Methylalumoxane – History, Production, Properties, and Applications

Abstract

Abstract Since its discovery, methylalumoxane (MAO) has become of great importance as a cocatalyst in homogeneous olefin polymerization. The working principles of single‐site polymerization catalysts are well‐understood, but those of the cocatalyst MAO itself are not. Thus far structural and functional investigations have yielded limited insights and often give contradicting results. MAO's complex nature is due to multiple equilibria between undefined oligomers and “free” trimethylaluminum. Fundamental studies do not clearly portray the molecular structure, and the exact functioning of MAO remains a topic of debate. This comprehensive overview starts with the historical background of MAO and then focuses on its synthesis and large‐scale production, structural characterization, properties, and different roles in the activation of olefin polymerization catalysts. Also given is an overview of potential modifications, immobilization on surfaces, and other alternative applications that have been reported for MAO.