| Metallocene catalysts have been studied widely since they were firstly developed in olefin polymerization in early 1980s. Many metallocenes with different structure were used in olefin polymerization. Not only conventional polyolefms but lots of novel materials such as syndiotactic polypropylene (s-PP), syndiotactic polystyrene (s-PS), polycycloolefins etc., which can not be synthesized with conventional Ziegler-Natta catalyst, are synthesized with metallocene catatlysts. Studies on the synthesis of the copolymer of olefin and polar monomer which can improve the surface properties of the polyolefin is one of the interesting field of metallocene catalyst. Because the polyolefin produced with metallocene has very narrow molecular weight distribution, it is very difficult to be processed. To produce bimodal polyolefms which not only have excellent strength but have good processability is also an active study field in metallocene catalysts.To produce excellent polyolefin materials, ten novel cyanoethyl cyclopentadienyl complexes CpCNCpMCln [CpCN=C5H4CH2CH2CN, Cp=C5H5, n=2, M=Ti(l), Zr(2); n=l, M=Sm(3)], CpCN2MCln [CpCN=C5H4CH2CH2CN, n = 2, M=Ti(4), Zr(5); n=l, M=Sm(6), Y(7)], CpCNTiCl3(8), [(CH3)2Si(C5H3CH2CH2CN)2][(C5H5)MCl2]2 [M=Ti(9), Zr(10)], three germanium-bridged metallocene compounds Me2Ge('BuC5H3)2LnCl [Ln=Y(ll), Nd(12), Sm(13)] and three germanium bridged dinuclear metallocene compounds [(CH3)2Ge(CsH4)2]-[(C5H5)TiCl2]2 (14), [(C5H5)MCl2][(C5H4)GeMe2(C5H4)][Sm(C5H5)Cl] (M=Ti(15), Zr(16)) were synthesized for the first time in this thesis. Single crystal of CpCNCpTiCl2(l) was obtained after recrystalized in toluene. Its structure was determined by X-ray diffraction. Several catalysts systems with high activity or distinctive catalytic properties were found after enormous polymerization investigation.Catalytic properties of non-bridged cyanoethyl metallocene compounds 1, 2, 3, 5 and silicon-bridged homo-dinuclear metallocene complexes 15, 16 in ethylene polymerization were studied detailedly. With MAO as the cocatalyst, cyanoethyl zirconocene 2 had a high activity (1.309 ×105 g PE/mol Zr-h). Effect of temperature on the catalytic property ofCpCN CpTiCl2(1)/MAO was very distinct. The molecular weight of polyethylene dropped quickly with the elevation of the temperature. The catalytic system had the highest activity at60℃ . Silicon-bridged cyanoethyl dinuclear metallocene complexes [(CH3)2Si(C5H3- CH2CH2CN)2][(C5H5)MCl2]2 [M=Ti(9), Zr(10)] had high activity in ethylene polymerization with MAO as cocatalyst. Compared with their corresponding mononuclear complexes (C5H4CH2CH2CN)(C5H5)MCl2 (M=Ti(3), Zr(4)), the dinuclear complexes had higher catalytic activity. And the polyethylene produced had a higher molecular weight than that obtained with mononuclear catalysts. 10 had a very high activity (2.506 × 106 g PE/mol Zr-h) under low catalyst concentration(10-5 mol/L) and high molar ration of Al/Zr (10,000). Molecular weight and molecular weight distribution were determined by GPC. Polyethylene produced under this condition showed a bimodal distribution (MJMn - 34.5). The melting point and crystallinity of the polymer were about 140℃ and 64%-83% respectively.Cyanoethyl monocyclopentadienyl titanium CpCNTiCl3(8) was developed for the styrene polymerization with MAO as cocatalyst. The catalytic system showed high activity (1.68 × 106 g PS/mol Ti-mol St-h) and high stereo selectivity (% sPS = 96%) under high molar ratio of Al/Ti condition (Al/Ti=4000).Ring-opening polymerization of caprolactone (CL) catalyzed by novel single component germanium-bridged lanthanocene chloride (CH3)2Ge('BuC5H3)2LnCl [Ln = Y(11), Nd(12), Sm(13)] was developed successfully for the first time. In presence of this lanthanocene, CL was 100% polymerized at 60℃ within 3-4 hrs. The highest molecular weight of the PCL was 60,000 and molecular weight distribution is from 1.3 to 2.0. The polymerization rate increased with the elevation of the temperature. The thermal-stability of germanium-bridged metallocene complexes was...
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