| In this thesis, the five ligands PN1, PN2, PN3, PN4, PN5 and their corresponding nickel complexes Ni(PN1)2, Ni(PN1)2, Ni(PN1)2 were successfully synthesized and characterized by IR and element analysis. The X-ray single crystal diffraction was used to determine the molecular structure of PN2, PN3, PN5 and Ni(PN1)2. Nickel complexes were used to catalyse norbomene polymerization under methylaluminoxane (MAO) activation, showing high acitivities. It was showed that the polymerization conditions, such as different catalysts, Al/Ni ratio, reaction temperature, reaction time, different solvents, monomer concentration and catalyst concentration, had great effects on the catalytic activities and the viscid average molecular weight of polynorbomene(PNB). The characterization of the polymers showed PNB was formed by vinyl-type polymerization, with high thermal stability and none-crystalline structure. The research also showed nickel complexes can catalyse ethylene oligomerization, styrene polymerization and styrene and norbomene copolymerization. But the copolymerization activities were low.In addition, the novel N^P^N ligands containing bispyrindine-phosphine and their corresponding titanium and chromium complexes were also synthesized and characterized by IR and element analysis. Under MAO activation, all the complexes were able to catalyse ethylene oligomerization and polymerization, showing good oligomerization activities. Likewise, the effects of different polymerization conditions on catalytic activities and product distribution, such as different metal centers, different ligands, Al/M ratio, reaction temperature, reaction time and auxiliary ligand PPh3, were discussed.
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