Study of the compositional heterogeneity of ethylene/1–hexene copolymers produced over supported catalysts of different composition
作者： Mikhail A. Matsko , Ludmila G. Echevskaya , Marina P. Vanina , Marina I. Nikolaeva , Tatyana B. Mikenas
DOI: 10.1002/APP.36643
关键词: Catalysis 、 Ethylene 、 Dispersity 、 Branching (polymer chemistry) 、 Fourier transform infrared spectroscopy 、 Materials science 、 Copolymer 、 Polymer chemistry 、 Comonomer 、 1-Hexene
摘要: Separation into narrow MWD fractions (liquid–liquid fractionation) and preparative TREF (temperature rising elution with subsequent analysis of by GPC, FTIR, 13C NMR spectroscopy were used to study the comonomer distribution ethylene/1–hexene copolymers produced over highly active supported titanium- vanadium-magnesium catalysts (TMC VMC) a zirconocene catalyst. These produce PE different MWD: Mw/Mn values vary from 2.9 for catalyst, 4.0 TMC, 15 VMC. 1-Hexene increases polydispersity 25 copolymer VMC hardly affects TMC catalysts. The most broad short chain branching (SCBD) was found TMC. catalyst uniform profile SCB content vs. molecular weight in spite great differences (22 2.5 respectively). data showed that majority eluted at 70–90°C (about 85 wt %). In case copolymer's temperature interval (40–100°C). Accordingly, indicate more homogeneous SCBD copolymer, © 2012 Wiley Periodicals, Inc. J Appl Polym Sci,
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