Ethylene Polymerization over SupportedTitanium-Magnesium Catalysts: Heterogeneity ofActive Centers and Effect of Catalyst Composition onthe Molecular Mass Distribution of Polymer

摘要

New experimental approach was used for analysis of molecular weightdistribution (MWD) of polymers produced over titanium-magnesium catalysts (TMC).Polymers were fractionated on to fractions with narrow MWD (polydispersity (PD)values Mw/Mn < 2). Then some of these fractions were combined to get the minimalquantity of fractions with PD values close to 2 (Flory components). It was found thatthree fractions corresponding to three groups of active centers are sufficient forproper fitting experimental MWD curve for PE obtained over TMC with different Ticontent and with different hydrogen concentration in polymerization.