| 초록 |
The effects of BF3 complex on the activation of the Ni(II) complex were studied in the polymerization of norbornene. The Ni(II) complexes, such as Ni(II)(2-ethylhexanoate)2 and Nickel(II) bis(2,2,6,6-tetramethyl-3,5-heptanedionate), in combination with BF3 complex and MAO, were determined to have high activity in the polymerization of norbornene. On the other hand, the polymerization performed with only the Ni(II) complex and MAO in the absence of BF3 complex provided a significantly lowered conversion. The use of other borane compounds with Ni(II)/MAO in place of BF3 complex clearly showed the main functions of BF3 complex. The high Lewis acidity of BF3 complex enabled it to activate catalytic complexes, thus accelerating polymerization. The polynorbornene obtained showed 2,3-connectivity of polymer backbone. The variation of the reaction parameters readily controlled catalyst activity and the molecular weight of polymer over a wide range. The characterization of the produced polymer was performed by 1H and 13C NMRs, TGA, and DSC. |
