Addition-type poly(norbornene)s with siloxane substituents: synthesis, properties and nanoporous membrane

Addition-type poly(norbornene)s with siloxane substituents were synthesized using the (η3-Allyl)(η5-cyclopentadienyl)palladium/tricyclohexylphosphine/[Ph3C][B(C6F5)4] system. The obtained polymers had very high glass transition temperature of up to 255 °C, and their films displayed high mechanical flexibility. The incorporation of siloxane groups in the chain resulted in significant increase in the gas permeability of their films, and the polymers with branched siloxane groups showed high oxygen permeability (P(O2)=66–360 Barrer). In addition, poly(norbornene) membranes with a unique porous structure were prepared.[graphic not available: see fulltext]