H Arabi - Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran.
H Dolatshahi - Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran.
H Abedini - Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran.
G.R Nejabat - Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran.

The morphology controlled Ziegler-Natta catalyst is widely being used to produce ordinary Polypropylene (PP) as well as specialty polyolefins such as reactor blends, multiphasepolyolefin alloys and functionalised PP in commercial processes [1]. This type of catalyst contains MgCl2.nROH adduct as one of its main constituents which is referred to as support on which the catalytic sites (TiCl4 species) are located.The support not only results in high catalyst activities but also controls its morphology which is finally imparted to polymer particles through a so-called replication phenomenon [2]. In this work4th generation Ziegler-Natta catalysts are made and the effects of different parameters including TiCl4 toadduct ratio as well as their reaction conditions are thoroughly investigated on the morphology and activity of the catalysts