Phthalate-free Ziegler-Natta catalyst that uses mixed internal donors to fine-tune the achievable XS range

Claims

The embodiments described herein relate to a precatalyst, a catalyst, and a process for the polymerization of propylene. The phthalate-free Ziegler-Natta precatalyst comprises a Mg-based support; a transition metal selected from Groups 4 to 8 of the periodic table; a first internal electron donor (ID1) consisting of at least one diester; and a second internal electron donor (ID2) consisting of at least one 1,3-diether. The at least one diester comprises one or more maleates and / or substituted maleates. The at least one 1,3-diether comprises one or more diethers represented by the general structure (1).