三维空旷骨架结构载体微环境调控及高效Ziegler-Natta催化剂的研究

The high performance of polyethylene production is the key point for science research and petrochemical industry application, so many researchers focus on the synthetize and control of high-efficient polyethylene Ziegler-Natta catalysts and the polymerazation behavior between polyethylene and catalysts.The 3D open skeletons with high specific surface areas, big porosity,pocket type structure and adjustable diameter are made by constructing the porous polymer template with a novel method of two-step phase separation in this project. It is emphasized on the adjustment between the synthetic process and the porous polymer performance, especially the synthetize of pocket microreactor to study the fine control method of skeleton structure. Furthermore, the proposal focuses on the ethylene polymerization of Ziegler-Natta catalyst immobilized with special skeleton for two purpose,firstly to slove micro-molecular diffusion mechanism and reaction mechanism in the micron porous carrier, and secondly to set up transmission coupling reaction with molecule simulation.Finally, the multi-particle model is revised to further improve the polyethylene morphology modulation theory, and the relations between particle morphology and carrier's micro-structure are set up to provide the theory basis of Ziegler-Natta catalyst's design. The proposal not only has academic significance but also has actual industry future on the nanoscale or microscale catalyst design and the controlling of polymer morphology. The proposal not only has academic significance, but also a broad prospect in industrial application for the synthesis of nano-scale or micro-scale catalyst and the improvement of polyethylene products performance.

聚乙烯产品的高性能化是学术界和石化业界共同关注的问题，高效聚乙烯催化剂载体微环境调控及其与乙烯聚合行为的构效关系是研究焦点。本项目提出二阶段相分离诱导控制及表面复制模板法的新思路，构建具有高比表面积、大孔隙率、孔径和扩散系数可调、含"袋式"结构特点的三维空旷骨架载体，重点研究骨架结构性能的调变规律，特别关注"袋式微反应器"的制作，探寻骨架结构的精细调控方案。进一步以该骨架负载传统Ziegler-Natta催化剂的乙烯聚合为研究对象，阐明载体纳微米孔径环境下小分子扩散机理与反应机制，结合分子模拟，建立反应扩散耦合模型；探索骨架材料中"袋式"结构微空间中聚乙烯颗粒形态的衍生规律，修订多粒模型，建立通过载体结构性能调控聚合动力学和颗粒形态的方法，为乙烯聚合催化剂的高效设计提供理论和实验依据。本项目研究对于纳微尺度上聚烯烃催化剂的精细制作及聚烯烃产品形态的完善具有重要的学术意义和工业意义。

项目围绕高效聚乙烯催化剂载体微环境调控及其与乙烯聚合行为的构效关系开展了详细的研究，提出了二阶段相分离诱导控制及表面复制模板法的新思路，构建了具有高比表面积、大孔隙率、孔径和扩散系数可调、含“袋式”结构特点的三维空旷骨架载体，建立通过载体结构性能调控聚合动力学和颗粒形态的方法，为乙烯聚合催化剂的高效设计提供理论和实验依据。研究取得了如下主要进展：.（1）采用反应诱导相分离与离子诱导相分离相结合的方法可控调变聚合物模板，实现了采用表面复制法对三维空旷骨架微环境的调控和性能研究；（2）建立了表面活性剂CmOhpNCn的分子结构-物化性质-分子聚集形态三者之间的联系，解释了孔道自组装规律及形成机制；（3）揭示三维空旷骨架Z-N催化剂分子设计、微环境结构与乙烯聚合行为关系，建立通过载体结构性能调控聚合动力学和颗粒形态的方法；（4）基于“POSS纳米粒子的空间隔离作用”的思路，通过倍半硅氧烷（POSS）修饰的三维空旷骨架Z-N催化剂调控聚乙烯缠结程度。研究结果发表在《ACS Adv. Mat. Int.》、《Ind. Eng. Chem. Res.》等SCI论文 15 篇，授权中国发明专利 3项。这些研究结果对于纳微尺度上聚烯烃催化剂的精细制作及聚烯烃产品形态的完善具有重要的学术意义和工业意义。