Premium
Synthesis of polyethylene thermoplastic elastomer by using robust α‐diimine Ni( II ) catalysts with abundant t Bu substituents
Author(s) -
Li Shuaikang,
Zhao Yihua,
Dai Shengyu
Publication year - 2021
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20210017
Subject(s) - polyethylene , catalysis , diimine , ethylene , polymerization , thermoplastic elastomer , polymer chemistry , elastomer , nickel , copolymer , materials science , chemistry , polymer , organic chemistry
The synthesis of polyethylene thermoplastic elastomers via α‐diimine‐nickel‐catalyzed ethylene polymerization using polymerization conditions of elevated temperatures and alkane solvents is highly desirable in industrial production. In this contribution, we constructed a series of highly sterically demanding α‐diimine Ni(II) catalysts with abundant t Bu substituents for this purpose. These nickel catalysts were examined for ethylene polymerization in hexanes at elevated temperatures (up to 90°C) and proved to be thermally robust at temperatures as high as 90°C. Generally, these nickel catalysts can generate highly branched (ca. 70–80/1000°C) polyethylenes with very high molecular weight ( M n up to 55.79 × 10 4 g/mol) and the resultant polyethylenes displayed characteristics of thermoplastic elastomers with excellent elastic recovery (SR up to 84%). Compared with some similar α‐diimine Ni(II) catalysts, it is shown that the presence of axial remote t Bu substituents not only facilitates the dissolution of the catalyst in alkanes, but also improves the elastic recovery value of the obtained polyethylene.