有机化学 ›› 2024, Vol. 44 ›› Issue (11): 3399-3408.DOI: 10.6023/cjoc202403034 上一篇    下一篇

研究论文

中性镍催化制备聚烯烃弹性体: 位阻与次级配位协同作用

李乾坤a,b, 穆红亮a,*(), 简忠保a,b,*()   

  1. a 中国科学院长春应用化学研究所 高分子物理与化学国家重点实验室 长春 130022
    b 中国科学技术大学应用化学与工程学院 合肥 230026
  • 收稿日期:2024-05-07 修回日期:2024-06-12 发布日期:2024-07-02
  • 基金资助:
    国家自然科学基金(22122110); 国家自然科学基金(U23B6011); 吉林省科技厅(20230101347JC)

Preparation of Polyolefin Elastomers by Neutral Nickel Catalysts: Synergistic Effect of Steric Hindrance and Secondary Interaction

Qiankun Lia,b, Hongliang Mua,*(), Zhongbao Jiana,b,*()   

  1. a State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022
    b School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026
  • Received:2024-05-07 Revised:2024-06-12 Published:2024-07-02
  • Contact: *E-mail:muhongliang@ciac.ac.cn;zbjian@ciac.ac.cn
  • Supported by:
    National Natural Science Foundation of China(22122110); National Natural Science Foundation of China(U23B6011); Jilin Provincial Science and Technology Department Program(20230101347JC)

水杨醛亚胺中性镍是一类经典的乙烯聚合催化剂, 通过对其结构的精细调控, 能够制备出多种不同特性的聚乙烯材料, 如高支化的聚乙烯油以及低支化的超高分子量聚乙烯等. 然而, 在制备弹性体材料方面, 该催化剂面临一定的挑战. 设计合成了两种同时含有大位阻和邻位杂原子基团的芳胺, 用于合成水杨醛亚胺配体及相应的中性镍催化剂[{N-[2,4-二(二苯并环庚基)-6-苯氧基]苯基-3-叔丁基水杨醛亚胺}-镍-(苯基)(三苯基膦)(Ni2)和{N-[2,4-二(二苯并环庚基)-6-苯磺酰基]苯基-3-叔丁基水杨醛亚胺}-镍-(苯基)(三苯基膦)(Ni3)]. 系统地考察了温度和乙烯压力对催化性能的影响, 揭示了催化剂热稳定性、催化活性, 以及聚乙烯分子量和支化度的变化规律. 杂原子基团的次级配位效应与芳胺的空间位阻效应相结合, 使得包含SO2Ph基团的催化剂Ni3实现了支化度(61 brs/1000C)与分子量(Mn=15.29×104)的平衡, 为制备性能优异的聚乙烯弹性体材料提供了有力支撑. 空间位阻与次级配位效应的协同作用为新型水杨醛亚胺中性镍催化剂的开发, 以及相关催化剂的设计和优化提供了新的思路.

关键词: 次级作用, 位阻效应, 中性镍催化剂, 水杨醛亚胺, 聚烯烃弹性体

Salicylaldiminato neutral nickel catalysts is a family of classic ethylene polymerization catalysts. Through elabrate modulation of the structures, various polyethylene materials with different characteristics can be prepared, such as highly branched polyethylene oil and ultra-high molecular weight polyethylene with low branching. However, these catalysts face certain challenges in the preparation of elastomeric materials. In this study, two arylamines containing both sterically hindered groups and adjacent heteroatom groups were designed and synthesized for the synthesis of salicylaldiminato ligands and the corresponding neutral nickel catalysts ({N-[2,4-bis(dibenzosuberyl)-6-phenoxy]phenyl-3-tert-butylsalicylideneiminato}-nickel(II)-(phenyl)(triphenylphosphine) (Ni2) and {N-[2,4-bis(dibenzosuberyl)-6-benzenesulfonyl]phenyl-3-tert-butylsalicyli- deneiminato}-nickel(II)-(phenyl)(triphenylphosphine) (Ni3)). The effects of temperature and ethylene pressure on catalytic performance were systematically investigated, revealing the variation patterns of catalyst thermal stability, catalytic activity, polymer molecular weight and branching density. The combination of the secondary coordination effect of the heteroatom groups and the steric effect of the arylamine allowed catalyst Ni3 containing SO2Ph group to achieve a balance between branching density (61 brs/1000C) and polymer molecular weight (Mn=15.29×104), providing strong support for the preparation of polyethylene elastomer with excellent mechanical properties. The synergistic effect of steric hindrance and secondary interaction provides new ideas for the development of novel salicylaldiminato neutral nickel catalysts and the design and optimization of related catalysts.

Key words: secondary interaction, steric hindrance, neutral nickel catalyst, salicylaldimine, polyolefin elastomer