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

Abstract

Abstract An insight on the influence of ethyl benzoate (EB) and diisobutyl phthalate (DIBP) as internal donors, differing in coordination nature on the structural aspects of MgCl 2 matrix in high‐performance MgCl 2 ‐supported titanium catalysts was developed using FTIR spectroscopy and WAXD studies. The analysis of the >CO stretching IR band of internal donors showed their coordination to (104) and (110) lateral cuts of MgCl 2 matrix. Transformation of magnesium ethoxide {Mg(OEt) 2 } to MgCl 2 during catalyst preparation resulted in different MgCl 2 phases, namely the α ‐form, β ‐form, and the disordered δ ‐form, which were analyzed by WAXD studies. The results from WAXD showed the relative preference of α ‐form over β ‐form in case of DIBP‐based catalysts, which might be due to interlayer bridging between adjacent layers due to the bidendate nature of DIBP. This can be one of the reasons for the high productivity of dialkyl‐phthalate‐based catalysts in comparison to ethyl‐benzoate‐based catalyst systems. magnified image