摘要 |
<p>A catalyst composition for polymerizing alpha-olefins is prepared by treating a carrier containing OH groups with an organomagnesium composition and contacting the thus- formed magnesium-containing carrier with a solution of a titanium (IV) alkoxide and a brominating and/or chlorinating agent. The adjustment of the molar ratio of the brominating and/or chlorinating agent to the titanium alkoxide yields catalysts which produce polymers of varying molecular weight distribution, as measured by the melt flow ratio (MFR) values.</p> |