Evidence of the quasi-living character of the ansa-zirconocene/MAO-catalyzed copolymerization of ethylene and norbornene

Jansen JC; Mendichi R; Locatelli P; Tritto I

Macromolecular Rapid Communications, Vol.22, No.17, 1394-1398, 2001

DOI10.1002/1521-3927(20011101)22:17<1394::AID-MARC1394>3.0.CO;2-B Export Citation

Evidence of the quasi-living character of the ansa-zirconocene/MAO-catalyzed copolymerization of ethylene and norbornene

Jansen JC, Mendichi R, Locatelli P, Tritto I

The kinetics of the ethylene-norbornene copolymerization, catalyzed by rac-Et(lnd)(2)ZrCl2/MAO, 90%rac/10%meso-Et(4,7-Me(2)Ind)(2)ZrCl2/MAO and rac-H2C(3-tert-BuInd)(2)ZrCl2/MAO was followed by sampling from the reaction mixture at fixed time intervals, Catalyst activity, copolymer composition and molar mass were studied as a function of time. The polymers showed an unusually low polydispersity and a significant increase in their molar mass with time, suggesting a quasi-living polymerization.

Keywords:copolymerization;kinetics (polym.);metallocene catalysts;molar mass distribution;norbornene