Polymer Bulletin, Vol.74, No.7, 2799-2817, 2017
Copolymerization of ethylene with norbornene or 1-octene using supported ionic liquid systems
Copolymerization of ethylene with norbornene (E/NB) and ethylene with 1-octene (E/Oct) is performed using supported ionic liquid (SIL) systems, in which metallocene (Cp2VCl2) or post-metallocene [VCl2(salenCl(2))] vanadium catalysts are immobilized in pyridinium chloroaluminate ionic liquid supported on silica. The studied SIL catalysts show higher activities as well as stability than their non-supported analogues. In addition, higher activities and better comonomer incorporation are observed for norbornene (above 30 mol%). The comonomer incorporation has considerable influence on copolymer molecular weight (M-w), melting temperature, crystallinity degree, and microstructure of the copolymers. Molecular-weight distribution is relatively narrow (1.5 <= M-w/M-n <= 3.0), which indicates the presence of single-site catalyst systems.