Ethylene polymerization using novel titanium catalytic precursors bearing N,N‐dialkylcarbamato ligands |
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| Authors: | Claudia Forte Mohammad Hayatifar Guido Pampaloni Anna Maria Raspolli Galletti Filippo Renili Stefano Zacchini |
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| Institution: | 1. CNR‐Consiglio Nazionale delle Ricerche, ICCOM, Area della Ricerca, Via G. Moruzzi 1, 56124 Pisa, Italy;2. Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy;3. Dipartimento di Chimica Fisica e Inorganica, University of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy |
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| Abstract: | Polymerization catalysts based on N,N‐dialkylcarbamato complexes of titanium(IV) appear particularly interesting, because these novel catalytic precursors are rather cheap and easy to synthesize and handle. This contribution reports ethylene polymerization behavior of titanium(IV) complexes of general formula Ti(O2CNR2)4 R = Me ( I ) and Et ( II ) and TiCl2(O2CNMe2)2 ( III ). These precursors in conjunction with methylaluminoxane resulted active catalysts for the polymerization of ethylene, affording high‐density polyethylene with limited branch content. The influence of the polymerization parameters was studied with particular reference to the type of catalyst components, solvent, temperature, monomer concentration, and Al/Ti ratio. The nature of the solvent appears crucial for catalytic performances: when toluene was replaced by chlorobenzene, a significant increase of the productivity was ascertained. The obtained polymers were characterized by DSC, size exclusion chromatography, FTIR, and NMR techniques. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 |
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| Keywords: | catalysis N N‐dialkylcarbamato ligand polyethylene (PE) titanium complex Ziegler‐Natta polymerization |
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