新型镍配合物乙烯聚合制备长支链聚乙烯

The properties and perspective applications of polyolefins are relied on their catalysts and polymerization processes, there is currently no industrial process of ethylene polymerization by the late-transition metal complex pre-catalyst because of more demanding the catalytic effectiveness and unique properties of the resultant polyethylenes. The nickel complex pre-catalysts are highly promising to have breakthrough in academic consideration, moreover, the branched polyethylenes could be obtained in the sole ethylene polymerization, indicating novel polyethylene materials. Within the project, heteroatom compounds will be synthesized through newly designing and modification, and used to form series of new nickel complexes; these nickel complexes would be tried and selected for highly active ethylene polymerization, especially for the thermo-stable polymerization processes. The microstructures of resultant polyethylenes would be carefully examined to realize the kinds and ratios of the branches within such polyethylenes. Any correlation between structures and catalytic activities of nickel complexes as well as the microstructures of the obtaining polyethylenes will be pondered over, and any conclusive results would be considered to finely tune the structures of nickel complexes in order to control the types and ratios of the branches within resultant polyethylenes; purposing on getting more long-branched polyethylenes with higher molecular weights and narrow molecular polydispersity. We could better understand influential relationships between finely tuned nickel complexes, their thermo-stable catalysis, the activity of ethylene polymerization and the micro-structures of the obtaining polyethylenes (potential property of such materials) in order to precede strategic researches on the obtaining regulations. The research observations could academically enhance the importance on nickel complex pre-catalysts in ethylene polymerization along showing unique properties of these polyethylenes as promising new functional materials.

决定聚烯烃材料性能和应用前景的关键在于其催化剂和聚合工艺，后过渡金属配合物催化体系尚没有实现产业化的根源在于催化效率和所得聚乙烯材料性能的特异性。镍配合物催化剂不仅有望在基础研究上实现突破，而且能够仅仅使用乙烯聚合获得支化聚乙烯，制备新材料。本项目将设计合成和调节配体，获得系列的新型镍配合物；筛选出高效乙烯聚合催化体系，提高聚合体系的耐热稳定性；研究所得聚乙烯的微结构，特别是确认支化链种类和比例。总结镍配合物结构、乙烯聚合活性和聚乙烯微结构间的关联，并用于指导镍配合物设计合成和调控所得聚乙烯中支化链种类和比例，提高"长支化链"比例和所得聚乙烯分子量，并且降低所得聚乙烯分子量分布。力求实现对于"镍配合物结构设计"、"催化剂稳定性"、"乙烯聚合活性"和"聚乙烯微结构（功能）"间相互关系和影响的认识，提升研究和调控的规律；提升镍配合物催化乙烯聚合的基础研究意义，展示所得聚乙烯的特效性和新型功能。

对于新型材料制备，具体到聚烯烃新品种发展，我们还是认为需要在新型催化剂发展的基础上实现新的聚合工艺，在聚合反应釜里一步到位制备高性能和新功能树脂；这样的树脂，才更有利于低能耗制备和高的附加值，而且有利于材料的稳定生产。本项目实施过程中，充分改良了已有的双齿氮配位镍催化剂体系，使得体系有更好的热稳定性，而且证实聚合温度升高时有利于形成含更多长支链聚乙烯；设计合成了多种新颖模型的双齿氮配位镍催化剂，筛选出乙烯聚合活性高和所得聚乙烯枝化度高并含有长支链的聚乙烯弹性体材料，实现了聚烯烃新材料的制备。这类新材料的微结构分析表明是一类分子量分布均匀的树脂，包含了高枝化树脂和低枝化树脂，其高枝化部分形成了材料弹性态特征，而低枝化部分具有结晶性能；尽管对于材料性能和应用范围的判定太早，初步性能测试认为是一类抗压、减震、形状记忆和阻尼材料，而且具有良好的树脂相容性和吸油材料。初步实现了对于“镍配合物结构设计”、“催化剂稳定性”、“乙烯聚合活性”和“聚乙烯微结构（功能）”间相互关系和影响的认识；对于调控所得聚合物微观结构所需的催化剂结构改进的因素有了直观认识，为镍配位催化乙烯聚合的基础和应用上获得突破铺就了道路。相关研究结果居国际引领地位，研究结果已经发表SCI学术论文52篇，课题执行期间申请中国发明专利11件其中2件获得授权。