高等学校化学学报 ›› 2026, Vol. 47 ›› Issue (7): 20260074.doi: 10.7503/cjcu20260074

• 高分子化学 • 上一篇    下一篇

Ziegler-Natta催化剂催化丙烯聚合的动力学——催化聚合扩散控制的影响机理

高文霄, 赵远进, 王爔卉, 王人弘, 贺爱华()   

  1. 青岛科技大学高分子科学与工程学院,高性能有机光学聚合物与先进制造技术全国重点实验室,橡塑材料与工程教育部重点实验室,山东省高性能聚烯烃材料与循环利用重点实验室,青岛 266042
  • 收稿日期:2026-02-07 出版日期:2026-07-10 发布日期:2026-05-14
  • 通讯作者: 贺爱华 E-mail:ahhe@qust.edu.cn
  • 基金资助:
    泰山学者工程、 国家重点研发计划项目[批准号(2022YFB3704700,2022YFB3704702);山东省重大科技创新工程项目(2021CXGC010901)

Polymerization Kinetics of Propylene Catalyzed by Ziegler-Natta Catalysts——The Influence Mechanism of Diffusion Control on Catalytic Polymerization

GAO Wenxiao, ZHAO Yuanjin, WANG Xihui, WANG Renhong, HE Aihua()   

  1. Shandong Key Laboratory of High Performance Polyolefin Materials and Recycling,Key Laboratory of Rubber & Plastics,Ministry of Education,State Key Laboratory of Advanced Optical Polymer and Manufacturing Technology,School ofPolymer Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,China
  • Received:2026-02-07 Online:2026-07-10 Published:2026-05-14
  • Contact: HE Aihua E-mail:ahhe@qust.edu.cn
  • Supported by:
    the Major Scientific and Technological Innovation Project of Shandong Province, China(2021CXGC010901);the Taishan Scholar Program, China, the National Key Research and Development Program of China([No.2022YFB3704700(2022YFB3704702)])

摘要:

研究了颗粒型Ziegler-Natta(Z-N)催化剂(Cat-P)及采用不同分散介质配制的Cat-P浆液催化剂(Cat-M1和Cat-M2)催化丙烯的聚合行为. 研究发现, Cat-P表现出最快的活性释放、 最高的催化活性与聚丙烯(PP)等规度, 且PP细粉含量最低(0.6%, 质量分数); 而浆液催化剂Cat-M1催化活性最低, 合成的PP细粉含量最高(10.7%)、 等规度最低; 通过调控M1的黏度与表面张力, 制备了浆液催化剂Cat-M2, 与Cat-M1相比, 其催化活性高, 制备的PP等规度提高且细粉含量降低. 研究发现, 高黏度、 高表面张力的分散介质会阻碍助催化剂、 外给电子体及丙烯单体等向催化剂颗粒内部的扩散, 扩散控制使得高立构规整性活性中心形成缓慢, 同时由于活性中心附近单体供应不足, 导致部分活性中心被烷基铝过度还原而失活, 因此Cat-M1聚合初期活性降低、 等规度下降并产生大量细粉. 颗粒型Cat-P及改性的Cat-M2催化剂有利于钛活性中心的快速引发与聚合, 迅速形成的长聚合物链可有效发挥“卫兵效应”, 保护活性中心, 防止失活. 本文阐明了非均相Ziegler-Natta催化剂活化过程中的扩散控制效应, 为工业烯烃聚合的稳定控制提供了理论依据.

关键词: 浆液催化剂, Ziegler-Natta催化剂, 丙烯, 扩散控制, 卫兵效应

Abstract:

This study investigated the propylene polymerization behaviors using particulate Ziegler-Natta(Z-N) catalyst(Cat-P) and slurry Z-N catalysts(Cat-M1 and Cat-M2) derived from Cat-P with different dispersion media. The results demonstrated that Cat-P exhibited the fastest activation, the highest catalytic activity and yielded polypropylene(PP) with the highest isotacticity and the lowest fine powder content(0.6%, mass fraction). In contrast, the slurry catalyst Cat-M1 showed the lowest catalytic activity and produced PP with the highest fine powder content(10.7%) and the lowest isotacticity. The slurry catalyst Cat-M2, prepared by modifying the viscosity and surface tension of dispersion medium M1, exhibited higher catalytic activity, improved isotacticity, and reduced fine powder content compared to Cat-M1. The study elucidated that the dispersion medium with high viscosity and surface tension impeded the diffusion of co-catalyst, external donor, and propylene monomer into the catalyst particles. Diffusion control slowed the formation of highly stereospecific active sites, while also leading to insufficient monomer supply locally, which in turn facilitated the deactivation of some active sites via further reduction by alkylaluminum. Consequently, Cat-M1 exhibited lower initial activity, decreased isotacticity, and increased fine powder generation during the early polymerization stage. The particulate Cat-P and modified Cat-M2 catalysts allowed for rapid initiation and polymerization at the Ti active sites. The rapidly growing polymer chains effectively exerted a “guard effect” to protect the active sites from deactivation. This work clarified the diffusion-controlled effects during the activation and chain propagation of heterogeneous Z-N catalysts, providing a theoretical basis for the stable control of industrial olefin polymerization.

Key words: Slurry catalyst, Ziegler-Natta catalyst, Propylene, Diffusion control, Guard effect

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