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中南民族大学 硕士学位论文 新型的-二亚胺钛、铬配合物催化乙烯聚合及乙烯与环烯烃共 聚性能研究 姓名:雷禄 申请学位级别:硕士 专业:高分子化学与物理 指导教师:谢光勇 2011-04-15 中南民族大学硕士学位论文 I 摘 要 高性能环烯烃共聚物(COC)在许多领域具有广泛的应用前景,聚合工艺的核 心就是催化剂的研发,开发具有高活性的可控聚合催化剂是目前国际上研究的热 点。本论文中我们设计合成含不同位置和数目的氟取代基的 -二亚胺钛配合物并 对其催化性能进行了研究,发现其对乙烯与环烯烃共聚具有很高的催化活性,我 们还合成了五种不同位置及数目氟取代基的 -二亚胺铬配合物,并研究其催化乙 烯聚合性能。 本文主要包括以下几方面的内容: 1. 研究五种不同位置和数目含氟的 -二亚胺钛配合物与 MMAO 组成催化剂 体系常压下催化乙烯与降冰片烯或环戊烯共聚的性能,四种配合物 4a、4b、4d 和 4e 均能以较高活性催化乙烯与降冰片烯或环戊烯共聚,其中 4a 活性高达 106g/molTi.h.atm 以上,与乙烯均聚活性相当。不同位置和数目氟取代基对配合物 的活性有很大的影响,配合物中配体上的亚胺邻位被氟取代可以明显增加配合物 的活性,且邻位氟取代基越多,配合物活性越高;而对位氟取代基的引入,则降 低配合物的催化活性。讨论邻位氟取代基能显著增加配合物活性的原因,除了氟 的吸电子效应可以增加中心金属的亲电性外,最主要是邻位氟可以与乙烯或环烯 烃单体 H 形成氢键,有利于中心金属周围乙烯或环烯烃的富积,从而有利于单体 配位和插入,从而增大配合物催化活性。 2. 制备新型含氟的 -二亚胺铬配合物并与 MMAO 组成催化剂体系,对催化 乙烯聚合的性能进行了研究,发现含氟取代基的 -二亚胺铬配合物比烷基取代基 的配合物催化活性明显增加,其中含邻氟取代基的四种配合物均能中等活性催化 乙烯聚合。氟取代基的不同位置和数目对 -二亚胺铬配合物的活性也有重要的影 响。对于单氟取代的配合物来说,含邻位氟取代基的配合物催化活性明显比对位 氟取代的配合物催化活性大,提出邻位氟取代基能显著增加配合物活性的原因, 除了氟的吸电子效应可以增加中心金属的亲电性外,最主要是邻位氟可以与乙烯 上的氢形成氢键作用,有利于中心金属附近乙烯的富积与配位,从而增大配合物 催化活性。氟取代基增多,配合物催化活性反而降低。 3. 采用微波加热成功地合成五种含氟的 -酮亚胺类配体, 无需要催化剂和溶 剂,反应时间短,后处理简单,收率较高。制备了新型桥连 -酮亚胺化合物,这 些化合物经过 1HNMR 和元素分析等表征。 以上研究既有重要理论意义,也有潜在的应用价值。 关键词:非茂金属催化剂;-二亚胺;乙烯聚合 新型的 -二亚胺钛、铬配合物催化乙烯聚合及乙烯与环烯烃共聚性能研究 II ABSTRACT High performance cycloolefin copolymers (COC) have broad applications in many areas. The topic is to exploit highly active catalysts for controllable ethylene polymerization, which has become one of hot points in this field. In this paper five -diiminato titanium complexes with different amounts of fluorine substituents on different positions have been designed and synthesized, and their catalytic performances have been studied. It has been found that these complexes have high catalytic activity for cycloolefins and ethylene copolymerization. Further more, five -diiminato chromium complexes with different amounts of fluorine substituents on different positions have been synthesized and the catalytic performances for ethylene polymerization have been researched. This paper includes the following parts: 1. The copolymerization behaviors for ethylene and norbornene or cyclopentene of -diiminato titanium complexes with fluorine substituents have been researched with MMAO as cocatalyst at atmospheric pressure, and found that four complexes 4a, 4b, 4d and 4e can copolymerize ethylene and cycloolefins with high activity, in which the catalytic activity of complex 4a can reach 106g/molTi.h.atm. The fluorine substituents with different positions and amounts have great influences on the catalytic activity. The catalytic activity would be significantly increased when the ortho-positions of imine ligands were substituted by fluorine, and the more ortho-fluoro substituents, the higher activity of the complexes, but the p-fluoro substituents decrease the activity of complexes. We think the reason of ortho-fluoro substituents significantly increasing the complexes catalytic activity , except for the fluoro substituents electron withdrawing effect, is mainly the formation of hydrogen bonds of o-fluorine with ethylenes or cycloolefinss hydrogen, which would help the ethylene or cycloolefins enrichment and coordination on the center metal, and increase the complexes catalytic activity. 2. Five novel -diiminato chromium complexes with different amounts of fluorine substituents on different positions have been synthesized and the catalytic performances for ethylene polymerization with MMAO as cocatalyst have been researched. It was found that fluorine substituents can increase greatly the catalytic activity of -diiminato chromium complexes compared with alkyl groups, in which four complexes with o-fluorine substitutients have middle catalytic activity for 中南民族大学硕士学位论文 III ethylene polymerization. The fluorine substituents with different positions and amounts have also great influences on the catalytic activity. For monofluoro substituted complexes, the complex with ortho-fluoro substituent has much higher activity than that with para-fluoro substituent. The reason of ortho-fluoro substituent significantly increasing the complexes catalytic activity, except for the fluoro substituents electron withdrawing effect, is mainly the formation of hydrogen bond of o-fluorine with ethylenes hydrogen, which would help the ethylene enrichment and coordination on the center metal, and increase the complexes catalytic activity. While the catalytic activity would decrease when more fluoro substituents were introduced. 3. Five fluorinated -ketoimine ligands were successfully synthesized by microwave with no solvent and catalyst. This method is very simple and has short reaction time and high yield. A new type of bridged -ketoimine compounds were prepared and characterized by 1H NMR and element analysis. Above researches have important academic value and potential industrialization prospect. Key words: non-metallocene catalysts; -diiminato; ethylene polymerization
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