Ring-opening metathesis polymerization (ROMP) of norbornene catalyzed by niobium(V) N,Ndialkylcarbamates Nb(O2CNR2)5, R¼Et (1), Me (2) was studied in the presence of methylaluminoxane (MAO) as a cocatalyst. These novel catalytic systems resulted very active in chlorobenzene: 1 in the presence of methylaluminoxane catalyzes the ROMP of norbornene with the highest activity (29 000 kg of polymer/mol of catalysthour) never reported up to now for niobium catalysts. The high productivity appears particularly attractive considering that these precursors are rather cheap and easy to synthesize and to handle. Polynorbornenes were characterized by FT-IR and NMR spectroscopies and by DSC calorimetry. A new FT-IR method for the swift determination of the cis/trans content of the polymer is presented.
Novel highly active niobium catalysts for ring opening metathesis polymerization of norbornene
PAMPALONI, GUIDO;RASPOLLI GALLETTI, ANNA MARIA;
2009-01-01
Abstract
Ring-opening metathesis polymerization (ROMP) of norbornene catalyzed by niobium(V) N,Ndialkylcarbamates Nb(O2CNR2)5, R¼Et (1), Me (2) was studied in the presence of methylaluminoxane (MAO) as a cocatalyst. These novel catalytic systems resulted very active in chlorobenzene: 1 in the presence of methylaluminoxane catalyzes the ROMP of norbornene with the highest activity (29 000 kg of polymer/mol of catalysthour) never reported up to now for niobium catalysts. The high productivity appears particularly attractive considering that these precursors are rather cheap and easy to synthesize and to handle. Polynorbornenes were characterized by FT-IR and NMR spectroscopies and by DSC calorimetry. A new FT-IR method for the swift determination of the cis/trans content of the polymer is presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
