Study on the microstructures of polypropylene synthesized by a novel MgCl2-supported and low Ti-loading Ziegler–Natta catalyst

Abstract

Abstract-A novel MgCl 2 -supported and low Ti-loading Ziegler-Natta (Z-N) catalyst was prepared by one-pot ball milling. Polypropylenes (PPs) with special microstructures were synthesized by using this catalyst. Complex gel-permeation chromatography (GPC) data of the resultant PPs were analyzed by fitting the molecular weight distribution (MWD) curves with multiple Flory-Schulz functions. 13 C-NMR spectra of the PPs were also analyzed. A multi-site active center model and the probable structures of the active centers were proposed. Simulation of the pentad intensities of the PPs showed that the modeling results could satisfactorily account for the experimental data, which indicated that the multi-site active center model was plausible and reasonable.

Synthesis of highly isotactic poly 1-hexene using Fe-doped Mg(OEt)2/TiCl4/ED Ziegler–Natta catalytic system

“…Stereospecific heterogeneous α-olefin polymerization has been a major research field since the first discovery of Ziegler-Natta (ZN) olefin polymerization catalysts. [1][2][3][4] Although most of the research efforts have been focused on the development of new catalytic systems for propylene polymerization, [5][6][7][8] the design and synthesis of efficient catalysts for the stereoselective polymerization of longer chain α-olefins have also attracted extensive research interests since the polymeric materials based on α-olefins could find variety of applications. Low molecular weight (MW) poly(α-olefin)s are used as base materials for lubricating oil formulation, while high MW ones are used as pour point depressant and drag-reducers.…”

Highly efficient FeCl3 doped Mg(OEt)2/TiCl4-based Ziegler–Natta catalysts for ethylene polymerization

“…[6,7] Although, Mg(OEt) 2 has a morphological subject regarding roundness and particle size distribution as compared with MgCl 2 ·nROH, the catalyst made by Mg(OEt) 2 shows a higher activity. [8,9] Industrial catalysts precursors containing magnesium compounds such as MgCl 2 or Mg(OEt) 2 in conjunction with TiCl 3 or TiCl 4 showed great performance in olefin polymerization; however, still there are lots of modifications of ZN catalysts varying in the way of preparation of the support [10][11][12][13][14] and differences in the active component compound structure and the presence of various modifying additives. [15][16][17][18] Lately, investigations have shown that doping a suitable amount of Lewis acids in MgCl 2 or Mg(OEt) 2 supports would be an effective way to improve their catalytic performance in α-olefin polymerization.…”