Τίτλος:
Controlled vinyl-type polymerization of norbornene with a Nickel(II) diphosphinoamine/methylaluminoxane catalytic system
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
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.
Συγγραφείς:
Georgios C. Vougioukalakis
Ioannis Stamatopoulos
Nikolaos Petzetakis
Catherine P. Raptopoulou
Vassilis Psycharis
Aris Terzis
Panayotis Kyritsis
Marinos Pitsikalis
Nikos Hadjichristidis
Περιοδικό:
Journal of Polymer Science Part A: Polymer Chemistry
Λέξεις-κλειδιά:
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
Κύρια θεματική κατηγορία:
Θετικές Επιστήμες
