| The application of Group IVs metallocene - aluminoxane systems to the polymerization of olefins, discovered by W.Kaminsky etc, has been regarded as a great breakthrough of polyolefin industry in 1990s. It is no doubt that metallocene catalysts became prominent in a special period in the history of polymer science and technology, a period that not only produced many new commercial polymers but also enhanced our knowledge of organometallic chemistry -, macromo-lecule chemistry and physics, etc. However, there were some serious problems, such as the unfavorable properties of mPO and the copolymerization of olefins and polar monomers. Several ways, such as using mix catalysts, dinuclearmetallocenev lanthanocene or late-transition metal catalyst, are available but far away from industrialization. Aimed at this target, dinuclear-metallocene and lanthanocene catalysts were studied in detail.It is well known that bridged metallocenes have great superiorities in advancing polymerization activity xStereoselectivity and copolymerization. In dinuclearmetallocene and lanthanocene catalysts, the effect of bridges is even more obvious. In this dissertation, germanium bridge were used and several novel germa-bridged lanthanocene. dinuclear(homo or heterobimetallic) or multinuclear complex catalysts with high activity or distinctive catalytic properties were found after enormous polymerization investigation. The main research work was concluded as follows: (1) single component germa-bridged lanthanocene chloride catalyst for polymerization of caprolactone. (2) germa-bridged homometallic titanocene-MAO catalyst for polymerization of ethylene. (3) germa-bridged lanthanide-transition metal heterometallic or multinuclear complex-MAO catalyst for polymerization of ethylene.Ring-opening polymerization of caprolactone (CL) catalyzed by novel single component germa-bridged lanthanocene chloride was realized successfully for the first time. In the presence of this lanthanocene chloride (Ln=Sm, Nd, Y), CL was 100% polymerized at 60℃ within 3~4hrs with molecular weight below 60,000 and molecular weight distribution in 1.3~2.0. Both the bridge and the rare earth metal could affect the polymerization. The order of activity was: Me2Ge = Me2$i ?Cil^OCjRt; Y > Nd > Sm. However, the order of molecular weight was opposite: Me^Si > Me2Ge; Sm > Nd. The polymerization of CL catalyzed by Cat-Nd or Cat-Sm was investigated carefully in bulk and solution. The thermal-stability of germa-bridge was more superior than silicon-bridge or ether-bridge. Even in 80℃, the activity, molecular weight and molecular weight distribution all kept good properties. The nonpolar or weak polar solvent was suitable for thepolymerization. The addition of little cocatalyst, such as NaBPlu or AlEts, could promote the polymerization obviously. The system seemed a near-living polymerization. The mechanism studied by IR, NMR indicated that the polymerization of CL catalyzed by lanthanocene chloride proceeded via a coordination-activation and selective cleavage of acyl-oxygen bond mechanism.The germanium bridge was used in the synthesis of homobimetallic metallocene for the first time and was developed as catalyst for polymerization of ethylene. The Ti-Ti dinuclear system [Me2Ge(C5H4)2][(C5H5)2TiCl2]2/MAO showed high activity as 0.5? X 105gPE/mol.Ti.h which was slower than Cp2TiCl2/MAO but was comparative with or even higher than analogous systems. At 50℃, the activity was also high which indicated that the thermal-stability of germa-bridge was superior in this system too. The molecular weight of PE catalyzed by this dinuclear metallocene (50,000~ 1,300,000) was higher than other long-bridge similar systems and even comparative with Cp2TiCl2/MAO. The polymerization behavior of PE was investigated in toluene solution. The behavior of polymerization time or MAO/Catalyst (molar ratio) was similar with homonuclear analogies. However, in low catalyst concentration ([Cat]<80(amol/l). lower concentration of catalyst preferred lower activity which was opposite to homonu...
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