非共轭双烯聚合中茂稀土催化剂结构与性能关系的研究

The cyclo(co)polymerization of non-conjugated dienes for preparing the performance outstanding cycloolefin (co)polymers has always been both a hot and difficult issue in the research of coordination polymerization.So far, the catalysts based on various metals such as Ti, Zr and V have been reported for the homopolymerization of only a few non-conjugated dienes,the catalysts suitable for the copolymerization of non-conjugated dienes with other monomers are rather limited, and the monomers utilized for the copolymerization of non-conjugated dienes were also limited only to ethylene and propylene. According to those facts, the homopolymerization and copolymerization of non-conjugated dienes with other olefins catalyzed by the half-sandwich rare earth metal complexes would be examined.The relationship between catalyst structures and catalytic properties in the cyclo(co)polymerization of non-conjugated dienes would be systematically analyzed. The coordinated modes of rare earth metal complexes and non-conjugated dienes and polymerization routes would be investigated in details by means of isolation of intermediates and terminal groups of polymers aided with the theoretical calculation method. The effects of the steric hindrances and electron characters of catalysts and the structures and the substituents of non-conjugated dienes on polymerization process would be illuminated,to achieve the stereoselective polymerization of non-conjugated dienes and the copolymerization of nono-conjugated dienes with various olefins.Eventually, synthesis of new organo rare earth metal complexes which have high chemistry activity and selectivity and are superior to the existing ones in the cyclo(co)polymerization of non-conjugated dienes,to achieve a series of high performance functional cycloolefin polymers with a great application potentical.The results of this project will provid some theoretical and practical bases for the production of the cycloolefin polymers as request.

非共轭双烯环化聚合及与烯烃环化共聚合制备性能优异的环烯烃聚合物一直是配位聚合研究领域的一个热点和难点。迄今，非共轭双烯聚合的研究仅局限于为数不多的几种烯烃，而且能够有效催化非共轭双烯与烯烃共聚的催化体系十分稀少，共聚的烯烃也仅限于小分子的乙烯和丙烯。本项目提出将茂稀土催化剂用于非共轭双烯均聚合及与大分子烯烃共聚合的研究课题。通过中间体和端基结构的捕获并辅以理论计算，开展催化剂结构与性能关系的研究，探索茂稀土催化非共轭双烯聚合时的配位方式和聚合路径；揭示茂稀土催化剂空间和电子结构特征以及非共轭双烯链长和取代基性质对聚合过程的影响，实现非共轭双烯可控高立体选择性聚合及其与大分子烯烃的共聚合。发展一类在非共轭双烯聚合中展现良好催化性能的新型茂稀土催化剂，实现其在一系列结构丰富的新型环烯烃聚合物合成中的应用，为根据需要定制环烯烃聚合物提供理论和实践依据。

非共轭双烯环化聚合及与烯烃环化共聚合制备环烯烃聚合物一直是配位聚合研究领域的一个热点和难点。迄今，非共轭双烯聚合的研究局限于为数不多的几种烯烃，而且能够有效催化非共轭双烯与烯烃共聚的催化体系十分稀少，共聚的烯烃主要局限于乙烯和丙烯。本项目开展了单茂钪催化非共轭双烯均聚合及与大分子烯烃共聚合的研究，通过改变配体结构，调控钪金属中心的空间位阻和电子特性，考察了单茂钪在催化非共轭双烯聚合中的催化性能，合成了一系列未见报道的新型环烯烃共聚物，探索单茂钪催化非共轭双烯均聚及共聚合的机理，揭示非共轭双烯聚合中单茂钪催化剂结构与催化性能的关系。单茂钪(C5Me4SiMe3)Sc(CH2C6H4NMe2-o)2可以有效催化1,5-己二烯、1,6-庚二烯、1,7-辛二烯和1,9-癸二烯均聚合，分别获得含有五元环、六元环、七元环的环烯烃聚合物和交联聚合物，非共轭双烯的链长对其聚合活性、产物分子量及微结构有较大影响。单茂钪(C5Me4SiMe3)Sc(CH2C6H4NMe2-o)2可以高效催化1,5-己二烯、1,6-庚二烯、1,7-辛二烯和1,9-癸二烯与乙烯共聚合，获得结构组成可控的共聚物，共聚物的热性能与非共轭双烯的插入量和环化结构相关。采用(C5Me4SiMe2CH2P(O)Ph2)Sc(CH2SiMe3)2实现了1,6-庚二烯与苯乙烯的共聚合，获得组成和微结构可控的含有芳环的环烯烃共聚物。单茂钪实现了非共轭双烯与异戊二烯高活性和高立体选择性共聚合，获得了结构组成可控、含有双键结构的环烯烃共聚物；通过调控单茂钪的配体结构，实现了非共轭双烯与异戊二烯无规共聚合和交替共聚合，并且非共轭双烯与异戊二烯交替共聚时非共轭双烯的环化聚合表现了极高的立体选择性；非共轭双烯/异戊二烯共聚物的环化结构和序列结构直接影响其机械性能。相关研究成果在Acc. Chem. Res.，Chem. Asian J.，Polymer，J. Polym. Sci., Part A: Polym. Chem.和高分子学报杂志上发表学术论文8篇，本项目发展一类在非共轭双烯聚合中展现良好催化性能的新型茂稀土催化剂，实现其在一系列结构丰富的新型环烯烃聚合物合成中的应用，为根据需要定制环烯烃聚合物提供理论和实践依据。