Preparation of MgCl2-Supported Ziegler-Natta Catalysts via New Surfactants Emulsion for Propylene Polymerization

Yansong Wu,Wei Ding,Jian Li,Tao Jiang

doi:10.3390/catal11050601

Abstract

This article describes a MgCl2-supported Ziegler-Natta catalyst for propylene polymerization prepared via an in situ emulsion technique with new surfactants. The effect of preparation conditions such as the TiCl4/toluene molar ratio, TiCl4-contacting temperature, amount of phthaloyl dichloride, stirring rate, mixing time of TiCl4/toluene with the Mg complex, and the n-butyl chloride loading was investigated in detail. Scanning electron microscopy and laser particle size analyzer measurements showed that the catalyst particles exhibit a perfectly spherical shape, narrow particle size distribution, and low fine powder content. Energy-dispersive X-ray spectrometry indicated that the Ti, Mg, and Cl elements were evenly distributed throughout the particles. Powder X-ray diffraction measurements indicated the presence of δ-MgCl2 in the catalyst, and FTIR and GC-MS studies confirmed the presence of in situ formed di(ethylhexyl)phthalate (DEHP). Bulk polymerization of propylene using the catalyst was studied, and it was found that the catalyst displayed high activity, high bulk density with high stereospecificity, and excellent hydrogen sensitivity. The polymer produced by the catalyst has a narrow particle size distribution with a low fine powder content.

Highlights

Since their discovery in the 1950s, Ziegler-Natta catalysts have been applied in the production of polyolefins [1,2,3,4]
We report a Ziegler-Natta propylene polymerization polymerization catalyst prepared by the in situ emulsion techniquecatalyst with new s prepared by the in situ emulsion technique with new surfactants
The dodecyl me tended to stabilize the interface between the two phases, but turbulence sig influenced the shape of the emulsion droplets

Summary

Introduction

Since their discovery in the 1950s, Ziegler-Natta catalysts have been applied in the production of polyolefins [1,2,3,4]. MgCl2 has been known as the most widely used support for Ziegler-Natta catalysts with high catalytic activity and high performance [7,8,9,10,11]. Three methods have been used to prepare activated MgCl2 supports for Ziegler-Natta catalysts, namely, ball-milling (physical route), recrystallization (chemical route), and the chemical reaction method (chemical route) [12,13,14,15,16]. In the synthesis of the MgCl2 support via this method, it is not easy to obtain compact and perfect morphology because it is difficult to control the alcohol content in the MgCl2 alcohol complexes; this affects the porosity and the strength of the catalyst particles and the

Methods

Results

Conclusion