Magnesium‐chloride‐supported high‐mileage catalysts for olefin polymerization. II. Reactions between aluminum alkyl and promoters

Abstract

Abstract The reactions between AlEt 3 and the modifiers, promoters, and coactivators of a typical magnesium‐chloride‐supported, high‐activity propylene polymerization catalyst were studied. Infrared, MS analysis of the gas evolved, and GC–MS of the hydrolysis products for the reaction between AlEt 3 and p ‐cresol showed rapid and quantitative reactions with p ‐cresol either in the support or solution. The reaction products from AlEt 3 and esters were hydrolyzed, acidified, and dehydrated. The resulting carbonyl and olefinic compounds were identified by GC–MS. Proton and carbon nuclear magnetic resonance (NMR) techniques were also used to study these reactions. The expected intermediates were found in the PMR and CMR spectra. The mechanisms of reactions were proposed. The results of this study showed that when AlEt 3 and esters are used as coactivators reaction products that can significantly influence the performance of the catalyst are formed.