Titanium-Based Catalysts for the Manufacture of Polyethylene

Catalyst developments for the manufacture of polyethylene with Ti-based catalysts can be best described as based on two different types of catalysts, which are broadly defined as first and second generation catalysts. 

The majority of the research summarized in this chapter will pertain to second-generation, magnesium-containing Ziegler catalysts due to their importance to the polyethylene industry today. However, a brief summary of first generation catalysts will be included due to the historical importance of these early ethylene polymerization catalysts from an academic and industrial perspective (see Appendix 2.1 for review references on first generation Ziegler catalysts). 

1 First Generation Ziegler Catalysts for the Manufacture of Polyethylene 

The first two commercial plants to manufacture low-pressure polyethylene were started up in 1956 using Zieglers Miilheim process (TiCl and AlEtj) and in 1957 using the chromium-based Phillips catalyst. 

the research by Ludlum and coworkers suggested that the active center of the Ti-based catalyst used in the Mulheim commercial process is based on a Ti (+2) species. 

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