A Novel, Highly Gas-Permeable Polymer Representing a New Class of Silicon-Containing Polynorbornens As Efficient Membrane Materials

The synthesis and gas permeation properties of addition-type poly­(3,3-bis­(trimethylsilyl)­tricyclononene-7) (<b>PTCNSi2g</b>) are first reported. High molecular weight <b>PTCNSi2g</b> was obtained via addition polymerization of 3,3-bis­(trimethylsilyl)­tricylononene-7 on a Pd-containing catalyst. It possessed a BET surface area as high as 790 m²/g. This new polymer is distinguished by extra high gas permeability and solubility controlled permeation of hydrocarbons. Positron annihilation lifetime spectroscopy revealed extremely large size of free volume elements (8.3 Å). <b>PTCNSi2g</b> is a promising membrane material for separation of natural gas