Activity and stability spontaneously enhanced toward ethylene polymerization by employing 2‐(1‐(2, 4‐dibenzhydrylnaphthylimino)ethyl)‐6‐(1‐(arylimino)ethyl) pyridyliron(II) dichlorides. Issue 6 (24th January 2017)

• Record Type: Journal Article
• Authors: Zhao, Weizhen; Yue, Erlin; Wang, Xinxin; Yang, Wenhong; Chen, Yan; Hao, Xiang; Cao, Xiaoping; Sun, Wen‐Hua
• Is Part Of: Journal of polymer science. Volume 55:Issue 6(2017)
• Page Start: 988
• Page End: 996
• Publication Date: 2017-01-24
• Subjects: calculations -- ethylene polymerization -- linear -- polyethylenes (PE) -- high molecular weight -- iron complexes; 547
• DOI: 10.1002/pola.28459
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: A series of 2‐(1‐(2, 4‐dibenzhydrylnaphthylimino)ethyl)‐6‐(1‐(arylimino)ethyl)pyridyliron(II) complexes (Fe1 −Fe5 ) was synthesized and characterized. The molecular structure of the representativeFe2 was determined by single‐crystal X‐ray diffraction, revealing a distorted pseudo‐square‐pyramidal geometry around the iron center. On activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all these iron complex precatalysts performed with high activities (up to 1.58 × 10 7 g (PE) mol −1 (Fe) h −1 ) toward ethylene polymerization, producing highly linear polyethylenes with high molecular weight and bimodal distribution, which was in accordance with high temperature 13 C NMR, high T m values ( T m ∼130 °C) and the GPC curves of the obtained polyethylenes. Meanwhile, DFT calculation results also showed the good correlation between net charges on iron and experimental activities. Compared with previous bis(imino)pyridyliron analogues, the current iron complexes containing the benzhydrylnaphthyl groups exhibited relatively higher activities and better thermal‐stability at elevated temperatures, especially at 80 °C as the industrial operating temperature, and still showed high activities toward ethylene polymerization up to 8.57 × 10 6 g (PE) mol −1 (Fe) h −1 in the presence of co‐catalyst MMAO. In addition, these iron complex precatalysts all exhibited long lifetimes. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2017, 55, 988–996 Abstract : The 2‐(1‐(2, 4‐dibenzhydrylnaphthylimino)ethyl)‐6‐(1‐(arylimino) ethyl)pyridyliron(II) dichlorides, activated with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), show high activities and good thermal stability toward ethylene polymerization, producing highly linear polyethylene with high molecular weight.