyclononene monomers bearing one and two Si(CH3)3 groups was performed in the presence of Pd-containing catalysts. The polymers were obtained with high yields and were completely saturated. Good mechanical and film forming properties are observed for the polymers prepared in the presence of Pd(OAc)2/B(C6F5)3 catalyst. Their glass transition temperature was not observed until the onset of thermal decomposition (>370 °C) and the molecular weights are high (M w up to 7 × 105). Study of gas permeation parameters of the obtained poly[3-(trimethylsilyl)tricyclononene-7] and poly[3,4- bis(trimethylsilyl)tricyclononene-7] showed that both glassy polymers revealed substantially high gas permeability. Other transport characteristics (increase in permeability in the series C1−C4 alkanes and negative activation energies of permeation) indicate that these polymers reveal so-called solubility controlled permeation, which is typical for some extra-high permeability polymers. Positron annihilation lifetime spectroscopy indicated that both polymers are characterized by very large sizes of free volume elements.

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