Ring-opening metathesis polymerization of cis-5-norbornene-endo-2,3-dicarboxylic anhydride derivatives using the grubbs third generation catalyst

A series of cis-5-norbornene-endo-2,3-dicarboxylic anhydride (NDCA, M1) derivatives (M2-M4) with different types of nonpolar substituted groups were synthesized and characterized by H-1/C-13-NMR and mass spectrometry (MS). Ringopening metathesis polymerization (ROMP) of these monomers using the Grubbs third generation catalyst (G3) generated high molecular weight polymers with much improved solubility compared with the NDCA's homopolymer. It was found that the solubility of these polymers increased with increased substituent's steric hindrance. The living polymerization of NDCA derivative containing the bulkiest substituent (M4) catalyzed by G3 in tetrahydrofuran was confirmed by the kinetic studies with low polydispersity indices (PDI) (< 1.30). By using sequential ROMP, well-defined diblock copolymers containing anhydride groups were synthesized.