【作者】 王伟；

【导师】 范志强； 封麟先；

【作者基本信息】 浙江大学 ， 高分子化学与物理， 2002， 博士

【摘要】 本文研究了新型非桥联茂金属化合物的合成，并以硅胶和蒙脱土为载体，对茂金属进行了负载，以均相和负载茂金属与甲基铝氧烷组成的催化体系进行了乙烯与己烯的共聚合，以均相茂金属与甲基铝氧烷组成的催化体系进行了丙烯聚合，分析表征了聚合物结构和性质，研究了聚合行为、聚合物结构性能与催化剂结构之间的关系，并提出了新的表征乙烯共聚物内共单体分布均匀性的方法。 本文按不同路线合成了两种茚酮：2,7-二甲基茚酮和2,5,7-三甲基茚酮。茚酮经还原脱水得到了相应的取代茚：2，4-二甲基茚和2,4,6-三甲基茚。讨论了不同反应起始物对茚酮产率和组成的影响；以化学方法分离了2,4,6-三甲基茚的双键位置异构体，并讨论了机理。 以取代茚为配体，合成了非桥联茂金属化合物：（2,4-Me₂Ind）₂ZrCl₂（cat24）和（2,4,6-Me3Ind）2ZrCl2（cat246）。讨论了不同溶剂和加料方式对茂金属产物组成的影响。本文所用的合成路线具有产率高，原料廉价和污染小的特点。 本文以大孔硅胶MS-3040（MS）和蒙脱土（MTT）为载体，对cat24和cat246进行了负载化，得到了三种负载催化剂：MS24，MS246，MTT24。通过紫外吸收法测定了负载催化剂的Zr含量。 采用3种均相催化剂：cat24，eat246，cat247和3种负载催化剂：MS24，MS246，MTT24研究了乙烯与1-己烯的共聚合。其中cat247为（2,4,7-Me3Ind）2ZrCl2。通过不同条件下的共聚合实验，发现cat24在0℃时的催化共聚合，其聚合活性随1-己烯浓度升高而变化的规律为先降后升再下降，这种变化规律不同于以往的任何报道。根据共单体介入所产生的诸多方面影响的综合作用，对这一现象进行了解释。这种解释也得到了cat24在50℃和cat24在0℃及 ：MrtrtotpedeototfPrt50C的聚合行为的证实。比较了均相催化剂浓度对活性的影响，提出活性种离子对的紧密程度对活性有重要影响，并由此预测了催化剂浓度对聚合物共单体含量的影响，发现实验结果与预测相符。发现茂金属经负载化后，其聚合行为有很大的改变。对硅胶负载体系，乙烯均聚活性较高而共聚活性明显下降，表明硅胶载体对乙烯的扩散影响较小，对己烯的扩散影响很大。以蒙脱土为载体时，均聚、共聚活性均较低。 用’℃NMR和 IR测定了乙烯门－己烯共聚物的共单体含量。发现聚合物共单体含量基本与共单体进料浓度成正比。发现非桥联茂金属配体上取代某的位I置和数量对共聚合能力影响很大。根据取代基数量和位置的差异造成的茂金属1构象和配体转动能垒的变化解释了共聚合能力的差别，提出了非桥联茂金属催I化剂催化共聚合的 TSAM（TWo Sites Alternating Mechanis叫机理。 用逐步等温结晶＊既考察了聚合物的热行为，计算了片晶厚度分布，用0盯I法和 NMR法结合计算了短支链分布侣CB），发现二者之间的差值与共聚物中共 B单体分布的均匀性有关，对此解释为：NMR法是聚合物SCB的真实体现，差g值越小，说明DSC法越接近真值；DSC法的SCB值小于NMR法时，说明较’ g多共单体形成了不可结晶的连续链段或无规共聚链段，对降低熔点没有贡献，「但对降低熔融烙或结晶度有贡献，此时共单体在聚合物链中的分布不均匀；DSC；值大于NMR值时，说明绝大部分共单体单元在聚合物链中处于孤立状态，而且乙烯连续链段长度分布不均匀，此时共单体对熔点降低的贡献大，但结晶度仍然很高；DSC值接近NMR值时，共单体在聚合物链中分布比较均匀，而且乙烯连续链段长度的分布也比较均匀，共单体对熔点和结晶度的降低都有较大贡献。定义了加权平均熔点的概念，发现加权平均熔点与聚合物共单体含量基本为线性关系。可用该直线的斜率表示共单体降低聚合物熔点的效率，斜率绝对值越大，效率越高。此外，在负载催化剂的聚合物中，发现存在部分由载体孔隙造成的受限结晶结构。 用GPC测定了聚乙烯和乙烯／1己烯共聚物的分子量及其分布，讨论了聚合条件对分于量和分子量分布的影响。各催化剂所得聚乙烯均表现出很高的分子量耐＞3O万)和较窄的分子量分布。共聚物的分子量低于均聚物。负载催化剂所得产物的分子量较均相催化体系有所提高。 n 浙江大学溶士学应讼义 以cat246和cat24为催化剂，催化丙烯聚合，得到了无规产物。用核磁共振检测了聚合物的微结构，并根据结果分析了催化剂纬构与聚合物结构的关系。得到以下结论：cat246的聚合活化能远大于cat24，与桥联茂金属接近，说明茂金属配体上取代基的数目和存在形式郡对聚合行为有重要影响；cat246的立构规整能量差与cat24接近，二者产生的聚合物结构分巾也相似，通过与文献值的比较，认为，4位甲基对增大立构能量差的作用十分重要，而2位和6位的?更多还原

