Schematic representation of the repeating units of poly(N-(1-adamantyl)-exo-norbornene-5,6-dicarboximide) (M1), poly(N-cyclohexyl-exo-norbornene-5,6-dicarboximide) (M2), poly-(N-phenyl-exo-norbornene-5,6-dicarboximide) (M3), and copolymers of N-(1-adamantyl)-exo-norbornene-5,6-dicarboximide with norbornene.