Effect of prepolymerization on propylene polymerization

Polymerization of propylene was performed using MgCl 2 . EtOH.TiCl 4 .ID.TEA.ED catalyst system in hexane, where internal donor (ID) was an organic diester and external donor (ED) was a silane compound and also triethyl aluminum (TEA) as activator. A new method called isothermal/nonisothermal method (INM), a combination of isothermal and nonisothermal methods, was applied to produce the spherical polymer particles. The effects of the INM method and prepolymerization temperature on the final polymer morphology, M w , and catalyst activity were also investigated. The morphology of the polymers was evaluated through scanning electron microscopy (SEM) images. GPC results were used for molecular weight ( M w ) evaluation. It was found that the polymers had a better morphology when they were prepared using INM method. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009