Synthesis and evaluation of two new FI‐Ti catalysts for living polymerization of ethylene

Abstract

Two new FI complexes, bis[N-(3-allylsalicylidene)-pentafluoroanilinato]titanium(IV) dichloride (AFI) and bis[N-(3-propylsalicylidene)-pentafluoroanilinato]titanium(IV) dichloride (PFI) were designed and synthesized as catalysts for living polymerization of ethylene. The two complexes were characterized by elemental analysis, spectroscopy and X-ray single diffraction. The catalysts were evaluated in ethylene polymerization under atmospheric pressure. It was found that both catalysts exhibited high activity and good livingness. The effects of temperature and dMAO/Ti molar ratio on the polymerization behavior of AFI were studied in detail. Elevating temperature increased self-immobilization of the AFI catalyst, which broadened the polymer molecular weight distribution.

Synthesis of Ultrahigh-Molecular-Weight Ethylene-1-Hexene Copolymers with High Hexene Content via Living Polymerization with Fluorinated Bis(phenoxy-imine) Titanium(IV)

“…[ 19 ] In this work, the polymerization temperature was set to 50 °C for a good solubility of the copolymers in the solvent. Table 1 summarizes the results of all runs in this work.…”

“…Ethylene was purchased from TOPGRAND Petrifaction Industry Gas Ltd. and passed through a purification box to remove trace oxygen and water. PFI was synthesized according to the literature …”

“…The detailed experiment procedures in this work were similar to ref. . It is included here for the reader's convenience.…”

“…[ 3,4,18 ] In a previous work, we synthesized and reported an FI catalyst, bis[ N -(3-propylsalicylidene)-pentafl uoroanilinato] titanium(IV) dichloride (PFI), which had good features of ethylene living polymerization with high activity. [ 19 ] In this work, we applied PFI to the preparation of UHMW EH copolymers with high 1-hexene content. The reactivity ratios of copolymerization are an important set of kinetic parameters for understanding features of the catalyst, as well as designing composition and sequence length distributions of the resulting copolymers, [ 5,6 ] which were also estimated in this work.…”

“…Fluorinated bis(phenoxy–imine) complexes of group IV transition metals, named FI catalysts, have outstanding performances in olefin living polymerizations . In a previous work, we synthesized and reported an FI catalyst, bis[ N ‐(3‐propylsalicylidene)‐pentafluoroanilinato] titanium(IV) dichloride (PFI), which had good features of ethylene living polymerization with high activity . In this work, we applied PFI to the preparation of UHMW EH copolymers with high 1‐hexene content.…”