What is "aluminoxane"

n. (context chemistry English) a class of organometallic compounds of aluminium having general formula R₂Al-O-AlR₂; they are used as catalysts in the polymerization of epoxides and oxetanes to form polyether elastomers.

Aluminoxanes refer to compounds that are obtained by the partial hydrolysis of trialkylaluminium compounds. Aluminoxanes serve as activators for catalytic olefin polymerisation, such as the Ziegler-Natta catalyst. They also serve a function as scavenger for impurities (e.g. water) in reactions that are sensitive to these impurities.

Examples of aluminoxanes include:

• Triisobutylaluminoxane (TiBAO), formed by the hydrolysis of triisobutylaluminium
• Methylaluminoxane (MAO), formed by the hydrolysis of trimethylaluminium

The hydrolysis of trialkylaluminium compounds is a highly exothermic process, and the starting trialkylaluminium compounds are often pyrophoric (i.e. burns on contact with air).