Preparation of ethylene/1-octene copolymers from ethylene stock with tandem catalytic system

• Published in: Journal of applied polymer science 2008-03, Vol.107 (5), p.3071-3075
• Main Authors: Jiang, Tao, Huang, Zhijun, Luo, Mingjian, Chen, Hongxia, Ning, Yingnan
• Format: Article
• Language: English
• Subjects: Applied sciences; Copolymerization; ethylene tetramerization; Exact sciences and technology; linear low-density polyethylene (LLDPE); metallocene catalysts; Organic polymers; Physicochemistry of polymers; Preparation, kinetics, thermodynamics, mechanism and catalysts; tandem catalytic system
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.27513

Tandem catalysis offers a novel synthetic route to the production of linear low-density polyethylene. This article reports the use of homogeneous tandem catalytic systems for the synthesis of ethylene/1-octene copolymers from ethylene stock as the sole monomer. The reported catalytic systems involving a highly selective, bis(diphenylphosphino)cyclohexylamine/Cr(acac)₃/methylaluminoxane (MAO) catalytic systems for the synthesis of 1-hexene and 1-octene, and a copolymerization metallocene catalyst, rac-Et(Ind)₂ZrCl₂/MAO for the synthesis of ethylene/1-octene copolymer. Analysis by means of DSC, GPC, and ¹³C-NMR suggests that copolymers of 1-hexene and ethylene and copolymers of 1-octene and ethylene are produced with significant selectivity towards 1-hexene and 1-octene as comonomers incorporated into the polymer backbone respectively. We have demonstrated that, by the simple manipulation of the catalyst molar ratio and polymerization conditions, a series of branched polyethylenes with melting temperatures of 101.1-134.1°C and density of 0.922-0.950 g cm⁻³ can be efficiently produced. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008