Variation of molecular weight distribution (MWD) and short chain branchingdistribution (SCBD) of ethylene/1-hexene copolymers produced with different in-situ supported metallocene catalysts

Copolymerization of ethylene and 1-hexene was carried out with different ca talysts: homogeneous Et[Ind](2)ZrCl2, Cp2HfCl2 and [(C5Me4)SiMe2N(tert-Bu)] TiCl2, the corresponding in-situ supported metallocenes catalysts (mixtures of Et[Ind](2)ZrCl2 and Cp2HfCl2, and Et[Ind](2)ZrCl2 and [(C5Me4)SiMe2N(te rt-Bu)]TiCl2). Carbon-13 nuclear magnetic resonance spectroscopy (C-13 NMR) , gel permeation chromatography (GPC) and crystallization analysis fraction ation (CRYSTAF) studies showed that, compared to the corresponding homogene ous metallocenes, in-situ supported metallocenes produced polymers having d ifferent 1-hexene fractions, molecular weight distributions (MWD) and short chain branching distributions (SCBD). It was also demonstrated that polyme rs with broader MWD and SCBD can be produced by combining two different in- situ supported metallocenes.