新型钛族烯烃聚合催化剂的合成及其催化性能研究

【作者】 张军；

【导师】 金国新；

【作者基本信息】 复旦大学 ， 无机化学， 2006， 博士

【摘要】 1、合成，表征了四个含烯丙基的茂锆配合物（C₃H₅C₅H₄）RCpZrCl₂（R=allyl，1；H，2；^tBu，3；^tBu₂，4）。X-射线单晶衍射解析了其中配合物1和3的分子结构。这类含烯丙基的茂锆配合物作催化剂催化烯烃聚合时，催化剂分子中的乙烯基团会共聚到增长的聚烯烃链上。因而，这种催化体系不需要任何载体，却具有为自身提供载体的能力。所以也被称作自固载烯烃聚合催化剂。这类自固载化烯烃聚合催化剂在MAO的作用下，显示出了较高的乙烯聚合活性。我们将配合物3与苯乙烯共聚制备了的高分子化的烯烃聚合催化剂5和壳核结构的高分子化烯烃聚合催化剂6，并进行了表征。高分子化的茂金属催化剂5的聚合实验表明这类催化剂保持了较高的活性，并能有效地避免粘釜的现象。壳核结构的高分子化催化剂6产生的聚乙烯有很好的形态和堆密度，基本达到了工业化的要求，具有很好的工业化前景。2、进行了茂锆配合物1的介孔分子筛SBA-15的负载化。这种SBA-15的负载化的茂金属催化剂不仅保持了茂金属均相催化剂的高活性，而且利用载体的孔道效应合成了纤维状聚乙烯产品。3、合成，表征了两个双β-二酮半夹心锆配合物CpZr（acac）₂Cl（7）、Cp^*Zr（acac）₂Cl（8）和两个三β-二酮半夹心锆配合物CpZr（acac）₃（9）、CpZr（tfac）₃（10）（acac=acetylacetonato，tfac=trisfluoroacetylacetonato）。X-射线单晶衍射表明双（β-二酮）半夹心锆配合物7采用一种不对称的顺式结构。三（β-二酮）半夹心锆配合物9和10的空间构型是五角双锥结构。乙烯聚合实验表明，这类锆配合物是优良的乙烯聚合催化剂。在5atm，70℃下，乙烯均聚高达7100kgPE／molZr.h，得到高分子量的聚乙烯（M_v=89×10⁴）。另外，锆配合物7和8还能够催化乙烯和1-己烯的共聚。4、合成了三齿席夫碱[O，N，O]类双苯酚半夹心钛配合物（11，12），锆的配合物（13，14）和含硫三齿席夫碱[S，N，O]类双苯酚半夹心钛（15）、锆的配合物（16）。X-射线单晶衍射显示配合物11、12、13和15的配体中的N原子都与中心金属原子有配位作用。乙烯聚合实验表明，钛配合物11的乙烯聚合活性较低。而锆配合物13的乙烯聚合活性较高，在常压，70℃时，活性达1.53×10⁵gPE／molZr.h，且活性随温度的升高而增大。含硫钛配合物15乙烯聚合活性高于钛配合物11。实验表明，钛配合物11还能催化乙烯和1-己烯共聚。更多还原

【Abstract】 1. Metallocene catalysts, （C₃H₅C₅H₄）RCpZrCl₂ （R= allyl, 1; H, 2; ^tBu; 3; ^tBu₂, 4）, containing an allyl group, have been synthesized and characterized. In the presence of excess methylaluminoxane （MAO）, the allyl group of the metallocene catalysts can be co-polymerized in the polymer chain as co-monomer in the polymerization process and so they were also called as self-immobilized catalysts for ethylene polymerization. The molecular structures of catalyst 1 and 3 have been determined by single-crystal X-ray diffraction. The polymerized metallocene catalyst 5 is prepared by the copolymerization of allyl metallocene complex with styrene in the presence of radical initiator. The result of ethylene polymerization showed that the polymerized metallocene catalyst kept high activity of 2300kgPE/molM.h for ethylene polymerization and was a potential supported catalyst for olefin polymerization.2. This thesis discussed the synthesis and characterization of SBA-15 supported metallocene catalyst. The function of SBA-15 in controlling the morphology and improving the properties of polymers was studied through ethylene polymerization. The two-dimensional ordered channel structure of SBA-15 could control the relative position of polyethylene chains. As a result, the polyethylene fibers were obtained.3. The half-sandwich Zr complexes of CpZr（acac）₂Cl（7）, Cp*Zr（acac）₂Cl（8）, CpZr（acac）₃（9） and CpZr（tfac）₃（10） （ acac=acetylacetonato, tfac= trisfluoroacetylacetonato） have been synthesized and characterized. The molecular structures of 7, 9 and 10 have been determined by X-ray diffraction methods. The geometrys around Zr atom in the tis（β-diketonato） Zr complexes 9 and 10 is pentagonal bipyramid. When activated by excess MAO, these catalysts were well active for ethylene polymerization, offering polyethylenes with high molecular weights. Catalyst 9 showed very high activity for ethylene polymerization of up to 7100kgPE/molZr.h at 5 atm and the resulted polymer has a high molecular weight （M_v = 89×10⁴）. Catalysts 7 and 8 were also active for ethylene/1-hexene copolymerization.4. The Ti and Zr half-sandwich catalysts 11-16 with [O（S）,N,O] tridentate Schiff base ligand have been synthesized. The molecular structures of catalysts 11,12, 13 and 15 have been determined by X-ray diffraction methods. The nitrogen atoms in 11,12,13 and 15 are coordinated to the metal centers. In the presence of excess MAO, the Zr catalyst 13 exhibited more active than the Ti complex for ethylene polymerization with a activity of 1.53×10⁵gPE/molZr.h at 70℃, 1atm. [S,N,O] tridentate Schiff base Ti complex 15 is more active than its analogue 11. Catalyst 11 was also active for ethylene/1-hexene copolymerization.更多还原