Yuan Shi-Fang, Fan Zhe, Yan Yi, Ma Yanping, Han Mingyang, Liang Tongling, Sun Wen-Hua
Institute of Applied Chemistry, Shanxi University Taiyuan 030006 People's Republic of China
Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
RSC Adv. 2020 Dec 10;10(71):43400-43411. doi: 10.1039/d0ra09333e. eCollection 2020 Nov 27.
A family of unsymmetrical 2-(2,4-bis(di(4-methoxyphenyl)methyl)-6-MeCHN)-6-(1-(arylimino)ethyl)pyridine-cobalt dichloride complexes has been synthesized and characterized by NMR spectroscopy, FT-IR spectroscopy and elemental analysis as well as single crystal X-ray diffraction for Co2 and Co4. Activated with either MAO or MMAO, all the cobalt precatalysts displayed high activities toward ethylene polymerization and produced highly linear polyethylenes with high molecular weights as well as wide polydispersities; for example, the performance using Co1/MAO at 50 °C reached 9.17 × 10 g PE (mol of Co) h with the production polyethylene of molecular weight as high as = 3.14 × 10 g mol, = 134.3 °C besides its wide polydispersity of / of 54.6. Besides the terminal vinyl group of the resultant polyethylenes, it is rare for a late-transition metal catalyst to achieve highly linear polyethylenes with not only wide polydispersity but also high molecular weights, being similar to high-density polyethylenes produced using Phillips catalyst.
合成了一系列不对称的2-(2,4-双(二(4-甲氧基苯基)甲基)-6-MeCHN)-6-(1-(芳基亚氨基)乙基)吡啶二氯化钴配合物,并通过核磁共振光谱、傅里叶变换红外光谱、元素分析以及对Co2和Co4进行单晶X射线衍射对其进行了表征。用MAO或MMAO活化后,所有钴预催化剂对乙烯聚合均表现出高活性,生成了具有高分子量和宽多分散性的高度线性聚乙烯;例如,在50℃下使用Co1/MAO时,性能达到9.17×10 g PE/(mol Co·h),生成的聚乙烯分子量高达 = 3.14×10 g/mol, = 134.3℃,此外其多分散性 / 为54.6。除了所得聚乙烯的末端乙烯基外,后过渡金属催化剂很少能得到不仅具有宽多分散性而且具有高分子量的高度线性聚乙烯,这类似于使用菲利普斯催化剂生产的高密度聚乙烯。