Sammendrag
Supported neodymium-based Ziegler-type catalysts are obtained by grafting homoleptic methylaluminate Nd(AlMe4)3 onto high-surface silicas including periodic mesoporous silica MCM-41, SBA-15, and KIT-6. Low [Et2AlCl]-cocatalyst contents allow for the fabrication of polyisoprenes with ultra-high molecular weight (UHMWPI). The synthetic rubbers display molecular weights as high as 3×106 g mol–1, polydispersity indices (PDIs) as low as 1.2, and microstructures with 99% cis-stereospecificity. Combined analysis of the organolanthanide/silica hybrid materials by nitrogen physisorption, FTIR and MAS-NMR spectroscopy, as well as elemental(metal) analysis, assist in elucidating the intra-pore surface organometallic chemistry, and suggest the formation of unprecedented organolanthanide species.
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