Homo- and copolymerisation of norbornene and styrene with nickel bis(acetyl acetonate)/methylaluminoxane system

Structural characteristics and gas permeation properties of polynorbornenes with retained bicyclic structure

“…Moreover, the molecular weights of the polynorbornenes used in this work (Table 1) are much higher than those of these copolymers [10]. Therefore the glass transition of our polynorbornene samples will be above 270ЊC, in accordance with the data reported by Peruch et al [7].…”

“…The nickel concentration was controlled at 0.001 mol l Ϫ1 and the Al/ Ni and the Ni/Monomer molar ratio were ranged from 100 to 1000 and from 1500 to 6000, respectively. Further description of the synthesis is given elsewhere [10]. Pro-analysis cyclohexane was supplied by Aldrich.…”

Polymerization of norbornene in the presence of ethene over tetrakis(triphenylphosphine)nickel/boron trifluoride etherate system

“…The average polymerization degree increased from P n = 9 at B/ Ni = 50 to P n = 17 at B/Ni = 500. Similar curves of activity versus cocatalyst/metal ratio for norbornene homopolymerization were reported in the literature [10,11] and the increase of activity with increasing cocatalyst/metal ratio was explained by an equilibrium formation of the active complex from inactive precatalyst and cocatalyst [10], i.e. by an increasing number of active species [11].…”

“…Similar curves of activity versus cocatalyst/metal ratio for norbornene homopolymerization were reported in the literature [10,11] and the increase of activity with increasing cocatalyst/metal ratio was explained by an equilibrium formation of the active complex from inactive precatalyst and cocatalyst [10], i.e. by an increasing number of active species [11]. The interaction of Ni(PPh 3 ) 4 with BF 3 OEt 2 in toluene at ratios B/ Ni = 2-160 resulted in the oxidation of Ni(0) to Ni(I) and the subsequent elimination of organophosphorus ligands from the coordination sphere of the transition metal until the formation of colloidal nickel [12].…”

Homo‐ and copolymerization of norbornene with styrene catalyzed by a series of copper(II) complexes in the presence of methylaluminoxane

“…The result is very similar to that for the nickel stearate-MAO system (r styrene = 0.02, r norbornene = 20.8), which results in a lower styrene incorporation ratio by the nickel stearate-MAO system under polymerization conditions. 39 The much higher reactivity of norbornene illustrates that the monomer reactivity order is rather unusual and is obviously not in agreement with a free radical or cationic-type polymerization but supports a coordination type mechanism.…”