Yuan Wenbin, Dai Shengyu
Anhui Laboratory of Molecule-Based Materials, Key Laboratory of Functional Molecular Solids, Ministry of Education, School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, China.
Yueyang Xingchang Petro-Chemical Co., Ltd., Yueyang 414021, China.
Precis Chem. 2024 Sep 16;2(10):553-558. doi: 10.1021/prechem.4c00057. eCollection 2024 Oct 28.
Recently, the chain-walking ethylene polymerization strategy has garnered widespread attention as an efficient and straightforward method for preparing polyolefin elastomers. In this study, a series of 2,4,8-triarylnaphthyl iminopyridyl nickel catalysts were synthesized and used in ethylene polymerization. These catalysts demonstrated moderate catalytic activity (10 g mol h), producing high-molecular-weight (up to 145.5 kg/mol) polyethylene materials with high branching degrees (75-95/1000C) and correspondingly low melting points. Detailed analysis using C NMR spectroscopy revealed that the polyethylenes primarily featured methyl and long-chain branches. Mechanical testing of the polyethylene samples obtained from catalysts - exhibited moderate stress at break (4.64-6.97 MPa) coupled with a very high strain at break (1650-3752%), indicating their very good ductility. Furthermore, these polyethylenes showcased great elastic recovery abilities, with strain recovery values ranging from 72% to 85%. In contrast, the polyethylene produced by displayed notably inferior tensile strength (0.16 MPa) and tensile recovery (43%). To the best of our knowledge, this study represents the inaugural utilization of a nickel iminopyridyl catalyst in the preparation of a polyethylene thermoplastic elastomer.
最近，链式行走乙烯聚合策略作为一种制备聚烯烃弹性体的高效且直接的方法，已受到广泛关注。在本研究中，合成了一系列2,4,8-三芳基萘基亚氨基吡啶镍催化剂，并将其用于乙烯聚合。这些催化剂表现出中等催化活性（10 g mol h），可生产高分子量（高达145.5 kg/mol）、高支化度（75 - 95/1000C）且熔点相应较低的聚乙烯材料。使用碳核磁共振光谱进行的详细分析表明，聚乙烯主要具有甲基和长链支链。对由催化剂获得的聚乙烯样品进行的力学测试显示，其断裂应力适中（4.64 - 6.97 MPa），同时断裂应变非常高（1650 - 3752%），表明它们具有非常好的延展性。此外，这些聚乙烯展现出出色的弹性恢复能力，应变恢复值在72%至85%之间。相比之下，由[此处原文缺失相关内容]制备的聚乙烯表现出明显较差的拉伸强度（0.16 MPa）和拉伸恢复率（43%）。据我们所知，本研究代表了亚氨基吡啶镍催化剂首次用于制备聚乙烯热塑性弹性体。
