Polymerization of ethylene by (α‐Diimine) nickel catalyst and statistical analysis of the effects of reaction conditions |
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| Authors: | Luis Carlos Ferreira Jr Priamo Albuquerque Melo Jr Geraldo Lopes Crossetti Griselda Barrera Galland Marcio Nele José Carlos Pinto |
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| Affiliation: | 1. Programa de Engenharia Química/COPPE, Universidade Federal do Rio de Janeiro, Cidade Universitária, CP: 68502, Rio de Janeiro, 21945‐970 RJ, Brazil;2. Escola de Química ‐ Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil;3. Departamento de Química e Física ‐ Universidade de Santa Cruz, Santa Crus do Sul, RS, Brazil;4. Instituto de Química ‐ Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil |
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| Abstract: | This article regards the ethylene polymerization catalyzed by a nickel catalyst and activated by ethylaluminum sesquichloride (EASC). The effects of the reaction conditions polymerization temperature, cocatalyst (EASC) concentration, and ethylene concentration] on the average molecular weights of the final polymers and reaction yields were evaluated with the help of empirical statistical models. It is shown that reaction temperature and cocatalyst (EASC) concentration exert the most important effects on average molecular weights and catalyst activity. The polydispersities of the obtained polyethylenes are larger than the polydispersities of polyethylenes obtained with typical Brookhart catalysts. The analysis of polymer branching frequencies shows new types of short branching and significant amounts of long branches, which may explain the relatively large polydispersities of the obtained polymer samples. POLYM. ENG. SCI., 50:1797–1808, 2010. © 2010 Society of Plastics Engineers |
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