Application of well-defined ruthenium alkylidenes to the ROMP of norbornene derivatives: Methoxyphenyl-substituted polynorbornene dicarboximides

The applicability of ruthenium alkylidenes as initiators in the ring opening metathesis polymerization (ROMP) of methoxyphenyl group containing norbornene derivatives has been investigated. The synthesis and polymerization of exo-N-4-methoxyphenyl-oxanorbornene-5,6-dicarboximide (MeOPhONDI) and exo-N-4-methoxyphenyl-norbornene-5,6-dicarboximide (MeOPhNDI) are reported. Polynorbornene derivatives were obtained via ROMP using first- and second-generation ruthenium alkylidene initiators. The structural properties of the polynorbornene derivatives were analyzed by NMR, DSC and GPC. Analyses of the polymer microstructures indicate that polymers contain trans stereoconfiguration of the double bonds (55–86% trans-content). The glass transition temperatures of the polymers obtained from exo-monomers are higher than 211 °C.

Figure optionsDownload high-quality image (40 K)Download as PowerPoint slideResearch highlights▶ Well-defined ruthenium initiators are effective metathesis catalysts for the syntheses of PMeOPhONDI and PMeOPhNDI. ▶ Methoxy group decreases the chain mobility and increases the rotational barrier of the polymer chains. ▶ Ruthenium alkylidene catalysts produced polymers with trans configuration of the double bonds.