Supported Neodymium Catalysts for Isoprene and rac-β-Butyrolactone Polymerization: Modulation of Reactivity by Controlled Grafting

摘要

A series of hybrid materials, bearing neodymium silylamide initiating groups, have been shown to mediate isoprene polymerization when combined with alkyl aluminum activators [methylaluminoxane, AlEt₂Cl, Al(iBu)₃]. The surface species nature and relative distribution were correlated with isoprene polymerization activity and selectivity. This approach to stereocontrol modulation has been extended to racemic β-butyrolactone isoselective ring opening polymerization.