“…An elegant demonstration of this fact was presented using mixtures of TiCl 4 /MgCl 2 INPETUS Ziegler-Natta catalyst with 3, 4, 6, 8 or CpZrCl 3 (26). [30] The mixtures of this Ziegler-Natta catalyst with Cp 2 MCl 2 (where M = Ti, Zr or Hf) produced monomodal narrow MWD (between 2.6 and 2.9), but the mixture with 26 gave bimodal PE with MWD = 11 as a consequence of the appearance of two GPC peaks, one corresponding to the PE obtained with the Ziegler-Natta catalyst and the other one to the PE obtained with the metallocene. Another binary catalyst system was obtained using inorganic supports, such as MgCl 2 , SiO 2 , and their mixtures, as prepared via recrystallization or sol-gel procedures.…”