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

Abstract

The synthesis and gas permeation properties of addition-type poly­(3,3-bis­(trimethylsilyl)­tricyclononene-7) (PTCNSi2g) are first reported. High molecular weight PTCNSi2g 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). PTCNSi2g is a promising membrane material for separation of natural gas.

Synthesis and Gas‐Transport Properties of Novel Copolymers Based on Tricyclononenes Containing One and Three Me3Si‐Groups

“…Previously it was shown that the most active catalytic systems for the addition polymerization (AP) of Si‐containing tricyclononene derivatives were Pd(OAc) 2 /[Ph 3 C] + [B(C 6 F 5 ) 4 ] − and Pd(OAc) 2 /[Ph 3 C] + [B(C 6 F 5 ) 4 ] − /PCy 3 . However, the attempts to synthesize addition type of high molecular weight poly(3,3,4‐tris(trimethylsilyl)tricyclononene‐7) in the presence of these systems failed (Scheme A).…”

“…Many highly permeable polymers exhibit strong swelling and increases in free volume and gas permeability caused by insertion into nonsolvents like lower alcohols, e.g., polyacetylenes and SiMe 3 ‐containing polynorbornenes . Because of this, certain experiments were conducted with the copolymer (CP(TCNSi3‐TCNSi1)‐20) studied in the present work.…”

“…The results of this table show that in agreement with our previous observations an increase in the number of bulky substituents leads to increases in gas permeability. Anticipated properties of this homopolymer put it in the family of the most permeable glassy materials such as polyacetylenes .…”

“…Although inorganic membranes and mixed matrix membranes that contain inorganic additives attracted much attention of the researchers it is namely polymer membranes proved the greatest feasibility for solving various complex problems of membrane gas separation . During the last decade a lot of new polymers have been synthesized for this purpose and their properties have been studied . As a result several classes of highly gas permeable polymers have been developed.…”

Addition Homo‐ and Copolymerizations of Dicyclopentadiene and 5‐n‐Hexylnorbornene in the Presence of Pd‐N‐Heterocyclic Carbene Complexes

“…Norbornene and its derivatives are an unusual class of monomers that can be polymerized by various mechanisms forming polymers with different structures of main chains and properties . This feature, along with the ability to synthesize series of norbornenes with a regularly varying structure, has made these compounds attractive for the macromolecular design of polymers with desired properties and for the systematic study of the relationships “polymer structure‐properties.” Depending on the nature of the side substituents and the structure of the main chain, norbornene‐based polymers can have attractive optical properties, low moisture absorption, thermal and chemical stabilities, promising membrane characteristics, etc. Dicyclopentadiene (DCPD) is one of the most readily available norbornene derivatives, which is obtained by dimerization of cyclopentadiene—a component of light fraction of oil pyrolysis.…”