【Abstract】 The dissertation involves the following works: the synthesis of non-bridged metallocene, supporting the metallocene by using silica(MS) and montmorillonite(MTT) as carriers, copolymerization of ethylene with 1-hexene by homogeneous and heterogeneous catalyst combined with methyl aluminoxane, polymerization of propylene by homogeneous catalyst combined with methyl aluminoxane, and characterization of the structure and its properties of the resultant polymer. And the correlation between metallocene structure and polymerization behavior and polymer properties is discussed. New methods to characterize the structural homogeneity of copolymer are developed.Two substituted indanones were synthesized through different procedures: 2,7-dimethylindanone and 2,5,7-trimethylindanone. After reduction and dehydration, substituted indenes, 2,4-dimethylindene and 2,4,6-trimethylindene, were obtained from the corresponding indanones.. The influence of different start substances on the composition and yield of the indanones was staudied. The isomers from double-bond position in 2,4,6-trimethylindene were separated by chemical approach, and the mechanism was discussed.Using the substituted indenes as the organic ligand, two non-bridged metallocenes were synthesized: (2,4-Me2lnd)2ZrCl2(cat24) and(2,4,6-Me3lnd)2ZrCl2(cat246). The adopted procedure gave high yield with cheap raw materials and less pollution.Using mesoporous silica gel(MS) and montmorillonite(MTT) as carriers, supported catalysts of cat24 and cat246 were prepared. Three heterogeneous catalysts,MS24, MS246, MTT24, were obtained. The Zr content in the supported catalyst was determined by UV spectroscopy.In the present study, copolymerization of ethylene with 1-hexene was carried out by using cat24, cat246, cat247, MS24, MS246 and MTT24 combined with MAO as cocatalyst, in which cat247 is (2,4,7-Me3Ind)2ZrCl2. A new activity-comonomer concentration relation was found in the copolymerization catalyzed by cat24 at 0癈. The polymerization activity underwent changes of decrease-increase-decrease with increase of hexene feed concentration. This phenomenon has not been reported in literatures. It is reasoned that the integration of various effects caused by the comonomer had made such changes. This explanation is proved by the polymerization behavior of cat24 at 50癈 and cat246 at 0癈 and 50癈. Through the comparison of activity at different homogenous catalyst concentration, the important influence of compact/loose ionpair of active site on activity was found. And according to this opinion, the copolymerization ability of catalyst is estimated. The estimation is identical with the observed result. Supporting of metallocene exerted important influence on the polymerization activity. The activity maintained a high level to ethylene homopolymerization and observably decreased to ethylene/1-hexene copolymerization for the silica supporting system. It indicates that the silica carrier has minor effect on the ethylene diffusion, but hinders the diffusion of 1-hexene. The activity of both homo- and co-polymerization decreased for montmorillonite suupporting system.The comonomer content incorporated in polymer was determined by using 13C-NMR and IR. The comonomer content is proportioned to the feeding concentration. The number and position of substituent on ligand of metallocene has strong effect on copolymerization ability. The difference in copolymerization ability of metallocenes were interpreted according to the different metallocene conformations and the change of ligand rotation energy barrier resulted from the number and position of substituent on ligand of metallocene. The number and position of substituents in ligand is the original reason. The "two sites alternating mechanism"(TSAM) of non-bridged metallocene is developed.Thermal property of the ethylene/1-hexene copolymer was characterized by using stepwise isothermal segregation fractionation DSC. The lamella thickness is calculated. The short-chain branching (SCB) d更多还原