Can I read Kinetic Studies of the Copolymerization of Ethylene with Norbornene by ansa ‐Zirconocene/Methylaluminoxane Catalysts: Evidence of a Long‐Lasting “Quasi‐Living” Initial Period on EtoBox?

Kinetic Studies of the Copolymerization of Ethylene with Norbornene by ansa ‐Zirconocene/Methylaluminoxane Catalysts: Evidence of a Long‐Lasting “Quasi‐Living” Initial Period by Johannes Carolus Jansen; Raniero Mendichi; Maria Carmela Sacchi; Incoronata Tritto is a Materials Science article available to read on EtoBox.

What is Kinetic Studies of the Copolymerization of Ethylene with Norbornene by ansa ‐Zirconocene/Methylaluminoxane Catalysts: Evidence of a Long‐Lasting “Quasi‐Living” Initial Period about?

## Abstract Copolymers of ethylene (E) with norbornene (N) were synthesized using the catalysts __rac__‐Et(Ind)~2~ZrCl~2~/MAO (1), 90%__rac__/10%__meso__‐Et(4,7‐Me~2~Ind)~2~ZrCl~2~/MAO (2), and __rac__‐H~2~C(3‐__t__‐BuInd)~2~ZrCl~2~/MAO (3). Catalyst activity, molar mass (MM), and copolymer composition were studied as a function of time. The polymers showed an unusually narrow molar mass distribution (MMD) and a significant increase of their MM with time for up to one hour, suggesting a “quasi‐living” polymerization at 30 °C. The experimental data were fitted to kinetic equations and the propagation and transfer reactions were described in quantitative terms. Norbornene greatly depressed the propagation rate, along with the chain transfer rate. The more sterically hindered catalysts of the series showed lower propagation and chain transfer turnover frequency than 1 and yielded polymers with a low (2) to very low (3) norbornene content. The presence of norbornene in solution seemed to be one of the main factors responsible for the observed “quasi‐living” character of the copolymerization, probably due to coordination of norbornene to the active site. Time‐resolved kinetic studies al

Who reads Kinetic Studies of the Copolymerization of Ethylene with Norbornene by ansa ‐Zirconocene/Methylaluminoxane Catalysts: Evidence of a Long‐Lasting “Quasi‐Living” Initial Period?

Author

Johannes Carolus Jansen; Raniero Mendichi; Maria Carmela Sacchi; Incoronata Tritto

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Ltd.; Wiley (ISSN 1022-1352)

Published

2003

Language

EN

Field

Materials Science (Physical Sciences)