Ethylene polymerization by 3-oxa-pentamethylene bridged asymmetric dinuclear titanocene/MAO system

被引：4

作者：

Lin, Feng ^{[1
]}

Zhu, Bochao ^{[2
]}

Zhao, Xutao ^{[2
]}

Li, Xu ^{[1
]}

Sun, Junquan ^{[1
]}

机构：

[1] Zhejiang Univ, Coll Mat & Chem Engn, Dept Chem Engn, Hangzhou 310027, Peoples R China

[2] Lanzhou Petrochem Res Inst Petrochina, Lanzhou 730060, Peoples R China

来源：

JOURNAL OF APPLIED POLYMER SCIENCE | 2008年 / 108卷 / 01期

关键词：

asymmetric dinuclear titanocene; metallocene catalyst; ethylene polymerization; polyethylene;

D O I：

10.1002/app.27545

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

An asymmetric 3-oxa-pentamethylene bridged dinuclear titanocenium complex (CpTiCl2)(2)(eta(5)-eta(5)-C9H6 (CH2CH2OCH2CH2)C5H4) (1) has been prepared by treating two equivalents of CpTiCl3 with the corresponding dilithium salts of the ligand C9H7(CH2CH2OCH2 CH2)C-5 H-5. The complex 1 was characterized by H-1-, C-13-NMR, and elemental analysis. Homogenous ethylene polymerization catalyzed using complex 1 has been conducted in the presence of methylaluminoxane (MAO). The influences of reaction parameters, such as [MAO]/[Cat] molar ratio, catalyst concentration, ethylene pressure, temperature, and time have been studied in detail. The results show that the catalytic activity and the molecular weight (MW) of polyethylene produced by 1/MAO decrease gradually with increasing the catalyst concentration or polymerization temperature. The most important feature of this catalytic system is the molecular weight distribution (MWD) of polyethylene reaching 12.4, which is higher than using common mononuclear metallocenes, as well as asymmetric dinuclear titanocene complexes like [(CpTiCl2)(2) (eta(5)-eta(5)-C9H6(CH2)(n)C5H4)] (n = 3, MWD = 7.31; n = 4, MWD = 6.91). The melting point of polyethylene is higher than 135 degrees C, indicating highly linear and highly crystalline polymers. (C) 2008 Wiley Periodicals, Inc.

引用

页码：504 / 509

页数：6