Abstract
The gas permeability of hydrocarbons (CH4, C2H6,n-C4H10) through four polynorbornenes obtained by modification of the addition poly(5-vinyl-2-norbornene) is studied. Upon modification, both polar (oxirane and thioacetyl fragments) and nonpolar substituents (cyclopropyl and ethyl groups) are introduced into side substituents. The introduction of polar groups leads to a decrease in gas permeability, while the hydrogenation or cyclopropanation of addition poly(5-vinyl-2-norbornene) causes an increase in gas permeability. Despite the fact that the synthesized polymers are glassy and nonmicroporous materials, they have an unusual feature for such polymers-the selectivity of hydrocarbon separation controlled by solubility (alpha(n-C4H10/CH4) >> 1). Among the studied polymers, the optimal combination of gas permeability and selectivity is observed for the cyclopropanated polymer.