1. A.V. Topchiev Institute of Petrochemical Synthesis, RAS, Moscow, Russia;2. N. N. Semenov Institute of Chemical Physics, RAS, Moscow, Russia;3. State Scientific Center of the Russian Federation “State Research Institute for Chemistry and Technology of Organoelement Compounds”, Moscow, Russia
Abstract:
A new metathesis polynorbornene containing three SiMe3 groups per monomer unit directly connected to the norbornene moiety via Si? C bonds is synthesized. The ring‐opening metathesis polymerization of sterically hindered 3,3,4‐tris(trimethylsilyl)tricyclononene‐7 is successfully conducted in yields 80–85% in the presence of first generation Grubbs catalyst. The corresponding polymer is obtained with molecular weight Mw up to 5.4 × 105 Da. It is an amorphous glassy (Tg = 200 °C) polymer with high thermal stability. Gas permeability and diffusivity coefficients are studied for a range of gases (He, H2, O2, N2, CO2, CH4). This polymer containing three SiMe3 groups per monomer unit turns out to be more permeable (P(O2) = 125 Barrer) than similar polymers with one or two SiMe3 groups per monomer unit (P(O2) = 30–50 Barrer). Wide angle X‐ray diffraction, positron annihilating lifetime spectroscopy, as well as Brunauer–Emmett–Teller investigations are also performed and discussed.
