Gas Transport in Polymers Prepared via Metathesis Copolymerization of exo-N-Phenyl-7-oxanorbornene-5,6-dicarboximide and Norbornene

This work reports the synthesis of exo-N-phenyl-7-oxanorbornene-5,6-dicarboximide and its ring-opening metathesis copolymerization with norbornene to yield poly(exo-N-phenyl-7-oxanorbornene-5,6-dicarboximide-co-norbornene), with molar ratio 50/50. The glass transition temperature of the copolymer is 125 °C. Permeation and sorption processes of different gases (hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethylene, and ethane) were measured in membranes prepared by casting from solutions of the copolymer in chloroform. The Langmuir capacity of the gases is relatively small due to the nearness of the glass transition temperature of the polymer to the working temperature. The solution of the most condensable gases in the continuous phase of the membrane is apparently described by the Flory−Huggins theory of polymer−diluent mixtures. In general, the membranes exhibit a reasonably high separation coefficient of hydrogen with respect to ethane, ethylene, nitrogen, and methane. The value of α(O2/N2) at room temperature lies in the vicinity of 5.