新型高效过渡金属催化剂与烯烃结构可控聚合

In order to obtain olefin polymerization catalysts with excellent thermal stability, long life, high activity, high stereoselectivity, and/or favorable copolymerization ability, the research about concerning electronic effect, steric hindrance and geometry of the ligands on the molecular structures of transition metal complexes will be carried out, and so will the regularity of the electronic structure of central ion, electronic and steric effect of the ligands on the catalytic performance of non-metallocene or half-metallocene complexes, which includes catalytic activity, stereoselectivity, copolymerization ability, thermal stability, functional group tolerance, cocatalysts and monomer adaptability, and branched structure, molecular weight and molecular weight distribution of polyolefins. By means of computational molecular simulation, structure-activity relationship of transition metal catalysts and mechanism of catalytic reaction will be explored, which offers theory evidence and practical guidance for the redesign of novel high efficient catalysts for olefin polymerization. New synthetic methods of functional polyolefin materials, which include the syntheses of olefin/functional monomer copolymers with random, block, and graft structure, are expected to be developed. New technology of controlled coordination polymerization is also to be explored. Herein, we expect to synthesize "reactive polyolefin intermediate" containing vinyl pendant group, which reacts with metallocene hydrohalide, initiating graft polymerization of olefin through activation, and thus homogeneous and/or hybridized long branched polyolefins will be synthesized. We also expect to explore the technology of controlled copolymerization of olefin with asymmetry diene monomer, and establish new synthetic methods of hyperbranched polyolefin.

以获得热稳定、长寿命、高活性、高立构选择性或高共聚能力的烯烃聚合催化剂为目标，系统研究配体电子效应、空间位阻和几何形状对过渡金属配合物分子结构的影响，揭示中心离子的电子结构、配体的电子和空间效应对非茂与半茂过渡金属催化剂活性、立构选择性、共聚能力、热稳定性、官能团耐受性、助催化剂和单体适应性、聚烯烃支化结构和分子量及其分布的影响规律。借助计算机分子模拟手段，研究过渡金属催化剂的构效关系与催化反应机理，为新型高效烯烃聚合催化剂的再设计提供理论依据和实际指导。发展功能化聚烯烃材料的新合成方法，包括合成烯烃与功能单体的无规、嵌段与接枝共聚合物。发展可控配位聚合新技术，合成含有乙烯侧基的"反应性聚烯烃中间体"，将其与茂金属氢卤化合物进行加成反应，再经活化引发烯烃接枝聚合反应，合成均质与杂化型的长链支化聚烯烃；研究烯烃与不对称双烯烃单体的可控共聚合技术，建立超支化聚烯烃的新合成方法。

聚烯烃是世界上产量最大、应用最广泛的合成高分子材料。新型高效过渡金属聚合催化剂是发展新型高性能聚烯烃材料的关键。本项目以获得热稳定、长寿命、高活性、高共聚能力或高立构选择性的烯烃聚合催化剂为研究目标，系统研究了取代水杨醛亚胺、beta-二酮亚胺、吡咯醛亚胺和酚膦衍生物等配体的电子效应、空间位阻和几何形状对非茂和半茂过渡金属配合物分子结构的影响，揭示了中心离子的电子结构、配体的电子和空间效应对非茂与半茂钛、锆、铪、钒、铬和中性镍催化剂活性、立构选择性、共聚能力、热稳定性、官能团耐受性、助催化剂和单体适应性、聚烯烃支化结构和分子量及其分布的影响规律。借助计算机分子模拟手段，研究了新型过渡金属催化剂的构效关系和共聚能力、立构选择性、烯烃与极性单体高效共聚的催化反应机理。建立了功能化等规聚丙烯的新合成方法，包括丙烯与omega-卤代-alpha-烯烃、烯丁基苯乙烯和omega-(9-蒽基)-alpha-烯烃的区域/立构选择性共聚及其后续的亲核取代、硫烯加成和D-A环加反应和接枝共聚反应。利用非茂铪催化剂，实现了丙烯与硅基alpha,omega-二烯烃的立构选择性-环化可控链转移共聚反应，建立了长链支化聚丙烯的合成新方法。