Ethylene-propylene copolymerization with bis(beta-enaminoketonato) titanium complexes activated with modified methylaluminoxane
Data(s) |
2006
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Resumo |
Ethylene-propylene copolymerization, using [(Ph)NC(R-2)CHC(R-1)O](2)TiCl2 (R-1 = CF3, Ph, or t-Bu; R-2 = CH3 or CF3) titanium complexes activated with modified methylaluminoxane as a cocatalyst, was investigated. High-molecular-weight ethylene-propylene copolymers with relatively narrow molecular weight distributions and a broad range of chemical compositions were obtained. Substituents R-1 and R-2 influenced the copolymerization behavior, including the copolymerization activity, methylene sequence distribution, molecular weight, and polydispersity. With small steric hindrance at R-1 and R-2, one complex (R-1 = CF3; R-2 = CH3) displayed high catalytic activity and produced copolymers with high propylene incorporation but low molecular weight. The microstructures of the copolymers were analyzed with C-13 NMR to determine the methylene sequence distribution and number-average sequence lengths of uninterrupted methylene carbons. |
Identificador | |
Idioma(s) |
英语 |
Fonte |
Tang LM;Li YG;Ye WP;Li YS.Ethylene-propylene copolymerization with bis(beta-enaminoketonato) titanium complexes activated with modified methylaluminoxane,JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY,2006,44(20):5846-5854 |
Palavras-Chave | #IMINE CHELATE LIGANDS #CONSTRAINED GEOMETRY CATALYST #MONOMER SEQUENCE DISTRIBUTION #OLEFIN POLYMERIZATION #C-13 NMR #MOLECULAR-STRUCTURE #CHAIN TRANSFER #BEARING |
Tipo |
期刊论文 |