A comparative study on supporting effect during copolymerization of ethylene/1-olefins with silica-supported zirconocene/MAO catalyst

The silica-supported MAO was in situ- and ex situ immobilized with zirconocene catalyst to produce ethylene copolymers. The in situ catalytic system exhibited higher activities compared with the ex situ one. The ethylene/1-hexene (EH) copolymerization showed the highest activities for both catalytic systems. 13C NMR revealed that the copolymers produced in all systems were random copolymers. In addition, the in situ system resulted in narrow molar mass distributions (MMD) for all copolymers indicating a uniform catalytic site present.