Variation of molecular weight distribution (MWD) and short chain branching distribution (SCBD) of ethylene/1-hexene copolymers produced with different in-situ supported metallocene catalysts

✍ Scribed by Kyung-Jun Chu; Joao B. P. Soares; Alexander Penlidis

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 117 KB
• Volume: 201
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/(sici)1521-3935(20000201)201:3<340::aid-macp340>3.0.co;2-x

✦ Synopsis

Full Paper: Copolymerization of ethylene and 1-hexene was carried out with different catalysts: homogeneous Et[Ind] 2 ZrCl 2 , Cp 2 HfCl 2 and [(C 5 Me 4 )SiMe 2 N(tert-Bu)]TiCl 2 , the corresponding in-situ supported metallocenes, and combined in-situ supported metallocene catalysts (mixtures of Et [Ind] 2 ZrCl 2 andCp 2 HfCl 2 , andEt[Ind] 2 ZrCl 2 and[(C 5 Me 4 )SiMe 2 N(tert-Bu)]TiCl 2 ). Carbon-13 nuclear magnetic resonance spectroscopy ( 13 C NMR), gel permeation chromatography (GPC) and crystallization analysis fractionation (CRYSTAF) studies showed that, compared to the corresponding homogeneous metallocenes, in-situ supported metallocenes produced polymers having different 1-hexene fractions, molecular weight distributions (MWD) and short chain branching distributions (SCBD). It was also demonstrated that polymers with broader MWD and SCBD can be produced by combining two different in-situ supported metallocenes.