Insight of polypropylene synthesis with high performance multidentate internal donor catalyst system

Propylene polymerization using magnesium dichloride (MgCl2) supported Ziegler-Natta (Z-N) system is a robust and preferred catalytic process for producing polypropylene (PP) grades. Herein, synthesis of polypropylene products is reported using MgCl2 supported multidentate (3,3,3',3'-tetramethyl-2,2',3,3'- tetrahydro-1,1'-spirobiindane-5,5',6,6'-tetracarbonate) Z-N pre-catalyst. The catalyst performance evaluation over propylene polymerization found that multidentate Z-N pre-catalyst has better hydrogen response with controlled isotacticity of PP products as compared to conventional bidentate Z-N pre-catalysts. Melt rheology analysis showed higher loss modulus and storage modulus for ultra-high molecular weight isotactic polypropylene (UHMWiPP) as compared to PP resins with medium molecular weight. Further, GPC analysis reveal medium to broad unimodal molecular weight distribution (MWD) of PP products produced with multidentate Z-N pre-catalyst system.

Automated summary

This study reports the synthesis of polypropylene products using a MgCl2 supported multidentate Ziegler-Natta (Z-N) pre-catalyst. Compared to conventional bidentate Z-N pre-catalysts, the multidentate Z-N pre-catalyst showed better hydrogen response and controlled isotacticity in propylene polymerization. Melt rheology analysis showed higher modulus values for ultra-high molecular weight isotactic polypropylene (UHMWiPP) compared to medium molecular weight PP resins. GPC analysis revealed a medium to broad unimodal molecular weight distribution (MWD) for PP products produced with the multidentate Z-N pre-catalyst system.