Combined metallocene catalysts: an efficient technique to manipulate long-chain branching frequency of polyethylene

Beigzadeh D; Soares JBP; Duever TA

Macromolecular Rapid Communications, Vol.20, No.10, 541-545, 1999

DOI10.1002/(SICI)1521-3927(19991001)20:10<541::AID-MARC541>3.0.CO;2-E Export Citation

Combined metallocene catalysts: an efficient technique to manipulate long-chain branching frequency of polyethylene

The solution polymerization of ethylene in Isopar E in a semi-batch reactor using combined CGC-Ti and Et[Ind](2)ZrCl2 catalysts was studied. Methylaluminoxane (MAO) and tris(pentafluorophenyl)borane were used as co-catalysts. Samples were analyzed by C-13 NMR and gel permeation chromatography (GPC) for their branching content and molecular weight distribution. It was shown that there was an optimum ratio of CGC-Ti/Et[Ind](2)ZrCl2 that maximizes the number of long-chain branches of the formed polyethylene.