High-Performanceα-Diimine Nickel Complexes for Facile Access of PE Elastomers with Exceptional Material Properties  

作　　者：Li-Dong Qin Xin-Yu Wang Qaiser Mahmood Zhi-Xin Yu Yi-Zhou Wang Song Zou Tong-Ling Liang Wen-Hua Sun 

机构地区：[1]School of Pharmaceutical Sciences,Changchun University of Chinese Medicine,Changchun,130117,China [2]Chemistry and Chemical Engineering Guangdong Laboratory,Shantou,515031,China [3]Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science,Institute of Chemistry,Chinese Academy of Sciences,Beijing,100190,China

出　　处：《Chinese Journal of Polymer Science》2024年第5期620-635,I0008,共17页高分子科学（英文版）

基　　金：This work was financially supported by the Chemistry and Chemical Engineering Guangdong Laboratory(Nos.2111018 and 2132012);Q.M.would like to express gratitude towards the Foreign Youth Talent Program(No.QN2022030008L)for their support.

摘　　要：For practicable elastomeric polyethylene,achieving high catalyst thermal stability and activity,along with precise control of polymer properties such as branching density,molecular weights,and distribution,is crucial but challenging.In this study,two sets of symmetricalα-diimine nickel complexes,each comprising four nickel bromide or chloride complexes,were synthesized and investigated their performance for ethylene polymerization under various reaction conditions.Upon activation with either Et2AlCl or MMAO cocatalysts,these complexes displayed not only high activity but also generated high molecular weight polyethylenes with controlled polydispersity and a substantial number of branches.The catalyst with the least steric hindrance displayed the remarkable high activity(up to 1.2×10^(7) g·mol^(-1)·h^(-1)).Notably,nickel bromides demonstrated higher activity compared to their chloride counterparts.The investigation into the effect of reaction temperature on catalytic performance revealed that NiBrMe-MMAO system displayed high thermal stability(activity up to 2.51×10^(6) g·mol^(-1)·h^(-1) at 100℃)and consistently yielded high polymer molecular weights with narrow polydispersity over a broad temperature range of 30-100℃.Of significant note,mechanical analysis of the resulting polyethylene demonstrated excellent ultimate tensile strength and high strain at break.Particularly,the polyethylene sample prepared at 100℃exhibited ultimate tensile strength up to 10 MPa with 1863%maximum strain at break and a strain recovery of up to 54.9%after ten cycles at a fixed strain of 300%,indicating excellent material properties of prepared thermoplastic polyethylene elastomers(TPE).

关 键 词：Thermoplastic polyethylene elastomers α-Diimine nickel pre-catalysts Ethylene polymerization Mechanical properties Highly branched polyethylene 

分 类 号：TQ334.2[化学工程—橡胶工业] O643.36[理学—物理化学] O641.4[理学—化学]