Structure and viscoelastic properties of amorphous ethylene/1-hexene copolymers obtained with metallocene catalyst

Copolymerization of ethylene and 1-hexene was performed with diphenylmethylidene (cyclopentadienyl-fluorenyl) zirconium dichloride (Ph2C(Cp)(Flu)ZrCl2) in combination with dimethylanilinium tetrakis-(pentafluorophenyl)borate ((Me2PhNH)(B(C6F5)4))/triisobutylaluminum (i-Bu3Al) catalyst. This catalyst system produced ethylene/1-hexene random copolymers (EHRs) with high molecular weight and narrow molecular weight distribution. The rheological properties of the rubbery EHRs were compared with those of the rubbery ethylene/propylene copolymer (EPR). It was found that the rubbery plateau modulus GN0 of the EHR is much lower than that of the EPR.