Synthesis, characterization, and gas permeation properties of a novel group of polymers with intrinsic microporosity: PIM-polyimides

A range of polyimides with characteristics similar to a polymer of intrinsic microporosity (PIM) were prepared by reaction with various aromatic diamines of a bis(carboxylic anhydride) incorporating a spiro-center. The polymers exhibited high surface area, as determined by nitrogen adsorption, and high thermal stability. Membrane gas permeation experiments showed PIM-polyimides to be among the most permeable of all polyimides and to have selectivities close to the upper bound for several important gas pairs. A group contribution method was used to predict permeability coefficients and separation factors for further PIM-polyimide structures, revealing worthwhile targets for future synthetic efforts

Glassy Polynorbornenes with Si–O–Si Containing Side Groups. Novel Materials for Hydrocarbon Membrane Separation

Polymers of a new class of glassy materials that demonstrate unusual solubility controlled permeabilitymetathesis Si–O–Si containing polynorbornenesare synthesized. The introduction of bulky Si­(OSiMe₃)₃ substituents into the polynorbornene backbone is shown to provide the polymers with increased gas permeability, higher than all other known metathesis polynorbornenes. The prepared glassy polymers reveal behavior similar to that known for rubbers and, in particular, siloxanes: permeability coefficients increase for the penetrants of larger size. That is, these polymers are capable to remove higher hydrocarbons from natural and associated petroleum gases

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