Advances in Catalysts Based on Aluminum Hydride Derivatives for the Synthesis of High-Cis Polyisoprene

Abstract

Abstract The stereospecific polymerization of isoprene with simple alanes and poly (N-alkyliminoalanes) (PIA) and TiCl4 is critically reviewed and related to the more recent finding on the “cage” structure and composition of PIA's. In particular, the polymer yield was found strictly dependent on the structure of the PIA, which in turn depends on the nature of the alkyl groups bonded to nitrogen. The effects of the chemical composition of the PIA and of the halogen level in its halogenated derivatives on the activity of the catalyst and on the possibility of side reactions is discussed with reference to conventional aluminum alkyl catalysts. The identification of new structures within this class of cocatalysts is discussed