DRIFT study of internal donors in supported Ziegler–Natta catalysts

Influence of Internal Donors on the Performance and Structure of MgCl2 Supported Titanium Catalysts for Propylene Polymerization

“…The position of the bands are in close agreement with those reported by Potapov et al for EB complexes with Mg#3, Mg#4, and Mg#5 ions, respectively. [37] Hence, the 1692 cm À1 band is attributed to Mg 2þ ions at (104) lateral cut, the 1675 cm À1 band to the (110) cut, and the 1651 cm À1 band to the Mg 2þ ions at corners and edges. On comparing the distribution of intensities' corresponding to the three fitted bands, determined from deconvolution, it is evident that the EB-Mg#4 complex has maximum intensity.…”

“…The >C --O IR band, in case of catalysts, is very complex, and to resolve it, deconvolution was performed using a Gaussian-line-shape function. Assignments have been performed based on literature, [36][37][38] Figure 2 shows the IR spectrum of the >C --O stretching band for catalyst 1A and 1B. For catalyst 1A, the IR band has been deconvoluted to three bands, at 1651, 1675, and 1692 cm À1 , as seen in Table 2, with Dn (>C --O) ¼ 69, 45, and 28 cm À1 , respectively.…”

Investigation of Planar Ziegler-Natta Model Catalysts Using Attenuated Total Reflection Infrared Spectroscopy

“…IR spectroscopy has been extensively applied to Ziegler-Natta catalysts [17]. With regard to propylene polymerization catalysts, most of the work has focused on the spectral changes in the m C=O of the internal aromatic ester in various stages of catalyst preparation [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

External Donor Induced Direct Contact Effects on Mg(OC2H5)2‐Based Ziegler‐Natta Catalysts for Propylene Polymerization

“…[12,13] In general, donors block aspecific sites on MgCl 2 surface selectively to increase the isospecific Ti dinuclear species and coadsorb with Ti species to transform aspecific sites into isospecific sites. [14][15][16] Even though many scientists explained isospecificity increase by the existence of donors according to these results, the effects of donors are considered to be more complicated. [17][18][19] For the further improvement of the Ziegler-Natta catalyst system, it is essential to understand how donors interact with other components of the catalyst.…”