Ind) 2 ZrCl 2 catalyst was synthesized and used for copolymerization of ethylene and propylene (EPR) and terpolymerization of ethylene propylene and 5-ethyldiene-2-norbornene (ENB). Methylaluminoxane (MAO) was used as cocatalyst. The activity of the catalyst was higher in copolymerization of ethylene and propylene (EPR) rather than in terpolymerization of ethylene, propylene and diene monomers. The effects of [Al] : [Zr] molar ratio, polymerization temperature, pressure ratio of ethylene/propylene and the ENB concentration on the terpolymerization behavior were studied. The highest productivity of the catalyst was obtained at 60 C, [Al] : [Zr] molar ratios of 750 : 1 and 500 : 1 for copolymerization and terpolymerization, respectively. Increasing the molar ratio of [Al] : [Zr] up to 500 : 1 increased the ethylene and ENB contents of the terpolymers, while beyond this ratio the productivity of the cata-lyst dropped, leading to lower ethylene and ENB contents. Terpolymerization was carried out batchwise at temperatures from 40 to 70 C. Rate time profiles of the polymerization were a decay type for both copolymerization and terpolymerization. Glass transition temperatures (T g ) of the obtained terpolymers were between À64 and À52 C. Glass transition temperatures of both copolymers and terpolymers were decreased with increased ethylene content of the polymers. Dynamic mechanical and rheological properties of the obtained polymers were studied. A compounded EPDM showed good thermal stability with time.

A series of methylaluminoxane (MAO)-modified PQ and EP 12 silicas, calcined at 110, 250, and 450 C, were prepared.The resulting MAO-modified supports were characterized by a set of complementary techniques: Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), small angle X-ray scattering (SAXS), and thermal gravimetric analysis (TGA). The Al/Si ratios of the MAO-modified PQ and EP12 silicas were in the ranges of 0.19-0.27 wt % and 0.17-0.30 wt %, respectively. MAO-modified silicas were used in the polymerization of ethylene using an Et 2 IndZrCl 2 catalyst. The MAO-modified PQ silica showed higher activity in comparison to the MAO-modified EP12.