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RESEARCH PRODUCT
Direct synthesis of fibrous high molecular weight polyethylene using vanadium catalysts supported on an SiO2ionic liquid system
Anna BihunWioletta Ochędzan-siodłaksubject
Materials sciencePolymers and PlasticsOrganic ChemistryPolyethylenePost-metallocene catalystBranching (polymer chemistry)Catalysischemistry.chemical_compoundCrystallinitychemistryChemical engineeringIonic liquidPolymer chemistryMaterials ChemistryMolar mass distributionFourier transform infrared spectroscopydescription
Polyethylene of fibrous morphology was obtained using Cp2VCl2 and VCl2(salenCl2) catalysts activated by AlEt2Cl and AlEtCl2 and heterogenized on a supported ionic liquid system prepared with SiO2 and 1-(3-triethoxysilyl)propyl-3-methylimidazolium chloroaluminate. The fibre length ranges from 15 to 60 µm, depending on the reaction conditions. The polyethylene is characterized by a high molecular weight ((1.1–2.4) × 106 g mol−1) and a narrow molecular weight distribution (1.4–2.5). It is a linear polymer, properly without branching. The DSC method reveals characteristic changes in melting temperature and crystallinity degree between the first and second scan heating cycles (141 °C and 136 °C, 71% and 46%, respectively). The wide angle X-ray spectroscopy and Fourier transform infrared spectroscopy methods give crystallinity degree values of 40% and 41%–51%. The influence of type of catalyst precursor, alkylaluminium activator, catalyst/activator molar ratio, reaction time and temperature is discussed. © 2015 Society of Chemical Industry
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-07-03 | Polymer International |