Novel monodentate phosphine modified Pd(acac)2/BF3OEt2 catalyst system for the synthesis of poly(5-alkyl-2-norbornene)s

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

“…This is in agreement with data reported in [10]. At the same time, it is worth noting that the substantial catalytic activity might be achieved at lower B/Ni ratios of 200 compared to that for the polymerization of norbornene in the absence of ethene, where a remarkable activity had been recorded only at B/Ni = 400 [8]. This contrast indicates that ethene not only acts as a chain transfer agent, but also shows a promoting effect in the polymerization of norbornene.…”

“…Here, again the promoting effect of ethene is noteworthy. For the homopolymerization of norbornene in the absence of ethane, the temperature dependence of catalyst activity is significant and shows a maximum at 65 8C [8]. At the same time, a strong drop of average polymerization degree from P n = 16 at 25 8C to P n = 9 was observed starting from 35 8C.…”

“…We have recently shown that boron trifluoride etherate, BF 3 OEt 2 , might be successfully used as a cocatalyst towards tetrakis(triphenylphosphine)nickel, Ni(PPh 3 ) 4 , for the polymerization of norbornene [8]. In this work, our interest focuses on polymerization of norbornene in the presence of ethene using the Ni(PPh 3 ) 4 /BF 3 OEt 2 catalyst system.…”

Metal catalysts for the vinyl/addition polymerization of norbornene

“…At the same time, the average molecular mass of the polymers increased with an increase in the B/Ni ratio and decreased with higher temperatures. Furthermore higher monomer concentration caused an increase of the activity [183].…”

“…Tetrakis(triphenylphosphane)nickel(0), Ni-172 was used in combination with BF 3 ·OEt 2 for norbornene polymerization with good activities in the range of 10 6 g polymer /mol Ni h [183]. The molar B/Ni ratio greatly influenced the polymerization activity and a variation of this ratio from 50 to 500 led to a steep increase until for a value of 300 an activity plateau was reached.…”