Norbornene-derived polymers represent a versatile platform in advanced materials due to their tunable molecular
architectures; however, unsubstituted norbornene dicarboximides (NDI) often suffer from poor solubility,
limited stability, and restricted control during polymerization. To address these challenges, we designed welldefined
norbornene-based homo- and copolymers incorporating ethylhexyl substituents via ring-opening
metathesis polymerization (ROMP), achieving a balance between rigidity and flexibility. Polymerization
behavior was systematically examined under living conditions by monitoring conversion, initiator-to-monomer
ratios, and the efficiency of Grubbs catalysts (G1, HG1, HG2, G3, G2), with G1 providing superior control and
narrow dispersities (PDI) Furthermore, a series of random copolymers (P1–P6) bearing diverse functional groups
was synthesized and characterized by FT-IR, FESEM, GPC (PDI = 1.15–1.24) and NMR spectroscopy, with further
analysis for P4 via 19F-NMR. Thermal studies revealed high decomposition (358–459 ◦C) and glass transition (80-
168 ◦C) temperatures, strongly influenced by sidechain identity and connectivity to the norbornene core. The
optical characteristics were evaluated with a wide optical bandgap (3.53–4.53 eV). These findings demonstrate
that the present norbornene dicarboximide frameworks thus combine excellent thermal robustness with high
optical transparency, establishing them as promising high-performance materials for advanced applications.