Imido-modified SiO2-supported Ti/Mg Ziegler-Natta catalysts for ethylene polymerization and ethylene/1-hexene copolymerization

Authors

  • Boping Liu State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
  • Ruihua Cheng State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
  • Ting Fu State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
  • Xuelian He State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
  • Zhen Liu State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
  • Zhou Tian State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
Abstract:

A novel imido-modified SiO2-supported Ti/Mg Ziegler-Natta catalyst for ethylene and ethylene/1-hexene polymerization is investigated. The catalyst is prepared by modification of (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalysts via supporting vanadium species followed by reaction with p-tolyl isocyanate as imido agents, to get the merits from both the SiO2-supported imido vanadium catalyst and the (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalyst. The effects of cocatalyst amount, hydrogen and dosage of 1-hexene on polymerization behavior and the microstructures of their polymers are systematically investigated. Compared with (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalysts and vanadium-modified (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalysts, the imido-modified SiO2-supported Ti/Mg catalysts show lower but more stable activity including homopolymerization, polymerization with hydrogen and copolymerization owing to imido ligands, indicating that p-Tolyl isocyanate was unfavorable to improving catalytic activity but benefited the stability, and the products of all catalysts show lower 1-hexene incorporation but much higher molecular weight (MW) with medium molecular weight distribution (MWD). The most unique feature of the novel catalysts is the excellent hydrogen response without lowering the polymerization activity, showing great potential for industrial application.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

Introduction of titanium species into fluorine-modified SiO2- supported Cr-V bimetallic catalyst for ethylene polymerization and ethylene/1-hexene copolymerization

Chromium-vanadium (Cr-V) bimetallic catalysts are prepared by the introduction of vanadium into the Phillips catalyst which is one of the most significant industrial ethylene polymerization catalysts for tuning the Phillips catalyst performances and improving polyethylene properties. In the present work, titanium species were introduced into the fluorine-modified chromium-vanadium bimetallic ca...

full text

Chromium(III) Based Ziegler-Natta Catalysts for Olefin Polymerization

Four chromium based oxo-trinuclear carboxylate complexes were prepared by reacting chromium(III) nitrate nonahydrate with acetic acid and substituted carboxylic acids. They were characterized using infrared spectroscopy (FT-IR). Chromium content of the complexes was determined by titrimetry method. The chromium(III) monochloroacetate complex, [Cr3O(ClCH2COO)6.3H2O]NO3.3H2O in combination with d...

full text

Active site nature of magnesium dichloride-supported titanocene catalysts in olefin polymerization

Heterogeneous Ziegler-Natta and homogeneous metallocene catalysts exhibit greatly different active sitenature in olefin polymerization. In our previous study, it was reported that MgCl2-supported titanocenecatalysts can generate both Ziegler-Natta-type and metallocene-type active sites according to the type of activators.The dual active site nature of the supported titanocene catalysts was furt...

full text

Design of stereoselective Ziegler-Natta propene polymerization catalysts.

After five decades of largely serendipitous (albeit formidable) progress, catalyst design in Ziegler-Natta olefin polymerization, i.e., the rational implementation of new active species to target predetermined polyolefin architectures, has ultimately become a realistic ambition, thanks to a much deeper fundamental understanding and major advances in the tools of computational chemistry. In this...

full text

Behaviors in ethylene polymerization of MgCl₂-SiO₂/TiCl₄/THF Ziegler-Natta catalysts with differently treated SiO₂.

The present research focuses on investigation of the catalytic behaviors of MgCl₂-SiO₂/TiCl₄/THF Ziegler-Natta (ZN) catalysts with fumed SiO₂ variously treated with silane compounds. The non-treated silica (NTS) and other silicas treated with dimethylsilicone fluid (TSDMSF), dimethyldichlorosilane (TSDMDCS), and hexamethyl-disilazane (TSHMDS) were employed. It was found that the Cat-TSDMDCS and...

full text

IN SITU SILICA SUPPORTED METALLOCENE CATALYSTS FOR ETHYLENE POLYMERIZATION

Bis(2-R-ind)ZrCl2 (R: H or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. In this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, TiBA) cocatalyst was used instead of expensive methyl aluminiumoxane (MAO) cocatalyst in the polymerization. The effect of surface ...

full text

My Resources

Save resource for easier access later

Save to my library Already added to my library

{@ msg_add @}


Journal title

volume 3  issue 2

pages  103- 117

publication date 2016-06-01

By following a journal you will be notified via email when a new issue of this journal is published.

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023