Propylene polymerization with the bimetallic “two-in-one” cat-alyst was first carried out with TEA or TIBA singular cocatalyst. Asshown in Table 2, both TEA and TIBA worked fairly well as activatorof the Ziegler–Natta part of the catalyst, rendering PP of relativelyhigh molecular weights (as high as 793,500 g/mol) and high meltingtemperatures (>159◦C), characteristics of Ziegler–Natta catalysisfor propylene polymerization. And the GPC and DSC profiles of the polymers both show unimodal contours, implying that both alky-laluminum, though good for Ziegler–Natta catalyst activation, areincapable of activating the metallocene. However, as indicated byRun 3 in Table 2, mating MAO with TEA in the polymerization seemsstill useless, as both GPC (Fig. 3) and DSC (Fig. 4) curves of the resul-tant polymer keep unimodal, with the molecular weight and melt-ing temperature data similar to those of PP from TEA alone (Run 1 inTable 2). This implies that TEA had deactivated the metallocene cat-alyst that should have been activated by MAO, which is consistentwith the above discussion on the effect of TEA on homogeneous pro-pylene polymerization with rac-CH2(3-t-Bu-1-Ind)2ZrCl2/MAO andrules out TEA as a suitable choice of cocatalyst for the Ziegler–Nattapartial catalyst in the bimetallic catalyst. Meanwhile, TIBA provesits compatibility with MAO. By pairing TIBA and MAO together, pro-pylene polymerization with the bimetallic “two-in-one” catalystnot only results in increased catalyst activity (run 4 in Table 2), but the resultant polymer displays a bimodal contour of GPC profile aswell as a bimodal contour of DSC melting thermogram, indicatingthat in this case both the Ziegler–Natta and the metallocene specieshad been effectively activated and the two catalytic species expressFig