不对称结构胺双酚四齿配体及其金属配合物的合成、表征及催化性质研究

发布时间：2018-04-26 09:37

  本文选题：不对称结构 + 钛配合物(IV)　； 参考：《吉林大学》2017年硕士论文

【摘要】：聚烯烃是一类产量大、应用多的高分子材料,由于原料丰富、价格低廉、容易加工成型、良好的机械性能和热性能、抗腐蚀性能优良等特点,国内外已广泛应用于包装、建筑材料、电气元件等诸多行业,而且世界各国对聚烯烃材料的需求将持续增长。催化剂决定着聚合物的形貌、结构以及性能,因此聚烯烃材料的发展与催化剂的进步密不可分。聚烯烃工业不断地发展,人们对于具有特殊性能聚烯烃产品需求也日益增加,因此对于具有优异性能的催化剂的研究与开发仍然有极其重要的意义。本文利用对叔丁基苯酚为基本原料,设计合成了一类具有不对称结构的胺双酚四齿配体L1H2-L6H2,对配体的结构进行了1H NMR、13C NMR等表征。采用一锅法高产率得到了红色或深红色钛配合物C1-C6。通过1H NMR、13C NMR、元素分析对配合物进行了表征,X射线单晶衍射分析确认了配合物C3、C4和C5的结构,表明金属中心具有六配位的配位结构。在配体中,其中一个N原子上连有两个甲基,另一个N'原子上连接了两个不同的取代基,在配体与金属发生反应之后,氮原子与金属中心形成配位键,O-则与金属中心形成σ键,配合物在空间上呈现非对称的结构。本文最后一章研究了配合物C1-C6的对烯烃聚合反应的催化活性。相同的聚合条件下,以MAO助催化剂,配合物C1-C6对乙烯聚合反应表现出了较高的催化活性,最高为3640 kg PE(mol Ti)-1h-1,活性顺序与配合物结构中取代基R1、R2空间位阻大小的顺序相同。最合适的Al/Ti为800,当Al/Ti为800时聚合产物分子量最高为C3,其Mw达到36.6×104 g mol-1;聚合物分子量分布中等至较窄,其PDI处于1-4之内。当聚合温度加热到80℃时,催化剂仍有较高的催化活性表明催化剂具有良好的热稳定性;通过延长聚合时间,发现其具有较长的催化寿命。聚乙烯的DSC及高温GPC表明得到的是线性聚乙烯。在MAO的作用下,研究了配合物C1-C6对乙烯与1-己烯共聚反应的催化性质,相同条件下活性随着取代基R1、R2的增大而降低,己烯插入率随着取代基R1、R2的增大而降低。己烯的初始浓度也影响着聚合反应和聚合产物的性质,当Chexene=0.75mol L-1时,催化剂活性最高,随着己烯浓度的升高,共聚反应活性逐渐降低,聚合产物的分子量逐渐降低。共聚物分子量Mw处于3-17×104 g mol-1间,分子量分布较窄,PDI处于2-3之间。
[Abstract]:Polyolefin is a kind of high molecular material with large output and many applications. It has been widely used in packaging at home and abroad because of its rich raw materials, low price, easy processing, good mechanical and thermal properties, excellent corrosion resistance and so on. Building materials, electrical components and other industries, and the world's demand for polyolefin materials will continue to grow. Catalysts determine the morphology, structure and properties of polymers, so the development of polyolefin materials is closely related to the progress of catalysts. With the continuous development of polyolefin industry and the increasing demand for polyolefin products with special properties, it is still of great significance for the research and development of catalysts with excellent performance. In this paper, an asymmetric tetradentate amine bisphenol ligand L1H2-L6H2 was designed and synthesized by using p-tert-tert Ding Ji phenol as the basic raw material. The structure of the ligand was characterized by 1H-NMR-13C NMR. The red or crimson titanium complexes C1-C6 were obtained by one-pot method. The complexes were characterized by elemental analysis by 1H NMR-13C NMRs and characterized by X-ray single crystal diffraction. The structures of the complexes C _ 3C _ 4 and C _ 5 were confirmed, indicating that the metal center has a six-coordination coordination structure. In the ligand, one N atom is connected with two methyl groups, the other N 'atom has two different substituents. After the ligand reacts with the metal, the nitrogen atom forms a coordination bond with the metal center and the O-forms a 蟽 bond with the metal center. The complexes exhibit asymmetric structures in space. In the last chapter, the catalytic activity of complex C1-C6 for olefin polymerization was studied. Under the same polymerization conditions, the coordination compound C1-C6 exhibited higher catalytic activity for ethylene polymerization under the same polymerization conditions with MAO co-catalyst, with the highest catalytic activity of 3640 kg PE(mol Ti-1h-1.The order of activity was the same as the order of steric resistance of the substituent R _ 1R _ 2 in the structure of the complex. The most suitable Al/Ti is 800. When Al/Ti is 800, the maximum molecular weight of the polymer product is C _ 3, and its MW is 36.6 脳 10 ~ 4 g mol ~ (-1). The molecular weight distribution of the polymer is moderate to narrow, and its PDI is within 1-4. When the polymerization temperature is heated to 80 鈩，

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