New Functional Monomers for Well-Controlled ROMP Polymerizations

The ring-opening metathesis polymerization of cyclobutene-containing monomers based on the endo -tricyclo[4.2.2.0 2,5 ]deca-3,9-diene structure bearing cyclic anhydride and N -alkyl- or N -phenyl-substituted succinimides at the 7- and 8-positions was investigated. Well-defined molybdenum and ruthenium complexes were used as catalysts. Cl 2 Ru(CHPh)(PCy 3 ) 2 ( III ) was shown to be the most suitable catalyst as a well-controlled and even living polymerization was observed. Mainly cis stereochemistry (≈75%) was observed in the main chain. Kinetic studies with different substituted succinimide moieties indicated that the polymerization rate depended on electronic effects in the monomer. 19 F NMR of fluorinated polymers suggests that through-space interactions between fluorine groups and the main polymer chain occur. These new polymers have a good thermal stability (304 °C < T d < 344 °C). Upon hydrogenation, the N -methylsuccinimide functionalized polymer exhibited a T g at 285 °C, and the thermal stability increased by about 100 °C.