新型双核稀土催化剂的设计、合成及在制备含立体规整性苯乙烯片段的共聚物中的应用

Random polystyrene is an amorphous polymer, which is characterized by poor heat resistance, low softening temperature and crisp. The stereo-specific polystyrene has high melting point, large modulus, good solvent resistance, good dimensional stability and excellent electrical properties, but it is very brittle and difficult to be used alone. This project is mainly focused on the design and synthesis of binuclear rare earth catalyst and its application in copolymer containing stereo-specific styrene fragment. Mainly through the design of ligands at the molecular level, rare earth catalyst with high catalytic activity, good tolerance, high regio-/stereo- selective will be screened rapidly. Series of catalyst will be obtained by finely electronic and stereoscopic regulation. Several catalysts with high efficient, easy synthesis and wide application and comparable to or exceeding the Hou catalyst will be selected. Furthermore, the catalyst was used to prepare copolymers containing stereoregular styrene fragments, so as to prepare high performance polystyrene plastic or elastomers with high strength and toughness. The intrinsic relationship of structure of catalyst, polymer structure and material morphology and properties will be elucidated by capturing intermediates and DFT calculations.

无规聚苯乙烯属无定形高分子聚合物，它具有如耐热性能较差，软化温度也较低、性脆。间规聚苯乙烯熔点高、模量大、耐溶剂、尺寸稳定性好及电气性能优良，但脆性大，很难单独使用。本项目主要集中在新型双核稀土催化剂的设计、合成及在含立体规整性苯乙烯片段共聚合物中的应用中。主要是通过在分子水平设计双核配体，快速筛选具有高催化活性、高热稳定性、高区域/立构选择性和较好极性官能团的容忍性的稀土基催化剂，通过电子和立体的精心调控得到数系列催化剂，从中优选出几种高效的、易合成的、应用范围广的，可以和侯催化剂相媲美或超过其的催化剂。进一步利用该催化剂制备含立构规整性苯乙烯片段的共聚物，从而制备出高强度和韧性好的高性能化聚苯乙烯树脂或弹性体。通过捕获中间体，应用DFT计算等办法阐明催化剂结构、共聚物组成和性能之间的关系，进一步阐明催化剂的分子设计－聚合物结构－材料形态与性能的内在关系。

本项目以制备含立体规整性苯乙烯片段的共聚物为研究对象，设计和合成新型双核稀土催化剂，探讨了该类催化剂的优缺点，并揭示金属催化剂在各种烯烃共聚合反应中的应用。项目完全按照计划任务书执行，未作变更。在项目执行过程中，由于一些意外发现，也开展了一些原计划没有列入的工作，均按期保质保量地完成了各项任务。通过四年的项目研究，我们取得了预期成果，建立和发展了一些新颖的催化剂合成方法，发表标注本基金资助的SCI 论文8 篇，其中在影响因子大于2.0 的国际期刊Polymer Chemistry、Polymer等发表高质量研究论文7 篇；培养硕士研究生7人。