基于烯烃活性/可控聚合的大位阻手性α-二亚胺镍、钯催化剂的合成及其性能研究

Living/controlled olefin polymerization is an effective method to regulate and control the microstructure of polymer. Currently, living/controlled olefin polymerization remains great challenges, including the polymer chain transfer to cocatalyst or monomer, poor thermal stability and short catalytic lifetime. A series of bulky chiral α-diimine nickel(II), palladium(II) complexes will be designed and synthesized in this project. The rigid and bulky backbone can enhance thermal stability and restrain chain transfer. Meanwhile, the combination of rigid backbone and chiral aromatic ring can effectively control the microstructure of polymer. Their catalytic properties for the copolymerization of α-olefin with polar monomer will be studied in detail, and their ability of steric control on the comonomer insertion is going to be examined. The effects of the catalyst structure and polymerization condition on the catalytic activity and selectivity will be investigated. The intermediates for the above reactions are also tried to study for addressing the reaction mechanism. This proposal is expected to provide the experimental and theoretical research foundation for exploring the relationship of catalyst structure and polymer properties.

烯烃活性/可控聚合是调控聚合物微观结构的一种有效方法。由于烯烃聚合过程中容易发生链转移，且催化剂存在稳定性差、催化寿命短等问题，因此烯烃活性/可控聚合还面临着巨大的挑战。本项目设计合成一系列新型大位阻手性α-二亚胺镍、钯催化剂。借助空间大位阻的分子骨架结构，能显著地提高金属配合物催化烯烃的稳定性以及有效抑制聚合过程的链转移反应，使催化烯烃聚合呈现活性聚合特征。同时，刚性骨架结构和手性芳环取代基，能够促使增长链和单体之间形成空间特异性立体效应，有效地控制共单体的插入率及共聚物链结构单元的序列分布和空间构型。本项目还系统研究了此类催化剂对α-烯烃与极性单体共聚的催化作用，特别是共单体插入的立体选择性。重点考察催化剂结构与聚合反应条件对其催化活性、选择性和聚合可控性的影响规律。通过分离反应活性中间体，深入探讨催化共聚合机理，为探索催化剂结构与聚合产物性能之间的关系提供实验和理论研究基础。

随着聚烯烃材料在日常生活中广泛的应用，开发合成新型高效催化剂在制备具有良好的加工、流变及热 性能等高性能聚烯烃材料方面具有重大意义。但目前大部分烯烃聚合催化剂存在稳定性差或催化成本高等缺陷。本研究借助分子设计，设计合成出一系列新型大位阻手性[N,N]和[N,O]配位原子二亚胺配体及其镍、钯配合物。在助催化剂三五氟苯基硼B(C6F5)3的活化下，高效催化了降冰片烯与极性降冰片烯单体的均聚合和共聚合反应。制备出了具有优良溶解性和加工性能的环烯烃聚合物。找出了刚性骨架结构和手性芳环对其催化活性，聚合可控性的影响规律。探究出聚合物结构与性能的本质联系。这些为探索催化剂结构与聚合物产物性能之间的关系提供实验和理论基础。相关研究成果在RSC Advance、Journal of Chemical Research、Chinese Journal of Chemistry等国际国内SCIE源刊物上发表研究论文8篇。部分研究成果申请并获授国家发明专利1项，参加国内外有关烯烃催化配位聚合、功能高分子方面的学术会议2次，指导硕士研究生2名。