Abstract: The present invention provides phthalate free impact resistant polypropylene copolymer and methods of preparation, which are produced directly from the polymerization reactor system without further compounding of components which significantly alters the physical properties of the resulting polymer. The copolymer according to the present invention possesses both low temperature ductility and high flexural modulus, wherein said polymer is produced in the presence of a phthalate free ZN catalyst comprising urea component.

Abstract: Disclosed is a Ziegler-Natta catalyst composition comprising one or more Ziegler-Natta procatalyst compositions which comprise magnesium, titanium, a halogen, one or more internal electron donors; one or more aluminum containing cocatalysts; optionally one or more stereo-selectivity control agents (SCA); and one or more activity limiting agents (ALA) comprising one or more alkyl-, cycloalkyl- or aryl carbonates and derivatives. Such a Ziegler-Natta catalyst composition exhibits self-limiting catalyst activity in olefin polymerization, particularly propylene polymerization.