Copolymerization of Norbornene and Butyl Methacrylate at Elevated Temperarure by Single Centre Nickel Catalyst Bearing Bulky Bis(α-diimine) Ligand with Strong Electron-Withdrawing Group
Three dimensional geometry bulky a-diimine ligand with strong electron-withdrawing groups (-NO2), 9,10-dihydro-9,10-ethanoanthracene-11,12-di(p-PhNO2)imine(L), and corresponding single nickel catalyst (NiL2Br2) were synthesized and the molecular structure of NiL2Br2 catalyst was confirmed by X-ray crystallography. After being activated with B(C6F5)3, the NiL2Br2 catalyst exhibited high activity toward homopolymerization and copolymerization of norbornene(NB) and butyl methacrylate(BMA). The obtained poly(NB-co-BMA)s were confirmed to be vinyl-addition copolymers and noncrystalline. The BMA monomer content in the copolymers could be controlled up to 6.0–78.7 % by varying the BMA monomer feed ratios from 10 to 90 %. The obtained poly(NB-co-BMA)s exhibited high thermal stability (Td > 390 oC), high-molecular-weight and narrow molecular weight distribution (PDI ≤ 1.4), and could be processed into films with good transparency and mechanical properties.