The metallocene compounds Ph2C(Flu,Cp)ZrCl2 (cat 1) and Et(FlU)(2)ZrCl2 (cat 2) activated with methylaluminoxane (MAO) were evaluated on ethylene and styrene copolymerization. The comonomer concentration (2.2 M), polymerization temperature (80 degrees C), and ethylene concentration (0.135 M) were maintained constant in the reaction medium. The materials were evaluated in a differential scanning calorimeter (DSC), in a rheometer with parallel plate geometry, and their specific gravities were determined. The copolymer obtained with the catalyst I was amorphous; however, that obtained with the catalyst 2 at the same reaction conditions presented melting temperature lower than that of polyethylene. For the rheological measurements, the TA Instruments Rheometer AR 2000 employing dynamic experiments at 190 degrees C was used. The rheological analyses indicated that the obtained polymers presented pseudoplastic behavior in the whole studied frequency range. The behavior of the synthesized copolymers was compared with that of the polyethylene obtained at the same reaction conditions.