Catalyst dialkylaluminum halide

The catalyst for the reaction between PVC and the high cis-1,4-polybutadiene was a dialkylaluminum halide—e.g., Et2AlCl—or sesquihalide. The catalyst could be added from an external source or could be generated in situ—e.g., by the reaction of an aluminum alkyl with either titanium tetrachloride or a reactive organic halide such as benzyl chloride or tert-butyl chloride. The concentration of Et2AlCl was varied from 0.2-5% by weight based on PVC, although the preferred concentration was between 0.5 and 1.5 wt %. 

A Theory of Initiation and Propagation of Carbonium Ion Polymerizations with Trialkylaluminum Catalysts. Trialkylaluminums or dialkylaluminum halides in conjunction with suitable cocatalysts in polar solvent are active polymerization catalysts. For example, when cocatalytic amounts of tert-butyl chloride are added to a quiescent mixture of trialkylaluminums or dialkylaluminum halides in methyl chloride solvent in the temperature range —30° to —100°C., immediate polymerization commences (2, 3, 4, 5, 6). 

Type (a) behavior is shown by many first generation catalyst systems, e.g., a-TiCla, VCI3, etc., when used with dialkylaluminum halides as co-... 

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