Novel norbornene copolymers with transition metal catalysts

Synthetic strategies to modify ethylene (E) and norbornene (N) copolymerization by single site transition metal catalysts, to expand their physical properties and to widen their applications, are reported. E-co-N polymerization and kinetics study with 1/d-MAO catalytic system demonstrated the living nature of the copolymerization. This allowed us to synthesize PE-block-P(E-co-N) with a crystalline PE block and an amorphous atactic P(E-co-N) block as well as P(E-co-N)1-block-P(E-co-N)2 having different norbornene content in the segments. A multinuclear NMR spectroscopic study allowed to assess the nature of species responsible for living E-co-N copolymerization reaction. The ¹⁹F spectra, in particular, gave evidence of the importance of the o-F{bullet operator}{bullet operator}{bullet operator}Ti interactions in living E-co-N polymerization.E-ter-N-ter-O, E-ter-N-ter-VCH, E-ter-N-ter-C8N, and E-ter-N-ter-DCPD terpolymers were synthesized. It was shown that the proper selection of termonomer or of the metallocene structure allows one to tune the thermal characteristics and thus to reach materials with desired properties.E-co-N polymers with monomodal molar mass distributions and with norbornene content, T g values and molar masses intermediate to those of copolymers prepared with the individual metallocenes under similar polymerization conditions were synthesized via chain shuttling polymerization.