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- Homogeneous Ziegler-Natta polymerisation: A kinetic approach .2. Transient-state kineticsPublication . Marques, M.M.; Dias, A.R.; Justino, Jorge; Costa, C.; Lemos, F.; Ribeiro, F.R.An integrated view is presented of several possible mechanisms applicable to the interpretation of homogeneous Ziegler-Natta polymerisation. In this paper, the transient aspects related to the kinetics of Ziegler-Natta polymerisation are investigated. Extensive data are used to construct kinetic profiles (rM vs. t) from a theoretical approach. Special attention is given to the duration of the transient period as a function of the different kinetic parameters. The kinetic models developed are fitted to experimental data, either directly obtained by the authors or published in the literature. These general models have a broad range of application.
- Study of low catalytic activity systems (Biscyclopentadienyl complexes-aluminoxane) on olefin polymerizationPublication . Justino, Jorge; Marques, M.M.; Correia, S.; Dias, A.R.; Lemos, F.; Ribeiro, F.R.Olefin polymerization using low activity catalyst systems: Cp2WCl2-methylaluminoxane, [Cp2Mo(CH3)2][PF6]-methylaluminoxane and Cp2Mo(CH3)2-methylaluminoxane, is described. All these catalyst systems were studied in ethylene and propylene polymerization; however, they only showed catalytic activity for ethylene. Only one type of methylaluminoxane (MAO) was used, prepared in an Al/H2O ratio of 2. The kinetics of polymerization were examined and the experimental data (either presented here or in previous papers) were fitted to the kinetic models developed previously and now extended to account for the methylaluminoxane effect.
- A kinetic approach to homogeneous Ziegler type polymerization. Transient statePublication . Marques, M.M.; Costa, C.; Justino, Jorge; Lemos, F.; Ribeiro, F.R.; Dias, A.R.In this paper we present a kinetic approach to the analysis of transient-state homogeneous Ziegler-Natta polymerization activity data. The main features of the experimental data are discussed and fitted to transient kinetic models.