Organometallic nickel complexes with bidentate P O chelating ligands of type Ph(PPh3)Ni(Ph2PCHCOPh) were heterogenized according to a new strategy - through the =CH- group of the ylidic ligand - and their behaviour in the polymerization and/or oligomerization of ethylene investigated. When anchored to polystyrene resins the catalytic systems showed a high and very selective activity in ethylene polymerization (1-2.5 kg of polymer (g Ni)-1 h-1) working in slurry or in gas-solid phase with reproduction of the morphology of the starting resins. When the matrix is a microspherical resin (0.1-0.3 mm diameter) the HDPE (high-density polyethylene) obtained is in the form of regular and very compact spheres of 3-7 mm diameter. Depending on the physical characteristics of the matrix (crosslinking, surface area, porosity, existence of spacing groups), compact spheres, hollow spheres ('eggs'), geminates, polymer powders, or liquid oligomers were obtained.
ORGANOMETALLIC NICKEL-CATALYSTS BOUND TO POLYMERIC MATRICES IN THE OLIGOMERIZATION AND OR POLYMERIZATION OF OLEFINS WITH A REPLICA OF THE SUPPORT MORPHOLOGY
RASPOLLI GALLETTI, ANNA MARIA;SBRANA, GLAUCO;
1992-01-01
Abstract
Organometallic nickel complexes with bidentate P O chelating ligands of type Ph(PPh3)Ni(Ph2PCHCOPh) were heterogenized according to a new strategy - through the =CH- group of the ylidic ligand - and their behaviour in the polymerization and/or oligomerization of ethylene investigated. When anchored to polystyrene resins the catalytic systems showed a high and very selective activity in ethylene polymerization (1-2.5 kg of polymer (g Ni)-1 h-1) working in slurry or in gas-solid phase with reproduction of the morphology of the starting resins. When the matrix is a microspherical resin (0.1-0.3 mm diameter) the HDPE (high-density polyethylene) obtained is in the form of regular and very compact spheres of 3-7 mm diameter. Depending on the physical characteristics of the matrix (crosslinking, surface area, porosity, existence of spacing groups), compact spheres, hollow spheres ('eggs'), geminates, polymer powders, or liquid oligomers were obtained.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
