TY - JOUR
TI - Controlled vinyl-type polymerization of norbornene with a Nickel(II) diphosphinoamine/methylaluminoxane catalytic system
AU - Georgios C. Vougioukalakis
AU - Ioannis Stamatopoulos
AU - Nikolaos Petzetakis
AU - Catherine P. Raptopoulou
AU - Vassilis Psycharis
AU - Aris Terzis
AU - Panayotis Kyritsis
AU - Marinos Pitsikalis
AU - Nikos Hadjichristidis
JO - Journal of Polymer Science Part A: Polymer Chemistry
PY - 2009
VL - 47
TODO - 20
SP - 5241--5250
PB - Wiley
SN - 0887-624X, 1099-0518
TODO - 10.1002/pola.23573
TODO - Catalytic activity;  Catalytic system;  Concentration of;  Controlled polymerization;  High molecular weight;  Isolated yield;  Linear dependence;  Methylaluminoxane;  Ni complexes;  NMR;  Norbornene;  Norbornenes;  Polynorbornenes;  Reaction time;  Solid-state structures;  Vinyl polymerization;  X-rays diffraction, Catalysis;  Catalyst activity;  Chromatographic analysis;  Chromatography;  Coordination reactions;  Crystal structure;  Diffraction;  Gelation;  Gels;  Molecular weight distribution;  Nickel;  Nickel alloys;  Nickel compounds;  Nuclear magnetic resonance;  Polymerization;  Single crystals;  Terpolymers, Polymers
TODO - A novel nickel-based complex coordinated with an asymmetric diphosphi-noamine ligand was synthesized and fully characterized. Single crystals of good quality were also obtained, and the solid-state structure of the complex was studied via X-rays diffraction. The catalytic activity of this Ni(II) complex in the vinyl-type polymerization of norbornene was studied with methylaluminoxane (MAO) as the cocatalyst/activator. The influence of the reaction time, the equivalents of MAO used, and the concentration of the monomer on: (i) the activity of the catalytic system; (ii) the isolated yield of the polymer; and (iii) the molecular weight and molecular weight distribution of the polymer were investigated. The isolated polynorbornene (PNB) yields are significantly higher compared with those reported for other similar nickel-based systems. The as-obtained PNBs are characterized by high molecular weights and relatively narrow and monomodal molecular weight distributions (amongst the narrowest reported in the literature). The linear dependence of the molecular weight of the obtained PNB on the concentration of norbornene points toward a controlled polymerization reaction. © 2009 Wiley Periodicals, Inc.
ER -